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Laboratory

Manual for

Anatomy &

Physiology

Connie Allen

Valerie Harper

Start Here, Go Anywhere.

I dedicate this book to my new granddaughters, Gianna Leigh Madden and Taralyn Kay Thomas. —Connie Allen

I dedicate this book to my husband Chuck, who has supported and encouraged me, my children Scott and Kate, who were patient when I worked long hours, and my nieces Jessica and Kristina Fatigati,

who are interested in studying anatomy. —Valerie Harper

5th E D I T I O N

Laboratory Manual for Anatomy and Physiology

CONNIE ALLEN Edison State College

VALERIE HARPER Colorado Mesa University

VP & EXECUTIVE PUBLISHER Kaye Pace EXECUTIVE EDITOR Bonnie Roesch ASSOCIATE EDITOR Lauren Elfers EDITORIAL ASSISTANT Grace Bagley MARKETING MANAGER Maria Guarascio PRODUCTION MANAGER Juanita Thompson PRODUCTION EDITOR Barbara Russiello SENIOR DESIGNER/COVER DESIGNER Madelyn Lesure SENIOR PHOTO EDITOR MaryAnn Price ILLUSTRATION EDITOR Claudia Volano SENIOR PRODUCT DESIGER Linda Muriello MEDIA SPECIALIST Svetlana Barskaya COVER IIIustration by Bryan Christie Design

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The procedures in this text are intended for use only by students with appropriate faculty supervision. In preparing the text, care has been taken to iden- tify potentially hazardous steps and to insert safety precautions where appropriate. The authors and publisher believe the procedures to be useful tools if performed with the materials and equipment specifi ed, in careful accordance with the instructions and methods in the text. However, these procedures must be conducted at one’s own risk. The author and publisher do not warrant or guarantee the safety of individuals using these procedures and specifi - cally disclaim any and all liability resulting directly or indirectly from the use or application of any information contained in this book.

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Preface

Anatomy and physiology is a challenging course, and this laboratory manual is written to help students meet that challenge. It is written for students interested in allied health fields, such as nursing; physical, respiratory, cardiovascular, or occupational therapy; radiology; and den- tal hygiene. This manual may be used with any two-semester anatomy and physiology textbook.

The design of this laboratory manual is based on the au- thors’ experience as anatomy and physiology instructors and uses three learning styles: visual, auditory, and kinesthetic. When students label diagrams, they focus on the structure rather than just the dot at the end of a line. Writing out the structure’s name and pronouncing it reinforces learning. Also, having students become subjects of laboratory exer- cises personalizes the learning process. Animal dissections give students an opportunity to physically manipulate struc- tures, comparing location and texture, and to observe how structures are supported, protected, and attached by connec- tive tissue.

Special features incorporated in this laboratory manual include:

• This lab manual can be used for online anatomy and physi- ology classes. New lab activities have been added that can be performed by students at home or used in the labora- tory. Online students can also use the Real Anatomy Virtual Dissection program and PowerPhys physiology activities to enhance their learning.

• Just enough text is provided to introduce concepts in each section and to set up and support the laboratory section. The exercises are written so students do not need their textbooks to complete the laboratory activities.

• New material is divided into small segments, starting with simple diagrams, illustrating the basic concepts and build- ing up to more complex diagrams. Subsequent activities add to the students’ knowledge in a stepwise fashion. This is especially noticed in the skeletal and muscular exercises.

• Each exercise contains a list of objectives, materials needed for the exercise, and easily identifiable laboratory activity sections.

• Unlabeled four-color drawings, photographs, and photomi- crographs are included for students to label either at home or in the laboratory. Students first write out the name of the structure to help learn it. Then the completed diagrams will be used to identify structures on models.

• Word derivatives for bolded terms are given in the text. • Phonetic pronunciation is included as new words are intro-

duced.

• Physiology experiments use students as subjects and can be completed with either simple, inexpensive equipment and materials or more complex lab setups.

• Experimental report sections after physiology experiments where students are asked to make predictions, collect and analyze data, and write simple lab reports.

• Discussion Questions are within the activities to make the students think about the material presented.

• An Answer Key is provided at the end of the laboratory manual for the activities in each exercise. Students receive immediate feedback, and they are not dependent on the in- structor for the correct answers.

• “Reviewing Your Knowledge” and “Using Your Knowl- edge” sections follow the activities at the end of each ex- ercise. “Reviewing Your Knowledge” provides a thorough review of the material in the exercise, whereas “Using Your Knowledge” requires students to apply information learned. Either or both of these sections may be handed in to the instructors for a grade, because neither section has answers in the back of the laboratory manual. Answers to these two sections are provided on the Instructor Companion site.

New Features to the Fifth Edition • Exercises are now organized into Before Going to Lab and

Lab Activities. Before Going to Lab sections are to be com- pleted at home or outside of class.

• Completely revised Exercise 15: Surface Anatomy and Exercise 26: Blood Components and Blood Tests.

• Suggested Real Anatomy activities are included throughout the lab manual.

• PowerPhys 3.0 is now tablet enabled and includes three new modules.

• New Biopac Laboratory Guide Experiments are available online for several Exercises. Activities include: ~ Recruitment and Fatigue ~ Isometric and Isotonic Contractions ~ Effect of Physical and Mental Distractions on Patellar

Reflex (Knee Jerk) Response ~ The Effect of Mental and Sensory Stimulations on Brain

Wave Patterns ~ Observing ANS Responses to Lying ~ Observing ANS Responses Following Meditation ~ Effect of Body Position and Exercise on ECG ~ Heart Sounds and Events of the Cardiac Cycle ~ Effect of Body Position on Resting Blood Pressure ~ Effect of Exercise on Blood Pressure ~ Effect of Exercise on Lung Volumes and Capacities ~ Comparison of Predicted and Measured FVC and FEV1

vi P R E F A C E

PowerPhys 3.0 is Tablet Enabled and Fully Integrated with The New Edition

Each Lab Manual contains online access to Power- Phys 3.0 for students. PowerPhys 3.0 is physiologi- cal simulation software for the A & P laboratory that allows students to explore physiology principles through 14 self-contained activities. Each activity follows the scientific method containing objectives with illustrated and animated review material, pre- lab quizzes, pre-lab reports (including predictions and variables), data collection and analysis, and a full lab report with discussion and application questions. Experiments contain real data that is randomly gener- ated, allowing users to experiment multiple times, but still arrive at the same conclusions. These activities focus on core physiological concepts and reinforce techniques experienced in the laboratory. www.wiley. com/go/powerphys • Three New Activities: Hematocrit and Hemoglobin Concentration and

Blood Typing

Acid-Base Balance

Effect of Dietary Fiber on Transit Time and Bile • Now available on mobile devices

Dissection Manuals • Depending on your needs, a Cat Dissection Man-

ual or Fetal Pig Dissection Manual is available to accompany the main Lab Manual. Both dissection manuals contain dissection activities for use in the lab accompanied by full color photos and figures.

• All cat and pig photographs have been updated in the new editions.

• New cat and pig dissection videos accompany this edition, available in WileyPLUS. Dissections per- formed by Shawn Miller and photographs taken by Mark Nielsen of the University of Utah.

Resources That Power Success

Anatomy Drill and Practice lets you test your knowledge of structures with simple-to-use drag and drop labeling exercises, or fill-in-the-blank labeling. You can drill and practice on these ac- tivities using illustrations from the text, cadaver photographs, histology micrographs, or anatomi- cal models, so you can practice labeling these models outside of the lab.

Anatomy Drill and Practice in

Student and Instructor Companion Websites www.wiley.com/college/allen

Resources for Students:

• Audio Glossary • Rat Dissection video • Pig Dissection video • Answers to figure questions • Interactions Review Sheets • Real Anatomy Review Sheets • Lab Safety Guidelines • Experimental Reports • Blood Activities

Resources for Instructors:

• Anatomy and Physiology Visual Library • Editable PowerPoints that include all figures from

the Lab Manual • All tables from the Lab Manual in PowerPoint • All images from the Cat Dissection Manual • All images from the Pig Dissection Manual • Answer Keys for “Reviewing Your Knowledge” • Answer Keys for “Using Your Knowledge” • Interactions Review Sheets • Real Anatomy Review Sheets

vii

Mark Nielsen and Shawn Miller, University of Utah

Real Anatomy is 3-D imaging software that allows you to dissect through

multiple layers of a three-dimensional real human body to study and

learn the anatomical structures of all body systems.

Real Anatomy 2.0

• Now available on the Web, acces- sible by iPad and Android tablets.

• All possible highlight structures on an image are now accessible via a drop-down list as well as being searchable.

NEW to Real Anatomy 2.0

• New crumb trail navigation shows context of system, image, structure.

• Fully integrated into WileyPLUS for Anatomy.

• Dissect through up to 40 layers of the body and discover the relationships of the structures to the whole.

• Rotate the body as well as major organs to view the image from multiple perspectives.

• Use a built-in zoom feature to get a closer look at detail.

• A unique approach to highlighting and labeling struc- tures does not obscure the real anatomy on view.

viii

Photographic Atlas of Human Anatomy, First Edition Mark Nielsen and Shawn Miller, University of Utah

This atlas, filled with outstanding photographs of me-

ticulously executed dissections of the human body, has

been developed to be a strong teaching and learning

solution, not just a catalog of photographs. Organized

around body systems, each chapter includes a narra-

tive overview of the body system followed by detailed

photographs that accurately and realistically represent

the anatomical structures. Histology is included. Pho-

tographic Atlas of Human Anatomy will work well in

your laboratories, as a study companion to your lab

manual, and as a print companion to the Real Anat-

omy DVD.

• Snapshots can be saved of any image for use in Power- Points, quizzes, or handouts

• Audio pronuncia- tion of all labeled structures is readily available

• Related Images provide mul- tiple views of structures being studied.

• Snapshots can be saved of any image for use in PowerPoints, quizzes, or handouts.

• View histology micrographs at varied levels of magnification with the virtual microscope.

• Audio pronunciation of all labeled structures is readily available.

For more information, visit www.wileyplus.com

WileyPLUS builds students’ confidence because it takes the guesswork out of studying by providing students with a clear roadmap:

• what to do • how to do it • if they did it right

It offers interactive resources along with a complete digital textbook that help students learn more. With WileyPLUS, students take more initiative so you’ll have

greater impact on their achievement in the classroom and beyond.

WileyPLUS is a research-based online environment for effective teaching and learning.

Now available for

http://www.wileyplus.com

ALL THE HELP, RESOURCES, AND PERSONAL SUPPORT YOU AND YOUR STUDENTS NEED!

www.wileyplus.com/resources

Technical Support 24/7 FAQs, online chat, and phone support

www.wileyplus.com/support

Student support from an experienced student user

Collaborate with your colleagues, find a mentor, attend virtual and live

events, and view resources

2-Minute Tutorials and all of the resources you and your students need to get started

Your WileyPLUS Account Manager, providing personal training

and support

www.WhereFacultyConnect.com

Pre-loaded, ready-to-use assignments and presentations

created by subject matter experts

Student Partner Program

Quick Start

Acknowledgments We deeply appreciate the support, instruction, and encour- agement from the members of our editorial, production, and marketing team at Wiley: Bonnie Roesch, Lauren Elfers, Barbara Russiello, MaryAnn Price, and Maria Guarascio. We also wish to thank Gerard Tortora and Bryan Derrickson for producing a wonderful textbook that provided many illustra- tions and ideas for our laboratory manual. A special thank you to Susan Baxley for reviewing all the exercises, making suggestions and to Bob Clemence for allowing us to use his figure of the Respiratory Volumes and Capacities. A special thanks to Charles Harper for answering many clinical ques- tions. We also wish to thank Kierstan Hong at Imagineering Art for the artwork she provided for our laboratory manual.

Thank you to our colleagues at Edison State College: Bob Clemence, Colleen Swanson, Jody Gootkin, Richard McCoy,

Jeff Davis, Dick Felden, Lyman O’Neil, Kitty Gronlund, Tony Contino, Cheryl Black, Jed Wolfson, Jay Koepke, and Roy Hepner who encouraged us, answered our questions, and pro- vided critiques of exercises. We also wish to thank Nicole Yarbrough George for her critique of the skeletal muscle chapter. Thank you to Chaim Jay Margolin of Regional Radiology Associates and David Michie of Clinical Physiol- ogy Associates for providing images for this manual. Special thanks to SOMSO for providing images for our online Anat- omy Drill and Practice: Anatomical Models section. Thanks to contributors Jerri Lindsey, Tarrant County College, and Terry Thompson, Wor-Wic Community College.

WileyPLUS for Anatomy and Physiology is an innovative, research-based online environment—designed for both effec- tive teaching and learning. Utilizing WileyPLUS in your lab course provides your students with an accessible, affordable, and active learning platform and the tools and resources to efficiently build presentations for a dynamic laboratory expe- rience and to create and manage effective assessment strategies. The underlying principles of design, engagement, and mea- surable outcomes provide the foundation for this powerful, new release of WileyPLUS.

Design • New research-based design helps students manage their

time better and develop better study skills • Course Calendars help track assignments for both students

and teachers • New Course Plan makes it easier to assign pre- and post-lab

activities and assessment. Simple drag-and-drop tools make it easy to assign the course plan as-is or in any way that best reflects your course syllabus

The new design makes it easy for students to know what it is they need to do, boosting their confidence and preparing them for greater engagement in lab.

Engagement • Complete online version of the Lab Manual for seamless

integration of all content • Online version of the Lab Manual includes interactive figure

labeling exercises for students • Relevant student study tools and learning resources ensure

positive learning outcomes

• Immediate feedback boosts confidence and helps students see a return on investment for each study session

• Resources like Cadaver Videos, Anatomy Drill, and Prac- tice help students study for laboratory practicals

• Course materials, including editable PowerPoint stacks and Wiley’s Visual Library for Anatomy and Physiology, help you personalize lessons and optimize your time

Concept mastery in this discipline is directly related to stu- dents keeping up with the work and not falling behind. The new Concept Modules, Activities, Self Study, and Progress Checks in WileyPLUS will ensure that students know how to study effectively so they will remain engaged and stay on task.

Measurable Outcomes • Progress check enables students to hone in on areas of

weakness for increased success • Self-assessment and remediation for all learning objectives

lets students know exactly how their efforts have paid off • Instant reports monitor trends in class performance, use of

course materials, and student progress towards learning objectives

• New gradable versions of the PowerPhys 2.0 laboratory re- ports allow you to assign and grade these within WileyPLUS

With new detailed reporting capabilities students will know that they are doing it right. With increased confidence, motiva- tion is sustained so students stay on task, and success will fol- low. Please contact your Wiley representative for details about these and other resources or visit our website at www.wiley. com/college/sc/aandp and click on the laboratory text cover to explore the assets more fully.

WileyPLUS and You

xii

E X E R C I S E 5 T R A N S P O R T A C R O S S T H E P L A S M A M E M B R A N E 43

Contents Preface

INTRODUCTION EXERCISE 1 Anatomical Language 1

EXERCISE 2 Organ Systems and Body Cavities 13

CELL AND TISSUES EXERCISE 3 Compound Light Microscope 23

EXERCISE 4 Cell Structure and Cell Cycle 31

EXERCISE 5 Transport Across the Plasma Membrane 41

EXERCISE 6 Tissues 51

INTEGUMENTARY SYSTEM EXERCISE 7 The Integumentary System Structure and

Function 83

SKELETAL SYSTEM AND JOINTS EXERCISE 8 Bone Structure and Function 95

EXERCISE 9 Axial Skeleton 105

EXERCISE 10 Appendicular Skeleton 137

EXERCISE 11 Joints and Synovial Joint Movements 159

MUSCULAR SYSTEM: SKELETAL MUSCLES EXERCISE 12 Skeletal Muscle Structure 173

EXERCISE 13 Contraction of Skeletal Muscle 185

EXERCISE 14 Skeletal Muscles and Their Actions 197

SURFACE ANATOMY EXERCISE 15 Surface Anatomy 233

NERVOUS SYSTEM EXERCISE 16 Nervous Tissue 255

EXERCISE 17 Spinal Cord Structure and Function 269

EXERCISE 18 Spinal Nerves 279

EXERCISE 19 Somatic Reflexes 289

EXERCISE 20 Brain Structure and Function 299

EXERCISE 21 Cranial Nerves 323

EXERCISE 22 Autonomic Nervous System Structure and Function 333

EXERCISE 23 General Senses 345 EXERCISE 24 Special Senses 359

ENDOCRINE SYSTEM EXERCISE 25 Endocrine Structure and Function 391

CARDIOVASCULAR SYSTEM EXERCISE 26 Blood Components and Blood Tests 411

EXERCISE 27 Heart Structure and Function 431

EXERCISE 28 Cardiac Cycle 451

EXERCISE 29 Blood Vessel Structure and Function 463

EXERCISE 30 Blood Vessel Identification 479

LYMPHATIC AND IMMUNE SYSTEMS EXERCISE 31 Lymphatic System Structure and Immune

System Function 507

RESPIRATORY SYSTEM EXERCISE 32 Respiratory System Structure and Function 527

EXERCISE 33 Pulmonary Ventilation 545

DIGESTIVE SYSTEM EXERCISE 34 Digestive System Structure and Function 561

EXERCISE 35 Mechanical and Chemical Digestion 589

URINARY SYSTEM EXERCISE 36 Urinary System Structure and Function 597

EXERCISE 37 Urine Formation and Urinalysis 615

REPRODUCTIVE SYSTEMS EXERCISE 38 Male Reproductive System Structure and

Function 627

EXERCISE 39 Female Reproductive System Structure and Function 643

HUMAN DEVELOPMENT AND HEREDITY EXERCISE 40 Human Development 661

EXERCISE 41 Heredity 675

Answer Key to Activities 689

APPENDIX A: Word Roots 709

APPENDIX B: Skeletal Muscle Origins and Insertions 711

APPENDIX C: Measurements 717

Photo Credits 719

Index 721

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E X E R C I S E 1 A N AT O M I C A L L A N G U A G E 1

Anatomical terms describe body positions, body regions, specific body areas, and land-marks. Most of these words are derived from Latin or Greek and are often part of the names of muscles, bones, nerves, and blood vessels. Learning these terms at this time will help you throughout the course.

A. Anatomical Terms

The anatomical position is the reference position anato- mists and people in medical fi elds use to describe the loca- tion of body parts or regions. In the anatomical position, the body is erect (vertical) and facing forward; the arms are straight and at the sides of the body with the palms facing forward; the legs are straight with the feet facing forward and fl at (Figure 1.1). In the supine position, the body is horizontal and lying on the back. In the prone position, the body is horizontal and lying on the stomach. Body regions refer to specifi c areas of the body. There are common misperceptions about the boundaries of a few body regions. Two common misconceptions are that the arm is the area between the shoulder and wrist and that the leg includes the

thigh. Actually, the arm is located between the shoulder and elbow, and the forearm is located from the elbow to wrist. The thigh is located between the groin and knee, and the leg is located between the knee and ankle. The chest is the area of the trunk between the neck and diaphragm and contains the heart and lungs. The abdomen is the area of the trunk between the diaphragm and hip bones and contains the digestive organs. The pelvis is the area of the trunk below the hip bones and contains internal reproductive organs and the urinary bladder. The groin is the area on the anterior (front) surface marked by a crease where the lower limb attaches to the pelvis. Many anatomical terms have one or more word roots with a prefi x and/or a suffi x added. For example, in the word antecubital, ante- is a prefi x meaning before or in front of, the word root cubit- means elbow, -al is a suffi x meaning pertaining to. Table 1.1 contains anatomical terms with four different suffi xes, all of which mean pertaining to. These suffi xes are -al, -ic, -ar, and -ary. When suffi xes like these are added to word roots they form adjectives, whereas nouns have different endings such as -um, -us, -is, and -a. For example, stern- is a word root meaning chest; sternum is the noun and sternal is the adjective. Anatomi- cal terms and their defi nitions are found in Table 1.1. Word roots and their defi nitions are found in Appendix A, as well as nouns and adjectives formed from the word roots.

O B J E C T I V E S M A T E R I A L S

• human models or anatomical charts • apples (1 per group) and plastic knives or

scalpels

• plastic tubing (eight-inch piece per group) or plastic straw

• 5 sheep brains (for class demonstration)

Anatomical Language 1

E X E R C I S E

1 Describe the anatomical position

2 Use anatomical and directional terms correctly

3 Identify the various body planes and sections

2 E X E R C I S E 1 A N AT O M I C A L L A N G U A G E

LAB ACTIVITY 1 Anatomical Terms

1 Use anatomical terms to identify the specific body regions or areas on models, anatomical charts, or yourself. ■

Before Going to Lab

1 Label Figure 1.1 with the appropriate anatomical terms for each body region or area. Refer to Table 1.1.

2 Refer to Appendix A to review how word roots, suf- fixes, and prefixes are combined to form nouns and adjectives.

TABLE 1 .1 Anatomical Terms

TERM

AXIAL

Cephalic (se-FAL-ik) • Cranial

• Facial • Frontal • Orbital • Otic (OH-tik) • Nasal • Buccal (BUCK-al) • Oral • Mental • Occipital (ox-SIP-i-tal)

Cervical Thoracic • Sternal • Pectoral • Mammary Abdominal • Umbilical (um-BIL-ih-cal) • Coxal (COX-al) Pelvic • Pubic (PYOO-bik) Dorsal • Scapular

• Vertebral (ver-TEE-brul)

• Lumbar

DEF IN IT ION

Pertaining to the central part of the body, the head and

trunk Pertaining to the head Pertaining to the portion of the skull surrounding the brain Pertaining to the face Pertaining to the forehead Pertaining to the eye Pertaining to the ear Pertaining to the nose Pertaining to the cheek Pertaining to the mouth Pertaining to the chin Pertaining to the back of head Pertaining to the neck Pertaining to the chest Pertaining to the breast bone Pertaining to the chest Pertaining to the breast Pertaining to the abdomen Pertaining to the navel Pertaining to the hip Pertaining to the pelvis Pertaining to the genital area Pertaining to the back Pertaining to the shoulder blade region Pertaining to the spinal column Pertaining to the area of the back between the lowest

rib and buttocks.

TERM

APPENDICULAR

Upper Limb (Appendage) • Acromial (a-KROM-ee-al)

• Axillary (AX-il-ary) • Brachial (BRAY-key-ul) • Antecubital (an-teh-

KYOO-bi-tul) • Olecranal (oh-LEK-ra-nul)

• Antebrachial • Carpal • Manual • Palmar

• Digital Lower Limb (Appendage) • Inguinal (ING-won-ul)

• Gluteal (GLUE-tee-ul) • Femoral (FEM-or-ul) • Patellar (pa-TEL-ur)

• Popliteal (pop-lih-TEE-ul)

• Crural (CROO-rul)

• Fibular (FIB-you-lur) or peroneal (peh-RONE-ee-ul)

• Sural (SIR-ul)

• Tarsal (TAR-sul) • Pedal • Plantar • Calcaneal (kal-KANE-ee-ul) • Digital

DEF IN IT ION

Pertaining to the extremities or limbs

Pertaining to the highest point of the shoulder Pertaining to the armpit Pertaining to the arm Pertaining to the anterior (front) surface of the elbow Pertaining to the posterior (back) surface of the elbow Pertaining to the forearm Pertaining to the wrist Pertaining to the hand Pertaining to the palm of the hand Pertaining to the digits (fingers)

Pertaining to the groin where the thigh attaches to the

pelvis Pertaining to the buttocks Pertaining to the thigh Pertaining to the anterior (front) surface of the knee Pertaining to the posterior (back) surface of the knee Pertaining to the anterior (front) surface of the leg Pertaining to the lateral side of the leg Pertaining to the posterior (back) surface of the leg Pertaining to the ankle Pertaining to the foot Pertaining to the sole of foot Pertaining to the heel Pertaining to the digits (toes)

E X E R C I S E 1 A N AT O M I C A L L A N G U A G E 3

Thoracic

Pelvic

Abdominal

(a) Anterior view (b) Posterior view

12 11

25 24

23 22 21 20 19 18 17

40 (sole)

9 41

TR U

N K

FIGURE 1.1 Anatomical terms.

(a) Anterior View

28 ________________________

(b) Posterior View

4 E X E R C I S E 1 A N AT O M I C A L L A N G U A G E

TABLE 1 .2 Directional Terms

DIRECT IONAL TERM DEF IN IT ION EXAMPLE OF USE

Superior Above The head is superior to the neck. Inferior Below The neck is inferior to the head. Anterior (Ventral) Closer to front of body The lips are anterior to the teeth. Posterior (Dorsal) Closer to back of body The teeth are posterior to the lips. Medial Closer to midline of body The nose is medial to the eyes. Lateral Farther from midline of body The eyes are lateral to the nose. Intermediate Between two structures The elbow is intermediate between

the shoulder and wrist. Ipsilateral On same side of body The right arm and right leg are ipsilateral. Contralateral On opposite sides of body The right arm and left arm are contralateral. Proximal Nearer to point of attachment of The elbow is proximal to the wrist. limb to trunk Distal Farther from point of attachment The wrist is distal to the elbow. of limb to trunk Superficial Closer to surface of body The skin is superficial to the muscles. Deep Farther from surface of body The muscles are deep to the skin.

B. Directional Terms

Directional terms are used to describe the location of body structures relative to other structures. An example of a di- rectional term is inferior, which means below. It would be correct to say that the neck is inferior to the head but incorrect to say that the neck is inferior. The directional terms are listed in Table 1.2, along with an example of how they are used. Note that opposite terms are paired. The directional terms proximal and distal apply to the point of attachment of a limb to the torso or the point of origin of a structure such as a blood vessel or nerve. These terms refer to the location of structures relative to the point of attachment or point of origin, whether they are closer (proximal) or farther away (distal). More than one directional term can apply to describe the location of a body structure. For example, the ears are posterior and lateral to the nose.

Before Going to Lab

1 Label Figure 1.2 with the directional terms from the bulleted list by writing the term in the appropriate num- bered blank.

2 3

6 5

• anterior or ventral

• distal

• inferior

• posterior or dorsal

• proximal

• superior

FIGURE 1.2 Directional terms.

LAB ACTIVITY 2 Directional Terms

1 With your partner, complete the sentences using the appropriate directional term from Table 1.2. Refer to the anatomical terms in Table 1.1 and Appendix A as needed.

a. The sternum is ______________ to the vertebrae.

b. The nose is ___________ and __________ to the eyes.

c. The heart is ______________ to the lungs.

d. The wrist is ______________ to the arm.

e. The right lung and right kidney are _____________ .

f. The skin is ______________ to the bones. ■

E X E R C I S E 1 A N AT O M I C A L L A N G U A G E 5

C. Body Planes and Sections

Planes are fl at surfaces that divide the body or organs in order to expose internal structures (Figure 1.3). The exposed surfaces produced by planes are called sections. Sagittal (sagitta � arrow) planes pass vertically through the body or organs and divide them into right and left sections (sag- ittal sections). If a plane passes vertically through the midline and di- vides the body into equal right and left halves, the plane is a midsagittal plane, but if a plane divides the body into unequal right and left portions, it is a parasagittal plane. A frontal or coronal plane passes vertically through the body or organs and produces anterior and posterior sections (frontal sections). A transverse plane passes horizontally through the body and produces superior and inferior sections (transverse sections or cross-sections). Oblique planes pass through the body at an angle forming oblique sections. We often look at sections of individual organs, such as blood vessels, intestines, or long bones. Sections that are produced by a plane running along the long axis of a long narrow structure are called longitudinal sections. Sections that are produced by a plane running perpendicular to the long axis are called cross-sections. Because blood vessels and intestines twist and bend, one body plane may produce longitudinal sections, cross-sections, and oblique sections of these structures.

(a) Right anterolateral view

6 7

(b) Longitudinal and cross-sections

• cross-section

• frontal plane

• longitudinal section

• midsagittal plane

• oblique plane

• parasagittal plane

• transverse plane

FIGURE 1.3 Body planes and sections.

CLINICAL NOTE: Transverse sections observed with com- puted tomography (CT) scans or magnetic resonance imaging (MRIs) are called axial sections.

Before Going to Lab

1 Label the planes in Figures 1.3(a) and the sections in Figure 1.3(b) with the terms in the accompanying bul- leted list by writing the term in the appropriate numbered blank.

2 Identify the type of sections of the human brain in Figure 1.4.

6 E X E R C I S E 1 A N AT O M I C A L L A N G U A G E

• frontal

• midsagittal

• transverse

(a) (b)

(c)

FIGURE 1.4 Human brain sections.

into a longitudinal section and another area into a cross-section.

• Do not cut the tube unless instructed to do so. • Show your instructor where a cut would produce

both a longitudinal section and a cross-section.

3 Identify sagittal, frontal, transverse, and oblique sections on sheep brains. • Your instructor will display five sheep brains—one

whole brain and four brains that have been cut into different sections.

• Determine the anterior, posterior, superior, and inferior surfaces of the brains.

• Decide which brain has been cut into sagittal, frontal, transverse, or oblique sections.

• Compare the appearance of the different sections.

Brain 1—Whole brain

Brain 2 section

Brain 3 section

Brain 4 section

Brain 5 section ■

LAB ACTIVITY 3 Body Planes and Sections

1 Observe sagittal, frontal, and transverse sections using an apple. • Working in a group, draw a face on the apple. • Cut sagittal, frontal, and transverse planes through

the apple to make sagittal, frontal, and transverse sections.

• Compare the appearance of the apple core in each section. Describe any difference in shape, size, and number of seed chambers.

• Keep sections together to form a whole apple to show to your instructor.

2 Observe longitudinal sections and cross-sections using plastic tubing or plastic straw. • Observe a demonstration provided by your instructor

of a tube cut along its longitudinal axis to produce a longitudinal section and a tube cut perpendicular to its longitudinal axis to produce a cross-section.

• Obtain an eight-inch piece of plastic tubing or plastic straw and twist it so you can visualize one plane that would simultaneously divide one area of the tube

Name ___________________________________ Date _________________ Section ______________________________

1 E X E R C I S E

Reviewing Your Knowledge

A. Body Regions

Complete the following sentences.

1. The leg is to the lower limb as the ____ is to the upper limb.

2. The arm is to the upper limb as the ____ is to the lower limb.

3. The armpit is to the upper limb as the ____ is to the lower limb.

4. The tarsal bones are to the lower limb as the ____ bones are to the upper limb.

5. The elbow is to the upper limb as the ____ is to the lower limb.

6. The shoulder is to the upper limb as the ____ is to the lower limb.

7. True or False. The hand includes the wrist and fingers and the foot includes the ankles and toes.

8. True or False. The bones of the face are also part of the skull.

B. Anatomical Terms

Write the anatomical terms that the phrase or word describes. Phrases or words referring to nouns are indicated. All other phrases refer to adjectives.

1. Navel (noun)

2. Pertaining to the area between the neck and abdomen

3. Pertaining to the ear

4. Pertaining to the palm of hand

5. Pertaining to the high point of the shoulder

6. Pertaining to the anterior surface of the elbow region

7. Pertaining to the face; anterior portion of the head

8. Pertaining to the nose

8 E X E R C I S E 1 A N AT O M I C A L L A N G U A G E

9. Pertaining to the neck

10. Pertaining to the posterior surface of the knee

11. Wrist (noun)

12. Pertaining to the area between the elbow and wrist

13. Back (noun)

14. Armpit area (noun)

15. Pertaining to the mouth

16. Pertaining to the anterior surface of the knee

17. Breast bone (noun)

18. Pertaining to the hip

19. Pertaining to the side of the leg

20. Pertaining to the calf

21. Pertaining to the area between the shoulder and elbow

22. Pertaining to the fingers or toes

23. Pertaining to the hand

24. Pertaining to the breast

25. Pertaining to the cheek

26. Pertaining to the heel

27. Pertaining to the sole of the foot

28. Pertaining to the groin where the thigh attaches to the pelvic region

29. Pertaining to the head

30. Pertaining to the chin

31. Pertaining to the foot

32. Pertaining to the eye

33. Pertaining to the genital area

34. Pertaining to the area between the hip and knee

35. Pertaining to the area that includes the bones enclosing the brain

36. Pertaining to the forehead

E X E R C I S E 1 A N AT O M I C A L L A N G U A G E 9

37. Pertaining to the spinal column

38. Pertaining to the inferior back of the head

39. Pertaining to the anterior surface of the leg

40. Pertaining to the area of the lower back or loin

41. Pertaining to the trunk below the abdomen

42. Pertaining to the area of the back that contains the shoulder blades

43. Pertaining to the posterior surface of the elbow

44. Arm (noun)

45. Pertaining to the chest

46.

C. Body Planes and Sections

Write the name of the plane that the phrase describes.

1. Divides body or organ into unequal right and left sections

2. Divides body or organ into anterior and posterior sections

3. Divides body or organ into superior and inferior sections

4. Divides body into right and left halves

5. Which planes when passed through the body would result in two sections, with each section containing a piece of the heart and a piece of each lung?

6. ¯̊ ˘̊

˙ ¯

˘ ˙

10 E X E R C I S E 1 A N AT O M I C A L L A N G U A G E

D. Directional Terms

Complete the sentences using directional terms. Use Figure 1.5 for reference.

1. The clavicle is to the ribs.

2. The ribs are to the sternum.

3. The humerus is to the radius.

4. The ulna is to the radius.

5. The tibia is to the femur.

6. The right humerus and the right radius are .

7. The pelvic girdle is to the ribs.

8. The sternum is to the vertebral column.

9. The scapula is to the clavicle.

10. The right fibula and left fibula are .

SUPERIOR SUPERIOR

Skull

Cranial portion

Facial portion

Pectoral (shoulder) girdle

Clavicle Scapula

Thorax Sternum

Ribs

Upper limb (extremity)

Humerus

Ulna Radius

Carpals Metacarpals Phalanges

Lower limb (extremity)

Femur

Patella

Tibia

Fibula

Tarsals Metatarsals Phalanges

Vertebral column

Pelvic (hip) girdle

Vertebral column

Pelvic (hip) girdle

(b) Posterior view(a) Anterior view

FIGURE 1.5 Human skeleton.

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Name ___________________________________ Date _________________ Section ______________________________

A. Body Regions, Anatomical Terminology, and Directional Terms

1. A 55-year-old male presented with an irregularly shaped and abnormally pigmented mole in the left scapular region, just lateral to the vertebrae. Indicate on Figure 1.6 where this mole is likely to be found.

2. A 37-year-old female presented to the emergency room with a severe burn (3rd degree) on the right brachial region just proximal to the antecubital region. Indicate on Figure 1.6 where the laceration is likely to be found.

3. A 19-year-old female was identified by a tattoo on the fibular surface of the right leg just proximal to the tarsal region. Indicate on Figure 1.6 where the tattoo is likely to be found.

1 E X E R C I S EUsing Your Knowledge

Questions 4–7 have italicized words that are derived from word roots used to form the adjectives in Table 1.1. Using the locations suggested by the italicized words, answer questions 4–7.

4. Is the popliteal artery proximal or distal to the femoral artery?

5. Is the pectoralis major muscle anterior or posterior to the subscapularis muscle?

(a) Anterior view (b) Posterior view

FIGURE 1.6 Body regions, anatomical language, and directional terms.

12 E X E R C I S E 1 A N AT O M I C A L L A N G U A G E

6. Is the sternocleidomastoid muscle superior or inferior to the rectus abdominis muscle?

7. Are the thoracic vertebrae medial or lateral to the scapulae?

B. Body Planes and Sections

Figure 1.7 contains three different sections through the thorax. Indicate which section (view a, b, or c) is a

8. Frontal section ______

9. Sagittal section ______

10. Transverse (axial) section ______

FIGURE 1.7 Sections through the thorax.

Right lung

Liver Vertebral column

Left kidney

Small intestine

Stomach

(a)

Liver Vertebra Stomach Spleen

(b)

Spinal cord

Vertebral column Trachea

Heart

Sternum

(c)

E X E R C I S E 2 O R G A N S Y S T E M S A N D B O D Y C A V I T I E S 13

Organ systems are like different depart-ments within a company. Within a company, departments work together to keep the com- pany functioning. Within the body, organ systems work together to keep the body alive. In this exercise, you will learn the basic function and location of each organ system.

A. Overview of Organ Systems and Major Organs

An organ system is a group of organs performing a com- mon function. All organ systems cooperate to maintain an optimal environment for body cells through a process called homeostasis (homeo- � same; stasis � standing). Failure to maintain homeostasis results in disorders, dis- ease, and possibly death.

O B J E C T I V E S M A T E R I A L S

• human torso models or charts • male and female human reproductive models or

charts

• paper or plastic large enough to outline student torsos, markers

• articulated skeleton • one-gallon zippered plastic bags (1 per group) • masking tape • rat dissection video in the Wiley Student

Companion Site

Organ Systems and Body Cavities 2

E X E R C I S E

1 Name the organ systems and describe the functions of each

2 Name and identify the major organs of each organ system

3 Describe the location of the body cavities and name the organs they contain

4 Describe the structure, location, and function of the serous membranes

5 Identify the abdominopelvic quadrants and regions and the major organs found in each

Before Going to Lab

1 Observe the organs in Figures 2.1(a) and (b). Refer to your textbook for a list of organ systems, their function, and the major organs in each organ system.

2 Write each labeled organ under the appropriate organ system. There may be organ systems that don’t have any organs in these figures, and some organs may function with more than one system.

14 E X E R C I S E 2 O R G A N S Y S T E M S A N D B O D Y C A V I T I E S

FIGURE 2.1 Selected organs and organ systems.

Body Systems

Cardiovascular System

Digestive System

Endocrine System

Integumentary System

Lymphatic System

Muscular System

Nervous System

Reproductive System

Respiratory System

Skeletal System

Urinary System

Trachea

Bronchus

Thoracic aorta

Diaphragm

Lung

Esophagus

Stomach

Inferior vena cava

Pancreas (posterior to stomach) Kidney

Abdominal aorta

Spleen

Ureter

Urinary bladder

(b) Deeper organs

Trachea

Lung

Heart

Aorta

Liver

Large intestine

Small intestine

Diaphragm

(a) Superficial organs

E X E R C I S E 2 O R G A N S Y S T E M S A N D B O D Y C A V I T I E S 15

8 Answer the following questions about the position of each organ on the torso model or Figure 2.1.

1. The stomach is _______ to the small intestine.

a. superior b. inferior c. medial d. lateral

2. The liver is _______ to the lungs.

a. superior b. inferior c. medial d. lateral

3. The lungs are _______ to the heart.

a. superior b. inferior c. medial d. lateral

4. The trachea is _______ to the esophagus.

a. medial b. inferior c. anterior d. posterior

5. The pancreas is _______ to the stomach.

a. superior b. anterior c. lateral d. posterior

6. The large intestine is _______ to the stomach.

a. superior b. inferior c. posterior d. lateral

7. The stomach is _______ to the spleen.

a. lateral b. medial c. superior d. inferior

8. The abdominal aorta and inferior vena cava are _______ to the kidneys.

a. medial b. lateral c. superior d. inferior

9. The kidneys are _______ to the small intestine.

a. anterior b. posterior c. superior d. inferior

10. The urinary bladder is _______ to the kidneys.

a. posterior and superior b. medial and inferior c. medial and superior d. lateral and posterior ■

LAB ACTIVITY 2 Organ Location

1 Draw the outline of a full-size torso on paper or plastic. 2 Using a marker, draw life-size outlines of all superficial

organs in the appropriate place on the paper or plastic torso. ■

LAB ACTIVITY 1 Identification of Organs on Torso

You will be identifying organs from anterior to posterior on a torso model and answering questions concerning their position relative to the organs around them.

1 Identify the following organs on the anterior surface of a torso model. Identify all the organs without removing any organs from the model. • brain • trachea • heart • lungs • liver • stomach (torso’s left side) • small intestine • large intestine (colon)

2 Remove the lungs, heart, liver, and stomach. Locate the gallbladder on the inferior surface of the liver.

3 Identify the following organs on the human torso model or chart: • esophagus • bronchi (right and left) • inferior vena cava • pancreas (posterior to stomach) • spleen

4 Remove the small intestine and large intestine. Locate the appendix at the inferior right end of the large intestine.

5 Identify the following organs on the human torso model: • abdominal aorta • adrenal glands (superior surface of kidneys) • kidneys • ureters • urinary bladder

6 Identify the female reproductive organs on a female reproductive model or chart. Observe the position of the urinary bladder relative to the uterus. • ovaries • uterus • urinary bladder

7 Identify the male reproductive organs on a male repro- ductive model or chart. • penis • scrotum (skin covering testes) • testes

16 E X E R C I S E 2 O R G A N S Y S T E M S A N D B O D Y C A V I T I E S

peritoneal cavity. Although most abdominal organs are positioned within the peritoneal cavity, a few organs are retroperitoneal (retro- � backward), or located posterior to the peritoneum. These organs are the pancreas, kidneys, adrenal glands, and portions of the large intestine, small intestine, aorta, and inferior vena cava. The pelvic cavity is the inferior portion of the abdominopelvic cavity. The pelvic cavity contains part of the large intestine, rectum, urinary bladder, female reproductive organs (ovaries, uter- ine tubes, uterus, vagina), and male reproductive organs (prostate, and part of ductus deferens). It is important to note that the testes and penis are not located in the pelvic cavity but are located inferior to it.

LAB ACTIVITY 3 Body Cavities

1 Locate the major body cavities on a skeleton and torso model. Identify the organs located in each body cavity.

2 Locate the mediastinum (meed-ee-uh-STINE-um) on a torso model or on Figure 2.1. Identify the organs located within the mediastinum. ■

Before Going to Lab

1 Label the major body cavities and the diaphragm on Figure 2.2(a) and (b).

• abdominal cavity • cranial cavity • diaphragm • pelvic cavity • thoracic cavity • vertebral canal

(a) Right lateral view (b) Anterior view

FIGURE 2.2 Body cavities.

B. Body Cavities

Many of the body’s organs are found within body cavities. The cranial cavity contains the brain, and it is continuous with the vertebral (vertebra � back) canal that contains the spinal cord. The thoracic cavity is a space enclosed by the ribs, sternum, and vertebral column. This cavity contains three small cavities: the pericardial cavity (peri- � around; -cardia � heart) and two pleural cavities (pleuro- � side or rib). The pericardial cavity surrounds the heart, and each pleural cavity contains a lung. The mediastinum (media- � middle; -stinum � partition), a central area within the thoracic cavity, extends from the neck to the diaphragm and from the sternum to the vertebral column. The organs located in the mediastinum are the heart, thymus gland, esophagus, trachea, blood vessels, and bronchi. The pleural cavities are located on either side of the mediasti- num. The diaphragm separates the thoracic cavity from the abdominopelvic cavity. The abdominopelvic cavity consists of two continuous cavities: the abdominal cavity and the pelvic cavity. The abdominal cavity is the superior portion located between the diaphragm and the brim of the pelvis (hip bones). This cavity contains the stomach, liver, gallbladder, pan- creas, spleen, small intestine, kidneys, appendix, and part of the large intestine. Within the abdominal cavity is the

E X E R C I S E 2 O R G A N S Y S T E M S A N D B O D Y C A V I T I E S 17

C. Serous Membranes

Most of the organs in the ventral body cavity are covered with thin serous (serum � any clear, watery fl uid) mem- branes, which are composed of two layers: a visceral layer and a parietal layer. The visceral (viscera � internal organs) layer covers the organ, whereas the parietal (paries � wall) layer attaches to and covers the ventral body wall. These two layers make up one continuous sheet that folds to form a sac. Between the two layers is a poten- tial cavity containing a small amount of serous fl uid se- creted by the membranes. The clear, watery serous fl uid prevents friction as the organs move within the ventral body cavity. For example, the heart has movement within the thoracic cavity as it fi lls with and ejects blood. Serous membranes are named for the cavities they sur- round. Thoracic serous membranes include the pleura, which covers the lungs, and the pericardium, which cov- ers the heart. The serous membrane that covers the abdom- inal organs is the peritoneum ( peri- � around; teinein � to stretch).

Before Going to Lab

1 In Figure 2.3, observe how the serous pericardium folds to form a double layer.

2 Label the two layers of the serous pericardium in Figure 2.3.

LAB ACTIVITY 4 Serous Membranes

1 Make a replica or model of a serous membrane with your lab group. • Obtain a 1-gallon zippered plastic bag. • Push all the air out of the bag and zip the bag. • Have a lab partner place a fist (simulating an organ)

on the bottom edge of the bag and push up into the bag so the bag surrounds the fist.

• Remove the fist, unzip the bag, and add about 40 to 50 mL of water to the bag. Push out the extra air before rezipping the bag.

• Now have the same lab partner place a fist (simulat- ing an organ) on the bottom edge of the bag and push up into the bag so the bag surrounds the fist.

2 Clean up as directed by your instructor. 3 Answer the Discussion Questions with your lab group.

DISCUSSION QUESTIONS Serous Membranes

1 In the bag with water, what is the name of the simulated serous membrane layer that is touching the fist (organ)?

2 In the same bag, what is the name of the simulated outer serous membrane layer?

3 What does the water represent?

4 Was it easier to push a fist into the bag with no water or into the bag with water?

5 Based on your observations, does the presence of serous fluid make it easier for organs to move? Explain.

■

D. Organ Systems, Body Cavities, and Serous Membranes in the Rat

The organ systems, body cavities, and serous membranes of the rat are similar to those of humans. The rat dissec- tion will allow you to see the relationship of organs to each other, organ location within body cavities, and serous membranes.

• parietal • visceral

FIGURE 2.3 Serous pericardium folds to surround the heart.

Heart

Serous pericardium Pericardial cavity with serous fluid

Pericardial cavity

LAB ACTIVITY 5 Rat Dissection Video

Go to the Wiley Student Companion Site to view the rat dissection video. ■

18 E X E R C I S E 2 O R G A N S Y S T E M S A N D B O D Y C A V I T I E S

e. pancreas

f. small intestine

g. spleen

h. stomach

4 Using four pieces of masking tape, divide the abdomino- pelvic cavity into regions on a human torso or on yourself.

5 Using the torso model or your textbook, identify in which abdominopelvic region each organ is primarily located.

a. appendix

b. gallbladder

c. left ovary

d. bifurcation of the abdominal aorta

e. spleen

f. stomach (majority of) ■

NOTE: Right and left always refer to the model’s or speci- men’s own right and left.

LAB ACTIVITY 6 Abdominopelvic Quadrants and Regions

1 Using a piece of masking tape, mark the location of the diaphragm on a human torso or on yourself.

2 Using two pieces of masking tape, divide the abdominopel- vic cavity into quadrants on a human torso or on yourself.

3 Using the torso model or your textbook, identify in which abdominopelvic quadrant(s) each organ is pri- marily located. Use the abbreviations RUQ, LUQ, RLQ, and LLQ.

a. appendix

b. large intestine or colon

c. liver

d. ovaries

Before Going to Lab

1 Draw lines on Figure 2.4(a) separating the abdomino- pelvic cavity into quadrants and label the quadrants.

2 Draw lines on Figure 2.4(b) separating the abdomino- pelvic cavity into regions and label the regions.

FIGURE 2.4 Abdominopelvic cavity.

(a) Quadrants

Location of umbilicus

(b) Regions

Location of umbilicus

E. Abdominopelvic Regions and Quadrants

Anatomists divide the abdominopelvic cavity into nine regions using two vertical and two horizontal lines in a tic-tac-toe grid so that the location of any organ is simple to describe. The two vertical lines are drawn mid-clavicular (mid-collar bone) and just medial to the nipples, beginning at the diaphragm and extending inferiorly through the pelvic area. The upper horizontal line is drawn across the abdomen, inferior to the ribs and across the inferior portions of the liver and stomach. The lower horizontal line is drawn slightly in- ferior to the superior portion of the pelvic bones. These nine regions from the top right to the lower left are right hypo- chondriac (hypo- � under; chondro- � cartilage), epigastric (epi- � upon; gastro- � stomach), left hypochondriac, right lumbar (lumbar � loin), umbilical, left lumbar, right in- guinal or iliac (inguinal � groin), hypogastric or pubic, and left inguinal or iliac. Clinicians are more apt to divide this cavity into four quadrants that are formed by transverse and sagittal planes running through the umbilicus (navel). These quadrants are useful clinically when one is trying to describe abnormalities or to determine which organ may be the cause of pain. The four quadrants are right upper quad- rant (RUQ), left upper quadrant (LUQ), right lower quadrant (RLQ), and left lower quadrant (LLQ).

Name ___________________________________ Date _________________ Section ______________________________

A. Functions and Identification of Organ Systems

Identify the organ system by its function as described below.

1. Maintains blood oxygen and carbon dioxide levels

2. Controls muscles and glands by electrical impulses; helps control homeostasis

3. Causes movement of bones

4. Waterproof barrier that blocks the entrance of pathogens into the body and prevents the loss of water from the body

5. Transports nutrients, oxygen, and carbon dioxide throughout the body

6. Changes food into absorbable nutrients; expels wastes

7. Regulates composition of blood by eliminating nitrogenous wastes, excess water, and minerals

8. Uses hormones to control cell function; helps control homeostasis

9. Provides framework for the body and protects body organs

10. Produces gametes (sperm and egg)

11. Returns fluid to the bloodstream and provides protection against pathogens that have entered the body

B. Organ System Identification

Identify the correct organ system for the following organs.

1. spleen 6. kidney

2. liver 7. uterus

3. trachea 8. pituitary gland

4. blood vessels 9. spinal cord

5. hair 10. testes (2 systems)

Reviewing Your Knowledge

2 E X E R C I S E

20 E X E R C I S E 2 O R G A N S Y S T E M S A N D B O D Y C A V I T I E S

11. prostate gland 14. adrenal gland

12. large intestine 15. thyroid

13. pancreas (2 systems)

C. Body Cavities

Identify all the cavities for each organ as follows: cranial (C), vertebral (V), thoracic (T), pleural (PL), pericardial (PC), peritoneal (PT), abdominal (A), or pelvic (P).

1. brain 7. spinal cord

2. small intestine 8. liver

3. heart 9. kidneys

4. lungs 10. uterus

5. bronchi 11. urinary bladder

6. stomach 12. ovaries

D. Abdominopelvic Quadrants and Regions

Name the quadrant(s) (RUQ, LUQ, RLQ, and LLQ) and region(s) (right hypochondriac, epigastric, left hypochondriac, right lumbar, umbilical, left lumbar, right inguinal or iliac, hypogastric or pubic, and left inguinal or iliac) that the follow- ing organs predominantly occupy.

1. liver 5. appendix

2. stomach 6. left kidney

3. spleen 7. right ovary

4. gallbladder 8. uterus

E. Serous Membranes

Write the term the phrase describes.

1. Attaches the heart to the body cavity

2. Covers the surface of the lungs

3. Covers the surface of abdominal organs

4. The lubricating liquid in serous cavities

5. Circle the organs that are found within the peritoneal cavity: pancreas, liver, kidney, spleen, adrenal glands, abdominal aorta, inferior portions of vena cava, stomach

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Name ___________________________________ Date _________________ Section ______________________________

A. Homeostatic Imbalances of Organ Systems

Using your textbook, identify the organ system that is homeostatically imbalanced in the following diseases or disorders.

1. muscular dystrophy

2. hypothyroidism

3. myocardial ischemia

4. infectious mononucleosis

B. Body Cavities and Serous Membranes

Identify all the cavities entered for each procedure, beginning with the largest cavity and ending with the most specific body cavity. Use these abbreviations for the body cavities: abdominal (A), cranial (C), pelvic (P), pericardial (PC), pleural (PL), peritoneal (PT), thoracic (T), and vertebral (V).

5. coronary bypass surgery

6. cholecystectomy (gallbladder removal)

7. spinal tap

C. Abdominopelvic Quadrants

8. A 44-year-old male went to the emergency room complaining of severe pain in his RLQ. The doctor palpated the area and determined that the pain was originating from an organ in that quadrant. Which organ might be involved?

(a) liver (b) appendix (c) gallbladder (d) spleen (e) stomach

9. A 23-year-old female went to the doctor with the chief complaint of RLQ pain. Which organ is most likely the cause?

(a) adrenal gland (b) ovary (c) gallbladder (d) pancreas (e) kidney

2 E X E R C I S EUsing Your Knowledge

22 E X E R C I S E 2 O R G A N S Y S T E M S A N D B O D Y C A V I T I E S

D. Organ Identification

Identify the organs in the color-enhanced medical images in Figure 2.5.

(a) MRI of head and neck, sagittal view

12 13 14

(b) Radiograph of thorax, anterior view

15 16

18 19 20

(d) Radiograph of abdomen and pelvis, anterior view

FIGURE 2.5 Identification of organs on medical images.

E X E R C I S E 3 C O M P O U N D L I G H T M I C R O S C O P E 23

Acompound light microscope is used to observe small structures such as cells and tissues. The term compound refers to the two types of lenses (ocular and objective) that are used simulta- neously to magnify the image. The term light refers to the necessity of using a light source to view the object. Most human cells must be magnified to be seen by the unaided human eye. The compound light microscope can magnify images up to approximately 1,000 times, depending on the magnifying power of the lenses. Microscopic examination of cells and tissues allows stu- dents to observe how cell and tissue structure determines function. Changes in normal cell and tissue structure cause changes in organ function that lead to a disorder or disease. Tissue biopsies are performed to observe whether normal cellular structure has changed, which would indicate the absence or presence of a disorder or disease.

O B J E C T I V E S M A T E R I A L S

• compound light microscopes, lens paper, immersion oil

• thin, clear plastic rulers • prepared microscope slides of the letter “e” • prepared microscope slides of the trachea

(or other organ)

• wet mount of cheek cells; clean microscope slides, coverslips, lens paper, flat toothpicks, and dropper bottle of dilute methylene blue, 0.9% saline solution, 10% bleach solution

Compound Light Microscope 3

E X E R C I S E

1 Describe and demonstrate how to carry, clean, use, and store a compound light microscope

2 Identify the parts of a compound light microscope and describe their function

3 Calculate total magnification for each objective lens

4 Demonstrate how to view an object with the microscope using all magnifications

5 Demonstrate how to measure the field of view

6 Measure the diameter of a cell

7 Prepare a wet-mount slide

A. Transporting the Microscope

The compound light microscope is an expensive, precision in- strument that must be handled appropriately. Demonstrate care in transporting, cleaning, using, and storing the microscope.

• Pick up the microscope with two hands, one holding the arm and the other supporting the base with the cord in a secure position.

• Carry the microscope upright so that a lens or eyepiece does not fall out, and carefully place the microscope on the lab table in front of you.

24 E X E R C I S E 3 C O M P O U N D L I G H T M I C R O S C O P E

of the large knobs needs to be used, depending on whether one is right- or left-handed. The large knob is used for coarse focusing and either moves the stage up and down quickly or moves the objective lenses up and down quickly. This knob is to be used with scanning or low-power lenses. Does your stage or objective lens move? _______.

• Fine focus knob—The smaller knob on each side of the microscope that is used for precision focusing.

• Condenser—Located just below the stage is a lens that condenses light through the specimen on the slide above. If the condenser has an adjustment knob that raises and lowers the condenser, it usually needs to be in the highest position to focus the most light on the specimen.

• Iris diaphragm—Located beneath the condenser, the iris diaphragm works similarly to the iris of the eye. By adjusting its lever, the aperture changes diameter and regulates the amount of light that passes through the condenser. Decreasing the aperture size decreases the amount of light on the specimen and increases contrast.

• Substage light—The light source is usually built into the base of the microscope and typically has a dial or sliding bar on one side to control the light intensity.

LAB ACTIVITY 1 Parts of the Microscope

1 Identify the parts of your microscope as shown in Figure 3.1.

2 Compare your microscope with the one in Figure 3.1 and identify any differences with your lab group. ■

LAB ACTIVITY 2 Calculating Magnification

1 Calculate the total magnification by multiplying the magnifying powers of your microscope lenses.

scanning lens � ocular lens � total magnification

low-power lens � ocular lens � total magnification

high-dry lens � ocular lens � total magnification

oil immersion lens � ocular lens � total magnification ■

C. Calculating Magnification

Total magnifi cation is determined by multiplying the ocu- lar lens power times the objective lens power. Example: Ocular lens power � 10�; Objective lens power � 4�; Total magnifi cation � 40�.

NOTE: All other microscope parts attach to the base, arm, and head—the three basic parts of the framework.

• Ocular lens(es)—Removable eyepieces used to observe the microscope slide. Microscopes with one ocular lens are called monocular (mono- � one; ocu- � eye), and those with two ocular lenses are called binocular (bi- � two). Typically, these lenses magnify an object tenfold (10�). Look at an ocular lens and record the magnification power. _______ One of the ocular lenses may have a pointer used to identify a specific area on the slide. A micrometer, used to measure the field of view and object size, may also be present in one ocular lens. State whether your microscope has a pointer and/or a micrometer. If it has a pointer or micrometer, give the ocular lens (right or left) in which each is found.

Pointer _______ Micrometer _______ • Objective lenses—A microscope will usually have

three or four objective lenses mounted on a revolving nosepiece. Most microscopes have objective lenses that magnify an object 4� (scanning), 10� (low-power), 40� (high-dry), and 100� (oil immersion). List the magnification powers of the objective lenses on your microscope. ________________ As the barrel of the objective lens increases in length, the magnifying power also increases.

• Stage—The flat platform located beneath the objective lenses on which the microscope slide is placed. The stage has a hole in the middle, the light aperture, through which light is focused on the slide. The slide may be held onto the stage with either two spring clips or a mechanical stage clamp. Does your microscope have 2 spring clips or a mechanical stage? _______

• Mechanical stage—Holds the slide securely in place with a spring clamp for viewing and can be moved with precision by using the adjuster knobs. One knob moves the slide side to side, and the other forward and backward.

• Coarse focus knobs—On each side of the microscope toward the base is a large knob or dial that may or may not have a smaller knob in the middle. Only one

B. Parts of the Microscope

• Base—The wide bottom part that supports the microscope.

• Arm—The straight or curved vertical part that connects the base to the head.

• Head (or body tube)—The upper part of the microscope that extends from the arm and contains the ocular lens(es) and the rotating nosepiece with the objective lenses.

E X E R C I S E 3 C O M P O U N D L I G H T M I C R O S C O P E 25

D. Using the Microscope

• Clean up your lab area and put nonessentials away so you will have plenty of room to use the microscope.

• Unwind the cord and plug it in. • Clean the ocular, objective lenses, and condenser

lenses only with the special lens paper (optical safe) provided by your instructor. Whenever the image on the slide cannot be focused clearly, it may be that the ocular, objective lens, or slide is dirty and needs additional cleaning. If all else has failed, consult your instructor.

• Turn on the light and adjust it to the lowest light setting feasible for good visibility and color to reduce eye strain. The scanning (4�) and low-power (10�) lenses will not need as much light as the high-dry (40�) and oil immersion (100�) lenses.

• Trouble-shooting: If no light comes on initially, check two things before consulting your instructor. (a) Turn the light dial to a higher setting. (b) Check the safety switch on the electrical outlet by pushing in the reset button. If the light still does not work, plug your microscope into an outlet that you know works.

Revolving nosepiece

Objective lens

Mechanical stage

Iris diaphragm

Condenser

Substage light

Head

Arm

Light intensity knob

Mechanical stage adjustor knob

Fine focus knob

Coarse focus knob

Base

Ocular lens Camera attachment tube

Stage

FIGURE 3.1 Parts of the microscope.

LAB ACTIVITY 3 Using the Microscope

1 Move the scanning objective lens into place so it is over the light aperture on the stage. This objective lens has the shortest barrel. Make sure you feel the lens click into position or your field of view will be black.

2 Obtain a prepared slide with the letter “e” from your instructor and place it on the stage, securing it with either the mechanical stage clamps or slide clips. Draw the letter “e” as it appears on the stage without looking in the ocular lens.

3 Without looking into the ocular lens, practice mov- ing the slide from side to side in addition to back- ward and forward using the mechanical stage knobs (or your hands if your stage has slide clips).

4 Using the mechanical stage knobs (or your hands if your stage has slide clips), position the letter “e” over the light hole in the stage.

5 Check to see that the condenser lens is raised com- pletely up to the stage.

26 E X E R C I S E 3 C O M P O U N D L I G H T M I C R O S C O P E

20 Center the area you want to view and then obtain a container of immersion oil made especially for the oil immersion lens.

21 Focus the slide with the high-power lens. Move the objective lens out of the way and apply a drop of oil directly on the part of the slide you wish to study.

22 Click the oil immersion lens into place, open the iris diaphragm as needed, adjust the light, and focus with only the fine focus knob.

23 What is the working distance from the bottom of the oil immersion lens to your specimen? _________ mm

24 When you finish, move the scanning power objective lens back into place.

25 Move the stage as far from objectives as possible by either lowering the stage or raising the objectives. Remove the slide and clean the oil from the oil im- mersion lens with lens paper. (Also clean the high-dry objective lens if you passed it through the oil.) Your instructor may ask you to use an additional cleaner.

26 Clean the slide with a new lens paper. If necessary, clean the stage as well. ■

E. Measuring the Field of View

The fi eld of view is the area on the slide that is being observed and is inversely proportional to the magnifi cation (the fi eld of view decreases in size with increasing magni- fi cation). Once you know the diameter of the fi eld of view in millimeters (mm) at various magnifi cations, you will be able to estimate the size of cells or other structures in the fi eld of view. The object being viewed should be in the cen- ter of the fi eld of view when you are switching to a higher objective lens (higher magnifying power). Measuring the fi eld of view at different magnifi cations demonstrates the advantage of scanning at a lower magni- fi cation to fi nd a structure of interest before working up to a higher magnifi cation.

6 If your stage is moveable, the coarse focus knob will move the stage. Raise the stage as far as it will go. If your objective is moveable, use the coarse focus knob to lower the objective lens until it stops. The slide and the scanning objective lens will not actually touch.

7 If you have a binocular microscope, adjust the two ocular lenses as you would a pair of binoculars so that the two lenses are a comfortable distance apart for your eyes.

8 Look through the ocular lens(es) and adjust the light. Use the coarse focus knob to focus in the letter “e.” Complete the focusing process by using the fine focus knob.

9 The working distance is the distance a specimen is from the bottom of the objective lens. Use a millime- ter ruler to measure the distance between the bottom of the scanning objective lens and your specimen. _________ mm

10 Using the mechanical stage knobs, bring the letter “e” directly into the center of the field of view (the lighted circular area you see as you look through the ocular lenses).

11 Draw the letter “e” as it appears through the micro- scope. Compare the appearance to your initial drawing. _________

12 While observing the letter “e” through the ocular lens(es), describe the movement that you observe as you move the slide:

• to the left ___________________________

• to the right _________________________

• forward ____________________________

• backward __________________________

13 Reposition the letter “e” directly in the middle of the field of view and switch to the low-power objective lens.

14 Most microscopes are parfocal so that when you move to a different magnification the specimen is al- most, but not quite, in focus. You will need only the fine focus knob to focus the image. Center the speci- men because the previously centered object is usually not in the center.

15 What is the working distance from the bottom of the low-power objective lens to your specimen? _________ mm

16 Use the iris diaphragm lever to adjust the amount of light and improve the contrast of your image.

CAUTION: Do not use the coarse focus knob with high-dry or oil immersion lenses.

NOTE: Most slides used in anatomy and physiology do not need the magnification of the oil immersion lens. Your instruc- tor will inform you if and when you will use this objective lens. Only use the oil immersion lens if instructed to do so.

17 Repeat the above procedure with the high-dry objective lens. Be sure to focus only with the fine focus knob.

18 What is the working distance from the bottom of the high-power objective lens to your specimen? _________ mm

19 Describe the change in diameter of the field of view as one switches from the scanning lens to the low-power lens and then to the high-power lens.

E X E R C I S E 3 C O M P O U N D L I G H T M I C R O S C O P E 27

LAB ACTIVITY 4 Measuring the Field of View and Estimating Object Size

1 Move the scanning objective lens in place. 2 Place a clear plastic ruler over the light opening in the

stage, or use the micrometer in the ocular lens or grid slide.

3 Look through the ocular lens, and move the ruler or grid slide so that a line touches the left edge of the field and count the number of millimeter intervals that can be seen. Record. _________ mm

4 Switch to the low-power objective lens and repeat this procedure to count the number of millimeter intervals that can be seen. Record. _________ mm

5 Switch to the high-dry objective lens and repeat this procedure to count the number of millimeter intervals that can be seen. Record. _________ mm. The close- ness of this lens to the slide may not allow a ruler to be added.

6 Move the scanning power objective lens in place and move the stage as far as possible from the objectives before removing the ruler.

7 Obtain a prepared slide with the letter “e” and place it on the stage. Using the scanning power objective lens, estimate the diameter of the letter e. If it occupies ½ of the field of view, then it is ½ times the mea- sured diameter of the field of view of the scanning objective lens. Record the diameter of the letter “e.” _________ mm

8 Move the stage as far as possible from the objectives before removing the ruler. ■

LAB ACTIVITY 5 Observation of an Organ

1 Obtain a prepared slide of the trachea or other organ supplied by your instructor.

2 Begin your observation using the scanning lens. Center and focus the organ, and note that you can see several different tissues (stained different colors) present at this magnifying power.

3 Switch to the low-power lens. Center and focus, and note the additional tissue detail that can be discerned at this magnifying power. Make a drawing of the tissues in Figure 3.2(a).

4 Switch to the high-power lens. Center and focus, and note that you can now observe the cells that constitute the various tissues in this organ. Make a drawing of the cells in Figure 3.2(b).

5 Estimate the diameter of 3 different types of cells.

_________ mm

6 Move the scanning power objective lens into place and move the stage as far as possible from the objectives before removing the slide. ■

FIGURE 3.2 Student drawings of tissues and cells.

(a) Low power (b) High power

F. Microscopic Structure of an Organ

An organ is composed of a variety of cells and tissues. This activity starts with an observation of a section of a whole organ with the scanning lens to get the “big picture” and then moves to higher magnifying powers to see addi- tional detail.

28 E X E R C I S E 3 C O M P O U N D L I G H T M I C R O S C O P E

Nucleus Cells folded over

Overlapping cellsCytoplasm

400�

(a) Photomicrograph of cheek cells

(b) Student drawing

FIGURE 3.3 Cheek cells.

DISCUSSION QUESTIONS Cheek Smear

1 Why was stain added to the cheek cells?

2 What cellular structures did you observe?

■

H. Storing the Microscope

It is important to put the microscope away properly.

• Check that the scanning objective lens is in place and that the slide is removed from the stage.

• Depending on the type of microscope, either lower the stage or raise the objective to put maximum distance between the objective and the stage.

• Center the mechanical stage. • Turn off the substage light. The bulb life is extended

if it cools before moving the microscope. • Clean the ocular and objective lenses with lens paper. • Coil the cord neatly according to your instructor’s

directions. • Place the dust cover over the microscope. • Using both hands and the proper carrying technique,

return the microscope to the appropriate cabinet.

LAB ACTIVITY 6 Wet Mount of Cheek Cells

1 Prepare a cheek smear slide and observe it under the compound microscope. • Obtain a toothpick, a clean microscope slide, and a

coverslip. • Place a drop of 0.9% saline on the microscope

slide. • Gently scrape the flat end of the toothpick (no blood,

please!) on the inner lining of your cheek only one time. Do not scrape hard enough to hurt.

• To apply the cells to the slide, rotate the toothpick between your thumb and forefinger to dislodge the cells into the saline.

• Dispose of the toothpick as your instructor directs.

• Add one drop of dilute methylene blue to the cells on your slide.

• Cover the sample with a coverslip as directed by your instructor.

• Using low-power, locate the blue-stained cells. Switch to high-power to observe more cellular detail.

2 Compare the cells on your slide with Figure 3.3(a). Draw a picture of your cells in Figure 3.3(b).

3 Estimate the diameter of the cheek cells. _________ mm 4 Move the scanning power objective lens in place and

remove the slide.

5 Place microscope slides in a 10% bleach solution as your instructor directs. Clean your lab top with a 10% bleach solution.

6 Answer Discussion Questions with your lab group.

G. Wet Mount of Cheek Cells

Cells that line the interior of the mouth fi t closely together like fl oor tiles and form a thick layer of thin cells that pro- tect the underlying tissue from abrasion and microbes (bac- teria and viruses). The superfi cial cells continually slough off and are replaced by underlying cells. Gently scraping the lining of the cheek removes the superfi cial cells that are about to slough off.

A. Care and Use of the Microscope

Correct each statement by crossing out the incorrect word(s) and inserting the correct word(s).

1. One hand is to be used to transport the microscope.

2. Tissue paper can be used to clean the microscope lenses and prepared slides.

3. The microscope should be put away with the high-dry lens in position.

4. The coarse focusing knob should be used when using the high-dry lens.

5. The iris diaphragm should be completely open to obtain maximum contrast.

6. The condenser should be in the lowest position (far from the stage) to focus the most light on the specimen.

B. Parts of the Microscope

Write the term that the phrase describes.

1. Large knob that moves the stage or objective lens a great distance. Used with scanning or low-power objective lenses only.

2. Flat platform beneath the objective lens on which the microscope slide is placed.

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

3 E X E R C I S E

30 E X E R C I S E 3 C O M P O U N D L I G H T M I C R O S C O P E

3. Removable lenses that you look through to observe the microscope slide.

4. Small knob that moves the stage or objective lens a very small distance and is used for precision focusing.

5. Extends from the arm and contains the ocular lenses and rotating nosepiece.

6. Lens that condenses light through the specimen and is located below the stage.

7. Light from specimen passes through these lenses first. These lenses are located in the rotating nosepiece.

8. Wide bottom part that supports the microscope.

9. Regulates the amount of light passing through the condenser.

10. Vertical portion that connects the base to the head.

C. Total Magnification and Field of View

1. Calculate the total magnification of an object viewed with a 10� ocular and a 60� objective lens.

2. Does the size of the field of view increase or decrease when going from a lower- to higher-power objective lens?

E X E R C I S E 4 C E L L S T R U C T U R E A N D C E L L C Y C L E 31

The human body contains over a trillion cells. These cells form the organs of the human body and are responsible for organ function. Cells take in nutrients delivered to them by the blood and use these nutrients to make carbohydrates, proteins, lipids, and nucleic acids. Cells use these macromolecules to make cellular and extracellular structures, repair themselves, and perform the tasks required for organ function.

A. Cell Structure

Cells are the smallest structural and functional units of living organisms. They are enclosed by a plasma mem- brane that controls the movement of substances into and out of the cell. The interior of the cell is fi lled with cyto- plasm that contains cytosol (a viscous fl uid) and organelles (little organs). Like an automobile, a cell has different parts or organelles that perform different functions. A “generalized” animal cell is shown in Figure 4.1, and functions of cellular organelles are described in Table 4.1.

O B J E C T I V E S M A T E R I A L S

• model or diagram of a cell • compound microscopes and lens paper, prepared

slides of human skeletal muscle cells, pseudos- tratified ciliated columnar epithelium (trachea), nonciliated simple columnar epithelium with microvilli (small intestine), motor neurons, sperm, and blood or Real Anatomy (Histology)

• 3-dimensional models of mitosis • whitefish blastula slides

Cell Structure and Cell Cycle 4

E X E R C I S E

1 Identify cellular components on a model or diagram

2 Describe the function of the plasma membrane and cellular organelles

3 Identify cells and observable cellular structures on prepared microscope slides or on photomicrographs

4 Identify the stages of mitosis

5 Describe the events of each stage of mitosis

DISCUSSION QUESTIONS Cell Structures

1 Which cell structures from Table 4.1 are not found in most human cells?

■

LAB ACTIVITY 1 Cell Structure

1 Point to each cell structure shown in Figure 4.1 on a cell model or chart.

2 Describe the function of each organelle in Figure 4.1(a). 3 Answer the Discussion Question with your lab group.

4000�

Nuclear envelopeChromatin

(darkarea)

Nucleus

Cytoplasm

Mitochondrion

Vesicle

Rough endoplasmic reticulum

(b) Transmission electron micrograph

32 E X E R C I S E 4 C E L L S T R U C T U R E A N D C E L L C Y C L E

8 9

17 (small dot)

15 (gel-like fluid)

(a) Sectional drawing

FIGURE 4.1 Generalized animal cell.

1 mitochondrion 2 peroxisome 3 smooth endoplasmic reticulum 4 lysosome 5 plasma membrane 6 centrioles

7 microvillus 8 flagellum 9 cilium 10 secretory vesicle 11 chromatin 12 nuclear membrane

13 nucleolus 14 nucleus 15 cytoplasm 16 rough endoplasmic reticulum 17 ribosome 18 Golgi complex

E X E R C I S E 4 C E L L S T R U C T U R E A N D C E L L C Y C L E 33

B. Cell Specialization

The human body contains over 200 different types of cells with different functions. These differences in function are refl ected in cell structure. Cells of the human body differ from the generalized animal cell in shape, size, or number and type of organelles present. In the next activity you will observe cells of skeletal muscle, pseudostratifi ed ciliated columnar epithelium, nonciliated simple columnar epithe- lium with microvilli, motor neurons, sperm, and blood.

• Skeletal muscle cells are long, cylindrical cells that contain specialized proteins (contractile proteins) that enable them to contract (shorten in length) to move bones. The contractile proteins are organized into repeating units that can be observed in the light microscope as striations.

• Pseudostratified ciliated columnar epithelial cells have cilia that move substances like mucus along the surface of the cells. Mucus is produced by specialized cells called goblet cells.

• Nonciliated simple columnar epithelium with microvilli. Microvilli increase the surface area of the plasma membrane which provides a larger area for absorption of nutrients along the gastrointestinal tract or secretion of product from glands.

• Motor neurons are nervous tissue cells with many processes (cell extensions) that receive information from other neurons and send electrical signals to muscle cells causing them to contract.

• Sperm cells (sperm) are small, oval cells with a flagellum that propels them through the female reproductive tract.

• Red blood cells do not have a nucleus (anucleate) but contain large amounts of hemoglobin, a red pigment that binds oxygen.

• White blood cells have nuclei with different shapes and defend the body from pathogens and cancerous cells.

TABLE 4 .1 Function of Cell Structures

STRUCTURE FUNCT ION

Plasma Membrane Controls movement of substances into and out of the cell Microvilli Folds of the plasma membrane that increase the surface area of the cell to increase absorption or secretion Nucleus Contains DNA molecules and nucleolus Nucleolus Assembly site for ribosomes Chromatin Long thin strands within nucleus. Each strand composed of one DNA molecule and associated proteins. Cytoplasm Area of the cell that includes the cytosol and organelles Cytosol Fluid portion of cytoplasm that surrounds organelles Organelles • Mitochondria Makes ATP via aerobic cellular respiration • Ribosomes Site of protein synthesis • Rough endoplasmic Processes and transports proteins made at attached ribosomes; reticulum (RER) synthesizes phospholipids • Smooth endoplasmic Fatty acid and steroid synthesis; detoxifies toxic substances reticulum (SER) • Golgi complex Receives and modifies proteins from RER; sorts and transports them • Secretory vesicles Secrete substances outside the cell by exocytosis • Lysosomes Enzymes digest and recycle worn-out organelles and substances entering the cell; can digest the cell • Peroxisomes Produce hydrogen peroxide; detoxify harmful substances • Cytoskeleton Three kinds of protein filaments; maintain cell shape and involved in cell movement and movement of organelles • Centrosomes (centrioles) Form mitotic spindle; needed to form cilia and flagella • Cilia Abundant, hair-like cell projections that move fluids and particles along the cell surface • Flagella Long cell projection; whip-like motion moves sperm

34 E X E R C I S E 4 C E L L S T R U C T U R E A N D C E L L C Y C L E

c. motor neuron: _____________________________

d. sperm cell: _______________________________

e. red blood cell _____________________________

f. white blood cell ___________________________

g. nonciliated simple columnar epithelium:

_________________________________________

■

LAB ACTIVITY 2 Cell Specialization

1 Observe each prepared slide (skeletal muscle, pseu- dostratified ciliated columnar epithelium, motor neuron, sperm, blood cells, and nonciliated simple columnar epithelium with microvilli) and identify the cells and cell components shown in Figure 4.2 or Real Anatomy (Histology).

2 Using Figure 4.2, describe each cell’s shape and list the cell structures that can be seen with the light microscope in each cell type.

a. skeletal muscle cell: ________________________

b. pseudostratified ciliated columnar epithelial cell:

_________________________________________

FIGURE 4.2 Cell specialization.

400�

Width of skeletal muscle cell Nucleus

(a) Skeletal muscle cells (c) Motor neuron

Processes Nucleus Cell body

(d) Sperm cells 400�

Nucleus Flagellum

630�

Goblet cell CiliaNucleus

(b) Ciliated cells (Pseudostratified ciliated columnar epithelium)

Red blood cells

Nucleus of white blood cell

(e) Blood cells

MicrovilliNucleus

(f) Nonciliated simple columnar epithelium with microvilli

500�

E X E R C I S E 4 C E L L S T R U C T U R E A N D C E L L C Y C L E 35

C. Somatic Cell Division: Mitosis and Cytokinesis

Somatic (soma- � body) cell division occurs when one cell divides to produce two genetically identical cells. Cell division is needed for growth of the individual and cell replacement. The cell cycle, a period during which a cell grows and divides into two genetically identical cells (daughter cells), begins when a cell is produced by cell division and ends when the cell divides (Figure 4.3). The length of the cell cycle differs according to the type of cell, with some cells dividing more frequently than others. The cell cycle can be divided into two basic periods: interphase, a long period during which the cell conducts its normal activity, grows, and prepares for cell division; and the mitotic phase, when the cell is dividing. The mitotic phase consists of mitosis, or nuclear division, and cytokinesis, or cytoplasmic divi- sion. The four stages of mitosis are prophase, metaphase, anaphase, and telophase (Table 4.2). To observe interphase and the stages of mitosis, you will examine a prepared microscope slide containing several sections of a whitefi sh blastula. The blastula is an early embryonic stage in which cells are dividing rapidly, pro- viding many cells in different stages of mitosis.

2 Obtain a prepared whitefish blastula slide and hold it up to the light. Notice that there are many blastula sections on each slide. It will be necessary to view several of these sections to find all of the phases.

3 Using a compound microscope, begin looking at your slide with the low-power objective lens. Use the high- power objective lens to identify interphase, the four stages of mitosis, and cytokinesis. ■

Before Going to Lab

1 Using Table 4.2, identify interphase, each phase of mitosis, and cytokinesis in Figure 4.4(a)–(e).

LAB ACTIVITY 3 Mitotic Phases

1 Observe the 3-dimensional models of the mitotic phases, noting the changes in each phase.

FIGURE 4.3 The cell cycle.

INTERPHASE

MITOTIC (M) PHASE

Prophase

M etaphaseA

na ph

as e

Te lo

ph as

S phase DNA replicated.

G2 phase Cell growth continues;

enzymes and other proteins are synthesized;

centrosome replication completed.

G1 phase Cell metabolically active; duplicates organelles and

cytosolic components; centrosome replication

begins.

8 hours

4–6 hours8–

10 ho

ur s

TABLE 4 .2 Phases of Somatic Cell Cycle

PHASE DESCR IPT ION OF ACT IV ITY

Interphase Normal cell work; cell metabolically active and growing; DNA replicates (inter- � between) Mitotic Phase Cell division Mitosis (mitos- � thread) Nuclear division • Prophase (pro- � first) Nucleolus and nuclear membrane disappear; chromatin condenses into chromosomes; centrioles move to opposite poles; spindle fibers form • Metaphase (meta- � next) Chromosomes line up at metaphasal plate; spindle fibers attach to centromeres of chromatids • Anaphase (ana- � apart) Chromatids of chromosomes separate; move to opposite poles • Telophase (telo- � end) Cell reverses prophase activities Cytokinesis (cyto- � cell; kinesio- � Cytoplasmic division into two genetically identical daughter cells movement)

36 E X E R C I S E 4 C E L L S T R U C T U R E A N D C E L L C Y C L E

• anaphase (AN-a-faze)

• interphase (IN-ter-faze)

• metaphase (MEH-ta-faze)

• prophase (PRO-faze)

• telephase and cytokinesis (TELL-o-faze and cyto-kih- NEE-sis)

a ________________________

b ________________________

c ________________________

d ________________________

e ________________________

Chromatin in nucleus Nuclear membrane

(a)

Chromosomes forming Plasma membrane

(b)

CentrioleSpindle fiber Chromosomes

(c)

Spindle fiberChromosomesCentriole

(d)

Cleavage furrowSpindle fibersChromosomes

(e)

FIGURE 4.4 Mitotic phases.

A. Cellular Structure

Fill in the blank with the name of the cell structure that fits the description.

1. short, hair-like projections for movement of substances along cell surface

2. intracellular fluid

3. site of energy production by cellular respiration

4. site of protein synthesis

5. site of steroid and fatty acid synthesis

6. small vesicle with digestive enzymes

7. organelles needed to form cilia and flagella

8. thread-like strand of DNA with associated proteins

9. site of secretory and membrane protein synthesis

10. site where protein products are stored, packaged, and exported

11. contains DNA that control cellular activities

12. site of ribosome synthesis

13. gives the cell shape, support, movement, and holds organelles in position

14. controls movement of substances into or out of the cell

15. folds of the plasma membrane that increase the cell’s surface area

16. detoxifies harmful substances, produces hydrogen peroxide, and oxidizes amino acids

17. double membrane that separates the nucleus from the cytoplasm

18. a small membranous sac that delivers proteins to the plasma membrane to exit the cell

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

4 E X E R C I S E

38 E X E R C I S E 4 C E L L S T R U C T U R E A N D C E L L C Y C L E

B. Phases of the Cell Cycle

Write the phase of the cell cycle that the phrase describes.

1. cytoplasmic division

2. cell performing normal functions; longest phase

3. nuclear division

4. chromatid pairs line up at equatorial plate

5. chromatin condenses into chromosomes

6. spindle fibers break up; nucleus reappears

7. centromeres divide; chromosomes move to opposite poles

8. nuclear membrane disassembles and disappears

9. chromosomes unravel to form chromatin

10. mitotic spindle forms

11. DNA replicates

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

4 E X E R C I S E

A. Cellular Organelles and Their Function

Write the letter for the correct answer in the blank.

____ 1. A cell makes and secretes a protein-based hormone. This particular cell would have a great amount of RER and:

(a) SER (b) Golgi complex (c) mitochondria (d) lysosomes

____ 2. Testes and ovaries that make steroids (lipids) would have a larger amount of:

(a) SER (b) RER (c) mitochondria (d) lysosomes

____ 3. Muscle cells that need large amounts of ATP would have many:

(a) Golgi complexes (b) ribosomes (c) SER (d) mitochondria

____ 4. Cells that line the small intestine are specialized for absorption and secretion. The plasma membrane structure they have to accomplish this is:

(a) centrioles (b) cilia (c) flagella (d) microvilli

____ 5. Immune cells that destroy bacteria with chemicals need an abundance of:

(a) SER (b) ribosomes (c) lysosomes (d) centrioles

B. The Cell Cycle and Mitosis

Answer each question with a short answer.

6. Explain the role of somatic cell division as a person ages from infancy to adulthood.

7. Explain the role of cell division in wound healing.

40 E X E R C I S E 4 C E L L S T R U C T U R E A N D C E L L C Y C L E

8. List the cell structures involved in mitosis.

9. Can red blood cells undergo mitosis? Explain.

10. Sperm and eggs have one-half the number of chromosomes of the somatic cells that divided to form them. Are sperm and eggs formed by mitosis? Explain.

11–14. Name four cellular organelles that are membrane bound.

11. _______________________ 13. _______________________

12. _______________________ 14. _______________________

15–17. Which cellular organelles are not membrane bound?

15. _______________________

16. _______________________

17. _______________________

18–20. Identify the three structures indicated in Figure 4.5.

18. _______________________

19. _______________________

20. _______________________

45,000�

19 20

TEM

FIGURE 4.5 Transmission electron micrograph of a cell section.

E X E R C I S E 5 T R A N S P O R T A C R O S S T H E P L A S M A M E M B R A N E 41

O B J E C T I V E S M A T E R I A L S

• Simple Diffusion: 2 agar Petri dishes per group, small millimeter rulers, forceps, methylene blue crystals, potassium permanganate crystals

• Diffusion and Osmosis Across a Dialysis Membrane (per group): dialysis tubing 12 cm long, 2 dialysis clips, scissors, Congo red or red food coloring, 40% sucrose solution, 500-mL beakers, distilled water, gram scale

• Osmosis Across the Egg Vitelline Membrane: uncooked egg, vinegar, Karo syrup or 25% sucrose solution, water, 500-ml beaker or glass container with lid, gram scale

• Osmosis in Living Red Blood Cells: blood (uncoagulated), disposable gloves, safety glasses, clean microscope slides and coverslips, 4 medicine droppers per group, compound microscope, filter paper

Transport Across the Plasma Membrane

5 E X E R C I S E

1 Describe diffusion and osmosis

2 Compare hypotonic, hypertonic, and isotonic solutions

3 Observe simple diffusion, diffusion and osmosis across a dialysis membrane, osmosis across egg viteline membrane, and osmosis in living red blood cells

The plasma membrane with its unique design is responsible for discriminately allowing substances into and out of a living cell. Active processes require cellular energy (ATP) to transport sub- stances against their concentration gradients across the plasma membrane. Passive processes do not require the cell to expend energy because the kinetic energy of the parti- cles causes them to move from an area of their higher concentration to an area of their lower concentration. In this exercise, we will look at the passive processes of diffu- sion and osmosis.

A. Simple Diffusion

Diffusion can occur in solids, liquids, or gas, and across the plasma membrane. The net movement of substances from a region of their greater concentration to a region of their lesser concentration is called moving substances “down the concentration gradient.” A concentration gra- dient indicates there is a difference in the concentration of molecules or ions inside the cell (intracellular) compared to outside the cell (extracellular).

42 E X E R C I S E 5 T R A N S P O R T A C R O S S T H E P L A S M A M E M B R A N E

5 Data Analysis: Calculate the diffusion rates for each time period for the two substances using Table 5.1.

6 Complete the Experimental Report with your lab group.

EXPERIMENTAL REPORT Simple Diffusion

Results: Which substance moved faster?

Discussion: Discuss why the diffusion rates of the two substances differed.

Conclusion: State how molecular weight affects diffusion rate.

■

Methylene blue dye crystal

Potassium permanganate dye crystal

FIGURE 5.1 Diffusion in agar plate setup.

TABLE 5 .1 Simple Diffusion Results

D IFFUS ION OF METHYLENE BLUE D IFFUS ION OF POTASS IUM PERMANGANATE

D IFFUS ION RATE D IFFUS ION RATE T IME (min ) D IFFUS ION D IAMETER (mm) (mm/min) D IFFUS ION D IAMETER (mm) (mm/min)

In the following activity, diffusion of two substances through a solid (agar) will be studied. Methylene blue has a molecular weight of 320, and potassium permanganate has a molecular weight of 158. The two substances move at different rates through the agar, which is made up mostly of water.

LAB ACTIVITY 1 Experiment: Simple Diffusion

1 Prediction: With your lab group, predict which substance will move faster. (Hint: Use the molecular weights.) Circle your answer: methylene blue or potas- sium permanganate.

2 Materials: Obtain the materials for simple diffusion. 3 Data Collection: Measure the diffusion rates of meth-

ylene blue and potassium permanganate. • Decide who will set up the experiment, who will

time, who will measure, and who will record. • Carefully using forceps, place a large crystal of

methylene blue on the surface of an agar Petri dish (Figure 5.1). Be careful not to drop any extra crystals on the agar surface.

• Using the same technique, place a similar size crystal of potassium permanganate on the other side of the Petri dish.

• Using a millimeter (mm) ruler, measure each substance’s diameter of diffusion at 15-minute inter- vals for at least 1 hour (or longer if desired).

• After each observation, record the diffusion diameter of each substance in millimeters (mm) in Table 5.1.

4 Clean up as directed by your instructor.

E X E R C I S E 5 T R A N S P O R T A C R O S S T H E P L A S M A M E M B R A N E 43

• Cut a 12-cm piece of dialysis tubing and soak the bag in water for 3 minutes to make it easier to open.

• Fold over one end of the dialysis tubing and secure it with a dialysis clip.

• Rub the open end of the dialysis tubing between your thumb and finger to separate the sides, and fill the dialysis tubing more than three-quarters full with the red 40% sucrose solution.

• Pushing the air out of the bag, fold over the end of the bag and clip it with a dialysis clip. The dialysis bag now looks like a large “cell.”

• Check to see that no liquid is leaking out of either end of the dialysis bag.

• Rinse the bag to remove excess sucrose solution, dry the bag, and weigh it. Record the beginning weight in Table 5.2.

• Submerge the dialysis bag in a beaker of distilled water. • Dry and weigh the dialysis bag after 15-minutes,

30-minutes, and 45-minutes. If your lab lasts longer, you may also do a 60-minute measurement.

• Record each measurement in Table 5.2.

4 Clean up as directed by your instructor. 5 Complete the Experimental Report with your lab group.

B. Diffusion and Osmosis Across a Dialysis Membrane

Osmosis is the diffusion of a solvent (dissolving medium, which is water in living organisms) across a selectively per- meable membrane that occurs in response to differences in solute (substance dissolved in solvent) concentrations. Water diffuses from an area of higher water concentration but lower solute concentration (hypotonic solution) to an area of lower water concentration but higher solute concentration (hyper- tonic solution). The terms hypotonic (hypo- � defi cient; -tonos � stretching) solution or hypertonic solution are used only when two solutions are compared. A solution’s tonicity is a measure of the solution’s ability to change the volume of a cell by changing water content. Water will move into the hypertonic solution until the solute concentrations of the two solutions equalize to become isotonic solutions (iso- � same) or if enough pressure is applied to stop the fl ow of water. In the following activity, a sucrose solution is added to a dialysis membrane bag (semipermeable membrane), which is placed in distilled water. Dialysis membranes contain small pores that allow water and small solutes to cross. If water enters the bag, the weight of the bag will increase, and if water leaves the bag, its weight will decrease. The dialysis membrane used in this experiment contains pores that are large enough to allow diffusion of sucrose and red dye molecules into and out of the dialysis membrane bag.

Before Going to Lab

1 Label Figure 5.2.

LAB ACTIVITY 2 Experiment: Diffusion and Osmosis Across a Dialysis Membrane

1 Prediction: With your lab group, predict the direction of water and sucrose movement in Figure 5.2 by circling the correct italicized choice.

• The net movement of water (measurable by weight) will be into or out of the dialysis bag (see Figure 5.2).

• The net movement of sucrose will be into or out of the dialysis bag (see Figure 5.2).

2 Materials: Obtain materials for osmosis and diffusion across a dialysis membrane.

3 Data Collection: Observe osmosis and diffusion through a dialysis membrane and record your results in Table 5.2. • Decide who will set up the experiment, who will

time, who will weigh and observe the color, and who will record.

NOTE: This experiment should be set up at the beginning of class so that changes can be observed and recorded throughout the lab time. The results become more dramatic the longer this experiment runs.

• hypertonic solution 1

• hypotonic solution 2

Sucrose solution

Distilled water

D ia

ly si

s cl

D ia

ly si

s cl

Dialysis tubing

FIGURE 5.2 Dialysis bag setup.

TABLE 5 .2 Dialysis Bag Results WE IGHT OF COLOR OF D IALYS IS BAG T IME (min ) BEAKER WATER (g rams)

0 min Start weight:

15 min

30 min

45 min

60 min

44 E X E R C I S E 5 T R A N S P O R T A C R O S S T H E P L A S M A M E M B R A N E

C. Osmosis Across the Egg Vitelline Membrane

The vitelline membrane of the egg is a thin, semiperme- able membrane found on the underside of the shell in a raw egg. The chicken egg is not a single cell, and the vitelline membrane is not equivalent to the cell plasma membrane. In this activity, a raw egg is soaked in vinegar for 24–48 hours to dissolve the eggshell and leave the vitelline mem- brane. The egg surrounded by the vitelline membrane is then placed in different solutions to observe osmosis.

EXPERIMENTAL REPORT Dialysis Bag

Results: • Describe how the weight of the bag changed over

time.

• Describe how the color of the beaker water changed over time.

Discussion: • Identify the solutes and solvent in this experiment.

• Why was the red dye added to the sucrose solution?

• Which direction did osmosis occur?

• Which direction did diffusion of solutes occur?

• Did net osmosis and diffusion of solutes stop? Did the two solutions become isotonic? Explain.

• In this experiment, what represented the plasma membrane, intracellular fluid, and extracellular fluid?

Conclusion: State what drives the osmosis and diffusion of solutes; when does the net movement of both stop?

■

LAB ACTIVITY 3 Experiment: Osmosis Across the Egg Vitelline Membrane

1 Prediction: With your lab group, predict the direction of water movement by circling the correct italicized choice. • When the egg is placed in distilled water, the net

movement of water will be into or out of the egg. • When the egg is placed in 25% sucrose solution (or

Karo syrup), the net movement of water will be into or out of the egg.

2 Materials: Obtain materials for osmosis across the egg vitelline membrane. The eggs used in this experiment are raw eggs that have been soaked in vinegar for 24–48 hours.

3 Data Collection: Observe osmosis across the vitelline membrane of the egg and record your results in Table 5.3. • Decide who will set up the experiment, who will

time, who will weigh, and who will record. • Remove two eggs from the vinegar solution and gently

rinse the eggs in water. Blot water off the eggs and then weigh the eggs. Record the weight in Table 5.3.

• Place one egg in a 25% sucrose solution (Karo syrup or maple syrup can also be used) and the other egg in a distilled water solution.

• Dry and weigh the eggs after 15-minutes, 30-minutes, 45-minutes, and 60-minutes. Observe any change in appearance of the eggs over time.

• Record each measurement in Table 5.3. • Break the vitelline membrane and observe the

appearance of the egg. Is it similar to a raw egg or a cooked egg?

4 Clean up as directed by your instructor. 5 Complete the Experimental Report with your lab group.

TABLE 5 .3 Osmosis Across the Vitelline Membrane

WEIGHT OF EGG IN SUCROSE WEIGHT OF EGG TIME (min) SOLUTION (grams) IN WATER (grams)

0 min Start weight: Start weight:

15 min

30 min

45 min

60 min

Change in Appearance of Egg over Time

Egg in sucrose solution

Egg in water

E X E R C I S E 5 T R A N S P O R T A C R O S S T H E P L A S M A M E M B R A N E 45

EXPERIMENTAL REPORT Egg Vitelline Membrane

Results: • Describe how the weight of the egg in 25% sucrose

solution (or syrup) changed over time.

• Describe how the appearance of the egg in 25% sucrose solution (or syrup) changed over time.

• Describe how the weight of the egg in distilled water solution changed over time.

• Describe how the appearance of the egg in distilled water solution changed over time.

Discussion: • When the egg was in the 25% sucrose solution (or

syrup), in which direction did osmosis occur?

• When the egg was in distilled water solution, in which direction did osmosis occur?

• Compare the appearance of the egg in 25% sucrose solution (or syrup) at the last weighing with the appearance of the egg in distilled water solution at the last weighing. Explain the difference in appearance.

• Is the 25% sucrose solution (or syrup) a hypertonic, hypotonic, or isotonic solution?

• Is water a hypertonic, hypotonic, or isotonic solution?

Conclusion: • Explain why osmosis occurs across the vitelline

membrane of the egg.

■

D. Osmosis Across a Living Plasma Membrane

Red blood cells (RBCs) are good examples to use for this osmosis experiment because their shape changes dramati- cally when they are exposed to hypotonic or hypertonic solutions. Their normal shape is a round biconcave disc with a smooth plasma membrane. The plasma membrane does not allow salts in the RBC cytoplasm to leave the cell, but water can freely enter or leave the cell through the plasma membrane. Under the microscope, RBCs look two-toned, with the center being lighter because of its concavity and thinness. If the cell loses most of its water by osmosis when put in a hypertonic solution, it becomes crenated or shriveled with spiked edges. If the cell gains a signifi cant amount of water by

being placed in a hypotonic solution, it swells and may even- tually burst—a process called hemolysis (hemo- � blood; -lysis � break down). As a basis for comparing various solu- tions to blood, the salt content (NaCl) of blood is 0.9% and is the same salt content as a physiologic saline solution.

NOTE: Remember . . . salt shrivels and water swells (a cell).

SAFETY NOTE: Wear safety glasses and disposable gloves when handling body fluids or animal blood.

LAB ACTIVITY 4 Experiment: Osmosis in Living RBCs

1 With your lab group, discuss and identify which solu- tions for this experiment are hypotonic, hypertonic, or isotonic to the RBCs (Figure 5.3). The isotonic solution is also called physiologic saline. The arrows in Figure 5.3 indicate the direction of water movement.

• 0.9% saline solution

• 5% saline solution

• distilled water

2 In Figure 5.3, identify the shape of the RBC (normal, swollen, or crenated) and the type of solution into which the RBC is immersed (isotonic, hypertonic, or hypotonic).

3 Prediction: With your lab group, predict the net move- ment of water in all three types of solutions. Circle your answer, from the italicized choices, for all three situations: • In the isotonic solution, the RBCs will swell, crenate,

or not change shape. • In the hypotonic solution, the RBCs will swell,

crenate, or not change shape. • In the hypertonic solution, the RBCs will swell,

crenate, or not change shape.

4 Materials: Obtain materials to observe osmosis in RBCs. 5 Data Collection:

• Decide who will set up and initially observe each slide. Every member of your group should observe each slide.

Slide #1: 0.9% saline solution • Place a drop of animal blood on a slide with a

medicine dropper. With a different medicine drop- per, add a drop of 0.9% saline solution to the blood. Tilt the slide to intermix the two solutions, and cover with a coverslip.

• Using high power, observe the slide for changes in cell shape. Blood cells are very tiny and difficult to see under low power.

• Record shape of RBCs and type of solution into which they were placed.

shape type of solution

46 E X E R C I S E 5 T R A N S P O R T A C R O S S T H E P L A S M A M E M B R A N E

Slide #2: 5% saline solution • Place a drop of animal blood on a second slide and

cover with a coverslip. Observe the RBCs using high power. On one side of the coverslip, add one drop of 5% saline solution with a clean medicine dropper. Place filter paper or a small piece of paper towel on the opposite side of the coverslip to absorb the liquid and pull the 5% saline solution into the RBCs.

• Immediately observe the second slide under high power and watch for changes in cell shape. You may have to wait a few minutes for cell changes to occur.

• Record shape of RBCs and type of the solution into which they were placed.

shape type of solution

Slide #2 again: distilled water • Using slide #2 again, add one drop of distilled water

to the same edge of the coverslip that was used for the saline solution.

• Hold a piece of filter paper at the opposite edge of the coverslip, observe the paper absorb the saline solution, and watch as the distilled water is drawn under the coverslip and into the RBCs.

• Immediately observe the slide under high power and watch if the RBCs change shape.

• Record shape of RBCs and type of solution into which they were placed.

shape type of solution

6 Clean up as directed by your instructor. • Place blood-stained items (slides, coverslips, and

droppers) in a 10% bleach solution or as directed by your instructor.

(a) shape

solution

(b) shape

solution

2000�

(a) (b)

Water molecules

(c)

Solute molecules

2000X 2000X 2000X

2000� 2000�

FIGURE 5.3 Osmosis in RBCs.

• Place gloves in an autoclavable bag or location indicated by your instructor.

• Wash down the lab counters with 10% bleach solution in a squirt bottle and wipe with paper towels wet with 10% bleach solution. Allow to air dry.

• Wash your hands with soap and water before leaving the lab area.

7 Complete the Experimental Report with your lab group.

EXPERIMENTAL REPORT Osmosis in Living RBCs

Results: Describe how the RBC shape changes when placed in each solution.

• 0.9% saline solution

• 5% saline solution • distilled water

Discussion: 1. Describe how extracellular solute concentration affects

osmosis across the plasma membrane.

2. Describe how water movement affects the cell shape.

Conclusion: State which solution(s) caused osmosis in RBCs.

■

A. Transport Across the Plasma Membrane

Match the definition with the term.

a. to shrink or shrivel b. water moving through selectively permeable membrane c. substance dissolved in a solution d. to burst a red blood cell e. difference between solute concentrations across a membrane f. same solute concentration on both sides of membrane g. lower concentration of solutes than in cytosol of cell h. a fluid that contains dissolved substances i. higher concentration of solutes than in cytosol of cell j. random movement of particles from their greater concentration to their lesser concentration

____ 1. concentration gradient

____ 2. crenate

____ 3. diffusion

____ 4. hemolysis

____ 5. hypertonic solution

____ 6. hypotonic solution

____ 7. isotonic solution

____ 8. osmosis

____ 9. solute

____ 10. solvent

Name ___________________________________ Date _________________ Section ______________________________

5 E X E R C I S EReviewing Your Knowledge

48 E X E R C I S E 5 T R A N S P O R T A C R O S S T H E P L A S M A M E M B R A N E

B. Diffusion

Select the correct lettered answer.

____ 1. In the dialysis bag experiment, sucrose and red dye molecules are:

(a) solutes (b) solvents

____ 2. If there is no concentration gradient, a substance will not have net movement.

(a) true (b) false

____ 3. Passive processes use ____ to move substances across a plasma membrane.

(a) ATP (b) kinetic energy

C. Osmosis

Select the correct lettered answer.

____ 1. An isotonic solution will ____ an RBC.

(a) crenate (b) hemolyze (c) cause no change to

____ 2. A hypertonic solution will ____ an RBC.

(a) crenate (b) hemolyze (c) cause no change to

____ 3. A hypotonic solution will ____ an RBC.

(a) crenate (b) hemolyze (c) cause no change to

A. Diffusion

Select the correct lettered answer in questions 1–3.

____ 1. White blood cells engulf bacteria. This is an example of diffusion.

(a) true (b) false

____ 2. Food cooking on the stove in the kitchen can be smelled in the living room. This is an example of diffusion.

(a) true (b) false

____ 3. Oxygen in the lungs moves into the bloodstream and carbon dioxide moves in the opposite direction. This is an example of diffusion.

(a) true (b) false

B. Osmosis

Select the correct lettered answer in questions 4–8.

____ 4. A test tube with blood in it has a particular solution added to it. After several minutes, the solution is not clear anymore but becomes red. Which solution was added to the blood to obtain this result?

(a) 0.9% saline (b) 5% saline (c) distilled water

____ 5. A 0.8% saline solution would be ____ to the cytosol of a cell.

(a) hypotonic (b) hypertonic (c) isotonic

____ 6. If a 50% sugar solution had been used in the dialysis bag in Activity 2, there would be a faster rate of osmosis.

(a) true (b) false

____ 7. If you placed a peeled apple or potato in a 5% salt solution, it would ____

(a) gain weight (b) lose weight (c) stay the same weight

Name ___________________________________ Date _________________ Section ______________________________

Using Your Knowledge

5 E X E R C I S E

50 E X E R C I S E 5 T R A N S P O R T A C R O S S T H E P L A S M A M E M B R A N E

____ 8. A person’s hands become wrinkled after spending a long, relaxing time in the tub. Tub water does not have as many solutes in it compared with the human body. The hands look wrinkled because ____.

(a) the tub water is hypotonic to body cells and water enters the cells (b) the tub water is hypotonic to body cells and water leaves the cells (c) the tub water is hypertonic to body cells and water enters the cells (d) the tub water is hypertonic to body cells and water leaves the cells

C. Application

9. When a person becomes dehydrated, the amount of water in extracellular fluids such as blood decreases, causing the solute concentration of these fluids to increase. State whether osmosis results in water entering or leaving cells.

10. Severe vomiting and diarrhea cause a loss of water and solutes from extracellular fluids. If a person was given only water, what effect would this have on the solute concentration of extracellular fluids? Would osmosis result in water entering or leaving cells?

E X E R C I S E 6 T I S S U E S 51

O B J E C T I V E S M A T E R I A L S

• compound microscope and lens paper • prepared epithelial tissue slides or Real Anatomy

(Histology): whole mount of mesothelium, simple squamous (lung), simple cuboidal (kidney), simple columnar nonciliated (small intestine), stratified squamous nonkeratinized (esophagus), transitional (relaxed urinary bladder), and ciliated pseudostrati- fied columnar (trachea)

• prepared connective tissue slides or Real Anatomy (Histology): areolar (spread), reticular, adipose, dense regular (tendon), dense irregular (skin), elastic, hyaline cartilage (trachea), elastic cartilage, fibrocartilage, dried compact bone, cancellous (spongy) bone, and blood

• prepared muscle tissue slides or Real Anatomy (Histology): skeletal muscle, cardiac muscle, and smooth muscle

• prepared motor neuron slide or Real Anatomy (Histology)

• Dissection: 1 fresh chicken leg per group, dissection equipment, disposable gloves, dissecting microscope, compound microscope, lens paper

Tissues 6 E X E R C I S E

1 Name the four primary tissue types

2 Compare and contrast primary tissue structure and function

3 Identify examples of epithelial, connective, muscular, and nervous tissue types on prepared microscope slides or photomicrographs and describe their location and function

There are four primary tissue types in the human body: epithelial, connective, muscle, and nervous. Epithelial tissue covers surfaces, lines cavities, and forms glands. Connective tissue, the most abundant primary tissue in the body, connects different tissues, pro-

vides a framework, resists pulling forces, and protects other tissues. Muscle tissue causes movement, and nervous tissue receives and generates nerve impulses. Organs are formed from two or more different tissues working together to perform a specific function. Histology is the study of the microscopic anatomy of cells and tissues.

52 E X E R C I S E 6 T I S S U E S

Epithelial cells have four shapes: squamous, cuboidal, columnar, and transitional. Cell shapes are best seen in side views of the cells [Figure 6.2(a)]. Squamous cells are the thinnest cells, and they have a fl attened nucleus. Cuboidal cells are cube-like with a round nucleus in the center of the cell. Columnar cells are tall with an oval nucleus close to the base of the cell. Transitional cells change shape; the apical cells are cuboidal when the tissue is relaxed and squamous when the tissue is stretched. Epithelial tissue with only one cell layer is simple epithelium, while epithelial tissue with two or more cell layers is stratifi ed epithelium [Figure 6.2(b)]. Simple epithelium provides a selective barrier allowing diffusion, fi ltration, secretion, or absorption of selected substances. There are three types of simple epithelium: simple squa- mous, simple cuboidal, and simple columnar. Stratifi ed epithelium is thicker, subject to wear and tear, and forms a protective barrier. Multiple cell layers make the tissue more resistant to damage, thereby preventing pathogens and foreign materials from crossing into underlying tis- sues. There are four types of stratifi ed epithelium: strati- fi ed squamous, stratifi ed cuboidal, stratifi ed columnar, and transitional. Pseudostratifi ed (pseudo- � false) columnar epithelium gives the illusion of several different layers of cells but is only one cell layer thick. All the cells touch the basement membrane, although not all cells reach the apical surface. Therefore, there are cells of different shapes and heights, and their nuclei are at different levels. The tallest cells are narrow where they touch the basement membrane but have a columnar shape toward the outer surface, while the shorter cells do not reach the apical surface.

A. Epithelial Tissue

Epithelial tissues or epithelia (epithelium, sing.) exhibit cellularity; that is, most of the tissue consists of cells packed together in an orderly fashion with little extracel- lular material (matrix) between cells. Epithelial tissues are avascular and receive nutrients from the vascular underly- ing connective tissue. A basement membrane separates epithelial and connective tissues. There are two categories of epithelial tissues: covering and lining epithelia, and glandular epithelia. Covering and lining epithelia cover the surface of the body and some organs, and line all hollow body structures. Tight junctions between neighboring cells enable this type of epithelium to form barriers that protect and control what substances can cross into adjacent tissues. Glandular epithelia form glands that produce and secrete products needed by the body. Covering and lining epithelia face exterior or interior spaces. The epithelial cell surface adjacent to the space is called the apical (apex � tip) surface, whereas the epi- thelial cell surface adjacent to the basement membrane is the basal surface. When viewed from the apical surface, one can observe how epithelial cells fi t together like fl oor tiles to form a lining or barrier (Figure 6.1). When viewed in cross-section (side view of cells), one can observe dif- ferences in structure of the apical and basal surfaces. The differences in structure are associated with differences in function. Epithelial tissue types are classifi ed according to the shape of the cell in the apical cell layer and the number of epithelial cell layers. Epithelial tissue function is deter- mined by the cell type and number of cell layers.

FIGURE 6.1 Epithelial tissue lining the mouth.

Basement membrane

Side view of epithelial cell

Nucleus of epithelial cell

Connective tissue

Nucleus of connective tissue cell

Surface view of epithelial cell

Simple

Stratified

ColumnarCuboidalSquamous

(a)

(b)

FIGURE 6.2 Epithelial tissue classification.

E X E R C I S E 6 T I S S U E S 53

NOTE: Observe each tissue first with a scanning or low- power objective lens, focusing with the coarse focus knob. Before switching to a more powerful objective lens, move the slide so that the area you want to observe is in the center of the field of view. After changing to a more powerful lens, use the fine focus knob only to bring the tissue into focus. Use this procedure with all tissue slides.

LAB ACTIVITY 1 Microscopic Examination of Epithelia

1 Examine a prepared microscope slide of a whole mount of mesothelium. Use Figure 6.3 to help you locate the major structures. Draw the tissue in the space provided and label the major structures.

2 Examine prepared microscope slides or use Real Anatomy (Histology) to observe tissue cross-sections. Use the survey photomicrographs in Figures 6.3–6.9 to help you locate the epithelia at low power. Use the photomicrograph at 400� to help you locate the major structures in each tissue.

3 Draw each tissue in the space provided and label the major structures. ■

FIGURE 6.3 Surface view of mesothelium.

• cytoplasm • nucleus • plasma membrane

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

243x

Simple squamous epithelium Student drawing

• Note whether there is one epithelial cell layer (simple epithelium) or two or more epithelial cell layers (stratified epithelium).

• On the higher magnification photomicrograph (400�) for each tissue: * Examine the shape of the epithelial cell at the

apical surface. This determines the tissue type as squamous, cuboidal, or columnar epithelium.

• Note any structural differences between apical surface and basal surface of epithelial tissue.

3 Label the photomicrographs in Figures 6.3–6.4. 4 Review the location and function for each epithelial

tissue type in Tables 6.1–6.6. Before Going to Lab

1 Examine the photomicrograph of a surface view of simple squamous epithelium from mesothelium in Figure 6.3. • This photomicrograph shows cells viewed from the

apical surface. • Observe how the epithelial cells fit close together to

form a good barrier.

2 Examine the photomicrographs of cross-sections of epithelial tissue types in Figures 6.4–6.9. Stratified cuboidal and stratified columnar are not included because they are less common. • On the survey photomicrograph (40�) for each

tissue: * Observe that the epithelial and connective tissue

layers stain differently. * Locate where the basement membrane forms the

border between the epithelial and connective tissue layers.

54 E X E R C I S E 6 T I S S U E S

FIGURE 6.4 Sectional view of lung.

• connective tissue • nucleus of simple squamous epithelial cell in

alveolar wall • nucleus of simple squamous epithelial cell in visceral

layer of pleura • simple squamous epithelium

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

(a) Survey photomicrograph 165�, H&E

Alveoli

Pleura

Student drawing

(b) Simple squamous epithelium 400�, H&E, human

2 3

Student drawing

TABLE 6 .1 Location and Function of Selected Simple Squamous Epithelia

LOCAT ION FUNCT ION

Mesothelium (epithelial layer of serous membranes) Secretion of serous fluid into serous cavity.

Alveoli (air sacs of lungs) Single layer of squamous cells creates a short distance for diffusion of oxygen and carbon dioxide.

Glomerular capsule (part of filtration membrane in kidney) Filtration of blood to form urine filtrate (substance that is converted into urine).

Endothelium of capillaries Single layer of squamous cells creates a short distance for diffusion of substances between blood and interstitial fluid (tissue fluid).

E X E R C I S E 6 T I S S U E S 55

FIGURE 6.5 Sectional view of kidney tubules.

• apical surface of simple cuboidal epithelial cell • lumen of kidney tubule • nucleus of simple cuboidal epithelial cell • simple cuboidal epithelium

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

Student drawing

(a) Survey photomicrograph 40�

Glomerulus

Lumen of kidney tubule

(b) Simple cuboidal epithelium 400�, H&E, human

1 2 3

TABLE 6 .2 Location and Function of Selected Simple Cuboidal Epithelia

LOCAT ION FUNCT ION

Walls of kidney tubules Modify urine filtrate by absorption of substances from the filtrate and secretion of other substances into the filtrate.

Glands Secretion of products made by the simple cuboidal epithelial cells.

56 E X E R C I S E 6 T I S S U E S

FIGURE 6.6 Sectional view of small intestine.

• connective tissue • microvilli on apical surface of simple columnar

epithelial cell • nucleus of simple columnar epithelial cell • simple columnar epithelium

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

Student drawing

40�

Lumen

Villus

(a) Survey photomicrograph

(b) Simple columnar epithelium 400�, H&E, human

Goblet cell 1

TABLE 6 .3 Location and Function of Selected Simple Columnar Epithelia

LOCAT ION FUNCT ION

Lining of stomach and intestines Secretion of digestive juices by simple columnar cells and secretion of mucus by goblet cells. In the small intestine the simple columnar epithelial cells have microvilli (micro- � small; villi � shaggy hair) to increase surface area for absorption.

Uterine tubes (fallopian tubes) Simple columnar epithelial cells have cilia that help move the egg to the uterus.

Central canal of spinal cord Ciliated cells move cerebrospinal fluid.

E X E R C I S E 6 T I S S U E S 57

FIGURE 6.7 Sectional view of esophagus.

• connective tissue • nucleus of epithelial cell in basal layer of epithelium • nucleus of squamous epithelial cell • stratified squamous epithelium

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

Student drawing

Lumen

Mucous glands

Epithelial tissue

Connective tissue

Smooth muscle

40� (a) Survey photomicrograph

200�, H&E, human

(b) Nonkeratinized stratified squamous epithelium

TABLE 6 .4 Location and Function of Selected Stratified Squamous Epithelia

LOCAT ION FUNCT ION

Surface of skin (keratinized stratified Epithelial layer of skin is a tough, dry, waterproof outer surface squamous epithelium) that forms a protective barrier.

Lining of mouth, esophagus, anus, and vagina Moist epithelial layer that forms a protective barrier in areas (nonkeratinized stratified squamous epithelium) subject to abrasion and friction.

58 E X E R C I S E 6 T I S S U E S

FIGURE 6.8 Sectional view of a relaxed urinary bladder.

• connective tissue • nucleus of transitional epithelial cell in apical layer • nucleus of transitional epithelial cell in basal layer • transitional epithelium

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

Student drawing

Smooth muscle

Lumen

Connective tissue

Epithelial tissue

40� (a) Survey photomicrograph

(b) Transitional epithelium

Lumen

34400�, H&E, human

TABLE 6 .5 Location and Function of Transitional Epithelia

LOCAT ION FUNCT ION

Lining of urinary bladder and parts of the ureters and Provides a protective barrier that permits distension. the urethra

E X E R C I S E 6 T I S S U E S 59

FIGURE 6.9 Sectional view of the trachea.

• cilia on apical surface of columnar epithelial cell • connective tissue • nucleus of ciliated columnar epithelial cell • pseudostratified ciliated columnar epithelium

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

Student drawing

Lumen Epithelial tissue

Connective tissue

40� (a) Survey photomicrograph

2 Goblet cell 1

400�, H&E, human (b) Pseudostratified ciliated columnar epithelium

TABLE 6 .6 Location and Function of Selected Pseudostratified Columnar Epithelia

LOCAT ION FUNCT ION

Lining of nasal cavity, trachea, and bronchi Secretion of mucus by goblet cells. The columnar cells have cilia, which move mucus toward the pharynx.

60 E X E R C I S E 6 T I S S U E S

platelets are suspended; however, plasma is not made by these cells.

1. Loose Connective Tissue

Loose connective tissue includes areolar, reticular, and adi- pose tissues. In loose connective tissue, the fi bers in the extracellular matrix are loosely arranged. Collagen, elastic, and reticular fi bers in this tissue provide strength, elasticity, and support. Ground substance is semi-fl uid (viscous), but interstitial fl uid can easily diffuse through it. Fibroblasts and adipocytes (lipid-storing cells) permanently reside in the tissue. Cells that are involved in body defense, such as macrophages, mast cells, and white blood cells, enter con- nective tissue from blood vessels that traverse through the extracellular matrix. Areolar connective tissue is the most abundant con- nective tissue. It contains fi broblasts, all three fi ber types, a semi-fl uid (viscous) ground substance, and a variety of cells involved in body defenses. Reticular (reticulo- � net-like) fi bers are the dominant fi ber type in reticular connective tissue. Reticular cells synthesize the reticular fi bers and the ground substance. Reticular cells are actu- ally fi broblasts, but they synthesize more reticular fi bers than collagen fi bers. Adipose (adipo- � pertaining to fat) tissue, like areolar connective tissue, contains fi broblasts, fi bers, ground substance, and adipose cells. However, adipose tissue has a greater number of adipocytes (lipid- storing cells) and very little extracellular matrix. Lipid within the adipose cells occupies most of the cell volume and pushes cytoplasm and organelles to the periphery. Some slides do not have the lipid stained, or the lipid has been removed during tissue preparation. In those slides, the nucleus and cytoplasm are stained, and the space inside the cell normally occupied by lipid appears “empty.”

2. Dense Connective Tissue

The extracellular matrix of dense connective tissue is packed with fi bers and contains very little ground substance and few fi broblasts. In dense regular connective tissue, the extracellular matrix is packed with parallel bundles of collagen fi bers that run in the direction of the pulling forces applied to the tissue. Fibroblasts are squeezed between the bundles, and the cytoplasm extends between and around collagen bundles. Collagen fi bers give unstained tissue a silvery white appearance, which is why this tissue is often called white fi brous tissue. Dense irregular connective tissue, like dense regular connective tissue, has little ground substance and few fi bro- blasts. The extracellular space is also packed with bundles of collagen fi bers with fi broblasts squeezed between these bundles. In dense irregular connective tissue, however, the bundles of collagen fi bers are irregularly arranged. This refl ects the direction of the pulling forces to which this tissue is exposed, usually from many different directions.

B. Connective Tissue

Connective tissue is the most abundant primary tissue in the body and has a variety of functions. It connects epithe- lial tissue to other tissues, forms the internal framework for soft organs, and forms tendons (connect muscle to bone) and ligaments (connect bone to bone). Bone, the hard- est connective tissue, protects body organs and provides a framework for movement of muscles. Adipose tissue (fat) insulates body tissues and stores lipids, and blood provides a liquid medium for transportation of substances throughout the body. Connective tissues are not very cel- lular, containing more extracellular matrix than cells (Fig- ure 6.10). Connective tissue function is determined by the properties of the extracellular matrix components. Extra- cellular matrix consists of fi bers and ground substance that are synthesized and secreted by connective tissue cells. The three major types of fi bers are collagen fi bers (which provide strength), elastin fi bers (which provide strength and elasticity), and reticular fi bers (fi ne, branching fi bers that provide a net-like framework). The number and type of fi bers present contribute to the strength, elasticity, and structure of the extracellular matrix. The ground sub- stance may be fl uid, semi-fl uid, gelatinous, or hard. It se- cures connective tissue cells and fi bers in the extracellular matrix and is the medium through which interstitial fl uid diffuses between blood and cells and through which mac- rophages and white blood cells move. Mature connective tissues include loose connective tissue, dense connective tissue, cartilage, bone, and blood. The connective tissue types have different connective tis- sue cells that form the extracellular matrix. The extracellu- lar matrix of loose and dense connective tissues is formed by fi broblasts (-blast � early, developing stage); the extra- cellular matrix of cartilage is formed by chondroblasts (chondro- � cartilage) and maintained by chondrocytes; and the extracellular matrix of bone is formed by osteo- blasts (osteo- � bone) and maintained by osteocytes. Plasma is the extracellular matrix in which blood cells and

FIGURE 6.10 Connective tissue (areolar).

CellGround substance

Cell

Cell Fiber Blood vessel Cell

Fiber

Collagen fiber

E X E R C I S E 6 T I S S U E S 61

is organized into repeating structural units called osteons. In the center of each osteon is a large central canal. Spongy bone has large spaces compared to compact bone and does not have osteons. Instead, the extracellular matrix of spongy bone is arranged in trabeculae (little beams)—fl at plates with a lattice-like network of thin, bony columns.

5. Blood

Blood is composed of red blood cells, white blood cells, platelets, and plasma. Plasma is the extracellular matrix, and its fi bers are produced and observed only during blood clotting. Red blood cells obtain their red color from hemo- globin, and the mature cells do not contain a nucleus (anu- cleate). White blood cells, which appear white or clear on unstained slides, are nucleated. Platelets, anucleate frag- ments of cells that are much smaller than red blood cells, participate in blood clotting.

In elastic connective tissue, the extracellular matrix is packed with elastic fi bers, and fi broblasts are found in the spaces between these fi bers. Elastic fi bers allow the tissue to be stretched and then regain its original size and shape (recoil).

3. Cartilage

Cartilage is a specialized form of connective tissue. Its extracellular matrix consists of collagen and elastic fi bers embedded in a fi rm gelatinous ground substance. Collagen fi bers give the tissue its strength, and the ground substance, which binds water to form a fi rm gel, gives cartilage its resiliency. Chondroblasts (chondro- � cartilage) secrete the fi bers and ground substance, become isolated in spaces called lacunae (little lakes), and transform into chondro- cytes. Since the tissue is avascular, the chondrocytes receive their nutrients through diffusion from adjacent vascular tissues. There are three types of cartilage: hyaline (hyalos � glass), elastic, and fi brocartilage. These cartilage types differ in the amount and kinds of fi bers and ground sub- stance molecules present in their extracellular matrix. Hyaline cartilage is the most predominant cartilage in the body and contains fi ne collagen fi bers in the extracellu- lar matrix. This cartilage type appears glassy to the naked eye, and under the compound microscope its matrix looks smooth and homogeneous. It contains collagen fi bers that are thin and not visible with a compound microscope. The matrix of hyaline cartilage is resilient and fi rm. Elastic cartilage is similar to hyaline cartilage, except the matrix is packed with elastic fi bers. The many elastic fi bers allow this cartilage to be much more fl exible. Fibrocartilage has fewer lacunae and chondrocytes, and its extracellu- lar matrix is packed with thick collagen fi bers that give it tensile strength similar to dense connective tissue. Under the microscope, collagen fi bers are the most prevalent structures seen.

4. Bone

Bone is the hardest of the connective tissues. The extracel- lular matrix is organized in layers called lamellae and con- sists of collagen fi bers, ground substance, and inorganic salts. Inorganic salts, especially calcium salts, give bone its hardness; collagen fi bers provide strength and fl exibility. Osteocytes (mature bone cells) are trapped in spaces called lacunae. Small canals called canaliculi connect lacunae to each other and to larger canals that contain blood vessels. Nutrients diffuse from a blood vessel through the canaliculi to the osteocytes, and waste materials diffuse back to the blood vessel for removal. The two types of bone tissue are compact (cortical) bone and spongy (cancellous or trabecular) bone. These two types of osseous tissue differ in the amount and size of spaces present. The extracellular matrix of compact bone

SAFETY NOTE: Use disposable gloves when handling fresh tissue specimens.

Before Going to Lab

1 Label and examine the photomicrographs of the connective tissue types in Figures 6.11–6.22. • Observe the extracellular matrix in each tissue. • Compare the amount of fibers and ground substance. • Identify the connective tissue cells.

2 Review the location and function for each connective tissue type in Tables 6.7–6.11.

LAB ACTIVITY 2 Microscopic Examination of Connective Tissue Types

1 Examine prepared microscope slides or use Real Anatomy (Histology) to observe the different connec- tive tissue types. Use Figures 6.11–6.22 to help you locate the major structures in each tissue. Draw each tis- sue in the space provided and label the major structures.

2 Identify the type of fibers in each connective tissue type. Collagen fibers are the thickest fibers. Elastic fibers are long, thin, dark fibers. Reticular fibers are short, thin, branching fibers.

3 Draw each tissue in the space provided and label the major structures. ■

62 E X E R C I S E 6 T I S S U E S

Student drawing

Mast cell

400�, Verhoeff Orange Safrin, human

FIGURE 6.11 Areolar connective tissue spread of mesentery.

• collagen fiber • connective tissue cells (fibroblasts or lymphocytes) • elastic fiber

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

400�, human

FIGURE 6.12 Sectional view of reticular tissue of the lymph node.

• reticulocyte • reticular fiber

1 _____________________________________________________

2 _____________________________________________________

E X E R C I S E 6 T I S S U E S 63

Student drawing

400�, H&E, human

FIGURE 6.13 Sectional view of adipose tissue.

• lipid storage area • nucleus of adipocyte

1 _____________________________________________________

2 _____________________________________________________

TABLE 6 .7 Location and Function of Loose Connective Tissues

LOOSE CONNECT IVE T ISSUE TYPE LOCAT ION FUNCT ION

Areolar Beneath all epithelial tissues Binds epithelium to underlying tissues and allows nutrients to diffuse to epithelial cells.

Reticular Liver, spleen, lymph nodes Forms support (framework) of these soft organs.

Adipose Under skin and surrounding Stores lipids for fuel and thermal insulation; cushioning organs organs.

64 E X E R C I S E 6 T I S S U E S

Student drawing

400�, H&E, human

Skeletal muscle fibers

FIGURE 6.14 Sectional view of dense, regular connective tissue-forming tendons.

• collagen fiber bundle • fibroblast

1 _____________________________________________________

2 _____________________________________________________

400�, H&E, human

FIGURE 6.15 Sectional view of dense, irregular connective tissue in skin.

• collagen fiber bundles running in different directions • fibroblast • parallel collagen fiber bundles

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

E X E R C I S E 6 T I S S U E S 65

Student drawing

2 31

400�, human

FIGURE 6.16 Sectional view of elastic connective tissue in the wall of the aorta.

• bundle of elastic fibers • fibroblast • individual elastic fiber

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

TABLE 6 .8 Location and Function of Dense Connective Tissues

DENSE CONNECT IVE T ISSUE TYPE LOCAT ION FUNCT ION

Dense regular Forms ligaments (connects bone to Resists pulling forces at attachment points. bone), tendons (connects muscle to bone), and aponeuroses (sheet- like tendons that connect muscle to muscle or muscle to bone)

Dense irregular Skin Resists pulling forces from many different directions that would tear skin when skin is stretched.

Elastic Lungs, trachea, and bronchi Allows respiratory organs to recoil after inhalation. Aorta and other elastic arteries Recoil of elastic tissue helps push blood through cardiovascular system.

66 E X E R C I S E 6 T I S S U E S

Student drawing

3 2

400�, H&E, human

FIGURE 6.17 Sectional view of hyaline cartilage in the wall of the trachea.

• extracellular matrix • lacuna (la-KOO-na) • nucleus of chondrocyte

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

FIGURE 6.18 Sectional view of elastic cartilage of the ear.

• elastic fibers • lacuna • nucleus of chondrocyte

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

Student drawing

321

400�

E X E R C I S E 6 T I S S U E S 67

Student drawing 400�

FIGURE 6.19 Sectional view of fibrocartilage of tendon.

• chondrocytes • collagen fibers • lacuna

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

TABLE 6 .9 Location and Function of Cartilage

CART ILAGE TYPE LOCAT ION FUNCT ION

Hyaline cartilage Ends of long bones Smooth surface that is resilient and reduces friction at joint. (articular cartilage) Trachea and bronchi Provide support and flexibility to ensure an open airway. Anterior ends of ribs Connect ribs to sternum with flexible joint (breastplate). (costal cartilage) Embryonic skeleton Provides template for bone formation.

Fibrocartilage Intervertebral discs Provide strength to discs that form joints between vertebrae and act as shock absorbers. Cartilage pads in knee Provide cushioning for bones forming knee joints. Pubic symphysis Forms strong, flexible joint between hip bones.

Elastic cartilage External ear Provides support and maintains shape of external ear. Auditory tube Provides support and elasticity to auditory tube as it changes diameter to equalize pressure in middle ear (ear pops). Epiglottis of larynx Provides support and elasticity to epiglottis as it folds to block entrance to trachea while swallowing food and liquid.

68 E X E R C I S E 6 T I S S U E S

Student drawing

3 421

400�, unstained, human

FIGURE 6.20 Sectional view of dried compact bone.

• canaliculus • central canal • lamella • lacuna

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

Student drawing

Red marrow cell

400�

FIGURE 6.21 Sectional view of spongy bone.

• osteocyte • trabecula

1 _____________________________________________________

2 _____________________________________________________

TABLE 6 .10 Location and Function of Osseous Tissue

TYPE OF OSSEOUS T ISSUE LOCAT ION FUNCT ION

Compact Exterior of bones Support, protection, storage of minerals.

Spongy Interior of bones Support, protection, storage of minerals.

E X E R C I S E 6 T I S S U E S 69

Student drawing

321

400�, H&E, human

FIGURE 6.22 Blood smear.

• red blood cells • nucleus of white blood cell • platelet

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

TABLE 6 .11 Location and Function of Blood Components

BLOOD COMPONENT LOCAT ION FUNCT ION

Plasma Liquid part of blood in arteries, capillaries, veins Transport of nutrients, blood gases, wastes, chemical messengers, blood cells and platelets.

Red blood cells Formed element of blood in arteries, capillaries, Transport of blood gases. veins

White blood cells Formed element of blood in arteries, capillaries, Attack pathogens and other substances veins. WBCs can also leave blood vessels and that invade the body. enter infected tissues.

Platelets Formed element of blood in arteries, capillaries, Participate in blood clotting. veins

70 E X E R C I S E 6 T I S S U E S

C. Muscle Tissue Overview

Muscle tissue is very cellular, with most of the tissue con- sisting of muscle cells (Figure 6.23). All muscle tissues are highly vascularized and are innervated. Muscle cells are elongated cells called fi bers that shorten (contract) when stimulated, causing movement. There are three types of muscle tissue—skeletal, cardiac, and smooth—with each type having a distinct appearance. Skeletal muscle cells are large, multinucleated, cylindrical cells. Cardiac muscle cells are smaller, branching cells with one or two centrally located nuclei per cell. Intercalated discs are dark bands where cardiac muscle cells connect end to end. Skeletal and cardiac muscle cells exhibit striations (light and dark bands). Smooth muscle cells are small, spindle- shaped (tapered at both ends) cells that are uninucleated and nonstriated.

Nucleus of skeletal muscle cell

Striation

Nerve

Blood vessel

FIGURE 6.23 Skeletal muscle tissue.

Before Going to Lab

1 Label and examine the photomicrographs of muscle tissue in Figures 6.24–6.26. • Compare the size of the three types of muscle fibers,

their shape, and the number of nuclei. • Look for striations in skeletal and cardiac muscle

fibers.

2 Review the location and function for each muscle tissue type in Table 6.12.

LAB ACTIVITY 3 Muscle Tissue

1 Examine prepared microscope slides or use Real Anatomy (Histology) to observe the different muscle tissue types. Use Figures 6.24–6.26 to help you locate the major structures in each tissue. Draw each tissue in the space provided and label the major structures.

2 Draw each tissue in the space provided and label the major structures. ■

TABLE 6 .12 Location and Function of Muscle Tissue Types

MUSCLE T ISSUE TYPE LOCAT ION FUNCT ION

Skeletal muscle Attached to bones and skin Movement of bones and skin. Contraction generates heat. Cardiac muscle Wall of heart Movement of blood through cardiovascular system. Smooth muscle Walls of digestive tract organs Movement of food through digestive tract. Walls of arteries and veins Contraction and relaxation controls blood flow and blood pressure. Walls of ureters, urinary Movement of urine through urinary tract. bladder, and urethra Intrinsic muscles of eye Contraction and relaxation controls pupil size.

E X E R C I S E 6 T I S S U E S 71

400�, H&E, human

1 2 3

Student drawing

• nucleus • striation (stry-AY-tion) • width of individual muscle fiber

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

FIGURE 6.24 Sectional view of skeletal muscle fibers.

400�, iron H&E

1 42 3

Student drawing

• branches of cardiac muscle fiber • intercalated discs • nucleus • width of cardiac muscle fiber

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

FIGURE 6.25 Longitudinal view of cardiac muscle fibers.

72 E X E R C I S E 6 T I S S U E S

Student drawing

• nucleus of smooth muscle fiber in cross-section • nucleus of smooth muscle fiber in longitudinal section

1 _____________________________________________________

2 _____________________________________________________

FIGURE 6.26 Sectional view of smooth muscle in wall of the ureter.

60� (a) Survey photomicrograph

Connective tissue Smooth muscle layers

Epithelial lining Lumen

400� (b) Smooth muscle fibers in cross-section and longitudinal section

E X E R C I S E 6 T I S S U E S 73

D. Nervous Tissue Overview

Nervous tissue, which forms the brain, spinal cord, and nerves, is very cellular (Figure 6.27). Two basic categories of nervous tissue cells are neurons and neuroglia (neuro � nerve; glia � glue). Neurons receive and send informa- tion, whereas neuroglia support the neurons and help them to function. Neurons have one or more processes (cellular extensions) that receive or send information as nerve im- pulses. Dendrites (dendro � tree) are processes that re- ceive signals from sensory receptors or other neurons. An axon is a process that sends signals to other neurons, mus- cles, or glands. Neurons have one axon but may have many dendrites. The main part of the cell where the nucleus is located is called the cell body. In the following activity you will observe only multipolar neurons, which are neurons with many processes.

Dendrites

Neuroglial cell

Nucleus

Neuron cell body

Blood vessel

Axon

Neuroglial cell

FIGURE 6.27 Nervous tissue.

Before Going to Lab

1 Label and examine the photomicrograph of nervous tissue in Figure 6.28. Compare the sizes of the neuron and neuroglia.

LAB ACTIVITY 4 Nervous Tissue

1 Examine prepared microscope slides or use Real Anatomy (Histology) to observe nervous tissue contain- ing multipolar neurons. Use Figure 6.28 to help you lo- cate the major structures.

2 Draw each tissue in the space provided and label the major structures. ■

Student drawing

FIGURE 6.28 Photomicrograph of nervous tissue.

• cell body of multipolar neuron • nucleus • processes

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

260�LM

�

Neuroglia

2 3

74 E X E R C I S E 6 T I S S U E S

• Under the dissecting microscope, first notice the regular arrangement of collagen fibers that appear as horizontal “wrinkles” perpendicular to the length of the tendon.

• As you tease the fibers apart with two dissecting probes, you will notice the deeper fibers run longi- tudinally in the tendon.

• Using the compound microscope observe the collagen fibers with the scanning objective lens (4�).

7 Observe the appearance of hyaline cartilage covering the ends of the leg bone. • Use a scalpel to cut a very thin piece of cartilage

from the proximal or distal end of the bone and place it on a clean slide.

• Tease small pieces of cartilage with two probes using a dissecting microscope. Notice that this tissue looks very different from the others and the surface of the cartilage looks like the surface of the moon.

• Using the compound microscope examine the carti- lage slide with the scanning objective lens (4�).

8 Observe skeletal muscles, blood vessels, and nerves. • Observe the thin layer of connective tissue covering

skeletal muscles. This layer is composed of dense regular connective tissue and is called fascia.

• Remove fascia from muscle and, using a blunt probe, separate the individual muscles.

• Look for blood vessels and nerves between muscles. Blood vessels are brownish-red hollow tubes, while nerves are white, thread-like structures. Cut the blood vessel to observe it in cross-section. Coagu- lated blood may be found within the blood vessel.

9 Observe the appearance of skeletal muscle tissue. • Use your dissecting probe to separate a small piece

of skeletal muscle and place it on a microscope slide.

• Add a drop of methylene blue stain. • Cover the microscope slide with a cover slip. • Use the scanning objective lens (4�) of the com-

pound microscope to center the muscle in the field of view and to bring the muscle in focus. Switch to the low-power objective (10�) to find muscle cells. Switch to the high-power objective (100�) to observe the muscle cells.

• Observe the shape of the muscle cells, nuclei, and striations.

10 Compare the appearance of each of these tissues with their prepared microscope slides.

11 Clean up as directed by your instructor. ■

LAB ACTIVITY 5 Observation of Fresh Tissue in Chicken Leg

1 Obtain a fresh chicken leg, dissecting pan, forceps, pointed dissecting probes, blunt dissecting probe, scalpel, dissecting microscope, compound microscope, and lens paper.

2 Observe the appearance of epidermis. • Epidermis of chicken skin is a waterproof layer

composed of stratified epithelial tissue. • Notice the “goosebumps” on the surface of the

epidermis. These goosebumps are formed when the chicken feathers are plucked out.

• The goosebumps contain a follicle that produces a feather.

3 Observe the appearance of areolar connective tissue • Using the forceps, slowly pull the skin away from

the muscle. Notice the very thin areolar connective tissue that holds the skin to the muscle tissue.

4 Observe the ability of dense, irregular connective tissue to resist pulling from different directions. • The dermis of the skin (layer of skin deep to the

epidermis) contains dense irregular connective tissue.

• Stretch the skin in different directions and observe how difficult it is to pull the skin apart.

5 Observe the appearance of adipose tissue. • Use a scalpel to cut a very small piece of adipose

tissue from the proximal end of the leg bone or from under the skin, place it on a clean slide, and observe it under a dissecting microscope.

• Using two pointed probes, tease small droplets of fat apart from the edge of the tissue.

• If teased enough, you can observe that the adipose tissue is made of many tiny fat globules adhering together.

• Using a compound microscope, observe the same tiny fat droplets with the scanning objective lens (4�) and then the low-power objective lens (10�). Compare their appearance with what you observed using the dissecting microscope.

6 Observe the appearance of the dense, regular connec- tive tissue forming a tendon. • Use a scalpel to cut a very thin piece of tendon from

the end of a muscle and place it on a clean slide.

SAFETY NOTE: Wear safety glasses and gloves when using preserved or fresh tissue. Wash hands thoroughly with soap and water when you are finished.

A. Primary Tissue Structure and Function

Name the primary tissue type (epithelial, connective, muscle, or nervous) that is described.

1. Cells contain processes that receive and generate electrical signals to communicate with other cells.

2. Tissue has elongated cells that shorten and cause movement.

3. Tissue contains more extracellular matrix than cells.

4. Cells either form a barrier that controls passage of molecules or form glands.

6. Primary tissue types that exhibit cellularity.

9. Cells determine function of these primary tissue types.

10.

11. The extracellular matrix determines function of this primary tissue.

Identify the primary tissue types in Figure 6.29.

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

6 E X E R C I S E

12. ____________________ 13. ____________________ 14. ____________________ 15. ____________________

FIGURE 6.29 Photomicrographs of primary tissues.

⎫ ⎥ ⎥ ⎬ ⎥ ⎥ ⎭

76 E X E R C I S E 6 T I S S U E S

B. Epithelial Tissues

Write the name of the epithelial tissue type that matches each description. An epithelial tissue type may be used more than once.

______________________ 1. Lines the mouth and protects underlying tissues in areas subject to abrasion.

______________________ 2. Located in the alveoli (the air sacs of the lung) and provides a short distance for the diffusion of oxygen and carbon dioxide.

______________________ 3. Forms kidney tubules and is involved in absorption and secretion.

______________________ 4. Lines the nasal cavities and moves substances over the epithelial surfaces.

______________________ 5. Forms the mesothelium of the peritoneum and secretes serous fluid into the peritoneal cavity.

______________________ 6. Lines the stomach and its microvilli; increases surface area for absorption and secretion.

______________________ 7. Lines the bladder and ureter and is distensible.

C. Connective Tissues

Write the name of the connective tissue type that matches each description. A connective tissue can be used more than once.

______________________ 1. Contains elastic fibers and is found in the lungs. This tissue allows the lungs to inflate during inhalation and return to their original shape after exhaling.

______________________ 2. Packed with parallel bundles of collagen fibers and found in tendons. This tissue resists pulling forces applied by muscles.

______________________ 3. Has a firm, gelatinous ground substance containing collagen fibers. This tissue is found in the tracheal wall to support and prevent the trachea from collapsing.

______________________ 4. Found under covering and lining epithelium. Its extracellular matrix contains a loose arrangement of fibers, and its viscous ground substance facilitates the flow of interstitial fluid containing nutrients to epithelial tissues. It also cushions and supports epithelia.

______________________ 5. Contains many elastic fibers in a firm gelatinous ground substance. Located in external ear, auditory tube, and epiglottis.

______________________ 6. Hard extracellular matrix forms trabeculae.

______________________ 7. Forms a framework in the spleen, bone marrow, and lymph nodes. It contains fine, branching fibers.

______________________ 8. Is packed with bundles of collagen fibers running in different directions. It is found in skin and allows skin to resist pulling forces from many different directions.

______________________ 9. Fluid extracellular matrix used to transport substances throughout the body.

______________________ 10. Contains a large number of lipid-storing cells. It is found throughout the body, cushions and insulates organs, and stores lipids for future energy needs.

E X E R C I S E 6 T I S S U E S 77

______________________ 11. Hard extracellular matrix containing osteons; involved in protection and support.

______________________ 12. Firm gelatinous ground substance packed with bundles of collagen fibers. This tissue is found in intervertebral discs, pubic symphysis, and knee meniscus.

______________________ 13.

______________________ 14.

______________________ 15. Fibroblasts produce extracellular matrix for these connective tissue types.

______________________ 16.

______________________ 17.

______________________ 18.

______________________ 19. Osteoblasts produce extracellular matrix.

______________________ 20.

______________________ 21.

______________________ 22. Chondroblasts produce extracellular matrix.

______________________ 23.

______________________ 24. Fibers not present unless injury occurs. Extracellular matrix not produced by cells present in this tissue.

D. Muscle and Nervous Tissue

Write the name of the tissue that matches each function. For muscle tissue, write the name of the muscle tissue type.

______________________ 1. Movement of urine through the urinary tract

______________________ 2. Movement of bone and/or skin

______________________ 3. Movement of blood through the heart and into arteries

______________________ 4. Receives and sends information

______________________ 5. Movement of food through the digestive tract

______________________ 6. Controls blood flow through arteries and veins and controls blood pressure

⎫ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎬ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎭

⎫ ⎥ ⎬ ⎥ ⎭

⎫ ⎥ ⎥ ⎬ ⎥ ⎥ ⎭

78 E X E R C I S E 6 T I S S U E S

E. Epithelial and Connective Tissue Identification

Identify the epithelia and connective tissues types in Figure 6.30.

1. ___________________________________________ 10. ___________________________________________

2. ___________________________________________ 11. ___________________________________________

3. ___________________________________________ 12. ___________________________________________

4. ___________________________________________ 13. ___________________________________________

5. ___________________________________________ 14. ___________________________________________

6. ___________________________________________ 15. ___________________________________________

7. ___________________________________________ 16. ___________________________________________

8. ___________________________________________ 17. ___________________________________________

9. ___________________________________________ 18. ___________________________________________

FIGURE 6.30 Identification of epithelial and connective tissue types.

1 2 3

4 5 6

E X E R C I S E 6 T I S S U E S 79

7 8 9

10 11 12

13 14 15

FIGURE 6.30 Identification of epithelial and connective tissue types, continued.

16 17 18

80 E X E R C I S E 6 T I S S U E S

F. Muscle and Nervous Tissue Identification

Identify the muscle tissue types and the nervous tissue in Figure 6.31.

1. _____________________________________________ 3. _____________________________________________

2. _____________________________________________ 4. _____________________________________________

FIGURE 6.31 Muscle and nervous tissue identification.

1 2

3 4

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

6 E X E R C I S E

A. Genetic Diseases and Tissue Function

Each of the following diseases is due to a gene mutation and the production of an abnormal protein. Look up the diseases in your textbook or other resource. For each disease identify the abnormal protein and state how the abnormal protein affects the function of the tissue.

Cystic Fibrosis and Epithelial Tissue 1. Abnormal protein:

2. The effect of the abnormal protein on tissue function:

Duchenne Muscular Dystrophy and Skeletal Muscle Tissue 3. Abnormal protein:

4. The effect of the abnormal protein on tissue function:

B. Nutritional Deficiencies and Tissue Function

Nutritional deficiencies interfere with cell metabolism and tissue structure. Look up scurvy in your textbook or other resource and name the nutritional deficiency that causes scurvy and describe the change in extracellular matrix and how this causes the symptoms of scurvy.

Scurvy and Connective Tissue 5. Nutritional deficiency:

6. Extracellular matrix changes and symptoms:

82 E X E R C I S E 6 T I S S U E S

C. Tissues Forming Organs

Name the tissue types that form the wall of each organ in questions 7–10. Use your textbook as a reference and list the tissues in order from lumen to outer surface.

7. esophagus: _____________________________________________________________________________________

______________________________________________________________________________________________

8. small intestine (within peritoneal cavity): ____________________________________________________________

______________________________________________________________________________________________

9. trachea: _______________________________________________________________________________________

______________________________________________________________________________________________

10. ureter: ________________________________________________________________________________________

______________________________________________________________________________________________

E X E R C I S E 7 T H E I N T E G U M E N T A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N 83

The integumentary system (inte- � whole; -gument � body covering) consists of organs including the skin, hair, nails, sweat and seba- ceous glands, and associated muscle and nervous tissue. This system provides a protective barrier for the body, contains cutaneous sensory receptors, aids in the produc- tion of vitamin D, is important in regulating body tempera- ture, and plays a minor role in excretion and absorption. The skin is classified as an organ because it has many types of tissues that work together to perform specific functions. The skin is also known as the integument or cutaneous membrane.

O B J E C T I V E S M A T E R I A L S

• integumentary system model or chart • compound microscopes and lens paper • prepared microscope slides or use Real Anatomy

(Histology): thick skin, thin skin with hair (scalp)

• Eccrine Gland Density: cornstarch, vegetable oil, Betadine (contains iodine) or 2% tincture of iodine, cotton swabs, two 100-ml beakers or small bowls

• Fingerprinting: ink pad, 3” � 5” index cards (2 per student), towelettes, magnifying glasses, data collection sheet

The Integumentary System Structure and Function

7 E X E R C I S E

1 Describe the structure and function of the integumentary system

2 Identify the layers of the epidermis, dermis, and hypodermis

3 Identify the accessory structures of the skin

4 Describe the function of the epidermal accessory structures

5 Compare eccrine sweat gland density on the forehead, forearm, palm, and anterior leg

6 Identify the main types of fingerprint patterns: arch, loop, and whorl

A. Major Divisions of the Skin

The skin has two major divisions: the superfi cial epider- mis and the deep dermis. The epidermis (epi- � above), the outer layer of the skin, is composed of epithelial tissue. The dermis is the connective tissue layer that is fi rmly at- tached to the epidermis by a basement membrane, provides the avascular epidermis with nutrients, and connects the epidermis to the underlying hypodermis. Although it is not a part of the integumentary system, the hypodermis (hypo- � below) or subcutaneous layer (subQ) is located below the skin and is usually discussed with the skin. The hypodermis is a major storage site for adipose tissue.

84 E X E R C I S E 7 T H E I N T E G U M E N T A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

2. Dermis

The dermis consists of two regions: the papillary (papilla � nipples) region and the reticular (reticul- � net-like) region. The papillary region is a thin layer of areolar connective tissue that is deep to the stratum basale of the epidermis and the basement membrane. Dermal papillae are fi nger- like projections of the papillary region that extend into the epidermis. In the palms, fi ngers, soles, and toes, the dermal papillae cause genetically determined whorls in the epi- dermis called epidermal ridges that increase surface area, friction, and grip. Sweat glands deposit their secre- tions onto these ridges, resulting in fi ngerprints when these ridges touch surfaces. The reticular layer is the deeper and much thicker region of the dermis. It is composed mainly of dense, irregular connective tissue whose collagen fi bers provide the skin with strength and whose elastic fi bers provide elasticity. Some adipose tissue is also found in the reticular region. The dermis is highly vascularized, allow- ing nutrients to diffuse from the dermis into the avascu- lar epidermis. Hair follicles, sweat glands, and sebaceous glands are all derived from epithelial tissue and extend into the dermis. Nerves and lymphatic vessels are also found in this layer.

1. Epidermis

The epidermis is keratinized stratifi ed squamous epithe- lium. This is a very thick epithelial layer in comparison with other epithelial layers of the body. Four types of cells are found in the epidermis: kerati- nocytes, melanocytes, Langerhans cells, and Merkel cells. Keratinocytes (keratino- � horn-like; -cytes � cells) comprise 90% of the cells of the epidermis and produce keratin, a tough fi brous protein that protects the skin and deeper tissues from chemicals, microbes, and heat. These cells also produce granules that secrete a lipid-rich product that helps to waterproof the skin. Melanocytes (melano- � black) comprise 8% of the epidermal cells and produce and secrete the pigment melanin. Langerhans cells are immune system cells that attack pathogens that enter the skin. Merkel cells are the least abundant cell type and are found only in the deepest layer of the epidermis. These cells function as touch receptors and are associated with sensory neurons. The layers of the epidermis are in order from deepest to most superfi cial: stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum. The stratum basale (strata � layers; basa- � base) or stratum germinativum (germ- � sprout), a single row of cells at- tached to the basement membrane, contains stem cells that divide to form new keratinocytes. As new cells are formed, the older cells are pushed toward the surface and undergo a process called keratinization, which produces tough, dead cells in the superfi cial layer. Melanocytes, Langerhans cells, and Merkel cells are also found within the stratum basale. The stratum spinosum (spinos- � thorn-like) contains 8 to 10 rows of cells, mainly keratinocytes. In prepared slides, cells in this layer have thorn-like projections caused by the tissue preparation process. Granules are observed within keratinocytes in the stratum granulosum (granulos- � little grains). This layer contains 3 to 5 rows of fl attened keratinocytes that are beginning to die. No dividing cells are present in this layer or in more superfi cial layers. The stratum lucidum (lucid- � clear) contains 3 to 5 rows of fl at, dead keratinocytes. This layer is translucent in specimens of fresh skin, but in prepared slides it may be clear or stained. The outermost layer, the stratum corneum (corn- � hard or hoof-like) is a very thick layer containing 25 to 30 or more rows of dead, squamous-shaped keratinocytes. This layer is tough and water-repellent. These cells con- tinually slough off and are replaced by cells in the adjacent layer. The epidermis differs in thickness in thin and thick skin. Thick skin is found on the palms of the hands and the soles of the feet and has all fi ve strata. Thin skin, which covers the rest of the body, does not have a visible stratum lucidum and has a thinner stratum corneum than thick skin.

Before Going to Lab

1 Label the skin structures in Figures 7.1 and 7.2. Observe where the basement membrane separates the epidermis and dermis.

2 Label the layers of the epidermis in thick skin in Figure 7.3.

LAB ACTIVITY 1 Major Divisions of the Skin

1 Identify the skin structures in Figures 7.1, 7.2, and 7.3 on a model or chart.

2 Examine a prepared microscope slide of thick skin or use Real Anatomy (Histology). • Using the scanning or low-power objective, identify

the structures in Figure 7.2. • Using the high-power objective, identify the layers

of the epidermis in Figure 7.3. Observe the different cell shapes in the various layers of the epidermis.

• Observe the areolar connective tissue in the papillary layer of the dermis, the dense irregular connective tissue in the reticular layer of dermis, and the adipose tissue in the hypodermis. ■

E X E R C I S E 7 T H E I N T E G U M E N T A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N 85

2 5

FIGURE 7.1 Diagram of the skin.

• dermal papillae • epidermis • hypodermis • papillary layer of

dermis • reticular layer of

dermis

1 _________________________

2 _________________________

3 _________________________

4 _________________________

5 _________________________

FIGURE 7.2 Photomicrograph of the skin. FIGURE 7.3 Photomicrograph of the epidermal layers.

30�

• epidermis (EPI-derm-is) • dermal papillae

(puh-PILL-ee) • hypodermis

(HY-poh-der-mis) • papillary (PAP-il-lary)

layer of dermis • reticular layer of dermis

1 _________________________

2 _________________________

3 _________________________

4 _________________________

5 _________________________

• dermis • stratum basale (bay-SAL) • stratum corneum

(kor-NEE-um) • stratum granulosum

(gran-you-LOW-sum) • stratum lucidum

(LOU-sih-dum) • stratum spinosum

(spy-NO-sum)

1 _________________________

2 _________________________

3 _________________________

4 _________________________

5 _________________________

6 _________________________

240xLM

86 E X E R C I S E 7 T H E I N T E G U M E N T A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

The arrector pili (arrect- � to raise; pili � hair) is a bundle of smooth muscle cells attached to the connective tissue sheath around the hair follicle. Contraction of the arrector pili muscle moves the hair from its normal angle to a 90� angle (perpendicular) with the skin surface, elevat- ing the skin surrounding the hair shaft and causing goose bumps. Arrector pili muscles contract in response to stress (including cold temperature). Examination of the hair in cross-section shows three layers: the cuticle (outer layer), the cortex (middle layer), and the medulla (inner layer). The cuticle, the layer of hair that we see, is a thin layer of dead, fl attened, keratinized cells that overlap each other like shingles on a roof. Split ends occur when the free ends of these cells are pulled away from each other. Cells in the cortex and medulla contain pigment granules that give hair its color. The shape of hair in cross-section indicates whether the hair is curly, wavy, or straight. Curly hair is fl at in cross-section, wavy hair is oval, and straight hair is round.

B. Accessory Structures of the Skin

The accessory structures of the skin include hairs, hair fol- licles, nails, sweat glands, sebaceous glands, ceruminous glands, and mammary glands. All of these are derived from epidermal tissue and extend into the dermis.

1. Sudoriferous and Sebaceous Glands

Sudoriferous glands (sudori- � sweat; -ferous � bear- ing), or sweat glands, secrete a watery substance that is important in excretion and body temperature regulation. There are two types of sudoriferous glands: eccrine glands and apocrine glands. Eccrine glands (eccrine � sweat- ing outwardly) are the most common type of sudoriferous gland and are found on most areas of the body. Ducts from the eccrine glands deposit their secretions, called sweat, on the epithelial surface. Apocrine glands are found only in the axilla, genital area, and pigmented area around the nipples (areolae). Apocrine glands produce a secretion similar in composition to sweat but more viscous. This secretion, which is deposited on the distal end of the hair root, is odorless until broken down by bacteria. Cerumi- nous glands and mammary glands are modifi ed sudorifer- ous glands. Ceruminous glands (ceri- � wax) are found in the ear canal and secrete a waxy substance called ceru- men that prevents foreign substances (including insects) from entering the auditory canal. Mammary glands are found in the breasts and synthesize and secrete milk after appropriate hormonal stimulation. Sebaceous glands (sebace- � greasy), or oil glands, are found surrounding hair follicles and deposit sebum, an oily substance that lubricates the skin and hair, into the neck of the follicle.

2. Hair and Hair Follicles

Hairs are found all over the body with the exception of the palms, soles, lips, and parts of the external genitalia. Hair consists of dead, keratinized epithelial cells and has two main sections: the shaft, which projects from the skin surface, and the root, which extends into the dermis of the skin and sometimes the hypodermis. The hair follicle, which surrounds the hair root, is formed from epidermal layers that project into the dermis. The expanded base of the hair follicle, the hair bulb, contains the papilla of the hair and the matrix. The papilla of the hair is a projec- tion of connective tissue into the hair follicle and contains blood vessels that provide nutrients to the dividing cells of the matrix. The matrix, which is derived from the stratum basale of the epidermis, forms new hair cells that are added to the base of the hair root. Surrounding the hair follicle is a connective tissue sheath comprised of dermal tissue.

Before Going to Lab

1 Label the diagram of the skin and accessory structures in Figure 7.4.

2 Label the photomicrograph in Figure 7.5.

LAB ACTIVITY 2 Hair, Hair Follicles, Sebaceous Glands, and Sudoriferous Glands

1 Point to the structures in Figure 7.4 on a model or chart of the integumentary system.

2 Examine a prepared microscope slide of hairy skin or use Real Anatomy (Histology) to identify the struc- tures in Figure 7.5.

3 Examine a strand of hair with the compound microscope. • Pull out one strand of scalp hair and lay the hair

horizontally on the stage over the light source. • Observe the dark cuticle and lighter medulla of the

hair shaft with the 4� objective lens. Switch to the low- and high-power lenses and look for the cells of the cuticle overlapping each other. Observe the root end of the hair. What differences do you see between the root end and the shaft area?

• If someone is willing to donate hair with “split ends,” compare the cuticle of a hair with split ends with undamaged hair. ■

E X E R C I S E 7 T H E I N T E G U M E N T A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N 87

2 Corpuscle of touch (Meissner’s)

3 4

7 8

Lamellated (Pacinian) corpuscle

FIGURE 7.4 Diagram of the skin and accessory structures.

• apocrine (AP-oh-krin) sweat gland • arrector pili (PIE-lee) muscle • eccrine (EK-rin) sweat gland • hair bulb • hair follicle • hair root • hair shaft • papilla (puh-PILL-uh) of hair • sebaceous (se-BAY-shus) gland

1 __________________________________________________

2 __________________________________________________

3 __________________________________________________

4 __________________________________________________

5 __________________________________________________

6 __________________________________________________

7 __________________________________________________

8 __________________________________________________

9 __________________________________________________

10�

FIGURE 7.5 Photomicrograph of the skin and accessory structures.

• hair bulbs • hair follicle • hair root • papilla of hair • sebaceous gland

1 __________________________________________________

2 __________________________________________________

3 __________________________________________________

4 __________________________________________________

5 __________________________________________________

88 E X E R C I S E 7 T H E I N T E G U M E N T A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

blue areas, then your skin was damp when you applied the oil/cornstarch mixture and you need to start over.

• Count the number of dots in your 1-cm2 area. If you do not want to count all the dots, you can rank the areas based on relative eccrine gland density (list them from greatest eccrine gland density to least eccrine gland density).

• Remove iodine from skin by washing the area with soap and water.

• Record the number of dots per cm2 in Table 7.1.

4 Clean up as directed by your instructor. 5 Data Analysis:

• Collect the individual eccrine gland density value for each body area from the subject for each group.

• Calculate the average eccrine gland density for each body area by adding the number of glands/cm2 for each subject and dividing by the number of subjects.

• Record the average values in Table 7.1.

6 Complete the Experimental Report with your lab group.

EXPERIMENTAL REPORT Eccrine Gland Density

Results: 1. Using the class averages in Table 7.1, state which body

area has the highest average eccrine gland density and which has the lowest.

2. State whether variation in eccrine gland density per body area was observed among the subjects.

Discussion: 1. Discuss how eccrine gland density correlates with the

amount of sweat that appears on these body areas during exercise or nervousness. Base this on your own observa- tions and experiences.

2. State whether eccrine gland secretion is continuous and discuss the role of insensible water loss.

Conclusion: 1. Write a sentence that postulates a correlation between

average eccrine gland density and the amount of sweat produced by an area.

2. Write a sentence that postulates why eccrine gland den- sity per area varied or did not vary among individuals.

LAB ACTIVITY 3 Experiment: Eccrine Gland Density

Iodine reacts with starch and water to form a blue-black colored compound. When eccrine glands secrete sweat, the water enables the iodine to react with the starch (corn- starch) to produce a small blue-black dot about the size of a straight pin point where the duct of the eccrine gland opens and secretes water onto skin surface.

1 Prediction: List where you predict the eccrine gland den- sity of the following body areas is from highest to lowest. • _____________________ (highest) • _____________________ • _____________________ • _____________________ (lowest)

2 Materials: Obtain supplies for Eccrine Gland Density (see Materials list).

3 Data Collection: Count eccrine gland density in differ- ent areas of the body and record your results in Table 7.1. • Decide who will be the subject and who will do each

of the following tasks: apply iodine solution, mix oil and cornstarch, time the experiment, count blue- black dots, and record data.

• Mix equal parts of vegetable oil and cornstarch. Approximately 1 tablespoon of each should be enough.

• If the room is cool and students are not producing enough sweat, have them exercise a little so the experiment will work.

• Find areas of your body that do not have large crease lines: forehead, anterior forearm, palm, and anterior leg.

• Clean and thoroughly dry these areas. If the skin is still damp, the procedure will not work and areas may be splotchy.

• For each location, use a cotton swab to apply iodine solution to a 1-cm2 area of skin. Allow Betadine to thoroughly dry.

• Apply the oil/cornstarch solution to each area of skin. Make sure the oil/cornstarch solution exceeds the iodine-covered area. Iodine reacts with starch and water to form a blue-black colored compound. After about 10 minutes you should see a few blue-black pinprick-size dots. Each of these dots represents a eccrine duct gland opening. If you see large splotchy

TABLE 7 .1 Eccrine Sweat Gland Density

BODY AREA ECCR INE SWEAT GLAND DENS ITY (no . o f g lands / cm 2)

Individual Value Class Average

Forehead

Right anterior forearm

Right palm

Right anterior leg

■

E X E R C I S E 7 T H E I N T E G U M E N T A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N 89

4. Fingerprints

Fingerprints are useful for identifying unknown bodies, missing children, adults with amnesia or Alzheimer’s, or criminals. The practice of using fi ngerprints to identify someone is called dactyloscopy. Fingerprints develop from dermal papillae that form epidermal ridges in the 3rd and 4th fetal month of development. The ridge arrange- ment on every fi nger of every human being is unique and does not alter with growth or age. Superfi cial injuries do not affect the ridge structure or alter the dermal papillae, and the original pattern is duplicated in any new skin. An

3. Nails

Nails, which are found on the distal ends of the digits, assist in grabbing and manipulating objects, and protect the digits. The nail consists of a nail body, a free edge, and a root. The nail body is the part of the nail that is vis- ible, the free edge extends beyond the digit, and the root is within the fold of skin at the proximal end of the nail body. The lunula (lunula � little moon) is the crescent-shaped area of the nail body distal to the nail root. The cuticle or eponychium (epi- � above; -onych � nail) is the thick- ened epithelial tissue along the proximal border of the nail body. The hyponychium (hypo- � below) or nail bed is deep to the free edge and attaches the nail to the fi ngertip. The nail matrix is the epithelial tissue deep to the nail root that divides to produce new cells that are added to the nail body as it grows.

Before Going to Lab

1 Identify the nail structures on the diagram in Figure 7.6. 2 Identify nail structures on your own nails.

FIGURE 7.6 Nail structures.

(a) Dorsal view • eponychium (eh-poh-NICK-ee-um) • free edge • lunula • nail body

(b) Sagittal section through finger • eponychium • free edge • hyponychium (hypo-NICK-ee-um) • lunula (LOON-you-luh) • nail root • nail body • nail matrix

1 ____________________________________________________

2 ____________________________________________________

3 ____________________________________________________

4 ____________________________________________________

5 ____________________________________________________

6 ____________________________________________________

7 ____________________________________________________

8 ____________________________________________________

9 ____________________________________________________

10 ____________________________________________________

11 ____________________________________________________

3 4

65 7 8 9

Epidermis

Dermis

Phalanx (finger bone)

(a) Dorsal view (b) Sagittal section through finger

90 E X E R C I S E 7 T H E I N T E G U M E N T A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

with both hands holds onto the index finger. Roll the finger, from the pad to at least the first joint, from side to side in the ink pad and then carefully roll the inked fin- ger the same way onto the index card. If the fingerprint smears, or is too light or dark, repeat the procedure.

4 Repeat the same process with the middle finger, but when applying the print to the same card, roll the finger in the opposite direction so the index print doesn’t get smeared. Clean your fingers with a towelette.

5 Repeat the procedure with the other hand and use the 2nd card.

6 Switch subjects and repeat with your lab partner. 7 Classify your prints into one of the recognized pattern

groups of loops, whorls, or arches and mark your clas- sification on the back of the cards.

8 Exchange fingerprint record cards with another group and compare classifications of your prints as well as identifying which two fingerprint cards belong to the same individual. If the other group agrees with your classification, give your instructor your fingerprint classification.

9 Your instructor will collect all fingerprint classifica- tion data from the class and write the results on the board, giving the class percentages of loops, whorls, and arches.

10 Make a bar graph of the class classification data and compare with the norms for the 3 recognized patterns: 65% loops (look like hairpins), 30% whorls (circles), 5% arches (hills).

11 Answer the Discussion Questions with your lab group.

injury that destroys the dermal papillae, however, will per- manently destroy the ridges. The epidermal ridges of thick skin in the distal pads of phalanges (fi ngers and toes) are dotted with openings for oil and perspiration glands that transfer the image of the ridges onto a surface. The fatty acid and amino acid secretions leave invisible fi ngerprints that can be on a nonporous or a porous surface, and those same prints can be visible if there is any dirt or additional material on the fi ngertips. Fingerprints are categorized into 3 generally recog- nized patterns, as shown in Figure 7.7: loops, whorls, and arches. Loops constitute about 65% of the total fi ngerprint patterns, whorls make up about 30%, and arches account for the other 5%. Forensic detectives acquire more details about the pattern area, including bifurcations, ridge end- ings, and islands. They also use the size of the patterns and the position of the patterns on the fi nger for further identi- fi cation. The United States FBI further divides the basic 3 fi ngerprint classifi cations into 8 subclassifi cations.

FIGURE 7.7 Main types of fingerprint patterns.

LAB ACTIVITY 4 Fingerprinting Lab

1 For each person in your group, obtain an ink pad, two 3� � 5� index cards, ¾� transparent tape, magnifying glass, and towelettes. Have the subject wash and dry the hands.

2 Using the lined side of the index card, write the sub- ject’s name and R or L hand.

3 The subject should stand, extending the arm, and relax while the lab partner stands to the side of the subject and

DISCUSSION QUESTIONS Fingerprints

1 Are the prints from your index and middle fingers on the same hand similar? Are those fingerprints similar com- pared to your other hand?

2 What classification pattern do you have?

3 How does your class compare with the total percentages of the 3 recognized patterns?

■

(a) Arch (b) Loop

A. Skin Layers and Structures

Write the name of the skin layer or structure that fits the description.

______________________ 1. Layer of epidermis where there is the most rapid cell division.

______________________ 2. Tough, water-repellent epidermal layer; contains dead squamous-shaped cells.

______________________ 3. Areolar connective tissue layer beneath basement membrane.

______________________ 4. Projections of dermis that cause epidermal ridges.

______________________ 5. Translucent layer found in thick skin, absent in thin skin.

______________________ 6. Appears to have thorn-like projections in prepared slides.

______________________ 7. Thick dermal layer containing dense, irregular connective tissue.

______________________ 8. Epidermal layer containing visible granules.

______________________ 9. Epidermal layer with stem cells.

______________________ 10. Dermal layer with hair follicles and glands.

B. Cells of the Epidermis

Write the name of the epidermal cell type that fits the description.

______________________ 1. Defends skin against microbes.

______________________ 2. Produces keratin.

______________________ 3. Produces the pigment melanin which shields cell nuclei from ultraviolet (UV) radiation.

______________________ 4. Associated with sensory neurons and functions in sensation of touch.

______________________ 5. Compose about 8% of epidermal cells.

______________________ 6. Compose about 90% of epidermal cells.

______________________ 7. Compose about 2% of epidermal cells.

______________________ 8.

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

7 E X E R C I S E

⎫ ⎥ ⎬ ⎥ ⎭

92 E X E R C I S E 7 T H E I N T E G U M E N T A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

C. Accessory Structures of the Skin

Write the name of the accessory structure that best fits the description.

______________________ 1. Sudoriferous glands located in axillary and genital areas; become active after puberty.

______________________ 2. Connective tissue projection; provides blood supply for hair matrix.

______________________ 3. Secures nail to digit.

______________________ 4. Epithelial layer that surrounds hair root.

______________________ 5. Secretes sebum onto hair and skin.

______________________ 6. Part of nail that is visible.

______________________ 7. Part of nail that extends beyond digit.

______________________ 8. Part of hair that contains the matrix.

______________________ 9. Sudoriferous glands that deposit sweat onto epidermal ridges causing fingerprints.

______________________ 10. Part of hair in epidermis and extending beyond skin surface.

______________________ 11. Moves hair shaft perpendicular to skin; causes goose bumps.

______________________ 12. Thickened epithelial tissue at proximal end of nail body.

______________________ 13. Crescent-shaped area of nail body near cuticle.

______________________ 14. Part of hair within dermis.

______________________ 15. Part of nail within skin.

______________________ 16. Part of nail deep to nail root that produces new cells, causing the nail to grow.

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

7 E X E R C I S E

A. Identification of Skin from Different Body Locations

Observe diagrams of skin from different body locations in Figure 7.8. Based on number of epithelial layers and skin acces- sory structures, determine if skin is from the axillary area, forearm, or sole of foot.

1. ____________________________________________

2. ____________________________________________

3. ____________________________________________

FIGURE 7.8 Identification of skin from different body locations.

1 2 3

94 E X E R C I S E 7 T H E I N T E G U M E N T A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

B. Application

Answer the following questions in the space provided.

4. Cortisone is a steroid that is applied to the skin to reduce inflammation. Cortisone acts on cells within the dermis and can travel through unbroken epidermis to reach cells in the dermis. If the epidermis is such a good barrier, how can cortisone easily travel through it?

5. Explain how dandruff is formed.

6. Joey has a splinter in his finger. His mother pulled the skin away from the splinter with a sterile needle and removed the splinter. Joey did not feel pain and did not bleed. Explain.

7. Identify the epidermal layer(s) in which the following cancers arise: (a) basal cell carcinoma; (b) malignant melanoma; (c) squamous cell carcinoma.

8. Name the part(s) of the skin that “peel(s)” off after a minor sunburn.

9. As we age, our skin wrinkles due to changes in collagen and elastic fibers in the dermis and a decrease in their production. Explain why topical application of collagen and elastic fibers would not eliminate wrinkles.

10. Permanent tattoos are made by injecting pigment into the skin. Into which part of the skin is the pigment injected, the epidermis or dermis? (You can answer this without research; just use your knowledge.)

11. If you had a third-degree burn on your scalp, would you expect for your hair to grow back in that area? Explain.

12. Pulling a hair out of your head hurts, but cutting your hair doesn’t. Explain the difference.

13. How do vitiligo and albinism differ? How are they similar?

14. What structure of skin helps you grip a wet glass?

15. Describe the mechanism for acquiring a suntan.

E X E R C I S E 8 B O N E S T R U C T U R E A N D F U N C T I O N 95

Bones are organs composed of a complex arrangement of several tissues. A typical bone has compact and spongy osseous tissues, connective tissues, cartilage, and adipose tissue. In addition, bones contain blood vessels and nerves.

A. Classification of Bones

Human bones have different shapes and distinct gross anatomical features. Bones are placed in fi ve classifi ca- tions according to their shapes: long, short, fl at, irregular,

O B J E C T I V E S M A T E R I A L S

• disarticulated bones for bone classification • Gross Features of a Human Long Bone: human

long bone cut longitudinally and transversely;

• Gross Features of a Fresh Long Bone: dissecting microscope, dissecting tray, blunt probe and forceps, disposable gloves, fresh chicken leg or thigh bone, fresh beef long bone sectioned longitudinally

• Microscopic Structure of Bone: compound microscope and lens paper, prepared slides of cross-section of ground compact bone and cancellous (spongy) bone, or use Real Anatomy (Histology)

• Collagen and Mineral Salts: 3 chicken thigh or leg bones: 1 raw, 1 baked for 2 hours or more at 250ºF, and 1 soaked in an acidic solution (vinegar or nitric acid) for 5 to 7 days

Bone Structure and Function 8

E X E R C I S E

1 Identify bones as either long, short, flat, irregular, or sesamoid

2 Describe the gross structure of a long bone and identify its parts

3 Describe the difference between compact (cortical) and spongy (cancellous or trabecular) bone

4 Identify microscopic structures of compact and spongy bone

5 Describe the effect of collagen and mineral salts on bone hardness and flexibility

and sesamoid. Long bones are longer than they are wide, with a thick compact bone exterior. Distribution of spongy bone in long bones is covered in detail later in this exer- cise. Short bones are almost equal in length and width and contain a thick interior of spongy bone covered by a thin veneer of compact bone. Flat bones are relatively fl at, but may be curved, and contain a thin, spongy bone inte- rior covered by a thin veneer of compact bone. Irregular bones are self-explanatory and do not easily fi t into any of these categories. Sesamoid bones (sesame � seed) are small bones that develop in tendons (e.g., patella) for pro- tection against wear and tear.

96 E X E R C I S E 8 B O N E S T R U C T U R E A N D F U N C T I O N

B. Gross Features of Long Bones

The enlarged proximal and distal ends of long bones are called epiphyses (epi- � above, over; -physis � growing), and the middle shaft area is called the diaphysis (dia- � through). Compact bone forms the exterior (or cortex) of long bones and most of the diaphysis. A small layer of spongy bone lines the interior of the diaphysis. Spongy bone also forms the interior of the epiphyses. The metaphyses are the areas in an adult bone where the epiphyses and diaphy- sis join. In a growing bone, the metaphyses contain a layer of hyaline cartilage called the epiphyseal plate. Division of cartilage allows the bone to grow in length. Bone growth stops when the epiphyseal plate cartilage becomes ossifi ed and forms a bony structure called the epiphyseal line. Articular cartilage (articul- � joint), composed of hyaline cartilage, covers both epiphyses; and the rest of the bone exterior is covered with a tough, connective tissue mem- brane, the periosteum (peri- � around; osteo- � bone). The hollow center of the bony diaphysis is called the medullary cavity (medulla � marrow, pith), and a small amount of spongy bone is found in this cavity. The med- ullary cavity is lined with a connective tissue membrane called the endosteum (endo- � within). The endosteum also lines the cavities within the spongy bone of the epiph- yses. Both the periosteum and the endosteum contain osteoblasts (-blast � builder) and osteoclasts (-klasis � breaking) for bone formation, bone tissue repair, and bone remodeling. Yellow marrow is a fatty substance found within the medullary cavity. Red marrow is found within the cavities of spongy bone and produces blood cells. The nutrient artery is a large artery that enters compact bone near the middle of the diaphysis. The nutrient artery immediately branches into proximal and distal portions which supply blood to the inner layer of compact bone, spongy bone, and red marrow. The nutrient foramen is the foramen through which the nutrient artery enters.

LAB ACTIVITY 1 Classification of Bones According to Shape

1 Classify each of the bones your instructor has displayed according to shape.

2 Discuss with the rest of the class which bones are dif- ficult to classify and why. ■

Before Going to Lab

1 Label Figure 8.1. FIGURE 8.1 Features of an adult long bone.

• articular cartilage • compact bone • diaphysis (die-AF-ih-sis) • distal epiphysis

(e-PIF-ih-sis) • endosteum

(en-DOS-tee-um) • epiphyseal (ep-i-PHY-zee-al

or ee-PIF-ih-seal) line • medullary (MED-yoo-lar-y)

cavity • nutrient artery • periosteum

(peri-OS-tee-um) • proximal epiphysis • spongy bone with red

marrow • yellow marrow

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

7 ________________________

8 ________________________

9 ________________________

10 ________________________

11 ________________________

12 ________________________

Longitudinal section

E X E R C I S E 8 B O N E S T R U C T U R E A N D F U N C T I O N 97

cut in cross-section. When viewed on a stained slide of compact bone, there are dark areas with thin lines extend- ing between the lamellae. The dark areas are lacunae (lacuna � little lake) that are found between concentric lamellae, and the thin lines are canaliculi (small channels) that connect the lacunae. Osteocytes are mature bone cells that reside in the lacunae, and osteocyte processes extend through the canaliculi. Canaliculi allow nutrients from the blood vessels in the central canal to diffuse to the osteo- cytes embedded in the solid bone material. The canaliculi are also the route by which waste materials are removed from these cells. Interstitial lamellae (inter- � between; -stitial � to stand) fi ll in the spaces between the osteons. Spongy (cancellous or trabecular) bone does not contain osteons but instead has trabeculae (little beams)— fl at plates with a lattice-like network of thin, bony columns lined with endosteum. The trabeculae have lamellae, lacunae, osteocytes, and canaliculi. Spongy bone has many spaces fi lled with red marrow. Blood vessels within the red marrow provide the osteocytes with nutrients. This fragile spongy bone needs the protection of an outer layer of compact bone. Spongy bone is found in the epiphyses of long bones and in the interior of short, fl at, and irregular bones.

C. Microscopic Structure of Compact and Spongy Bone Tissue

Compact (cortical) bone is composed of repeating units of osteons, with each unit having a central (Haversian) canal running longitudinally. The central canal contains blood vessels, lymphatic vessels, and nerves that serve compact bone tissue. The blood vessels, lymphatic vessels, and nerves travel from the periosteum, dense regular con- nective tissue covering the bone surface, to the central canal through perforating (Volkmann) canals. These canals run horizontally in compact bone and connect with the central canal. The main feature of each osteon is the concentric rings, or concentric lamellae (lamella � small plate or ring), which look similar to the rings of a tree trunk

LAB ACTIVITY 2 Gross Features of a Human Long Bone

1 Identify as many items as you can from Figure 8.1 on a human long bone that is partially sectioned longitudi- nally and transversely.

2 Use a dissecting microscope to observe spongy bone in the epiphyses and lining the medullary cavity. ■

LAB ACTIVITY 3 Grow Features of a Fresh Long Bone

1 Using gloves, examine a fresh chicken tibia (leg bone) or femur (thigh bone) and identify as many structures as you can from Figure 8.1. • Note the shiny appearance of the articular cartilage. • Use a blunt probe and forceps to loosen the periosteum,

ligaments, or tendons. • Locate the center of the diaphysis and look for the

nutrient artery passing through a hole (nutrient foramen) in the compact bone.

• Examine a cross-section of the bone to observe marrow in the medullary cavity, spongy bone, and compact bone.

2 Examine a longitudinal section of fresh beef bone. • Find the epiphyseal line or the epiphyseal plate. • Use a dissecting microscope to observe spongy bone

in the epiphyses and lining the medullary cavity. • Note the difference between the yellow and red bone

marrow.

3 Clean up as directed by your instructor. ■

SAFETY NOTE: Wear gloves when using fresh tissue!

Before Going to Lab

1 Label the structures in Figures 8.2(a) and (b), and Figure 8.3(a) and (b).

LAB ACTIVITY 4 Microscopic Structure of Ground Compact Bone and Spongy Bone

1 Examine a prepared slide or use Real Anatomy (Histology) to observe ground compact bone. Blood vessels, osteocytes, and periosteum cannot be observed on ground bone slides. • Using the low-power objective lens, identify an

osteon, a central canal, concentric lamellae, and interstitial lamellae. Count the number of osteons in one field of view.

• Using the high-power objective lens, identify cana- liculi and lacunae.

2 Examine a prepared microscope slide or use Real Anatomy (Histology) to observe spongy bone. Note that on slides of spongy bone the preparations are gen- erally demineralized (mineral salts removed) and do not show the lamellae and canaliculi as depicted in the draw- ing in Figure 8.2(b). • Using the low-power objective lens, identify the

trabeculae. • Using the high-power objective lens, identify the lacu-

nae, which appear as darker areas in the trabeculae. ■

98 E X E R C I S E 8 B O N E S T R U C T U R E A N D F U N C T I O N

FIGURE 8.2 Microscopic features of bone.

(a) Osteons (Haversian systems) in compact bone and trabeculae in spongy bone

Medullary cavity

Osteon

Medullary cavity

Periosteum

Spongy bone

Compact bone

13 14

Space for red bone marrow

12 Osteoblasts aligned along trabeculae of new bone

(b) Enlarged aspect of spongy bone trabeculae

(a) • blood vessels • canaliculus

(can-a-LIK-yoo-lus) • central canal • compact bone • concentric lamellae

(la-MEL-lee) • lacuna (la-COO-na) • osteocyte (OS-tee-o-site) • perforating canal

• periosteum (per-ee-OS-tee-um)

• spongy bone • trabeculae (trah-BEK-

yoo-lee) of spongy bone covered with endosteum

(b) • interstitial lamellae • osteocyte in lacuna • trabeculae covered with

endosteum

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

7 ________________________

8 ________________________

9 ________________________

10 ________________________

11 ________________________

12 ________________________

13 ________________________

14 ________________________

E X E R C I S E 8 B O N E S T R U C T U R E A N D F U N C T I O N 99

(a) • compact bone • medullary cavity • metaphysis • proximal epiphysis • spongy bone

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

(b) • canaliculi • central canal • concentric lamella • lacuna

6 ________________________

7 ________________________

8 ________________________

9 ________________________

10 ________________________

11 ________________________

(a) Longitudinally sectioned femur (thigh bone)

285�LM (b) Cross-section of ground compact bone

FIGURE 8.3 Gross and microscopic features of compact and spongy bone.

Red marrow cell

200�LM (c) Photomicrograph of spongy bone

100 E X E R C I S E 8 B O N E S T R U C T U R E A N D F U N C T I O N

DISCUSSION QUESTIONS Collagen and Mineral Salts

1 Compare the flexibility of the untreated, baked, and acid-treated bones.

2 Which bone is brittle?

3 What substance has been damaged in the brittle bone? __________ Why would this increase bone breakage?

4 Which bone is the softest?

5 What substance has been leached from the soft bone? ________________ What clinical disorder is this bone simulating? ■

D. Role of Collagen and Mineral Salts in Osseous Tissue

The properties of osseous tissue are determined by its extracellular matrix, which contains approximately 25% water, 25% collagen fi bers, and 50% mineral salts. Colla- gen fi bers are a fi brous protein that provide tensile strength and fl exibility so that bone does not break with normal stress. The mineral salts consist mainly of calcium phos- phate and calcium carbonate salts, giving the “backbone” or hardness to bone. As we age, the collagen content of osseous tissue decreases, causing bones to become brittle and break more easily. Decreased mineral content of bone, as occurs with rickets, causes bones to be soft and to bend due to body weight.

LAB ACTIVITY 5 Role of Collagen and Mineral Salts in Osseous Tissue

1 With your group, examine a chicken thigh or leg bone baked at about 350�F for a minimum of 2 hours or until brittle. Compare what happens when you try to bend a baked and fresh bone.

2 Examine a chicken thigh or leg bone that has been soaked in an acidic solution (vinegar or nitric acid) for 5 to 7 days. Try bending the bone soaked in the acidic solution and compare this with the fresh bone and the baked bone.

3 Clean up as directed by your instructor. 4 Answer Discussion Questions with your lab group.

■

101

A. Gross Features of Long Bones

Write the answer in the space provided for questions 1–5.

1. What area of the long bone is covered with cartilage? __________________________________

2. What type of cartilage is articular cartilage? __________________________________

3. What area (epiphysis or diaphysis) is made up of a thin layer of compact bone and a thick spongy bone?

__________________________________

4. What area (epiphysis or diaphysis) is made up of a thick layer of compact bone and a very thin layer of spongy bone?

__________________________________

5. The long bone in Figure 8.1 is from an adult. If this figure were from a child, what structure would be present instead

of the epiphyseal line? __________________________________

B. Microscopic Features of Long Bones

Identify the term that describes the phrase about long bones.

______________________ 1. bone cell found in lacunae

______________________ 2. vertical canal in an osteon

______________________ 3. cavity that contains yellow marrow in adults

______________________ 4. bone shaft

______________________ 5. spaces where the osteocytes are located

______________________ 6. horizontal canal in an osteon

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

8 E X E R C I S E

102 E X E R C I S E 8 B O N E S T R U C T U R E A N D F U N C T I O N

______________________ 7. small canal connecting lacunae

______________________ 8. membrane lining medullary cavity

______________________ 9. membrane covering surface of bone

______________________ 10. thin bony columns in spongy bone

C. Comparison of Compact and Spongy Bone

Identify whether the statements below describe compact bone, spongy bone, or both.

______________________ 1. composed of osteons

______________________ 2. contains osteocytes and lacunae

______________________ 3. has lamellae

______________________ 4. has trabeculae

______________________ 5. has perforating canals

______________________ 6. located in the epiphyses

______________________ 7. located in the diaphysis

______________________ 8. has a central canal

______________________ 9. spaces filled with red marrow

______________________ 10. has canaliculi

D. Chemical Composition of Bone

Fill in the blanks with the correct term.

______________________ 1. The hardness of bone is due to _____________.

______________________ 2. The flexibility and tensile strength of bone are due to _____________.

______________________ 3. What type of a macromolecule (carbohydrate, lipid, protein) is collagen?

______________________ 4. A bone that has the collagen removed is flexible or inflexible?

______________________ 5. A bone that has calcium removed is flexible or inflexible?

103

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

8 E X E R C I S E

FIGURE 8.4 Longitudinal section of a long bone. FIGURE 8.5 X-ray of a child’s knee joint.

5 _____________________________________________________

6 _____________________________________________________

7 _____________________________________________________

8 _____________________________________________________

6 8

A. Bone Tissue

Fill in the blanks with the correct term.

1. Two bone cells located in the periosteum and endosteum are ____________ and ____________.

2. Which type of bone tissue, compact bone or spongy bone, significantly degenerates first in osteoporosis?

________________________________________________________________________________________________

3. As we age, the amount of collagen in the extracellular matrix of bone decreases and bones become more brittle. Identify the osseous tissue cell that secretes collagen. ____________________

4. Explain the importance of the integumentary system to bone formation.

B. Bone Images

Identify the structures indicated on Figure 8.4 and the structures and corresponding name of bone on Figure 8.5.

104 E X E R C I S E 8 B O N E S T R U C T U R E A N D F U N C T I O N

9. Observe the bones in Figure 8.6(a) and (b). Identify the child’s hand and the adult’s hand.

(a) _________________________________________ (b) ____________________________________________

10. Observe Figure 8.7(a) and (b). Identify the normal bone and osteoporotic bone.

(a) _________________________________________ (b) ____________________________________________

FIGURE 8.7 Normal and osteoporotic bone tissue.

FIGURE 8.6 X-rays of the child and adult hand.

(a) (b)

(a)

30�SEM

(b)

30�SEM

E X E R C I S E 9 A X I A L S K E L E T O N 105

There are 206 named bones in the adult skeleton, which can be separated into the axial and the appendicular divisions. The axial skeleton is composed of 80 bones located along a vertical line, the longitudinal axis of the body. Its bones support and protect the organs of the head, neck, and torso. The appendicular skeleton (appendere � to hang upon) is composed of 126 bones that make up the upper limbs (or extremities), lower limbs, and the bones of the girdles that attach the limbs to the axial skeleton. The appendicular skeleton will be studied in the next exercise.

O B J E C T I V E S

Axial Skeleton 9 E X E R C I S E

1 Identify the 3 main parts of the axial skeleton

2 Identify the major bones of the axial skeleton

3 Identify selected bone surface markings and sutures

4 Identify paranasal sinuses and bones of the nasal septum, hard palate, and orbit of eye

5 Identify the fontanels in the fetal skull

6 Identify the parts of a typical vertebra

7 Compare the 3 individual types of vertebrae and the identifying features of each

8 Compare and contrast the normal and abnormal curvatures of the vertebral column

9 Identify the bones of the thoracic cage and selected surface markings

105

The axial skeleton includes the skull, hyoid bone, vertebral column, and thoracic cage (rib cage). Smaller bones included in this division are the ear ossicles (bones).

A. The Skull

The major bones of the skull include the cranial and facial bones. The cranial bones form a bony cavity that harbors and protects the brain and houses organs of hearing and equi- librium. Facial bones provide the shape of the face, house the teeth, and provide attachments for all the muscles of

• articulated skeleton or use Real Anatomy (Skeletal) • disarticulated skeleton • articulated skulls, Beauchene (disarticulated)

skull, and fetal skull

• articulated vertebral column with intervertebral discs

• small plastic straws (coffee stirrers) or pipe cleaners for pointers

M A T E R I A L S

106 E X E R C I S E 9 A X I A L S K E L E T O N

facial expression. Other major features of the skull include sutures, orbit of eye, bone markings, paranasal sinuses, nasal septum, hard palate, and fontanels in the fetal skull.

1. Cranial Bones

There are a total of 8 bones in the cranium, 2 paired and 4 single bones.

• (2) parietal bones (paries � wall)—superior lateral walls of cranial cavity

• (2) temporal bones—inferior lateral walls of cranial cavity; house organs of inner ear

• (1) frontal bone—anterior portion of cranial cavity • (1) occipital bone (occipit- � atlas)—posterior wall

of cranial cavity • (1) sphenoid bone (sphen- � wedge; -eidos �

form)—floor of cranial cavity posterior to ethmoid • (1) ethmoid bone (ethmos � sieve)—floor and

anterior wall of cranial cavity

2. Sutures

Sutures are immovable joints between bones of the skull. The 4 main sutures in the skull are the:

• coronal (corona � crown)—joins frontal and parietal bones

• sagittal (sagitta- � arrow)—joins parietal bones • lambdoid (shape of the Greek letter lambda)—joins

both parietal bones with occipital bone • (2) squamous (squama � scale)—join temporal and

parietal bones

3. Facial Bones

There are a total of 14 facial bones, 6 paired and 2 single bones.

• (2) maxillae (mala � jaw)—fused upper jaw bones • (2) zygomatic bones (zygoma � yoke or bar)—

cheek bones • (2) lacrimal bones (lacri- � tear)—portion of orbit

of eyes near nasal bones • (2) nasal bones—bridge of nose

• (2) inferior nasal conchae (concha � shell or scroll-shaped) or turbinate—forms lateral walls of nasal cavity

• (2) palatine bones (palatum � palate)—fused bones that form posterior part of hard palate

• (1) mandible (mandere � to chew)—lower jaw bone

• (1) vomer (vomer � plowshare)—inferior portion of nasal septum

Before Going to Lab

1 Label the cranial bones, facial bones, and sutures in Figures 9.1–9.5.

NOTE: BE ACCOUNTABLE FOR THE CARE OF SKULLS AND BONES. Please be careful not to use pencils, pens, or markers as pointers while you are studying the skull and other bones. Thin bones can be broken, and all bones can be permanently marked. Your instructor will provide a small plastic straw, pipe cleaner, or other suitable pointer.

LAB ACTIVITY 1 Cranial Bones, Facial Bones, and Sutures

1 Identify the bones and sutures in Figures 9.1–9.5 on an articulated skull, disarticulated skull, or use the search text box to locate these structures in Real Anatomy (Skeletal).

2 Palpate as many of the cranial and facial bones as you can on your own skull and say their names.

3 Palpate the joint between the temporal and mandibular bone (temporomandibular joint, or TMJ) by putting your fingers on either side of your jawbone just ante- rior to the ears. Open and close your mouth to feel this joint. ■

CLINICAL NOTE: A dislocated or defective TMJ has a history of causing clinical problems characterized by pain, tenderness, dysfunction, and clicking noises.

E X E R C I S E 9 A X I A L S K E L E T O N 107

FIGURE 9.1 Lateral view of skull.

Frontal bone

Coronal suture

Squamous suture

Parietal bone

Temporal bone

Occipital bone

Lambdoid suture

Sphenoid bone

Ethmoid bone

Lacrimal bone

Nasal bone

Zygomatic bone

Maxilla

Mandible

Hyoid bone

• coronal (cor-RONE-al) suture • ethmoid bone • frontal (FRON-tal) bone • lacrimal (LAK-rih-mal) bone • lambdoid (LAMB-doid) suture • mandible • maxilla (ma-XIL-la) • nasal bone • occipital (oc-CI-pi-tal) bone • parietal (pa-RYE-e-tal) bone • sphenoid (SFEE-noid) bone • squamous (SQUAY-mus) suture • temporal (TEM-por-ul) bone • zygomatic (zy-go-MA-tic) bone

1 _________________________________

2 _________________________________

3 _________________________________

4 _________________________________

5 _________________________________

6 _________________________________

7 _________________________________

8 _________________________________

9 _________________________________

10 _________________________________

11 _________________________________

12 _________________________________

13 _________________________________

14 _________________________________

108 E X E R C I S E 9 A X I A L S K E L E T O N

FIGURE 9.2 Superior view of skull.

Frontal bone

Sagittal suture

Coronal suture

Parietal bone

Occipital bone

Lambdoid suture

Posterior

• coronal suture • frontal bone • lambdoid suture • occipital bone • parietal bone • sagittal suture

1 ________________________________________________

2 ________________________________________________

3 ________________________________________________

4 ________________________________________________

5 ________________________________________________

6 ________________________________________________

E X E R C I S E 9 A X I A L S K E L E T O N 109

Parietal bone

Maxilla

Palatine bone

Occipital bone

Posterior

Temporal bone

Sphenoid bone

Vomer

Zygomatic bone

FIGURE 9.3 Inferior view of skull.

• maxilla • occipital bone • palatine (PAL-a-tin) bone • sphenoid bone • temporal bone • vomer (VOH-mer) • zygomatic bone

1 __________________________________

2 __________________________________

3 __________________________________

4 __________________________________

5 __________________________________

6 __________________________________

7 __________________________________

View

110 E X E R C I S E 9 A X I A L S K E L E T O N

FIGURE 9.4 Superior view of floor of cranial cavity.

• ethmoid bone • frontal bone • lambdoid suture • occipital bone • parietal bone • sphenoid bone • temporal bone

1 __________________________________

2 __________________________________

3 __________________________________

4 __________________________________

5 __________________________________

6 __________________________________

7 __________________________________

Posterior

Occipital bone

Frontal bone

Ethmoid bone

Sphenoid bone

Temporal bone

Parietal bone

Lambdoid suture

Anterior Transverse plane

View

E X E R C I S E 9 A X I A L S K E L E T O N 111

FIGURE 9.5 Anterior view of skull.

Frontal bone

Temporal bone

Nasal bone

Zygomatic bone

Maxilla

Mandible

Vomer

Inferior nasal concha

Lacrimal bone

Ethmoid bone

Sphenoid bone

Parietal bone

Sphenoid bone

Ethmoid bone

• ethmoid bone • frontal bone • inferior nasal

concha (CON-cha) or turbinate

• lacrimal (LAC-ri-mal) bone

• mandible (MAN-di-ble)

• maxilla • nasal bone • parietal bone • sphenoid bone • temporal bone • vomer • zygomatic bone

1 _________________________________

2 _________________________________

3 _________________________________

4 _________________________________

5 _________________________________

6 _________________________________

7 _________________________________

8 _________________________________

9 _________________________________

10 _________________________________

11 _________________________________

12 _________________________________

112 E X E R C I S E 9 A X I A L S K E L E T O N

5. Selected Bone Surface Markings of the Skull

The bones of the skull are not totally smooth but have depressions, openings, and projections. These bone sur- face markings have specifi c functions. Depressions and openings form joints or passageways for blood vessels and nerves. Processes form joints or points of attachment for ligaments or tendons. The major types of bone markings found on the axial skeleton are listed in Table 9.1 along with their descriptions and functions. Selected bone sur- face markings are listed below.

Cranial Bones: Selected Bone Surface Markings 1. Frontal bone (1)

• supraorbital foramina (supra- � above; orbit � wheel rut; foram- � opening)—1 opening located above the orbit of each eye for supraorbital nerve and artery

• supraorbital ridges or margins—thickening of frontal bone superior to orbit of each eye

2. Temporal bone (2)—Each temporal bone has one of each structure listed below: • external auditory meatus (meatus � passageway)—

tube-like opening for the ear canal • mastoid process (mastoid � breast-like)—rounded

projection posterior to external auditory meatus; attachment for muscles

• styloid process (stylo- � point)—long, thin projection on inferior skull surface; attachment for muscles and ligaments of tongue and neck

• zygomatic process—projection that articulates with the zygomatic bone

• mandibular fossa—depression in mandible for articulation with condylar process (mandibular condyle)

• foramen lacerum (lacerare � torn or lacerated)— jagged opening filled with cartilage in a living person

• carotid foramen (canal)—foramen for internal carotid artery

• jugular foramen ( jugula � throat)—foramen for jugular vein and cranial nerves IX, X, and XI

• stylomastoid foramen—opening for an artery and cranial nerve VII

• internal auditory meatus—opening for cranial nerve VIII

4. Orbit of the Eye

The orbit of the eye is a mosaic of 7 different bones, 3 cra- nial bones (frontal, sphenoid, and ethmoid), and 4 facial bones (maxilla, zygomatic, lacrimal, and palatine). The piece of the palatine bone that is part of the orbit is small and not readily observable in Figure 9.6.

Before Going to Lab

1 Label the bones forming the orbit of the eye in Figure 9.6.

LAB ACTIVITY 2 Orbit of the Eye

1 On a skull or using the search text box in Real Anatomy (Skeletal), locate the 6 bones that constitute the orbit of the eye. Palatine bone is difficult to see. ■

FIGURE 9.6 Orbit of the eye.

• ethmoid bone • frontal bone • lacrimal bone • maxilla • sphenoid bone • zygomatic bone

1 _______________________________

2 _______________________________

3 _______________________________

4 _______________________________

5 _______________________________

6 _______________________________

6 5

SUPERIOR

INFERIOR

E X E R C I S E 9 A X I A L S K E L E T O N 113

• superior orbital fissures ( fissure � cleft)— openings for blood vessels and cranial nerves III, IV, V, and VI (ophthalmic branch)

• pterygoid processes (medial and lateral) (pterygoid � wing-shaped)—wing-like projections on the base of the skull in the middle section of the sphenoid bone

Facial Bones: Selected Bone Surface Markings 1. Maxillae (2)

• alveoli (alve- � socket)—tooth sockets (alveolus, sing.)

• palatine process—fused processes that form the anterior part of hard palate

2. Mandible (1) • alveoli—tooth sockets • body—curved, anterior portion of mandible • mental foramina (menta � chin)—openings in chin

for nerves and blood vessels • rami—posterior branches, one on either side of the

body of mandible • condylar processes (mandibular condyles)—

rounded processes on rami that articulate with temporal bone at the mandibular fossa to form the TMJ

• coronoid processes—triangular projections of rami anterior to the condylar processes

3. Lacrimal bone (2) • lacrimal fossa—canal that houses lacrimal sac;

formed from the maxilla and lacrimal bone 4. Zygomatic bone (2)

• temporal process—projects posteriorly; temporal process of zygomatic bone and zygomatic process of temporal bone form the zygomatic arch

3. Occipital bone (1) • foramen magnum (magnum � large)—opening

through which spinal cord connects to lower brain • hypoglossal foramina—openings for cranial

nerves XII • occipital condyles—rounded processes that

articulate with the atlas (C1) • external occipital protuberance—projection at

base of skull posterior to foramen magnum 4. Ethmoid bone (1)

• cribriform plates (cribr- � sieve)—one on either side of crista galli; form roof of nasal cavity

• crista galli (crist- � crest; galli � rooster)— projection for attachment of membranes covering brain

• olfactory foramina (olfact- � smell)—tiny holes in cribriform plates for cranial nerve I

• perpendicular plate—forms superior part of nasal septum

• middle nasal conchae—scroll-like projections on each lateral wall of nasal cavity

• superior nasal conchae—scroll-like projections on each lateral wall of nasal cavity

5. Sphenoid bone (1) • foramina ovale (ovale � oval)—openings for

mandibular branch of cranial nerve V • foramina rotundum—openings for maxillary

branch of cranial nerve V • sella turcica (sella � saddle; turcica � Turkish)—

bony projection that surrounds and protects pituitary gland

• greater and lesser wings—form anterior and lateral floor of cranial cavity

• optic foramina—openings for cranial nerve II • inferior orbital fissures—openings for blood

vessels and nerves

TABLE 9 .1 Bone Markings

MARKING DESCR IPT ION PURPOSE

Depressions or Openings

1. Fissure (FISH-er) Narrow slit or cleft in a bone Opening for blood vessels and nerves 2. Foramen (for-AY-men) Opening or hole (foramina, pl.) Opening for blood vessels and nerves 3. Fossa (FOS-sa) Shallow depression (fossae, pl.) Muscle attachment or articulation (joint) 4. Meatus (me-AY-tus) Tube-like passageway or opening (meati, pl.) Passageway or canal for blood vessels and nerves

Processes

5. Condyle (CON-dile) Smooth, rounded articular process Articulation 6. Ramus (RAY-mus) A small branch (rami, pl.) Articulation 7. Spine Pointed process Articulation

114 E X E R C I S E 9 A X I A L S K E L E T O N

that the straws cross above the sella turcica. This simulates the crossing of the optic nerves, called the optic chiasma.

3 Palpate the supraorbital ridges of the frontal bone and the body, ramus, and condylar process of the mandible.

4 Palpate the mastoid process of the temporal bone by placing your fingers on the projection inferior and pos- terior to the external auditory meatus.

5 Palpate the condylar process by placing fingers anterior to the external auditory meatus and opening and closing your mouth. ■

Before Going to Lab

1 Label the bone markings listed in Figures 9.7–9.10.

LAB ACTIVITY 3 Bone Surface Markings

1 Identify the bone markings in Figures 9.7–9.10 on an ar- ticulated skull, unarticulated skull, or use the search text box to locate these structures in Real Anatomy (Skeletal).

2 Using two small plastic straws, poke each straw into an orbit of the eye and through an optic foramen. Observe the straws in the superior view of the cranial floor and notice

FIGURE 9.7 Anterior view of skull.

4 3

bserve the and notice

Orbit

Perpendicular platee of ethmoid

Mental foramen

Middle nasal concha

Inferior orbital fissure

Superior orbital fissure

Supraorbital margin

Supraorbital foramen

• inferior orbital fissure • mental foramen • middle nasal concha • orbit of eye • perpendicular plate of ethmoid • superior orbital fissure • supraorbital (supra-OR-bi-tal) foramen • supraorbital margin

1 _________________________________

2 _________________________________

3 _________________________________

4 _________________________________

5 _________________________________

6 _________________________________

7 _________________________________

8 _________________________________

E X E R C I S E 9 A X I A L S K E L E T O N 115

5 6

Styloid process

External auditory meatus

Zygomatic process of temporal bone

Mastoid process

Lacrimal fossa

Ramus of mandible

Hyoid bone

Coronoid process

Condylar process (mandibular condyle)

Body of mandible

FIGURE 9.8 Lateral view of skull.

• body of mandible • condylar (CON-dih-lur)

process (mandibular condyle)

• coronoid process • external auditory meatus • lacrimal fossa in lacrimal

bone • mastoid (MAS-toid)

process • ramus of mandible • zygomatic process of

temporal bone

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

7 ________________________

8 ________________________

116 E X E R C I S E 9 A X I A L S K E L E T O N

FIGURE 9.9 Inferior view of skull.

POSTERIOR

12 11

processPalatine aof maxill

Occipital condyle Jugular foramen

Carotid foramen Mandibular fossa

Foramen ovale

Posterior

bonePalatine

Pterygoid processes

Styloid process

Foramen lacerum

Hard palate

Stylomastoid foramen

External auditory meatus

Mastoid process

Foramen magnum

Hypoglossal foramen

External occipital protuberance

• carotid foramen (canal)

• external occipital protuberance

• foramen lacerum (LA-sir-um)

• foramen magnum • foramen ovale

(o-VAL-ee) • hard palate • hypoglossal foramen

• jugular foramen • mandibular fossa • mastoid process • occipital (ox-CI-pi-tal)

condyle • palatine bone • palatine process of

maxilla • pterygoid processes • stylomastoid (sty-lo-

MAS-toid) foramen

1 ____________________________________________

2 ____________________________________________

3 ____________________________________________

4 ____________________________________________

5 ____________________________________________

6 ____________________________________________

7 ____________________________________________

8 ____________________________________________

9 ____________________________________________

10 ____________________________________________

11 ____________________________________________

12 ____________________________________________

13 ____________________________________________

14 ____________________________________________

15 ____________________________________________

E X E R C I S E 9 A X I A L S K E L E T O N 117

Internal auditory meatus

Hypoglossal foramen

Foramen ovale

Foramen rotundum

Foramen magnum

Olfactory foramina

Cribriform plate

Lesser wing of sphenoid

Optic foramen

Crista galli

Sella turcica

Greater wing of sphenoid

Foramen lacerum

Jugular foramen

Posterior

View

Transverse plane

4 5

(Holes) 2

9 8

FIGURE 9.10 Superior view of floor of cranial cavity.

• cribriform (CRIB-ri-form) plate

• crista galli (CRIS-ta GAL-li)

• foramen lacerum

• foramen magnum

• foramen ovale

• foramen rotundum

• greater wing of sphenoid

• internal audi- tory meatus

• jugular foramen

• lesser wing of sphenoid

• olfactory foramina

• optic foramen • sella turcica

(SEL-la TUR-si-ca)

1 ______________________________

2 ______________________________

3 ______________________________

4 ______________________________

5 ______________________________

6 ______________________________

7 ______________________________

8 ______________________________

9 ______________________________

10 ______________________________

11 ______________________________

12 ______________________________

13 ______________________________

118 E X E R C I S E 9 A X I A L S K E L E T O N

6. Paranasal Sinuses

Paranasal ( para- � next to; nasal � nose) sinuses (sinu- � hollow) are cavities lined with mucous mem- branes that are located near and have openings into the nasal cavities. The ethmoid, frontal, maxillary, and sphenoid bones contain paranasal sinuses.

7. Nasal Septum

The nasal septum (saeptum � wall or partition) is com- prised of 2 bones and cartilage. The vomer is inferior to the perpendicular plate of the ethmoid bone. The septal cartilage is anterior to the 2 bones.

8. Hard Palate

The hard palate, or roof of the mouth, is formed by the fusion of 4 bones: 2 palatine processes of the maxillary bones and 2 palatine bones. Approximately three-fourths of the hard palate is composed of the palatine processes of the maxillary bones, and one-fourth is the palatine bones.

CLINICAL NOTE: A cleft palate is a common congenital malformation of the hard palate. This defect is the result of bones of the palate failing to fuse along the midline during embryonic development. The cleft can be partial or complete.

Before Going to Lab

1 Label the 4 paranasal sinuses in Figure 9.11. 2 Label the bones and cartilage of the nasal septum and

hard palate in Figure 9.12.

LAB ACTIVITY 4 Paranasal Sinuses, Nasal Septum, and Hard Palate

1 Locate the bones that contain the paranasal sinuses on a skull or use the search text box to locate these structures in Real Anatomy (Skeletal).

2 Identify the structures of the nasal septum on an articu- lated skull (and a Beauchene skull, if available) or use the search text box to locate these structures in Real Anatomy (Skeletal).

3 Locate the bones of the hard palate on a skull or use the search text box to locate these structures in Real Anatomy (Skeletal).

4 Palpate your nasal septum to find the junction of the nasal bones and nasal cartilage.

5 Palpate your own palate with your tongue or finger, noting the junction of the hard and soft palates. ■

2 3 4

(a) (b)

FIGURE 9.11 Paranasal sinuses.

• ethmoidal sinus • frontal sinus • maxillary sinus • sphenoidal sinus

1 _________________________________

2 _________________________________

3 _________________________________

4 _________________________________

FIGURE 9.12 Nasal septum.

• perpendicular plate of ethmoid

• septal cartilage • vomer

1 _________________________________

2 _________________________________

3 _________________________________

Frontal sinusSphenoidal sinus

Sella turcica

1 2

Crista galli

Nasal bone

E X E R C I S E 9 A X I A L S K E L E T O N 119

9. Fetal and Newborn Skull

The newborn skull is not completely ossifi ed but has mem- branous sections composed of fi brous connective tissue called fontanels ( fontaine � fountain) or “soft spots.” Fontanels allow the cranial bones to compress during the journey through the birth canal, and they also permit rapid growth of the brain and skull during the early years. At birth, the physician or midwife can tell how the baby is pre- senting itself in the birth canal by palpating the fontanel. If the fontanel is a diamond shape, the baby is presenting the frontal bone fi rst and is face down. If the fontanel is trian- gular in shape, the baby is presenting the occipital bone and is face up. These membrane templates that are present at birth eventually ossify.

Before Going to Lab

1 Label the fontanels in Figures 9.13(a)–(c).

LAB ACTIVITY 5 Fetal Skull and Major Fontanels

1 Identify the fontanels on a fetal skull (if available) or use the search text box to locate these structures in Real Anatomy (Skeletal).

2 Compare the location of the fontanels and sutures in the fetal skull with adult sutures.

3 Compare the size of the facial bones in the fetal skull with the adult skull. ■

FIGURE 9.13 Major fontanels of the fetal skull.

Posterior fontanel

Occipital bone

Parietal bone

Posterolateral fontanel

Future squamous suture

(a) Right lateral view

Anterior fontanel Future coronal suture Frontal bone

Anterolateral fontanel

Sphenoid bone

Temporal bone

Sphenoid bone

Temporal bone

Parietal bone

Future squamous suture

Future coronal suture

(b) Right anterolateral view

Frontal bone

Frontal suture

Perpendicular plate

Maxilla

Mandible

Parietal bone

Future sagittal suture

Occipital bone

Future lambdoid suture

• anterior (frontal) fontanel (fon-ta-NEL) • anterolateral (sphenoidal) fontanel • posterior (occipital) fontanel • posterolateral (mastoid) fontanel

1 _____________________________________________

2 _____________________________________________

3 _____________________________________________

4 _____________________________________________

120 E X E R C I S E 9 A X I A L S K E L E T O N

B. Hyoid Bone

The hyoid bone is not attached to the axial skeleton but is included with the axial skeleton because of its mid- line location and proximity to the mandible and vertebral column. This bone is U-shaped and has the distinction of not articulating with any other bones. It is secured in place by ligaments and muscles, including many muscles of the tongue and neck. It is located in the anterior neck region between the mandible and larynx. (This is the bone that is crushed during strangulation.)

1. Regions and Normal Curvatures of the Vertebral Column

The 5 regions of the vertebral column and the number of vertebrae in the adult, from superior to inferior, are: cervical (7), thoracic (12), lumbar (5), sacral (1), and coccygeal (1). To remember the number of vertebrae in the fi rst 3 groups, students say they eat “breakfast at 7, lunch at 12, and dinner at 5.” There are 4 normal curvatures that correspond with the regions of the vertebral column: cervi- cal, thoracic, lumbar, and sacral (pelvic) curvatures. A newborn has a single anteriorly concave primary curve that will become the thoracic curve and sacral curve (Fig. 9.14). Two anteriorly convex secondary curves—the cervical and lumbar—develop several months later. The cervical curve develops when the baby can hold its head erect, while the lumbar curve develops when the baby can stand.

Before Going to Lab

1 Locate the hyoid bone in Figure 9.8.

LAB ACTIVITY 6 Hyoid Bone

1 Identify the hyoid bone on an articulated skeleton and on a disarticulated skeleton or use the search text box to locate these structures in Real Anatomy (Skeletal).

2 Palpate your hyoid bone by placing the thumb and middle finger of one hand on either side of the neck about 1 inch inferior to the mandible. This bone can be moved laterally (from side to side). ■

C. Vertebral Column

The vertebral column protects the spinal cord and provides attachment points for back and abdominal muscles. The curved vertebral column (backbone) is a fl exible struc- ture that can be bent, twisted, and rotated, especially in the cervical region. The vertebral column consists of cervical (cervic- � neck), thoracic (thorac- � chest), and lumbar (lumb- � loin) vertebrae, the sacrum (sacer � sacred), and coccyx (coccyx � cuckoo’s beak). The sacrum consists of 5 sacral vertebrae that are fused in the adult. The coccyx (tailbone) is usually composed of 4 small, fused coccygeal vertebrae. An infant has 33 individual vertebrae, and the adult has 26 due to fusion of the sacral and coccygeal ver- tebrae. The vertebral column articulates with the skull, the ribs, and the pelvis.

Single curve in fetus Four curves in adult

FIGURE 9.14 Fetal and adult curves of the vertebral column.

Before Going to Lab

1 Label the 5 regions of the vertebral column in Figure 9.15. 2 Label the 4 normal curvatures in Figure 9.15.

LAB ACTIVITY 7 The Vertebral Column

1 Identify the 5 regions on an articulated skeleton or vertebral column model.

2 Identify the 4 curvatures on an articulated skeleton or vertebral column. ■

E X E R C I S E 9 A X I A L S K E L E T O N 121

• cervical curve • cervical vertebrae (VER-te-bray) • coccyx (COCK-six) • lumbar curve • lumbar vertebrae • sacral curve • sacrum (SAY-crum) • thoracic curve • thoracic vertebrae

1 _________________________________

2 _________________________________

3 _________________________________

4 _________________________________

5 _________________________________

6 _________________________________

7 _________________________________

8 _________________________________

9 _________________________________

Intervertebral foramen

Intervertebral disc

POSTERIOR ANTERIOR

1 2

6 7

1 2 3 4 5

6 7

Intervertebral disc

1 2 3 4 5 6 7 1 2

8 9

FIGURE 9.15 Normal spinal curvatures of the vertebral column.

122 E X E R C I S E 9 A X I A L S K E L E T O N

2. Parts of a Typical Vertebra

The cervical, thoracic, and lumbar vertebrae have similar as well as different structures. The similarities are studied in this activity, and the differences will be studied in the next activity.

• body—located anteriorly; is the largest part of the vertebra

• pedicle ( pediculus � little foot)—attached to and extends posteriorly on either side of the body

• transverse process—extends laterally from each pedicle

• lamina (lamin- � plate)—connects transverse processes to the spinous process

• spinous process—projects posteriorly from fused lamina

• vertebral arch—formed by the fusion of pedicles and laminae

• vertebral foramen—large opening formed by the vertebral arch that protects the spinal cord

• superior and inferior articular processes (with facets)—extend from the vertebra at the junction of the pedicle and lamina to articulate with a superior and inferior vertebra, respectively

Before Going to Lab

1 Locate the parts of a typical vertebra shown in Figure 9.16.

LAB ACTIVITY 8 Parts of a Typical Vertebra

1 Identify the parts of a typical vertebra on a disarticu- lated thoracic vertebra or use the search text box to locate these structures in Real Anatomy (Skeletal).

2 Palpate the spinous processes of your vertebral column. ■

FIGURE 9.16 Parts of a typical vertebra.

POSTERIOR

Body

Facet of superior articular process

Spinal cord

Vertebral foramen

Facet for head of rib

Spinous process

Transverse process

Vertebral arch: Lamina

Pedicle

3. Comparison of Cervical, Thoracic, and Lumbar Vertebrae

The fi rst two of the seven cervical vertebrae look different from the others as seen in Figure 9.17(a). The atlas is the fi rst cervical vertebra (C1) and is named for the mythical Greek god who held up the world on his shoulders. The large superior articular facets of the atlas articulate with the occipital condyles of the skull and allow the head to tilt up and down in a nodding motion. The axis, C2, has a superior tooth-like protuberance called the dens (dens � tooth in Latin) or odontoid process (odous � tooth in Greek). The dens extends superiorly into the vertebral foramen of the atlas and allows the atlas to pivot later- ally in a “no” type motion. Some head traumas push the head onto the vertebral column, and the dens is shoved into

the medulla oblongata (brain stem). This is the cause of death in such head injuries. C3 through C6 have bifurcated (forked) spinous processes. In Figure 9.17(a), observe the vertebra prominens (C7) which has a prominent single spinous process that protrudes at the base of the neck and can be seen and palpated. A whiplash, which occurs in some rear-ended auto accidents, causes partial or complete dislocation of the cervical vertebrae. The easiest way to distinguish any cervical vertebra is by its three foramina (pl.; foramen, sing.)—a vertebral foramen plus two transverse foramina. The transverse foramina, found only in cervical vertebrae, allow passage of the vertebral arteries, veins, and sympathetic nerves to and from the brain. Since the cervical vertebrae do not carry much weight, they are lightweight and have small bodies.

E X E R C I S E 9 A X I A L S K E L E T O N 123

A thoracic vertebra has a medium-size body and usu- ally a long, narrow spinous process that commonly slants inferiorly at a sharp angle. Thoracic vertebrae also have facets ( facette � little face) on the transverse processes and demifacets (demi- � half) on the bodies, both of which articulate with ribs. Lumbar vertebrae have the largest bodies to support more weight and thick, hatchet-shaped spinous processes that extend horizontally. Intervertebral discs can be found between the bodies of vertebrae from C2 to the sacrum. As you recall, they are made of fi brocartilage to give strength, permit movement, and absorb shock. The outer portion of the disc is called the annulus fi brosus (annulus � ring-like) and consists of tough fi brocartilage. The inner part, the nucleus pulposus ( pulposus � pulp-like), is soft and pulpy. A herniated or slipped disc occurs when the fi brocartilage of the annulus is stressed and torn or cracked. In this situation, the inner pulp-like center protrudes outward and causes pressure on the spinal cord or a spinal nerve. A laminectomy (removal of the lamina and sometimes spinous process of the verte- bra) relieves the pressure. Intervertebral foramina are formed between adjacent vertebrae when vertebrae are stacked on one another. Spinal nerves exit the vertebral column through these foramina.

Before Going to Lab

1 Label the parts of an atlas, axis, and cervical vertebra in Figure 9.17(b), (c), and (d).

2 Label the parts of a thoracic vertebra in Figure 9.18(a) and (b) and a lumbar vertebra in Figure 9.19(a) and (b).

3 Label the parts of articulated vertebrae in Figure 9.20(a) and a herniated disc in (b).

LAB ACTIVITY 9 Comparison of Cervical, Thoracic, and Lumbar Vertebrae

1 Place all three types of disarticulated vertebrae side by side and note their differences. Mix them up and iden- tify each type of vertebra with a partner.

2 Palpate your own spinous process of C7 (vertebra prominens).

3 Identify the structures in Figures 9.17–9.19 on disar- ticulated vertebrae or use the search text box to locate these structures in Real Anatomy (Skeletal).

4 Using articulated vertebrae, identify the intervertebral disc and intervertebral foramen in Figure 9.20. ■

Location of cervical vertebrae

(a) Posterior view of articulated cervical vertebrae

C1 (atlas)

Dens of axis

Atlas (C1)

Axis (C2)

Typical cervical vertebra

Groove for vertebral artery and first cervical nerve

C2 (axis)

INFERIOR

ANTERIORPOSTERIOR

SUPERIOR

C7 (vertebra prominens)

FIGURE 9.17 Cervical vertebrae.

124 E X E R C I S E 9 A X I A L S K E L E T O N

Dens

(b) Superior view of the atlas (C1)

Transverse foramen

Transverse process

Bifurcated spinous process

Superior articular facet

Lamina

Posterior

Pedicle

(d) Superior view of a typical cervical vertebra (C3)

2 3

(b) Atlas • superior articular facet • transverse foramen • transverse process

• dens (odontoid process) • lamina • spinous process

(d) Typical cervical vertebra • bifurcated spinous process • body • pedicle • transverse process

1 ____________________________________________________

2 ____________________________________________________

3 ____________________________________________________

4 ____________________________________________________

5 ____________________________________________________

6 ____________________________________________________

7 ____________________________________________________

8 ____________________________________________________

9 ____________________________________________________

10 ____________________________________________________

FIGURE 9.17 Cervical vertebrae (continued).

E X E R C I S E 9 A X I A L S K E L E T O N 125

Superior demifacet

(a) Superior view

Superior articular facet

Facet for articular part of tubercle of rib

Inferior demifacet

(b) Right lateral view

(a) Superior view

POSTERIOR

2 1

SUPERIOR

(b) Right lateral view

ANTERIORPOSTERIOR

(a) Superior view • facet for articular part of tubercle of rib • superior articular facet • superior demifacet • transverse process

(b) Right lateral view • facet for articular part of tubercle of rib • inferior demifacet • slanted spinous process • superior articular facet • superior demifacet

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

5 _____________________________________________________

6 _____________________________________________________

7 _____________________________________________________

8 _____________________________________________________

9 _____________________________________________________

FIGURE 9.18 Thoracic vertebrae.

126 E X E R C I S E 9 A X I A L S K E L E T O N

(a) Superior view

POSTERIOR

SUPERIOR

(b) Right lateral view

ANTERIORPOSTERIOR

(a) Superior view • body • pedicle • superior articular process • transverse process • vertebral foramen

(b) Right lateral view • hatchet-shaped spinous

process • inferior articular facet

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

7 ________________________

FIGURE 9.19 Lumbar vertebrae.

(b) Superior view of herniated disc(a) Right lateral view of articulated vertebrae with intervertebral disc

Posterior

Anterior 1

3 Spinal nerve

Spinal cord

(a) Articulated vertebrae • annulus fibrosus • intervertebral disc • intervertebral foramen • nucleus pulposus

(b) Herniated disc • annulus fibrosus • herniation • nucleus pulposus

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

7 ________________________

FIGURE 9.20 Intervertebral discs.

E X E R C I S E 9 A X I A L S K E L E T O N 127

surfaces of the sacrum, the auricular surfaces, are rough- ened to articulate with the iliac portion of the os coxa on each side, forming sacroiliac joints. The vertebral column ends with a small coccyx, or tailbone. The tiny, fused vertebrae of the coccyx are attached to the sacrum with ligaments.

4. Sacrum and Coccyx

The sacrum is formed by the fusion of 5 sacral vertebrae and has a slightly curved, triangular shape. The broad su- perior portion is called the base and the two lateral wing- like projections are called alae (ala, sing.). The sacral promontory ( promontory � a projecting part), which pro- trudes anteriorly from the base, is an important landmark in females during labor and delivery. The sacrum has sacral foramina that provide exits for spinal nerves. From the posterior view, the opening of the sacral canal, a continuation of the vertebral canal, is located just pos- terior to the body of the sacrum. The inferior opening of the sacral canal, the sacral hiatus, is due to failure of the lamina of the 5th sacral vertebrae (and sometimes the 4th) to fuse. (Note: On many plastic models, the sacral canal is closed.) Two superior articular processes with facets that articulate with the fi fth lumbar vertebra are located on either side of the opening of the sacral canal. The lateral

Before Going to Lab

1 Label the parts of the sacrum and coccyx in Figure 9.21.

LAB ACTIVITY 10 Sacrum and Coccyx

1 Identify the structures in Figure 9.21(a) and (b) on a model of the sacrum and coccyx or use the search text box to locate these structures in Real Anatomy (Skeletal). ■

(a) • base • coccyx • sacral ala • sacral foramen • sacral promontory

(b) • auricular surface (for

sacroiliac joint) • sacral canal • sacral hiatus • superior articular facet

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

7 ________________________

8 ________________________

9 ________________________

(a) Anterior view (b) Posterior view

4 S1

Sacral canal

Superior articular facet

Superior articular process

Auricular surface

Sacral hiatus

Sacral promontory Base of sacrum Sacral ala

Superior

Inferior

FIGURE 9.21 Sacrum and coccyx.

128 E X E R C I S E 9 A X I A L S K E L E T O N

D. Thoracic Cage (Rib Cage)

The bony cage that encircles the chest is called the thoracic cage, or rib cage, and is composed of the sternum, ribs, costal cartilages, and thoracic vertebrae. The sternum is a narrow fl at bone that is composed of three fused bones: the manubrium, the body of the ster- num, and the xiphoid process. The manubrium (handle), the superior portion of the sternum, has a concave superior surface called the suprasternal notch or jugular notch. Between the body of the sternum and the manubrium is the sternal angle, an important clinical landmark indicat- ing the attachment of the second rib, below which is the second intercostal space. The manubrium and body ar- ticulate (articul- � pertaining to a joint) with the costal cartilages of the ribs. The xiphoid process (sword-like) is the inferior portion of the sternum that is shaped like a small sword. There are 12 pairs of ribs in both males and females. The fi rst 7 pairs are called the true ribs or vertebrosternal ribs because their costal (rib) cartilages have a direct attachment to the sternum. The last 5 rib pairs (8–12) are called false ribs. Rib pairs 8 through 10 are vertebrochondral ribs (vertebro � ribs; chondral � car- tilage) because their costal cartilages do not have a direct attachment to the sternum but attach to the costal cartilage of the seventh rib instead. Rib pairs 11 and 12 do not have any attachment to the sternum or cartilage and are called fl oating ribs or vertebral ribs. The space between the ribs is called the intercostal space. The main parts of a rib are the head, neck, tubercle, and body. The head projects from the posterior part of the rib and articulates with demifacets on the bodies of thoracic vertebrae. The neck is the constricted part lateral to the head. The tubercle is a small, knob-like projection close to the neck that articulates with the facet of a transverse process. The body is the main part of the rib.

5. Abnormal Vertebral Curvatures

Three abnormal curves of the vertebral column are sco- liosis, kyphosis, and lordosis. The vertebral column bends laterally in scoliosis (scolio- � crooked). Kyphosis is an exaggerated thoracic curve that results in a hunched back with rounded shoulders. Lordosis is an exaggerated lum- bar curve that appears as a swayback with the abdomen protruding anteriorly.

Before Going to Lab

1 Label the 3 different types of abnormal curves in Figure 9.22(a), (b), and (c).

FIGURE 9.22 Abnormal curves of the vertebral column.

(a) (b) (c)

• kyphosis • lordosis • scoliosis

a ________________________

b ________________________

c ________________________

E X E R C I S E 9 A X I A L S K E L E T O N 129

2 Identify the parts of a rib and its articulation with a vertebra on an articulated thorax or use the search text box to locate these structures in Real Anatomy (Skeletal).

3 Identify the four parts of a rib and its articulations on a skeleton.

4 Palpate the suprasternal notch and then move your fingers inferiorly until a ridge (sternal angle) is reached. Move your fingers laterally until the 2nd rib can be pal- pated. Palpate the body of the sternum inferior to the sternal angle. Palpate down the sternum until you reach the inferior point of the xiphoid process. ■

Before Going to Lab

1 Label the parts of the thorax in Figure 9.23. 2 Label the parts of a rib and its articulation with a verte-

bra in Figure 9.24(a) and (b).

LAB ACTIVITY 11 Thoracic Cage and Rib Articulations

1 Identify the structures in Figure 9.23 on an articulated thorax or use the search text box to locate these structures in Real Anatomy (Skeletal).

• body of sternum • costal cartilage • false ribs • floating ribs • manubrium • sternal angle • sternum • suprasternal notch (jugular notch) • true ribs • xiphoid process

1 _______________________________

2 _______________________________

3 _______________________________

4 _______________________________

5 _______________________________

6 _______________________________

7 _______________________________

8 _______________________________

9 _______________________________

10 _______________________________

T12

T11

T10

Clavicular notch 7

Scapula Clavicle

10 9

SUPERIOR

INFERIOR

FIGURE 9.23 Thoracic cage.

130 E X E R C I S E 9 A X I A L S K E L E T O N

Superior facet

Tubercle

Costal angle

Articular facet

Costal groove

Inferior facet

Neck

Body

Head

(a) Posterior view of left rib

Facet for costal cartilage

POSTERIOR

(a) Superior view

SUPERIOR

POSTERIOR

(b) Right lateral view

(a) Superior view • articular part of tubercle • facet for articular part of tubercle • head of rib • tubercle

1 ________________________________________

2 ________________________________________

3 ________________________________________

4 ________________________________________

(b) Right lateral view • body of rib • head of rib • inferior demifacet of vertebra • intervertebral foramen • superior demifacet of vertebra • tubercle

5 ________________________________________

6 ________________________________________

7 ________________________________________

8 ________________________________________

9 ________________________________________

10 ________________________________________

FIGURE 9.24 Rib and its articulation with thoracic vertebrae.

131

A. Cranial Bones and Bone Surface Markings

Identify the cranial bones that have the following bone markings.

1. Middle nasal concha

2. Foramen magnum

3. Alveoli (2 bones)

5. Sella turcica

6. External auditory meatus

7. Crista galli

8. Greater wing

9. Mastoid process

10. Occipital condyle

11. Optic foramen

12. Mandibular fossa

13. Olfactory foramina

14. Supraorbital ridges

15. Lacrimal fossa

16. Zygomatic process

17. Styloid process

18. Palatine process

19. Mental foramina

20. Carotid foramen (canal)

21. Condylar processes (mandibular condyle)

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

9 E X E R C I S E

¯ ˘

132 E X E R C I S E 9 A X I A L S K E L E T O N

Identify the bone surface marking(s) that have the following function:

22. Form the TMJ

23.

24. Opening for carotid artery

25. Opening for the ear canal

26. Holes for cranial nerve I (olfactory nerves)

27. Holes for cranial nerve II (optic nerve)

28. Opening through which the spinal cord connects to lower brain

29. Anterior part of hard palate

30. Rounded processes on skull that articulate with the atlas

31. Tooth sockets

32. Form zygomatic arch

33.

34. Protects the pituitary gland

B. Vertebral Column and Thorax

Write the name of the structure that is described.

1. Softens jolts to the vertebral column

2. Opening for spinal nerve exit

3. Bony protection for thoracic organs

4. First cervical vertebra

5. Second cervical vertebra

6. Articulates with rib posteriorly

7. Tailbone

8. Encloses and protects the spinal cord

9. Primary curvatures

10.

11. Secondary curvatures

12.

13. Formed by the fusion of pedicles and lamina

¯ ˘

˙ ¯

˘ ˙

¯ ˘

˙ ¯

˘ ˙

E X E R C I S E 9 A X I A L S K E L E T O N 133

14. Passageway for vertebral arteries in cervical vertebrae

15.

16. Name the 4 parts of the thoracic cage

17.

18.

19.

20. Name the 3 bones of the sternum

21.

22. Concave depression in superior surface of manubrium

23. False ribs

24. True ribs

25. Floating ribs

26. Space between ribs

27. A special feature present on the transverse process of cervical vertebrae

28.

29. Special features present on the thoracic vertebrae for rib articulations

30.

31. A part of the rib that articulates with the body of the thoracic vertebrae

32. A part of the rib that articulates with the transverse process of the thoracic vertebrae

33. The odontoid process is a part of which bone?

C. Other Major Features of the Axial Skeleton

Identify the major skull feature or structure that is described.

1. The suture that joins the occipital bone to the parietal bones.

2. Paired facial bones that contain a paranasal sinus.

3. The articulation between the mandible and skull.

4. Neck and tongue muscles are attached to this bone.

5. These structures allow the baby’s skull to compress during childbirth.

6. Name the bone marking that forms the superior part of the nasal septum.

7. Name the inferior bone of the nasal septum.

¯ ˚

˚ ˘

˚ ˚

˙ ¯

˚ ˘

˚ ˙

¯ ˚

˘ ˚

134 E X E R C I S E 9 A X I A L S K E L E T O N

D. Skull Bones and Bone Markings

Identify the bones and bone markings in Figure 9.25(a) and (b).

(a)

1. ______________________

2. ______________________

3. ______________________

4. ______________________

5. ______________________

6. ______________________

7. ______________________

8. ______________________

9. ______________________

10. ______________________

11. ______________________

12. ______________________

13. ______________________

14. ______________________

15. ______________________

(b)

1. ______________________

2. ______________________

3. ______________________

4. ______________________

5. ______________________

6. ______________________

7. ______________________

8. ______________________

9. ______________________

10. ______________________

11. ______________________

12. ______________________

13. ______________________

14. ______________________

15. ______________________

16. ______________________

17. ______________________

18. ______________________

19. ______________________

(a) Anterior view

(Bone) 7

(Bone) 8

(Bone marking) 6

(Bone) 5

(Bone) 4

(Suture) 3

(Bone) 2

(Bone) 1 9 (Suture)

10 (Bone) 11 (Bone)

12 (Bone marking) 13 (Bone) 14 (Bone)

15 (Bone)

Posterior

(b) Inferior view

Foramen lacerum

16 (Bone marking)

17 (Bone marking)

11 (Bone marking)

14 (Bone marking)

12 (Bone) 13 (Bone)

18 (Bone)

19 (Suture)

15 (Opening)

(Bone) 4 (Bone) 3

(Bone) 10

(Bone) 1

(Foramen) 5

(Bone marking) 2

(Bone marking) 6

(Bone marking) 9

(Foramen) 7 (Foramen) 8

FIGURE 9.25 Skull bones and bone markings.

135

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

9 E X E R C I S E

A. Identifying Bones and Bone Markings on Radiographs of Skull

Identify the structures in Figure 9.26(a).

1 ________________ (bone marking)

2 ________________ (bone)

3 ________________ (bone)

4 ________________ (bone)

5 ________________ (bone)

Identify the structures in Figure 9.26(b).

6 ________________ (bone marking)

7 ________________ (bone marking)

8 ________________ (bone marking)

9 ________________ (bone marking)

10 ________________ (space between bones)

(a) Anterior view of skull.

(b) Lateral view of skull and vertebral column.

FIGURE 9.26 Radiographs of skull.

136 E X E R C I S E 9 A X I A L S K E L E T O N

B. Identifying Bones and Bone Markings on CT Scans

Identify the structures in Figure 9.27(a).

11 ________________ (bone)

12 ________________ (bone)

13 ________________ (sinus)

14 ________________ (bone marking in sphenoid)

15 ________________ (opening)

(b) Thansverse section through skull at the level of the atlas.

FIGURE 9.27 CT scans of skull.

Identify the structures in Figure 9.27(b).

16 ________________ (bone marking)

17 ________________ (bone marking)

18 ________________ (bone sinus)

19 ________________ (bone marking)

20 ________________ (bone)

DensOccipital condyles

POSTERIOR

(a) Lateral view of skull.

E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N 137

The appendicular skeleton (appendere � to hang upon) has larger bones than the axial skeleton and bears more weight. The bones of this division are separated into four main areas: the pectoral girdles ( pectus � breast; girdle � encircles), the upper limbs

O B J E C T I V E S M A T E R I A L S

• articulated skeletons or use Real Anatomy (Skeletal) • disarticulated skeletons • small plastic straws (coffee stirrers) or pipe

cleaners for pointers

• tape measure

Appendicular Skeleton 10

E X E R C I S E

1 Identify the bones of the appendicular skeleton and be able to identify selected bones as right or left

2 Identify the principal bone markings of the pectoral (shoulder) girdle and the upper limb

3 Describe the articulation of the pectoral girdle with the humerus

4 Describe the articulation of the humerus with the forearm bones

5 Identify the bone markings of the pelvic girdle and the lower limbs

6 Describe the articulation of the bones of the pelvic girdle with the femur

7 Describe the articulation of the femur with the leg bones

8 Determine gender and height using femur measurements

9 Determine height using the length of the radius or the humerus

137

(extremities), the pelvic girdle ( pelvis � basin), and the lower limbs. The bone markings include sites of muscle attachment and articulations with other bones to form a joint. Bone surface markings that pertain to the appendicular skeleton are given in Table 10.1.

138 E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N

FIGURE 10.1 Pectoral girdle.

Scapula

Pectoral girdle:

Clavicle

(a) Anterior view

Scapula

Clavicle

(b) Posterior view

A. The Pectoral Girdle

There are 2 pectoral girdles, and each attaches an upper limb to the axial skeleton. Each pectoral (or shoulder) girdle is composed of a scapula and a clavicle (clavicle � key) (Figure 10.1).

Clavicle (collar bone) • sternal end—blunt, medial end • acromial end (acrom- � topmost)—broader, flat,

roughened, lateral end Scapula (shoulder blade)

• spine—sharp ridge located on posterior side • acromion—flattened process at lateral end of spine • glenoid cavity (glene � joint socket) or fossa—

depression inferior to acromion • coracoid process (coracoid � crow’s beak)—superior

and medial to glenoid cavity; projects anteriorly • supraspinous fossa (supra- � above; spinous �

spine)—depression superior to spine • infraspinous fossa (infra- � below)—depression

inferior to spine • subscapular fossa (sub- � under)—depression on

anterior surface of scapula • lateral or axillary border—margin near axilla • medial or vertebral border—margin near vertebral

column

To form the pectoral girdle, the acromial end of the clav- icle articulates with the acromion (acromial process) of the scapula laterally. The pectoral girdle is attached to the axial skeleton by the articulation of the sternal end of the clavicle with the manubrium of the sternum. The scapula does not articulate directly with the axial skeleton but is attached to it with muscles.

Before Going to Lab

1 Label the parts of the clavicle and scapula in Figure 10.2(a), (b), and (c).

LAB ACTIVITY 1 The Pectoral Girdle

1 Identify the bones and bone markings in Figure 10.2 on disarticulated bones or use the search text box to locate these structures in Real Anatomy (Skeletal).

2 Palpate these structures on your own body: clavicle, acromion (process), spine of scapula, and muscles located in the supraspinous and infraspinous fossae.

3 Distinguish between right and left scapula. • Spine of scapula is superior and posterior. • Glenoid cavity is laterally located. ■

TABLE 10 .1 Selected Bone Surface Markings of the Appendicular Skeleton

MARKING DESCR IPT ION PURPOSE

1. Foramen Opening or hole Opening for blood vessels and nerves 2. Fossa Shallow depression Muscle attachment or articulation 3. Crest Prominent ridge Muscle attachment 4. Condyle Smooth, rounded articular process Articulation 5. Epicondyle Projection above a condyle Muscle attachment 6. Head Rounded articular projection supported on the Articulation neck of a bone 7. Line Long, narrow ridge (less prominent than a crest) Muscle attachment 8. Trochanter Very large projection Muscle attachment 9. Tubercle Small, rounded projection Muscle attachment 10. Tuberosity Large, roughened projection Muscle attachment

E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N 139

FIGURE 10.2 The right pectoral girdle.

Acromion

Coracoid process

Glenoid cavity

Lateral (axillary) border

LATERAL

MEDIAL

SUPERIOR

LATERAL

Glenoid cavity

Medial (vertebral) border

Subscapular fossa

Supraspinous fossa

Infraspinous fossa

Spine

Acromion

1 2 (a) Clavicle, inferior view

(b) Scapula, anterior view

Superior angle

SUPERIOR

LATERAL MEDIAL

Inferior angle

SUPERIOR

12 13

(a) Clavicle • acromial (a-CROHM-ee-al) end • sternal end

(b) Scapula, anterior view • acromion (a-CROW-mee-yon) or

acromial process

• coracoid (COR-a-coid) process • glenoid (GLEN-oid) cavity or fossa • lateral (axillary) border • medial (vertebral) border • subscapular (sub-SCAP-u-lar) fossa

(c) Scapula, posterior view • acromion or acromial process • glenoid cavity • infraspinous (in-fra-SPINE-us) fossa • spine of scapula • supraspinous (su-pra-SPINE-ous) fossa

1 _________________________________

2 _________________________________

3 _________________________________

4 _________________________________

5 _________________________________

6 _________________________________

7 _________________________________

8 _________________________________

9 _________________________________

10 _________________________________

11 _________________________________

12 _________________________________

13 _________________________________

140 E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N

3. Radius (Lateral Bone of Forearm)

• head—flat, disc-shaped proximal end • radial tuberosity—rough, anterior projection on

medial side just distal to the head • styloid process—slender, pointed projection;

distal end

4. Shoulder and Elbow Joints

The shoulder joint that connects the upper limb to the pectoral girdle is formed by the head of the humerus (humeri � shoulder), articulating with the glenoid cavity of the scapula. The elbow joint is formed by the articula- tion of the coronoid process and olecranon process of the ulna into the coronoid and olecranon fossae of the humerus and by the trochlea of the humerus with the trochlear notch of the ulna. At the elbow joint, the head of the radius articu- lates with the capitulum of the humerus and with the radial notch of the ulna at the proximal radioulnar joint.

B. The Upper Limb

The upper limb consists of the humerus, ulna, radius, carpals, metacarpals, and phalanges. Of the 30 bones in each upper limb, 1 is in the arm, 2 in the forearm, and the other 27 are in the hand (includes wrist).

1. Humerus (Arm Bone)

• head—rounded, proximal end • anatomical neck—constriction immediately distal

to head • greater tubercle (tuber � swelling)—lateral projec-

tion distal to anatomical neck • lesser tubercle—smaller, anterior projection distal to

anatomical neck • intertubercular sulcus—groove between the two

tubercles • surgical neck—constriction distal to the tubercles • deltoid tuberosity—raised area on lateral side

between the proximal and distal ends of humerus • trochlea (trochlea � pulley)—spool-shaped medial

condyle on distal end • capitulum (caput � head)—rounded, knob-like

condyle lateral to trochlea • medial epicondyle (epi- � upon)—rough projection

above trochlea • lateral epicondyle—rough projection above

capitulum; smaller than medial epicondyle • radial fossa—anterior depression that receives the

radial head with flexed forearm • coronoid fossa (corona � crown)—shallow anterior

depression on distal end • olecranon fossa (olekranon � tip of the elbow)—

largest depression on posterior, distal end

2. Ulna (Medial Bone of Forearm)

• olecranon—large, curved, lip-like projection on posterior side of proximal end

• coronoid process—smaller, curved, lip-like projection on anterior side of proximal end; distal to olecranon

• trochlear notch—deep, curved area between olecranon and coronoid process

• styloid process (stylos � pole; -oid � like)—slender, pointed projection on distal end

• radial notch—depression on proximal end where head of radius articulates with ulna

Before Going to Lab

1 Label the parts of the humerus in Figure 10.3(a) and (b) and the ulna and radius in Figure 10.4(a) and (b).

LAB ACTIVITY 2 The Upper Limb Bones and Bone Markings

1 Identify the bones and bone markings in Figures 10.3 and 10.4 on disarticulated bones, articulated skeleton, or use the search text box to locate these structures in Real Anatomy (Skeletal).

2 Palpate the following bone parts on your own body: medial and lateral epicondyle of the humerus, olecranon of the ulna, and styloid processes of the radius and ulna.

3 Distinguish between the right and left humerus. • The trochlea and the capitulum are on the anterior

surface of the distal end of the humerus. • The olecranon fossa is on the posterior surface of the

distal end of the humerus. • The head is medially located on the proximal end of

the humerus. ■

E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N 141

FIGURE 10.3 Right humerus.

Radial fossa

Capitulum

Lateral epicondyle

Radius

Greater tubercle

Lateral epicondyle Olecranon

Radius

Head

Anatomical neck

Lesser tubercle

Greater tubercle

Intertubercular sulcus (groove)

Head

Scapula

Surgical neck

Deltoid tuberosity

Humerus

Coronoid fossa

Body (shaft)

Olecranon fossa

Trochlea Medial epicondyle

Ulna

Coronoid process

(a) Anterior view (b) Posterior view

(a) Anterior view

4 5

Radial fossa

1 2 3

SUPERIOR

LATERAL

9 10 11

Surgical neck

(b) Posterior view

SUPERIOR

MEDIAL LATERAL

(a) Anterior view • anatomical neck • capitulum (ca-PIT-u-lum) • coronoid (COR-a-noid) fossa • deltoid tuberosity

(tu-ber-OS-ity) • greater tubercle

(TU-ber-cul) • head • intertubercular (in-ter-tu-BER-

cue-lar) sulcus • lateral epicondyle

(epi-CON-dile) • lesser tubercle • medial epicondyle • trochlea

1 ____________________________

2 ____________________________

3 ____________________________

4 ____________________________

5 ____________________________

6 ____________________________

7 ____________________________

8 ____________________________

9 ____________________________

10 ____________________________

11 ____________________________

(b) Posterior view • lateral epicondyle • medial epicondyle • olecranon (o-LEH-cra-non)

fossa

12 ____________________________

13 ____________________________

14 ____________________________

142 E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N

FIGURE 10.4 Right ulna and radius.

Radius

Olecranon Head of radius Neck of radius Radius

Olecranon fossa

Styloid process of radius

Lateral Medial Lateral

Ulna

Interosseous membrane

Carpals

Styloid process of ulna

Humerus

Coronoid process

Ulnar tuberosity Radial tuberosity

Trochlea Coronoid fossa

Head of ulna

Styloid process of radius

Capitulum

Neck of radius Head of radius

(a) Anterior view (b) Posterior view

SUPERIOR SUPERIOR

(a) Anterior view (b) Posterior view

LATERALLATERAL MEDIAL

9 10

4 5

3 8

(a) Anterior view • coronoid process • head of radius • olecranon (process) • radial notch • radial tuberosity • styloid (STY-loid) process

of radius • styloid process of ulna • trochlear notch (semilunar)

1 ____________________________

2 ____________________________

3 ____________________________

4 ____________________________

5 ____________________________

6 ____________________________

7 ____________________________

8 ____________________________

(b) Posterior view • radius • ulna

9 ____________________________

10 ____________________________

E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N 143

to the little fi nger. The thumb has 2 phalanges, proximal and distal. Digits II through V each have proximal, middle, and distal phalanges ( phalanx � closely knit row).

5. Carpus (Wrist)

The carpus is composed of 8 short bones of the wrist, the carpal bones, which are lined up to form a proximal and a distal row of bones. Two of the carpal bones articulate with the radius, but there is no articulation of the carpal bones with the ulna.

6. Metacarpus (Palm of Hand)

The metacarpus is composed of 5 metacarpal bones that make up the palm of the hand. They are numbered as Roman numerals I to V from the metacarpal of the thumb (lateral side) to the little fi nger side. The metacarpals artic- ulate with the carpals proximally and with the phalanges distally.

7. Phalanges (Fingers)

The phalanges (phalanx, sing.) make up the fi ngers or digits. The fi ngers are also numbered I to V from the thumb ( pollex)

• carpals • distal phalanx (FAY-lanx) V • metacarpals (meta-CAR-puls) • middle phalanx V • proximal phalanx V

1 _____________________________

2 _____________________________

3 _____________________________

4 _____________________________

5 _____________________________

Before Going to Lab

1 Label the bones of the hand in Figure 10.5. For each phalanx, include the Roman numeral.

LAB ACTIVITY 3 The Hand

1 Identify the bones of the hand in Figure 10.5 on an ar- ticulated hand, articulated skeleton, or use the search text box to locate these structures in Real Anatomy (Skeletal).

2 Identify and palpate the bones in Figure 10.5 on yourself. ■

FIGURE 10.5 Right hand and wrist.

Scaphoid Trapezium Trapezoid

PhalangesMiddle

Proximal

Hamate

Metacarpals

Capitate

Pisiform Triquetrum Lunate

Distal

I II III IV V

Palm anterior

Radius

Lateral Medial

Ulna

Palm posterior

Carpals

Radius

Lateral

Ulna

IIIIIIVV

MEDIALLATERAL

2I II III IV V

Anterior view

144 E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N

• true pelvis—portion of pelvis inferior to pelvic brim; surrounds the pelvic cavity

• pelvic inlet—superior opening of true pelvis; bordered by pelvic brim

• pelvic outlet—inferior opening of true pelvis; bordered by the coccyx, ischial spines, and ischial tuberosities

There are defi nite anatomical differences between the male and female pelves (pl.). The bones of the male are typically heavier and rougher, with larger bone markings than the female. The male pelvis is more vertical and nar- rower, has a pelvic inlet that is heart-shaped, and has a 90� or less pubic arch angle. The female pelvis generally has more space in the true pelvis for childbirth and is tilted backward and fl ared. The pelvic inlet is round or oval, the angle of the pubic arch is generally greater than 90�, and the angle of the sciatic notch is wider. The pelvic girdle articulates with the axial skeleton at the sacroiliac joints (sacro- � sacrum; iliac � ilium). The sacroiliac joints are located where the articulated ossa coxae unite posteriorly with the sacrum.

C. Bones and Selected Bone Markings of the Pelvic Girdle

The pelvic girdle ( pelvis � basin) is composed of 2 hip (coxal) bones called the ossa coxae (os- � bone; cox- � hip) that attach the lower limb to the axial skeleton. Each os coxa is formed by the fusion of 3 separate bones: the ilium (ilia � fl ank), ischium (ischion � hip joint), and pubis ( pub- � grown up or adult) bones. These 3 bones are identifi able as separate bones in children.

1. Os Coxa

ilium—largest and most superior of the three components of os coxa

• iliac crest—superior border of ilium • anterior superior iliac spine—anterior end of iliac

crest • anterior inferior iliac spine—below the anterior

superior iliac spine • posterior superior iliac spine—posterior end of

iliac crest • posterior inferior iliac spine—below the posterior

superior iliac spine • greater sciatic notch—large notch on posterior side • iliac fossa—depression on anterior surface

ischium—inferior, posterior portion of os coxa • ischial tuberosity—large, roughened projection on

posterior and inferior edge • ischial spine—posterior projection between greater

and lesser sciatic notches • lesser sciatic notch—smaller indentation between

ischial spine and ischial tuberosity pubis—anterior inferior portion of os coxa

• pubic symphysis (symphysis � growing together)— joint where the two pubic bones join anteriorly

bone markings formed by ilium, ischium, and pubis • acetabulum (acetabulum � little saucer)—deep

indentation, or cup, for head of the femur • obturator foramen—largest foramen in the skeleton

2. Pelvis

• pelvic brim—divides the false pelvis from the true pelvis; begins at the sacral promontory and extends laterally and inferiorly to end at the pubic symphysis

• false pelvis—portion of pelvis superior to pelvic brim; wide area extending to top of iliac crest

Before Going to Lab

1 Label the bones and bone markings of an os coxa in Figure 10.6.

2 Label the bones and bone markings of the pelvis in Figure 10.7.

LAB ACTIVITY 4 Os Coxa and Pelvis

1 Identify the bones and bone markings in Figures 10.6 and 10.7 on a disarticulated os coxa, an articulated pelvis, or use the search text box to locate these structures in Real Anatomy (Skeletal).

2 Distinguish between the right and left os coxa. • The iliac crest is on the superior part of the os coxa. • The ischium is the inferior and posterior part of the

os coxa. • The pubic bone is on the anterior and medial part of

the os coxa. • The acetabulum is on the lateral part of the os coxa.

3 Palpate the iliac crest, the anterior superior iliac spine, and the pubic symphysis on your own body.

4 Locate these markings on an articulated pelvis or skeleton. 5 Identify the differences between male and female pelves

on models or articulated skeletons. ■

E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N 145

FIGURE 10.6 Right os coxa.

Posterior superior iliac spine

Posterior inferior iliac spine Greater sciatic notch

Ischial spine

Lesser sciatic notch

Ischial tuberosity

Iliac crest

Anterior inferior iliac spine

Anterior superior iliac spine

Acetabulum

Obturator foramen

Ilium

Ischium

Pubis

POSTERIOR

Lateral view

SUPERIOR

14 (Bone)

(Bone)

• acetabulum (asa-TAB-u-lum) • anterior inferior iliac spine • anterior superior iliac spine • greater sciatic (sigh-A-tic) notch • iliac crest • ilium (IL-lee-um) • ischial (ISH-ee-ul) spine • ischial tuberosity (tu-ber-OS-ity) • ischium (ISH-ee-um) • lesser sciatic notch • obturator (OB-tur-a-tur) foramen • posterior inferior iliac spine • posterior superior iliac spine • pubis (PYU-bis)

1 ______________________________

2 ______________________________

3 ______________________________

4 ______________________________

5 ______________________________

6 ______________________________

7 ______________________________

8 ______________________________

9 ______________________________

10 ______________________________

11 ______________________________

12 ______________________________

13 ______________________________

14 ______________________________

146 E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N

FIGURE 10.7 Pelvis.

Iliac crest

Iliac fossa

Pelvic brim

Ischial spine

Anterior superior iliac spine

Acetabulum

Obturator foramen

Ilium

Sacrum

Coccyx

True pelvis

False pelvis

Ischium Pubic symphysis

Pubic archPubis

(Bone) 2

8 (Bone)

15 (Bone)

(a) Superior view of female pelvis ANTERIOR

(b) Superior view of male pelvis

(a) Female pelvis • false pelvis • iliac crest • ilium • ischial spine

• pelvic brim • pubic symphysis (PYU-bic

SYM-fah-sis) • pubis • true pelvis

(b) Male pelvis • coccyx (COCK-six) • false pelvis • ischial spine • pubis

• sacroiliac (say-crow-ILL-ee- ac) joint

• sacrum (SAY-crum) • true pelvis

1 _______________________

2 _______________________

3 _______________________

4 _______________________

5 _______________________

6 _______________________

7 _______________________

8 _______________________

9 _______________________

10 _______________________

11 _______________________

12 _______________________

13 _______________________

14 _______________________

15 _______________________

E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N 147

• medial malleolus—medial process on distal end, forms medial bump of ankle

4. Fibula (Leg Bone)

The slender fi bula is the lateral leg bone that is important for muscle attachment but not for bearing weight. The lateral malleolus is distal and articulates with the talus laterally.

• head—proximal end • lateral malleolus—distal end, forms lateral bump of

ankle

5. Hip and Knee Joints

The hip or coxal joint is formed by the acetabulum articu- lating with the head of the femur to form a ball-and-socket joint. There is a strong ligament that connects these two structures deep inside the joint itself. The knee joint is formed by the articulation of the me- dial and lateral condyles of the femur with the medial and lateral condyles of the tibia. The patella articulates with the condyles of the femur. The fi bula does not form part of the knee joint; however, the head of the fi bula articulates with the tibia but not the femur.

D. Bones and Selected Bone Markings of the Lower Limb

The lower limb consists of bones of the femur, patella, tibia, fi bula, tarsals, metatarsals, and the phalanges. Of the 30 bones in each lower limb, 4 are in the thigh and leg, and the other 26 are in the foot (including ankle).

1. Femur (Thigh Bone)

The femur is the largest and strongest bone in the human skeleton. This bone is bowed anteriorly in a slight curve.

• head—large, rounded, knob-like proximal end • neck—narrower, constriction distal to head • greater trochanter (trochanter � runner)—large

and roughened superior projection; lateral to neck • lesser trochanter—smaller, posterior-medial

prominence distal to greater trochanter • medial condyle—rounded, medial process on

posterior side of distal end • lateral condyle—similar to medial condyle on

lateral side • intercondylar fossa—deep fossa between medial

and lateral condyles • medial epicondyle—bump-like projection superior

to medial condyle • lateral epicondyle—bump-like projection superior

to lateral condyle; a little smaller • gluteal tuberosity—posterior surface of body of

femur; roughened projection inferior to lesser trochanter

• linea aspera—vertical ridge on posterior surface

2. Patella (Kneecap)

This small, triangular bone has an anterior surface that is smoother than the posterior surface. Shallow, irregular- shaped articular facets are on the posterior surface that articulate with the condyles of the femur.

3. Tibia (Leg Bone)

The tibia is the weight-bearing bone of the 2 leg bones and is medially located.

• medial condyle—flattened, expanded medial projec- tion on proximal end

• lateral condyle—similar to medial condyle on lateral side

• tibial tuberosity—large, roughened projection on anterior surface, inferior to condyles

• anterior border (crest)—slender ridge on anterior surface; shin

Before Going to Lab

1 Label the bones and bone markings of the femur in Figure 10.8(a) and (b) and the patella, tibia, and fibula in Figure 10.9(a) and (b).

LAB ACTIVITY 5 The Thigh and Leg

1 Identify the bones and bone markings in Figures 10.8 and 10.9 on disarticulated bones, an articulated skeleton, or use the search text box to locate these structures in Real Anatomy (Skeletal).

2 Distinguish between the right and left femur. • The head is on the proximal end and faces medially. • The medial and lateral condyles are on the anterior

surface of the distal end of the femur (the medial condyle is larger).

3 Distinguish between the right and left tibia. • The tibial tuberosity is anterior and superior to the

anterior crest. • The medial malleolus is on the medial surface of the

distal end of the tibia.

4 Palpate these bone markings on your own body: greater trochanter, medial and lateral epicondyles, patella, head of the fibula, tibial tuberosity, anterior crest (shin) of the tibia, medial malleolus of the tibia, and lateral malleolus of the fibula. ■

148 E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N

FIGURE 10.8 Right femur.

Greater trochanter

Linea aspera

Gluteal tuberosity

Lateral epicondyle

Lateral condyle

Fibula

Intercondylar fossa

Os coxa

Neck

Head

Intertrochanteric line crest

Body (shaft)

Femur

Lesser trochanter

Medial epicondyle

Patella

Tibia

Medial condyle

Greater trochanter

Lateral epicondyle

Lateral condyle

Fibula

(a) Anterior view (b) Posterior view

SUPERIOR

MEDIAL

6 9

Gluteal tuberosity

Intercondylar fossa

(a) Anterior view (b) Posterior view

Greater trochanter

Neck

Head

Fovea capitis

Lesser trochanter

• greater trochanter (tro-CAN-ter) • head of femur • lateral condyle (CON-dile) • lateral epicondyle (epi-CON-dile) • lesser trochanter • linea aspera (LIN-ee-uh ASP-er-uh) • medial condyle • medial epicondyle • neck

(a) Anterior view

1 ____________________________________

2 ____________________________________

3 ____________________________________

4 ____________________________________

5 ____________________________________

6 ____________________________________

(b) Posterior view

7 ____________________________________

8 ____________________________________

9 ____________________________________

E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N 149

FIGURE 10.9 Right tibia, fibula, and patella.

Lateral condyle Head

Fibula

Lateral malleolus

Femur Intercondylar eminence

Medial condyle

Tibial tuberosity

Tibia

Interosseous membrane

Anterior border (crest)

Medial malleolus Talus

Calcaneus

Patella Lateral condyle

Fibula

Head

Lateral malleolus

(a) Anterior view (b) Posterior view

MEDIAL

(a) Anterior view (b) Posterior view

Anterior border

Intercondylar eminence

SUPERIOR

(Bone) 3

7 (Bone)

8 4

6 • fibula (FIB-u-la) • head of fibula • lateral condyle • lateral malleolus (mal-LAY-e-lus) • medial condyle • medial malleolus • tibia • tibial tuberosity

1 _________________________________

2 _________________________________

3 _________________________________

4 _________________________________

5 _________________________________

6 _________________________________

7 _________________________________

8 _________________________________

150 E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N

(hallux) to the little toe. The great toe is made of 2 phalan- ges (proximal and distal), and digits II to V have 3 bones each—proximal, middle, and distal phalanges.

6. Tarsus (Ankle)

The tarsus is composed of 7 tarsal bones of the foot, with 2 of them being larger than the rest. The largest tarsal bone is the calcaneus (calcaneum � heel), also known as the heel bone. The other large tarsal bone is the talus (talus � ankle), which articulates with the medial malleolus of the tibia and lateral malleolus of the fi bula.

7. Metatarsus

The metatarsus is composed of 5 metatarsal bones (meta- � after or next) that are analogous to the metacarpals in the hand. They are numbered the same way, I to V, from the great toe to the little toe.

8. Phalanges (Toes)

The phalanges (toes or digits) are similar to the phalanges in the hand. The toes are numbered I to V from the great toe

Before Going to Lab

1 Label Figure 10.10(a) and (b). For each phalanx, include the Roman numeral.

LAB ACTIVITY 6 The Foot

1 Identify the bones of the foot in Figure 10.10 on an articulated foot or use the search text box to locate these structures in Real Anatomy (Skeletal).

2 Palpate these parts on your own body: lateral malleolus, calcaneus, and talus. ■

FIGURE 10.10 Bones of the right foot.

Talus

Navicular

Lateral cuneiform

Intermediate cuneiform

Medial cuneiform

Proximal

Middle Distal

Calcaneus

Cuboid

Tarsals

Metatarsals

Phalanges

Head

(a) Superior view

POSTERIOR

MEDIALLATERAL

IIIIIIIVV

(a) Superior view • calcaneus (cal-CANE-ee-us) • distal phalanx II (FAY-lanx) • middle phalanx II • metatarsals (meta-TAR-suls)

• phalanges • proximal phalanx II • talus (TA-lus) • tarsals (TAR-suls)

1 _______________________

2 _______________________

3 _______________________

4 _______________________

5 _______________________

6 _______________________

7 _______________________

8 _______________________

E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N 151

(b) Lateral view • calcaneus • lateral malleolus of fibula • tibia

• metatarsals • phalanges • talus • tarsals

9 _______________________

10 _______________________

11 _______________________

12 _______________________

13 _______________________

14 _______________________

15 _______________________

FIGURE 10.10 Bones of the right foot, continued.

(b) Lateral view

129

151413

LAB ACTIVITY 7 Assembly of a Complete Disarticulated Skeleton

1 Obtain a disarticulated skeleton from your instructor. 2 With your lab partners, assemble the skeleton. 3 Have your instructor check it to see that you have

assembled it properly. ■

LAB ACTIVITY 8 Determining Gender and Height Using Femur Measurements

1 Determining gender: The diameter of the head of a femur is a very accurate way of determining gender. • Use a femur from a disarticulated or articulated

skeleton. • Use a tape measure to measure in cm the circumfer-

ence of the head of the femur. Record your value in Table 10.2.

1Institute for Algorithmic Medicine. The Medical Algorithms Project. Chapter 38: Forensic Medicine; Determination of Gender from Physical Remains; Determination of Gender of Measurement of the Femur. www.medal.org (accessed September 27, 2007). 2Institute for Algorithmic Medicine. The Medical Algorithms Project. Chapter 38: Forensic Medicine; Estimation of Body Height from Physical Remains; Pearson’s Formulas for Estimating Adult Body Height from Length of Long Bones. www.medal.org (accessed September 27, 2007).

TABLE 10 .2 Determining Gender and Height from a Femur

EST IMAT ING GENDER EST IMAT ING HE IGHT

Femur circumference (cm) Femur length (cm)

Femur diameter (cm) Height (cm)

Gender Height (in)

• Calculate the diameter of the femur using the follow- ing equation.

Diameter (cm) � Circumference (cm)

3.14

Record your value in Table 10.2. • Males have a diameter greater than 4.5 cm (45 mm)

and females have a diameter less than 4.3 cm (43 mm).1 Record gender in Table 10.2.

2 Estimating height: • Measure the longest possible length of the femur in

cm. Record your values in Table 10.2. • Use the appropriate equation for each bone (male or

female) to estimate height in cm.2 Record your value in Table 10.2.

Male: Height (cm) � (1.88 � length of femur in cm) � 81.306

Female: Height (cm) � (1.945 � length of femur in cm) � 72.844

• To convert height in cm to height in inches, divide height in cm by 2.54. Record your value in Table 10.2. ■

152 E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N

• Use the appropriate formulas to calculate your height in inches.3 Record your value in Table 10.3.

Males: Height (in) � (length of humerus in inches � 2.9) � 27.8

Females: Height (in) � (length of humerus in inches � 2.8) � 28.1

3 Measure your height in inches and record the value in Table 10.3.

4 Compare the calculated and measured values. ■

3Scientifi c American Frontiers, “Science Safari Teaching Guide: The First People,” Scientifi c American Frontiers Archives (Fall 1990 to Spring 2000). www.pbs.org/safarchive/4_class/45_pguides/pguide_702/4572_ fi rstpeople.html (accessed September 27, 2007).

LAB ACTIVITY 9 Estimating Your Height from Bone Length

1 Estimate your height from length of radius: • With the hand in anatomical position, palpate the

lateral epicondyle of your humerus and then move your hand just a little distally to the head of the radius. Slowly pronate and supinate your forearm to feel the rotation of the disc-shaped head of the radius. To find the styloid process of the radius, palpate the lateral side of your wrist.

• Measure the length of the radius in inches from the head to the styloid process. Record the value in Table 10.3.

• Use the appropriate formulas to calculate your height in inches.3 Record the value in Table 10.3.

Males: Height (in) � (length of radius in inches � 3.3) � 34

Females: Height (in) � (length of radius in inches � 3.3) � 32

2 Estimate your height from length of humerus: • Palpate the head of your humerus as you rotate your

arm in the shoulder socket. Then locate the medial epicondyle by palpating this “bump” just above the elbow hinge.

• Measure the length of the humerus in inches from the head of the humerus to the medial epicondyle.

TABLE 10 .3 Estimating Your Height from Bone Length

RADIUS

Length of radius (in)

Calculated height (in)

Measured height (in)

HUMERUS

Length of humerus (in)

Calculated height (in)

Measured height (in)

153

A. Pectoral Girdle (Shoulder)

Fill in the blank with the correct term.

______________________ 1. The acromion (process) articulates with what bone?

______________________ 2. Is the clavicle anterior or posterior compared to the scapula?

______________________ 3. The clavicle articulates medially with which bone?

______________________ 4. The humerus articulates with what bone marking of the scapula?

______________________ 5. Is the subscapular fossa located anterior or posterior to the supraspinatus and infraspinatus fossae?

______________________ 6. Name the two bones that make up the pectoral girdle.

B. Upper Limb

Fill in the blank with the correct term.

______________________ 1. What part of the radius articulates with the humerus?

______________________ 2. What part of the ulna fits into the olecranon fossa of the humerus?

______________________ 3. The coronoid process articulates with what depression on the distal end of the humerus?

______________________ 4. Is the ulna medial or lateral compared with the radius?

______________________ 5. What are the bones called that make up the fingers?

______________________ 6. What are the bones called that make up the palm of the hand?

______________________ 7. What is the name of the lateral condyle on the humerus?

______________________ 8. What is the name of the medial condyle on the humerus?

______________________ 9. What is the name of the slender, pointed projection on the distal end of the radius?

______________________ 10. What is the name of the slender, pointed projection on the distal end of the ulna?

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

10 E X E R C I S E

154 E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N

C. Pelvic Girdle and Pelvis

Fill in the blank with the correct term.

______________________ 1. When you put your hands on your hips, which bone marking of each os coxa are you touching?

______________________ 2. With your hands on your hips, you can feel a point of the pelvis protruding out anteriorly just above your thigh. Name this bone marking.

______________________ 3. Name the 2 bones that form the pelvic girdle.

______________________ 4. What prominent bone marking on each os coxa do you sit on?

______________________ 5. Name the bones of the ossa coxae that articulate anteriorly.

______________________ 6. The female pelvis has smoother bone markings than the male. True or False?

______________________ 7. Name the anterior joint between pubic bones.

______________________ 8. Deep indentation formed by fusion of ilium, ischium, and pubis.

______________________ 9. Largest foramen in the skeleton.

______________________ 10. The pelvic outlet is larger in females. True or False?

D. Lower Limb

Fill in the blank with the correct term.

______________________ 1. Is the fibula medial or lateral to the tibia?

______________________ 2. What is the correct term for the process at the distal end of the tibia that forms the medial bump of the ankle?

______________________ 3. What is the heaviest and strongest bone of the leg (not thigh)?

______________________ 4. Name the thigh bone.

______________________ 5. The fibula is a weight-bearing bone. True or False?

______________________ 6. Name the tarsal bone that articulates with the tibia.

______________________ 7. Name the heel bone.

______________________ 8. Name the bones of the distal part of the instep.

______________________ 9. Bone marking that is commonly called the shin.

______________________ 10. Bone that is commonly called the kneecap.

______________________ 11. Processes on the femur and tibia that form the knee joint.

______________________ 12. Name of the bone marking of the femur that articulates with the pelvic girdle.

______________________ 13. Does the fibula form part of the knee joint?

______________________ 14. Name the phalanges in the great toe.

______________________ 15. The number of metatarsal bones.

E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N 155

FIGURE 10.11

2 3 4

Anterior view

16 15 14

12 11

10 (bone)

(bone)

(group of bones)

1. ___________________________________

2. ___________________________________

3. ___________________________________

4. ___________________________________

5. ___________________________________

6. ___________________________________

7. ___________________________________

8. ___________________________________

9. ___________________________________

10. ___________________________________

11. ___________________________________

12. ___________________________________

13. ___________________________________

14. ___________________________________

15. ___________________________________

16. ___________________________________

17. ___________________________________

18. ___________________________________

19. ___________________________________

20. ___________________________________

E. Bones and Bone Markings of the Pectoral Girdle and Upper Limb

Identify the bones and bone markings in Figure 10.11.

156 E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N

FIGURE 10.12 Pelvic girdle and lower limb.

Anterior view

13 (bone)

(bone)14

2(bone)

4 5

6(bone)

11(bone)

15 (bone)

20 (group of bones)

(group of bones)

1. ___________________________________

2. ___________________________________

3. ___________________________________

4. ___________________________________

5. ___________________________________

6. ___________________________________

7. ___________________________________

8. ___________________________________

9. ___________________________________

10. ___________________________________

11. ___________________________________

12. ___________________________________

13. ___________________________________

14. ___________________________________

15. ___________________________________

16. ___________________________________

17. ___________________________________

18. ___________________________________

19. ___________________________________

20. ___________________________________

21. ___________________________________

22. ___________________________________

F. Bones and Bone Markings of the Pelvic Girdle and Lower Limb

Identify the bones and bone markings in Figure 10.12.

157

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

10 E X E R C I S E

A. Upper Limb

Identify the bones and bone markings of the upper limb as shown in Figure 10.13(a), (b), and (c).

3 421

6 5 987

10 11

FIGURE 10.13a Radiograph of the shoulder joint, posterior view.

1 _______________________ (bone marking)

2 _______________________ (bone marking)

3 _______________________ (bone marking)

4 _______________________ (bone)

FIGURE 10.13b Radiograph of the elbow joint.

5 _______________________ (bone)

6 _______________________ (bone)

7 _______________________ (bone)

8 _______________________ (bone marking)

9 _______________________ (bone marking)

FIGURE 10.13c Radiograph of the left hand.

10 _____________________ (bone marking)

11 _____________________ (bone)

12 _____________________ Draw a band on the specific bone

where the wedding ring is worn.

13 _____________________ Name the bone the ring is on.

158 E X E R C I S E 1 0 A P P E N D I C U L A R S K E L E T O N

B. Lower Limb

14 15 16

FIGURE 10.14a Surface anatomy of the upper limb and pectoral girdle.

14 ____________________________________ (bone marking)

15 ____________________________________ (bone marking)

16 ____________________________________ (bone marking)

FIGURE 10.14b Surface anatomy of the hip and lower limb.

17 ____________________________________ (bone marking)

18 ____________________________________ (bone)

19 ____________________________________ (bone marking)

20 ____________________________________ (bone marking)

E X E R C I S E 1 1 J O I N T S A N D S Y N O V I A L J O I N T M O V E M E N T S 159

A joint or articulation (articulare � to divide into joints) connects a bone with another bone, cartilage, or tooth. Joints are commonly classi- fied according to their structure and function.

A. Structural and Functional Classification of Joints

The structural classifi cation of joints depends on the type of connective tissue forming the joint and on whether or not there is a space or synovial cavity between the bones.

O B J E C T I V E S M A T E R I A L S

• articulated skeleton or Real Anatomy (Skeletal) • Dissection: whole and longitudinally cut fresh,

frozen, or glycerinated mammalian synovial joint, dissection equipment, disposable gloves, safety glasses

• model or chart of a knee joint or Real Anatomy (Arthrology)

Joints and Synovial Joint Movements 11

E X E R C I S E

1 Describe the 3 major structural categories of joints and give examples of each

2 Distinguish between the 3 major functional categories of joints and give an example of each

3 Describe the basic structure of a typical synovial joint

4 Describe the structure of the knee joint

5 List 6 different types of synovial joints and give an example of each

6 Describe the types of movements of synovial joints and demonstrate them

159

Fibrous joints have dense fi brous connective tis- sue with strong collagen fi bers that hold the joints fi rmly together with no synovial cavity. This type of joint permits little to no movement. Examples are the skull joints, teeth sockets, and the distal joint between the tibia and fi bula. Cartilaginous joints have either hyaline cartilage or fi brocartilage connecting the bones with no synovial cavity. Usually, there is a small degree of movement with this type of joint. Examples are the intervertebral joints, the pubic symphysis, and the joint between the manubrium and body of the sternum. Synovial joints (syn- � together; ovum � egg) have a small synovial cavity (space) between the two bones that permits a greater amount of movement than

160 E X E R C I S E 1 1 J O I N T S A N D S Y N O V I A L J O I N T M O V E M E N T S

fi brous or cartilaginous joints. The term synovial comes from the synovial fl uid present in the synovial cavity that resembles the albumin of an uncooked egg, only more vis- cous. Dense fi brous connective tissue on the exterior of the joint holds the bones together. The majority of the joints in the human body are synovial joints—for example, the shoulder, elbow, hip, and knee joints. The functional classifi cation of joints is made on the basis of the amount of movement the joint allows. Immov- able joints or synarthroses (syn- � union; arthro- � joint) include the sutures between the skull bones and the teeth sockets. Intervertebral joints, the tibiofi bular joint, (the joint between the manubrium and the body of the sternum), and the pubic symphysis are examples of slightly movable joints or amphiarthroses (amphi- � on both sides). Most of the joints in the body, about 90%, are freely movable joints, or diarthroses (di- � apart; away from). As you can see from the description of structural and functional joints, there are similarities in the amount of movement and certain types of structural joints. Most of

the fi brous joints, such as sutures and teeth sockets, are im- movable joints. However, the fi brous tibiofi bular joint is a slightly movable joint. Most of the cartilaginous joints are slightly movable joints, such as the intervertebral discs and the pubic symphysis. The cartilaginous epiphyseal plates of long bones, however, are immovable joints. All synovial joints are diarthroses.

Before Going to Lab

1 Label the structural and functional category of each joint in Figure 11.1 (two answers for each joint).

LAB ACTIVITY 1 Structural Classification of Joints

1 Identify the joints in Figure 11.1 on an articulated skeleton.

2 Point out these joints and palpate the ones you can on your own body. ■

FIGURE 11.1 Structural classification of joints.

(b) Tooth in alveolus(a) Anterior view

• amphiarthrosis (amphi-ar-THROW-sis) • cartilaginous (car-tih-LA-jih-nous) joint • diarthrosis (die-ar-THROW-sis) • fibrous joint • synarthrosis (syn-ar-THROW-sis) • synovial (sih-NO-vee-ul) joint

1 ___________________________________________

2 ___________________________________________

3 ___________________________________________

4 ___________________________________________

5 ___________________________________________

6 ___________________________________________

7 ___________________________________________

8 ___________________________________________

9 ___________________________________________

10 ___________________________________________

11 ___________________________________________

E X E R C I S E 1 1 J O I N T S A N D S Y N O V I A L J O I N T M O V E M E N T S 161

B. Basic Structure of Synovial Joints

Although synovial joints vary in structure, they have several common features as seen in Figure 11.2(a).

• synovial cavity—small space between the two articulating bones

• articular cartilage—hyaline cartilage covering the ends of the bones in the synovial cavity

• articular capsule—structure that encloses the synovial joint and synovial cavity; has two layers: the fibrous membrane and synovial membrane

• fibrous membrane—outer dense fibrous connective tissue layer of the articular capsule that is continuous with the periosteum of the bone; also forms liga- ments when fibrous bundles are parallel

• synovial membrane—inner layer of the articular capsule; composed of areolar connective tissue containing elastic fibers and adipocytes

• synovial fluid—secreted by the synovial membrane; lubricates the articular cartilages to reduce friction

Before Going to Lab

1 Label the simple synovial joint in Figure 11.2b.

• articular (ar-TIH-ku-lar) bone • articular capsule • articular cartilage • fibrous membrane • synovial cavity (contains synovial fluid) • synovial membrane

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

5 _____________________________________________________

6 _____________________________________________________

Articulating bone

Articular cartilage

Frontal plane

(a) Frontal section

Articular (joint) capsule:

Periosteum

Fibrous membrane

Synovial membrane

Synovial (joint) cavity (contains synovial fluid)

Periosteum

(b) Frontal section

FIGURE 11.2 Typical synovial joint.

162 E X E R C I S E 1 1 J O I N T S A N D S Y N O V I A L J O I N T M O V E M E N T S

LAB ACTIVITY 2 Typical Synovial Joint and Dissection

1 Dissect a whole synovial joint following the dissection instructions. • After placing your synovial joint in a dissecting tray,

observe the external white articular capsule that holds the bones together. Note that the articular capsule is continuous with the periosteum of the bone.

• Using a scalpel, cut open the joint capsule. Feel the slippery synovial fluid between your fingers.

• Try to detect the difference between the outer fibrous membrane layer and the inner synovial membrane layer of the articular capsule.

• Note the synovial cavity or space between the articular bones.

• Observe the ends of the joint bones for the articular cartilage. Cut out a small piece of hyaline cartilage to observe its thickness.

2 Clean up as directed by your instructor. ■

• articular cartilage of femur • anterior cruciate (KRU-she-ate) ligament • lateral (fibular) collateral ligament • lateral meniscus (meh-NIS-cus) • medial (tibial) collateral ligament • medial meniscus • posterior cruciate ligament

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

5 _____________________________________________________

6 _____________________________________________________

7 _____________________________________________________

Before Going to Lab

1 Label the parts of the knee joint in Figure 11.3(a).

C. The Knee Joint

The knee joint is specifi cally studied here because it has the distinction of being the most complex and highly stressed joint, as well as being the location of many joint injuries. The knee joint is classifi ed as a hinge joint, but when fl exed it also demonstrates gliding and rotation movements. In addition to the common joint features, the knee joint also has the following accessory structures.

Accessory structures of knee joint: • medial meniscus—inside of joint cavity; cushions

knee joint • lateral meniscus—inside of joint cavity; cushions

knee joint • medial (tibial) collateral ligament—extracapsular

ligament; adds strength to joint medially

• lateral (fibular) collateral ligament—extracapsular ligament; adds strength to joint laterally

• anterior cruciate ligament (cruci- � cross) or ACL—intracapsular ligament; attaches the femur and tibia anteriorly

• posterior cruciate ligament or PCL—intracapsular ligament; stabilizes joint posteriorly

• patellar ligament—extension of tendon from quadriceps muscle; connects patella to tibial tuberosity and stabilizes the joint anteriorly

• infrapatellar fat pad (infra- � beneath)—cushion between patellar ligament and synovial capsule

• bursa—reduces friction; 13 bursae in knee

LAB ACTIVITY 3 The Knee Joint

1 Identify knee joint structures in Figures 11.3(a)–(c) on a model or chart of the knee or use the search text box in Real Anatomy (Arthrology) to find these structures.

2 In Figure 11.3(d), locate the suprapatella bursa, pre- patellar bursa, infrapatellar bursa, and infrapatellar fat pad. ■

SAFETY NOTE: If you are using fresh or frozen joints, wear protective gloves. Wash your hands thoroughly with soap and water after the dissection.

E X E R C I S E 1 1 J O I N T S A N D S Y N O V I A L J O I N T M O V E M E N T S 163

FIGURE 11.3 Knee joint.

(d) Sagittal section

Femur

Patella

Articular cartilage

Infrapatellar fat pad

Prepatellar bursa

Infrapatellar bursa

Medial meniscus

Tibia

POSTERIOR ANTERIOR

Patellar ligament

Suprapatellar bursaSagittal

plane

Tendon of quadriceps femoris muscle

Lateral meniscus

Fibular collateral ligament

Fibula

POSTERIOR ANTERIOR

Patellar ligament

Femur

Synovial membrane

Articular capsule (cut)

Patella Articular cartilage

Periosteum

Tibia

Fibula

LATERAL MEDIAL (a) Anterior deep view

3 2

Transverse ligament of the knee

(b) Posterior deep view

Articular cartilage

Fibular collateral ligament

Lateral meniscus

Posterior ligament of head of fibula

Fibula

LATERAL

Oblique popliteal ligament (cut)

Tibia MEDIAL

Femur

Posterior cruciate ligament (PCL)

Medial meniscus

Tibial collateral ligament

Anterior cruciate ligament (ACL)

164 E X E R C I S E 1 1 J O I N T S A N D S Y N O V I A L J O I N T M O V E M E N T S

D. Types of Movement at Synovial Joints

Skeletal muscle contraction causes bone movement at synovial joints. Professionals in kinesiology and physical therapy use particular terms to describe the movements of these joints. Many movements are grouped to demonstrate opposite movements. The four main categories of synovial joint movements are gliding, angular, rotation, and special movements (Table 11.1).

Before Going to Lab

1 Label the movements illustrated in Figures 11.4–11.8.

LAB ACTIVITY 4 Types of Movement at Synovial Joints

1 Demonstrate each movement in Figures 11.4–11.8 with a partner(s).

2 Use an articulated skeleton to demonstrate each move- ment. During pronation, observe the radius crossing over the ulna.

3 Pronate forearm to feel the radius crossing over the ulna. ■

TABLE 11 .1 Types of Movement at Synovial Joints

MOVEMENT DESCR IPT ION

A. GLIDING Nearly flat bone surfaces slide or glide over each other.

B. ANGULAR

Flexion (flex- � to bend) Decrease in the angle between bones of a joint; usually occurs on a sagittal plane.

Extension (exten- � to stretch out Increase in the angle between bones of a joint; restore to anatomical position.

Hyperextension (hyper- � excessive) Excessive extension movement beyond normal anatomical position.

Abduction (ab- � away; duct- � to lead) Move appendage away from the midline.

Adduction (ad- � toward) Move appendage toward midline.

Circumduction (circ- � circle) Move a distal part of an appendage in a circle.

C. ROTATION (rota- � revolve) Turn on a pivot with a circle.

D. SPECIAL JOINT MOVEMENTS

Elevation Upward movement raising body part vertically.

Depression Downward movement lowering body part vertically.

Protraction (pro- � in front of; Move a body part forward or anterior on a horizontal plane. trahere � to draw)

Retraction (retractare � to draw back) Move a body part backward or posterior.

Supination (supine � lying on the back) Turn palm of the hand to face forward, or, if arm is outstretched, turn palm upward.

Pronation (pronate � lying face downward) Turn palm of the hand to face backward, or, if arm is outstretched, turn palm downward.

Inversion Turn the sole of the foot inward.

Eversion Turn the sole of the foot outward.

Dorsiflexion Point your toes upward; stand on your heels. Plantar flexion Point your toes downward; raise your heels.

E X E R C I S E 1 1 J O I N T S A N D S Y N O V I A L J O I N T M O V E M E N T S 165

FIGURE 11.4 Angular joint movements of flexion, extension, and hyperextension.

(a) Atlanto-occipital and cervical intervertebral joints

(b) Shoulder joint (c) Elbow joint

(d) Wrist joint (e) Hip joint (f) Knee joint

(a)

1 _________________________________

2 _________________________________

3 _________________________________

(d)

9 _________________________________

10 _________________________________

11 _________________________________

(b)

4 _________________________________

5 _________________________________

6 _________________________________

(e)

12 _________________________________

13 _________________________________

14 _________________________________

(c)

7 _________________________________

8 _________________________________

(f)

15 _________________________________

16 _________________________________

• extension • flexion • hyperextension

166 E X E R C I S E 1 1 J O I N T S A N D S Y N O V I A L J O I N T M O V E M E N T S

FIGURE 11.5 Angular joint movements of abduction, adduction, and circumduction.

(a)

1 _________________________________

2 _________________________________

(d)

6 _________________________________

(b)

3 _________________________________

(e)

7 _________________________________

8 _________________________________

(c)

4 _________________________________

5 _________________________________

(f)

9 _________________________________

10 _________________________________

• abduction (ab-DUK-shun) • adduction (ad-DUK-shun) • circumduction (sir-cum-DUC-shun)

(a) Shoulder joint

(b) Hip joint (c) Right wrist joint

4 5

Lateral Medial

(d) Shoulder joint

(e) Hip joint

7 (f) Metacarpophalangeal joints of the fingers

(not the thumb)

109

E X E R C I S E 1 1 J O I N T S A N D S Y N O V I A L J O I N T M O V E M E N T S 167

FIGURE 11.6 Joint movements of rotation.

FIGURE 11.8 Special joint movements of the foot.

(a) Atlanto-axial joint

(b) Shoulder joint

• lateral rotation • medial rotation • rotation

1 __________________________________________

2 __________________________________________

3 __________________________________________

FIGURE 11.7 Special joint movements.

Temporomandibular joint

(a) (b) Temporomandibular joint(c) (d)

3 4

(e) Radioulnar joint

5 6

Palm posterior

Palm anterior

• depression • elevation • pronation (pro-NAY-shun) • protraction (pro-TRAC-shun) • retraction (re-TRAC-shun) • supination (soup-in-NAY-shun)

1 __________________________________

2 __________________________________

3 __________________________________

4 __________________________________

5 __________________________________

6 __________________________________

Intertarsal joint(a)

• dorsiflexion • eversion • inversion • plantar flexion

1 __________________________________

2 __________________________________

3 __________________________________

4 __________________________________

168 E X E R C I S E 1 1 J O I N T S A N D S Y N O V I A L J O I N T M O V E M E N T S

• Pivot joint—feel the proximal part of your forearm until you locate the head of the radius. Rotate the radioulnar joint as you palpate this rotation movement.

• Condyloid joint—feel the joint between the 2nd metacarpal and the 2nd proximal phalanx. Extend and flex, abduct and adduct, and circumduct this joint.

• Saddle joint—the thumb joint is the only saddle joint in the body. Feel the movement of trapezium bone (carpal bone) with the 1st metacarpal as you move this joint on two different axes.

• Ball-and-socket joint—feel your shoulder joint as you move your arm in different motions. Make a full circle with your shoulder joint.

2 Identify the joints listed above on an articulated skele- ton and note the shape of the articulating surfaces. Refer to Table 11.2.

3 Identify the bones involved in these joints with your lab group. ■

E. Six Types of Synovial Joints

There are 6 types of synovial joints based on the structure of the articulating bone surfaces at the joints (Table 11.2). The joint structure determines the movement of the joint.

TABLE 11 .2 Types of Synovial Joints

NAME OF JO INT ART ICULAR SURFACE DESCR IPT ION MOVEMENT

Planar (gliding) Flat or slightly curved plane Gliding motion back and forth and/or side to side Hinge Convex bone surface articulates with a Flexion and extension concave bone surface Pivot Rounded or pointed projection articulates Rotation with ring formed by bone and ligament Condyloid Oval convex projection articulates Flexion and extension, abduction and adduction, with oval concave depression circumduction Saddle Saddle-shaped depression articulates with Same as condyloid joint, except more exaggerated projection that fits into the saddle Ball-and-socket Ball-shaped head articulates with cup-shaped Freely movable joint; flexion and extension; socket abduction and adduction; circumduction; rotation

LAB ACTIVITY 5 Palpation of Synovial Joint Movements

1 Palpate the following synovial joints on your body and use an articulated skeleton to observe the structure of the joint. • Planar joint (gliding)—flex your arm up and feel

the gliding movement at the acromioclavicular joint. • Hinge joint—flex and extend your elbow and your

knee as you feel this joint type. Note how this joint type only moves by flexion and extension.

169

A. Structural and Functional Classification of Joints

Fill in the blank with the most appropriate term: cartilaginous, fibrous, synovial, amphiarthrosis, diarthrosis, or synarthrosis.

______________________ 1. Functional category that has the greatest amount of movement.

______________________ 2. Functional category that has the least amount of movement.

______________________ 3. Functional category that is slightly movable.

______________________ 4. Structural category that has an articular ( joint) capsule.

______________________ 5. Structural category that has cartilage joining the ends of the articulating bones.

______________________ 6. Structural category with a joint cavity.

______________________ 7. Structural category that is tightly held together by fibrous connective tissue.

B. Basic Structure of Synovial Joints

Fill in the blank with the correct answer.

______________________ 1. Name the type of cartilage that covers the articular ends of bones.

______________________ 2. Name the fluid that lubricates, reduces friction, and gives nutrition to a joint.

______________________ 3. Name the tissue at the end of a bone that reduces friction in a joint.

______________________ 4. Identify the sac-like structure in a synovial joint that is sometimes present to reduce friction.

______________________ 5. Identify the structure that secretes synovial fluid.

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

11 E X E R C I S E

170 E X E R C I S E 1 1 J O I N T S A N D S Y N O V I A L J O I N T M O V E M E N T S

C. Types of Synovial Joints

There are six different types of synovial joints. Fill in the blank with the correct type.

______________________ 1. The type of synovial joint between the atlas and axis.

______________________ 2. The type of synovial joint between the humerus head and the glenoid cavity at the shoulder (between scapula and humerus).

______________________ 3. The type of synovial joint at the knee.

______________________ 4. The type of synovial joint between the scapula and clavicle.

______________________ 5. The type of synovial joint between the trapezium (carpal bone) and the 1st metacarpal.

______________________ 6. The type of synovial joint between the metacarpal and proximal phalanx.

D. Movement at Synovial Joints

Fill in the blank with the correct term for the type of movement of the synovial joint.

______________________ 1. Moves appendage toward the midline

______________________ 2. Increases the angle of a joint

______________________ 3. Downward movement, lowering the body part vertically

______________________ 4. Palm of hand faces forward or upward

______________________ 5. Pointing toes downward; raising the heel, on your tiptoes

______________________ 6. Decreases the angle of a joint

______________________ 7. Moves an appendage away from the midline

______________________ 8. Turns on a pivot with a circular motion

______________________ 9. Movement that raises mandible

______________________ 10. Move body part forward along horizontal plane

______________________ 11. Turn sole of foot inward

171

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

11 E X E R C I S E

A. Synovial Joints

Identify the synovial joint structures of the synovial joint in Figure 11.9(a), (b), and (c).

FIGURE 11.9 Synovial joints.

Frontal plane Acromion

of scapula

(space) 2

Scapula

Supraspinatus muscle

Subscapularis muscle

LATERAL MEDIAL

SUPERIOR

INFERIOR

Sagittal plane

Subcutaneous bursa

Articular (joint) capsule

Ulna

Head of radius

Trochlea of humerus

Articular capsule

INFERIOR

SUPERIOR

POSTERIOR ANTERIOR

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

(a) Right shoulder joint, frontal section

(b) Right elbow joint, frontal section

172 E X E R C I S E 1 1 J O I N T S A N D S Y N O V I A L J O I N T M O V E M E N T S

B. Synovial Joint Movements

Identify the joint movements involved in walking that are described in the sentences below. Use the following terms dorsiflex, plantar flex, flex, and extend to describe the movement of the right leg. First you flex the thigh, (11) the leg at the knee, and (12) the foot. Then you (13) the leg at the knee, (14) the thigh, and (15) the foot.

11. __________________________________

12. __________________________________

13. __________________________________

14. __________________________________

15. __________________________________

Frontal plane

(space) 7

Acetabular labrum

(bone marking) 8

(bone marking) 6

LATERAL MEDIAL

9 (bone)

10 (bone marking)

Ligament of the head of the femur

Articular capsule

Subcutaneous fat

6 __________________________________

7 __________________________________

8 __________________________________

9 _________________________________

10 _________________________________

FIGURE 11.9 Synovial joints, continued.

E X E R C I S E 1 2 S K E L E T A L M U S C L E S T R U C T U R E 173

Skeletal muscles are organs composed of skeletal muscle tissue and connective tissue. These organs also contain nerves and blood vessels. The skeletal muscle fibers within skeletal muscles contract (shorten) and cause movement of our skeleton or skin. The signal for contraction is carried by neurons that innervate each skeletal muscle fiber. We consciously control contrac- tion of skeletal muscles, so the contraction is called voluntary.

A. Skeletal Muscle Tissue and Connective Tissue Coverings

Skeletal muscle fi bers (cells) are striated and multinucle- ated. The striations are light and dark stripes along the muscle cell. A skeletal muscle fi ber is actually many em- bryonic cells that have fused together to form one large cell with multiple nuclei.

O B J E C T I V E S M A T E R I A L S

• compound microscope, lens paper, prepared microscope slides of skeletal muscle tissue and neuromuscular junction

• model of 3-D skeletal muscle fiber(s)

Skeletal Muscle Structure 12

E X E R C I S E

1 Describe the structure of skeletal tissue and skeletal muscle fibers

2 Identify the connective tissue structures in skeletal muscle

3 Describe the structure of the sarcomere

4 Describe the structure of the neuromuscular junction

173

Individual skeletal muscle fi bers are surrounded by a layer of areolar connective tissue called endomysium (endo- � within; mys � muscle). Skeletal muscle fi bers are grouped into bundles called fascicles that are sur- rounded by a layer of dense regular connective tissue called perimysium (peri- � around). A muscle is formed from a number of fascicles that are surrounded by a dense regular connective tissue layer called epimysium (epi- � on; upon). Tendons, connective tissues that attach the muscle to bone, are formed from endomysium, perimy- sium, and epimysium that extend beyond each skeletal muscle fi ber. The connective tissues surrounding skeletal muscle fi bers separate and electrically insulate these cells. There- fore, electrical impulses that initiate contraction in one skeletal muscle fi ber are not spread to another fi ber. Recall that two or more tissues working together form an organ. Because skeletal muscle tissue and connective tissues form a skeletal muscle, each skeletal muscle can be considered an organ.

174 E X E R C I S E 1 2 S K E L E T A L M U S C L E S T R U C T U R E

Before Going to Lab

1 Label Figures 12.1(a) and (b) and 12.2(a) and (b). 2 Observe the structures within a muscle fiber in

Figure 12.2(c).

LAB ACTIVITY 1 Skeletal Muscle Tissue and Connective Tissue Coverings

1 Examine a prepared microscope slide of skeletal muscle.

• Using the low-power objective, locate a cross-section through the muscle showing a fascicle. Identify the perimysium surrounding the fascicle and an endomysium surrounding a skeletal muscle fiber.

• Locate a section of skeletal muscle fiber in longitudinal section.

• Using the high-power objective, identify nuclei and striations. ■

Bone

Fascicle

Transverse sections

Periosteum

Tendon

Striations

Sarcoplasm 10

Nucleus

Somatic motor neuron Blood capillary 8

(a) Skeletal Muscle Components

(b) Fascicle Components

Skeletal muscle

FIGURE 12.1 Skeletal muscle.

(a) Skeletal muscle components • endomysium (endo-MY-zee-um) • epimysium (epi-MY-zee-um) • fascicle (FAS-i-kul) • muscle fiber • myofibril • perimysium (peri-MY-zee-um)

1 __________________________________________

2 __________________________________________

3 __________________________________________

4 __________________________________________

5 __________________________________________

6 __________________________________________

(b) Fascicle components • endomysium • filament • muscle fiber • myofibril • perimysium • sarcolemma

7 __________________________________________

8 __________________________________________

9 __________________________________________

10 __________________________________________

11 __________________________________________

12 __________________________________________

E X E R C I S E 1 2 S K E L E T A L M U S C L E S T R U C T U R E 175

21 43

(a) Cross-section of a fascicle 400�, H&E, human 400�, H&E, human

(b) Longitudinal section of muscle fibers

5 6 7

FIGURE 12.2 Sectional views of a fascicle and skeletal muscle fibers.

• endomysium • fascicle • perimysium • skeletal muscle fiber in cross-section

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

• nucleus • striation (stry-AY-tion) • width of skeletal muscle fiber

5 _____________________________________________________

6 _____________________________________________________

7 _____________________________________________________

Mitochondria

Myofibrils

Nucleus

Endomysium

TEM

176 E X E R C I S E 1 2 S K E L E T A L M U S C L E S T R U C T U R E

and contractile unit of a muscle myofi bril. Sarcomeres are composed of an orderly arrangement of thin and thick fi la- ments and shorten when the muscle fi ber is stimulated to contract. Thin fi laments contain actin, tropomyosin, and tropo- nin molecules. Actin molecules make up the majority of the thin fi lament and contain a binding site for the myosin molecules of the thick fi lament. A strand of tropomyosin molecules is nestled between the actin molecules. Several troponin molecules bind at precise intervals along the tropomyosin strand. Thick fi laments are composed of myosin molecules. A myosin molecule resembles two golf clubs twisted to- gether. The tails of many myosin molecules form the thick fi lament, whereas the heads project toward the thin fi la- ments. When the myosin-binding sites on the actin mol- ecules are uncovered, myosin heads attach and pull the thin fi laments past the thick fi laments. When myosin heads attach to actin, they are called crossbridges.

B. Skeletal Muscle Fibers

Skeletal muscle tissue contains elongated cells called muscle fi bers. Muscle fi bers have specialized features im- portant to their function. The plasma membrane, called the sarcolemma (sarco � fl esh; lemma � sheath) in muscle fi bers, can conduct an electrical signal called an action potential. The sarcoplasmic reticulum is endoplasmic re- ticulum that is specialized to store calcium ions. Muscle cells contain thick and thin fi laments or myofi laments (myo � muscle) that contain different contractile proteins. Movement of the myofi laments causes muscle shortening or contraction. The sarcolemma has tube-like invaginations called T tubules (transversetubules) that transmit the action potential deep inside the fi ber to widened areas of the sarcoplasmic reticulum called terminal cisternae. The arrangement of two terminal cisternae with a T tubule between them is called a triad. An action potential travel- ing down the T tubules causes calcium to be released from the terminal cisternae into the cytoplasm of the muscle fi ber. Thick and thin fi laments, which are bundled into my- ofi brils, occupy 80% of the volume of the fi ber. Each my- ofi bril is a chain of sarcomeres, the smallest structural

Before Going to Lab

1 Label the skeletal muscle fiber in Figure 12.3.

FIGURE 12.3 Skeletal muscle fiber.

(a) Skeletal muscle fiber • myofibril (myo-FY-bril) • sarcolemma (sar-co-LEM-ma) • sarcoplasmic reticulum

(sar-co-PLAZ-mic re-TIC-u-lum) • terminal cisternae (cis-TER-nee)

of sarcoplasmic reticulum • triad • T tubule

1 _________________________________

2 _________________________________

3 _________________________________

4 _________________________________

5 _________________________________

6 _________________________________

(b) Thick and thin filaments • sarcomere • thick filament • thin filament

10 _________________________________

11 _________________________________

12 _________________________________

13 _________________________________

14 _________________________________

7 _________________________________

8 _________________________________

9 _________________________________

E X E R C I S E 1 2 S K E L E T A L M U S C L E S T R U C T U R E 177

FIGURE 12.3 Skeletal muscle fiber, continued.

MitochondrionM

(a) Muscle fiber

MiM

5 4

Z disc 8 9 M line

10 11 12 1413

(b) Thick and thin filaments

178 E X E R C I S E 1 2 S K E L E T A L M U S C L E S T R U C T U R E

C. The Sarcomere

The regular arrangement of thin and thick fi laments in the sarcomeres gives the myofi brils and the skeletal muscle fi bers light and dark bands (Figure 12.4). Lighter color bands with a dark stripe down the middle are the I bands. The I bands contain only thin fi laments, and the stripes are Z discs which secure the thin fi laments. A bands are dark- colored bands that extend the length of the thick fi laments. In the A band of relaxed muscle, thin fi laments overlap the thick fi laments except in the middle of the A band, the H zone, which appears lighter. The M line is found in the middle of the H zone and secures the thick fi laments. Muscle fi bers shorten because myosin heads on the thick fi laments attach to the thin fi laments and pull the thin fi laments past the thick fi laments toward the M line. This action increases the overlap of thin and thick fi laments (Figure 12.4). As these fi laments slide past each other in each sarcomere within each myofi bril, the ends of the mus- cle fi ber are brought closer together, the I bands decrease in length, and the H zone (lighter area) disappears. The in- crease in overlap of thin and thick fi laments can be readily observed in sarcomeres of skeletal muscle.

FIGURE 12.4 Sarcomere structure.

I band

M line M lineZ disc Z disc Z disc

Sarcomere Sarcomere

H zone

A band A band

I bandI band H zone

Before Going to Lab

1 Label the electron micrograph of the sarcomere in Figure 12.5.

• A band • H zone • I band • M line • Z disc

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

5 _____________________________________________________

FIGURE 12.5 Transmission electron micrograph illustrating sarcomere structure.

Sarcomere

1 2

4 4

21,600�TEM

E X E R C I S E 1 2 S K E L E T A L M U S C L E S T R U C T U R E 179

3 Does the I band length change when a muscle contracts? Explain.

4 Does the H zone length change when a muscle contracts? Explain.

5 Is the sarcomere in Figure 12.5 fully contracted? Explain.

■

DISCUSSION QUESTIONS Sarcomere Structure

1 Do the lengths of the thin or thick filaments change when a muscle contracts? Explain.

2 Does the A band length change when a muscle contracts? Explain.

LAB ACTIVITY 2 The Sarcomere

1 Using Figure 12.6, answer Discussion Questions with your lab group.

2 Sarcomeres

H zone I band A band

Z disc Thin filament Thick filament

Z disc M line Z disc

(a) Relaxed muscle

(b) Partially contracted muscle

21,600�TEM

FIGURE 12.6 Sliding filament mechanism of muscle contraction.

180 E X E R C I S E 1 2 S K E L E T A L M U S C L E S T R U C T U R E

D. The Neuromuscular Junction

Each skeletal muscle fi ber is stimulated to contract by a motor neuron. A motor neuron and all the skeletal muscle fi bers it innervates are a motor unit. Within the muscle, the axon of a motor neuron divides into many branches or axon terminals, each of which forms a neuromuscular junction with a skeletal muscle fi ber. At the neuromuscu- lar junction, each axon terminal divides into synaptic end bulbs. Within the synaptic end bulbs are synaptic vesicles fi lled with acetylcholine (neurotransmitter molecules). When a nerve impulse reaches the synaptic end bulb, acetylcholine is released and diffuses across the synaptic cleft (the space between the synaptic end bulb and the sarcolemma). Acetylcholine molecules bind to receptors in the motor end plate, the region of the sarcolemma directly across from the synaptic end bulb. If enough acetylcholine binds, an action potential is generated, stimulating the skeletal muscle fi ber to contract.

Before Going to Lab

1 Label the neuromuscular junction in Figure 12.7. 2 Label the photomicrograph in Figure 12.8.

LAB ACTIVITY 3 Neuromuscular Junction

1 Examine a prepared microscope slide of the neuro- muscular junction and identify the structures listed in Figure 12.8. ■

4 (Space)

Muscle

Muscle fibers

Motor neuron axon

Motor unit 1

Motor unit 2

Nerve

Motor neuron cell body

Spinal cord

365�

2 31

FIGURE 12.7 Structure of the neuromuscular junction.

FIGURE 12.8 Section of skeletal muscle showing axon terminals and synaptic bulbs.

• axon terminal • motor end plate • receptors • synaptic cleft • synaptic end bulb • synaptic vesicle with

acetylcholine

• skeletal muscle fibers • axon terminal with

synaptic end bulbs • motor neuron axon

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

1 ________________________

2 ________________________

3 ________________________

181

A. Skeletal Muscle Structure

Number the following nestled, cylindrical structures in order from largest (1) to smallest (5).

____ myofibril ____ muscle fiber

____ fascicle ____ muscle

____ filaments

B. Skeletal Muscle Structural Terms

Identify the structure that matches the description.

______________________ 1. Connective tissue covering surrounding a fascicle

______________________ 2. Finger-like invaginations of plasma membrane; extend into interior of fiber and surround myofibrils

______________________ 3. Plasma membrane of skeletal muscle fiber

______________________ 4. Connective tissue covering surrounding the muscle

______________________ 5. Smallest contractile unit within individual muscle fibers

______________________ 6. Stores calcium within muscle fiber

______________________ 7. Connective tissue covering surrounding individual muscle fibers

______________________ 8. Two terminal cisternae and a T tubule

______________________ 9. Rod-like structures within skeletal muscle fiber that contain thin and thick filaments organized into sarcomeres

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

12 E X E R C I S E

182 E X E R C I S E 1 2 S K E L E T A L M U S C L E S T R U C T U R E

C. Sarcomere Structure and the Sliding Filament Mechanism of Contraction

Write the name of the sarcomere structure defined. A structure may be used more than once, and a definition may apply to more than one structure.

______________________ 1. Length does not change when sarcomere shortens.

______________________ 2. This area is the length of thick filaments.

______________________ 3. Center point of attachment for thick filaments.

______________________ 4. Length decreases when sarcomere shortens.

______________________ 5. This area contains only thin filaments.

______________________ 6. Point of attachment for thin filaments.

______________________ 7. This area contains only thick filaments.

______________________ 8. This area contains overlapping thin and thick filaments.

______________________ 9. The area from Z disc to Z disc.

______________________ 10. This area disappears in a fully contracted muscle.

D. The Neuromuscular Junction

Write the name of the structure(s) described.

______________________ 1. Found in synaptic end bulbs of axon terminal; contains neurotransmitter molecules

______________________ 2. Area of sarcolemma across from synaptic end bulbs of axon terminal; contains neurotransmitter receptors

______________________ 3. Space between synaptic end bulbs of axon terminal and sarcolemma

______________________ 4. Divides into synaptic end bulbs at neuromuscular junction

______________________ 5. Parts of axon terminal that form neuromuscular junction

183

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

12 E X E R C I S E

1. With age, the collagen-containing connective tissue coverings of skeletal muscles increase and the number of muscle fibers decreases. Is meat from an older or a younger animal more tender? Explain.

2. Weight training increases muscle fiber size by increasing the number of myofibrils. Explain.

3. The diaphragm is a muscle that controls inspiration. Is control of the diaphragm voluntary, involuntary, or both? Explain.

Using your textbook or another reference, for each condition below indicate which part of the neuromuscular junction is affected: the motor end plate or the axon terminal.

______________________ 4. Myasthenia gravis

______________________ 5. Curare poisoning

______________________ 6. Botulinum toxin poisoning

Put a check mark next to the muscles that are skeletal muscles. Hint: Consider location and whether muscle contraction is voluntary or involuntary.

______________________ 7. Arrector pili

______________________ 8. Tongue

______________________ 9. Muscle in gallbladder

______________________ 10. Muscles that control movement of the eyeball

184 E X E R C I S E 1 2 S K E L E T A L M U S C L E S T R U C T U R E

11–13. In Figure 12.9, rank the TEMs from 1 (least) to 3 (greatest) according to number of cross-bridges formed.

FIGURE 12.9 Skeletal muscle contraction.

11.

12.

13.

21,600�TEM

E X E R C I S E 1 3 C O N T R A C T I O N O F S K E L E T A L M U S C L E 185

O B J E C T I V E S M A T E R I A L S

• Role of ATP in Contraction of Skeletal Muscle Fibers: ATP-glycerinated muscle kit from biological supply house and the following items per group: 1 Petri dish, 3 test tubes, marker, 2 teasing needles or straight pins, watchmaker forceps, sharp scissors, 3 microscope slides, 1 millimeter ruler, and 3 plastic transfer pipettes. Dissecting microscope, compound microscope, and coverslips are optional.

• Control of Muscle Tension: rulers and ankle weights (students may bring them from home).

• PowerPhys Experiments: • Twitch Contractions and Summation • Recruitment and Isometric and Isotonic

Contractions

• • Biopac Laboratory Guide Experiments: • Recruitment and Fatigue • Isometric and Isotonic Contractions

• Record Frog Gastrocnemius Muscle Contractions: frogs, needle probes, dissecting equipment, Ringer’s solution in squeeze bottle, femur clamp, recorder, stimulator, force transducer.

Contraction of Skeletal Muscle 13

E X E R C I S E

1 Describe the role of ATP in skeletal muscle contraction

2 Describe the three muscle fiber types and their influence on contraction

3 Identify and describe the three phases of a twitch contraction

4 Describe how skeletal muscles achieve a smooth, sustained contraction

5 Describe how skeletal muscles vary the force of contraction

6 Describe and compare isotonic and isometric contractions

7 Define threshold stimulus, maximal stimulus, motor unit recruitment, wave summation, unfused tetanus, fused tetanus, and fatigue, and explain how to observe them

185

Muscle cells have the ability to convert the chemical energy of ATP into mechanical energy of contraction. All muscles (skeletal, cardiac, and smooth), in turn, exert force and produce movement. The following activities focus on skeletal muscles at the molecular and cellular level of contraction.

A. Contraction of Skeletal Muscle Fibers

Three main events occur in contraction of a skeletal muscle fi ber—electrical excitation of a muscle fi ber, excitation- contraction coupling, and muscle fi ber contraction due to the sliding fi lament mechanism.

186 E X E R C I S E 1 3 C O N T R A C T I O N O F S K E L E T A L M U S C L E

• Electrical excitation of a muscle fiber. Skeletal muscle fibers (cells) can be stimulated either by a motor neuron in the body or by a voltage stimula- tor in the lab. Stimulation given by either method results in a depolarization of the sarcolemma. If the depolarization reaches threshold, an action potential (electrical signal) is initiated.

• Excitation-contraction coupling. The action poten- tial is transmitted along the sarcolemma and down the T tubules (transverse tubules). This action causes calcium ions to be released from the terminal cis- ternae of the sarcoplasmic reticulum. Calcium ions couple electrical excitation to muscle fiber contrac- tion by binding to troponin, which is attached to the actin filament and tropomyosin. Troponin changes shape and pulls tropomyosin away from the myosin- binding sites on the actin filament.

• Muscle fiber contraction. A muscle fiber contracts (shortens) when thin filaments (actin) slide past the thick filaments (myosin). Each contraction cycle shortens each muscle fiber about 1% of its resting length. The 4 steps of the contraction cycle are:

1. ATP hydrolysis. Myosin heads contain an ATP binding site and an ATPase. When ATP binds to the ATP-binding site, the ATPase hydrolyzes ATP to form ADP and inorganic phosphate. Hydrolysis of ATP energizes the myosin head.

2. Attachment of myosin to actin to form crossbridges. Energized myosin heads bind to the unblocked myosin-binding site on actin and the inorganic phosphate is released from the myosin head.

3. Power stroke. The release of the inorganic phos- phate starts the power stroke, which is the rotation of the myosin head that pulls the thin filament toward the center of the sarcomere. During the power stroke, ADP is released from the myosin head, but the myosin head remains attached.

4. Detachment of myosin from actin. Another ATP molecule binds to the myosin ATP-binding pocket, releasing the myosin head from actin, and the contraction cycle begins again.

The contraction cycle continues as long as intracellular calcium levels remain high. As the intracellular calcium levels drop, tropomyosin blocking of the myosin-binding sites on actin returns, energized myosin is prevented from binding, and the muscle fi ber relaxes. The amount of shortening that occurs when a muscle is stimulated to contract depends on how long the contraction cycle continues. With each contraction cycle, sarcomeres shorten a little more until maximal contraction of a sarco- mere is reached. Muscle fi bers can shorten up to 40% of their resting length. Exposure of skeletal muscle fi bers to glycerin creates holes in the sarcolemma allowing ions and ATP to diffuse

LAB ACTIVITY 1 Experiment: Role of ATP in Contraction of Skeletal Muscle Fibers

1 Prediction: With your lab group, predict which solu- tion will cause muscle fiber shortening by selecting one of the choices below. • 0.25% ATP in distilled water • 0.25% ATP, 0.05 M KCl, and 0.001 M MgCl2 in

distilled water • 0.05 M KCl and 0.001 M MgCl2 in distilled water,

no ATP

2 Materials: Obtain materials for Role of ATP in Con- traction of Skeletal Muscle Fibers.

3 Data Collection: Measure muscle length of glycerin- ated skeletal muscle fibers before and after exposure to the different solutions. • Decide who will mix the solutions; prepare the

muscle strands; apply the solutions to the muscle strands; and time, measure, and record.

• Label test tubes and microscope slides 1, 2, and 3. • Place the following in the appropriate test tube:

Test tube 1 (0.25% ATP in distilled water)— 5 drops from dropper bottle labeled 0.25% ATP in distilled water

Test tube 2 (0.25% ATP in salt solution)— 5 drops from dropper bottle labeled 0.25% ATP, 0.05 M KCl, and 0.001 M MgCl2 in distilled water

Test tube 3 (salt solution, no ATP)—5 drops from dropper bottle labeled 0.05 M KCl and 0.001 M MgCl2 in distilled water

• Obtain a Petri dish containing a 2-cm-long piece of glycerinated skeletal muscle in a small amount of glycerin from your instructor.

• Using teasing needles or straight pins, separate the skeletal muscle (in the Petri dish) into at least 9 strands not more than 0.2 mm in diameter (2–4 muscle fibers per strand).

• Using forceps, place 3 (of the 9) thin strands of muscle fibers on a microscope slide. Arrange the strands so they are straight and parallel. Do not cover the strands with a cover slip. Note: The amount of glycerol that is transferred with the strands should be enough to keep them moist. Add a small drop of

into and out of the muscle fi ber. Glycerination also dis- rupts the troponin-tropomyosin complex so that calcium is not needed to bind to troponin and pull tropomyosin to unblock the myosin-binding sites on the actin molecules. Although calcium is not needed for contraction of glycer- inated muscle fi bers, other ions are needed to ensure the proper functioning of enzymes. In this activity, you will observe contraction in glycerinated skeletal muscle fi bers.

E X E R C I S E 1 3 C O N T R A C T I O N O F S K E L E T A L M U S C L E 187

• Switch to the high-dry objective lens. Identify the light-colored I bands and the dark-colored A bands.

• Compare the distance between the bands. • Repeat for each slide.

5 Clean up as directed by your instructor. 6 Data Analysis:

• Calculate the percentage of contraction by divid- ing the length after exposure to the solution by the resting length.

• Average the values for each solution and record in Table 13.1.

7 Complete the Experimental Report with your lab group.

glycerol only if the strands are exposed to heat from the microscope lamp for a sustained period.

• Measure the length of each muscle strand with a millimeter ruler and record the value in Table 13.1. Measurements can be made using a dissecting microscope, if desired.

• Using a clean transfer pipette, transfer all the solution from test tube 1 to the microscope slide and measure the length of the strands after 40 seconds. Record the results in Table 13.1.

• Repeat the above steps for the solutions in test tubes 2 and 3 using 3 new muscle strands, transfer pipettes, and microscope slides for each solution. Record the results in Table 13.1.

• Optional—Save all 3 slides to observe striations. See instructions below.

4 Observation of Striations in Skeletal Muscle Fibers (optional): • Place a coverslip over each microscope slide. • Using a compound microscope, observe one micro-

scopic slide with the low-power objective lens and note the striations on each strand.

TABLE 13 .1 Role of ATP in Contraction of Skeletal Muscle Fibers

TEST TUBE 2 TEST TUBE 3 TEST TUBE 1 0 .25% ATP 0 ATP 0 .25% ATP 0 .05 M KC l 0 .05 M KC l D IST I LLED WATER 0 .001 M MgCl 2 0 .001 M MgCl 2

Muscle Strand 1

Length before solution

Length after solution

% Contraction

Muscle Strand 2

Length before solution

Length after solution

% Contraction

Muscle Strand 3

Length before solution

Length after solution

% Contraction

Average % contraction

188 E X E R C I S E 1 3 C O N T R A C T I O N O F S K E L E T A L M U S C L E

B. Influence of Muscle Fiber Type on Skeletal Muscle Contraction

There are 3 types of skeletal muscle fi bers: slow oxida- tive (SO), fast oxidative-glycolytic (FOG), and fast gly- colytic (FG). These muscle fi ber types differ in diameter, myosin ATPase, and methods of ATP production.

1. Muscle Diameter and Force of Contraction

Fast glycolytic fi bers have the largest diameter of the mus- cle fi ber types and develop more force than slow oxidative fi bers that have the smallest diameter of the three muscle types. Muscle fi bers with a larger diameter develop more force because they have more myofi brils, and therefore, more myosin heads that can attach to actin. The amount of force a muscle fi ber develops is dependent on the number of myosin heads attached to actin.

2. Myosin ATPase and Speed of Contraction

Fast glycolytic fi bers and fast oxidative-glycolytic fi bers have a myosin ATPase that breaks down ATP faster than the myosin ATPase in slow oxidative fi bers. The speed at which the contraction cycle can occur is determined by how fast myosin ATPase can break down ATP. The faster the myosin ATPase, the greater the speed at which the contraction cycle can occur, and the faster the muscle can contract.

3. Methods of ATP Generation and Fatigability

Fibers with fast myosin ATPase need ATP to be produced quickly to achieve a fast contraction cycle. Fast glycolytic fi bers produce the majority of ATP by glycolysis, while slow oxidative fi bers use aerobic cellular respiration to produce ATP. Fast oxidative-glycolytic fi bers use both ATP production methods. Glycolysis produces ATP quickly but cannot produce large amounts of ATP over time. Therefore, muscle fi bers that primarily use glycolysis fatigue quickly. Glycolysis re- quires large glycogen (glucose source) stores, and muscle fi bers that primarily use glycolysis to make ATP are paler due to lower myoglobin content and less blood supply. Aerobic cellular respiration produces ATP slowly but can produce large amounts of ATP over time if there is a suffi cient blood supply and myoglobin (red pigment that stores oxygen) stores. Therefore, muscle fi bers that use aerobic respiration take longer to fatigue. These muscle

EXPERIMENTAL REPORT Role of ATP in Contraction of Skeletal Muscle Fibers

Results: • Name the solution(s) that caused muscle strand

contraction.

• State the average percentage contraction for each solution.

Discussion: • Estimate the number of contraction cycles that occurred

in the contracted muscle fi bers.

• Discuss whether the sarcomere length increased, decreased, or stayed the same in muscle fi bers from each solution.

• Explain what limits the amount of shortening that is observed in the skeletal muscle fi bers.

• Discuss why calcium was not needed to cause muscle contraction in glycerinated muscle fi bers.

• Discuss the role of KCl and MgCl2 in the experiment.

Conclusion: • State how adding ATP to the glycerinated muscle fi bers

affected muscle fi ber and sarcomere length.

■

E X E R C I S E 1 3 C O N T R A C T I O N O F S K E L E T A L M U S C L E 189

DISCUSSION QUESTIONS Influence of Muscle Fiber Type on Skeletal Muscle Contraction

1 Discuss why fast glycolytic fibers develop more force than slow oxidative fibers.

2 Discuss why fast glycolytic fibers have a greater contraction velocity than slow oxidative fibers.

3 Discuss why slow oxidative fibers are more fatigue- resistant than fast glycolytic fibers.

4 Discuss why slow oxidative fibers have more capillaries and mitochondria than fast glycolytic fibers.

5 Discuss why fast glycolytic fibers have more glycogen stores than slow oxidative fibers.

6 Weight training causes fast glycolytic fibers to hypertro- phy (increase in diameter). Explain why this increases strength.

7 Identify which muscle fiber types would be recruited for each of the following functions. Explain your answer. a. walking

b. standing

c. lifting a heavy object and immediately putting it down

■

fi bers have lower glycogen stores, are darker due to higher myoglobin content, and have a greater blood supply. These fi bers also have greater numbers of mitochondria because the enzymes for aerobic cellular respiration are located in the mitochondria.

4. Recruitment of Muscle Fiber Types

Skeletal muscles contain all 3 fi ber types. The proportion of muscle fi ber types in a muscle type differs depending on muscle action. Slow oxidative fi bers are stimulated fi rst. If more force is needed, then the fast oxidative-glycolytic fi bers are stimulated and fi nally the fast glycolytic fi bers.

Before Going to Lab

1 Label the muscle fiber types in Figure 13.1. This slide has been stained so that the different muscle fiber types can be easily identified.

LAB ACTIVITY 2 Influence of Muscle Fiber Type on Skeletal Muscle Contraction

1 Observe a cross-section of skeletal muscle. Are all the muscle fibers the same diameter?

2 Answer the Discussion Questions with your lab group.

LM 440�

FIGURE 13.1 Cross-section of skeletal muscle showing all three fiber types.

• fast glycolytic fiber • fast oxidative-glycolytic

fiber • slow oxidative fiber

1 ________________________

2 ________________________

3 ________________________

190 E X E R C I S E 1 3 C O N T R A C T I O N O F S K E L E T A L M U S C L E

Maximal force development occurs when all motor units of a muscle are stimulated and all muscle fi bers are contracting. In the lab, the stimulus that produces maximal force is called the maximal stimulus. Therefore, a stimu- lus to the muscle greater than maximal does not produce a greater force.

C. Control of Muscle Tension

Muscle contraction results in development of tension or force, usually measured in grams. The muscle tension developed by a contracting muscle is determined by the frequency of stimulation of motor units and the number of motor units stimulated.

1. Frequency of Stimulation and Muscle Tension

The minimal stimulus that results in a muscle twitch is called the threshold stimulus. A threshold stimulus ap- plied to a motor nerve or directly to the muscle results in a single contraction called a twitch contraction. The amount of force developed by this threshold stimulus is dependent on the number of motor units that are stimulated to contract. The 3 phases of a twitch contraction are the latent pe- riod, the contraction period, and the relaxation period. The latent period lasts about 2–10 msec (milliseconds) and is the time between stimulation of muscle cells and force gen- eration. The contraction period lasts about 10–100 msec and is the period during which force (measured in grams) is increasing, whereas the relaxation period, which lasts 10–100 msec, is the period when force is decreasing. Nor- mal muscle contractions are not twitch contractions but are sustained contractions of varying force. If the contracting motor unit(s) is (are) stimulated again before the relaxation phase of a muscle twitch is complete, then the next contraction will produce a greater force or tension. This is called wave summation. Increasing the frequency of muscle stimulation produces sustained force generation. Unfused tetanus (tetan � rigid) occurs when there is a partial relaxation between muscle twitches. Fused tetanus is a sustained contraction with no relaxation observed between twitches. Most sustained voluntary skel- etal muscle contractions are unfused tetanic contractions with different motor units stimulated at different times (asynchronous contractions). The asynchronous contrac- tions delay muscle fatigue, which is an inability to con- tract caused by long periods of muscle contraction.

2. Number of Motor Units Stimulated and Muscle Tension

Increasing the number of motor units contracting at the same time, motor unit recruitment, also increases force generated. Lifting a feather requires fewer motor units than lifting your anatomy and physiology textbook. Slow oxi- dative motor units are recruited fi rst, and if more force is needed, fast oxidative-glycolytic motor units are also re- cruited. If maximal force is required, fast glycolytic motor units are recruited.

LAB ACTIVITY 3 Control of Muscle Tension

1 Draw a twitch contraction that has a latent period of 2 msec, a contractile period of 10 msec with a maximum force of 2 g, and a relaxation period of 10 msec. Use the graph in Figure 13.2. Add an arrow for the stimulus.

2 Observe unfused tetanus, motor unit recruitment, and fatigue in the muscles that cause bending of the knee. • In your lab group, decide who will be the subject,

observer, and recorder. • Have the subject stand while holding onto the lab

bench for support. Have subject bend the left leg to a 90-degree angle and hold this position. The ham- string muscles on the posterior thigh are used to bend the leg.

• Observe the unfused tetanic contraction. Start timing. • Time how long it takes for the muscle to fatigue,

which is demonstrated by any vertical movement in the leg.

• Time until fatigue: ______ min. • Place a 5-lb weight on the subject’s right ankle and

repeat the steps. • Time until fatigue: ______ min.

3 Answer the Discussion Questions with your lab group. 4 Complete PowerPhys Experiment: Twitch Contrac-

tions and Summation.

5 Complete the Biopac Laboratory Guide Experiment: Recruitment and Fatigue.

F or

ce (

gr am

Time (msec)

5 10 15 20 25

FIGURE 13.2 Student drawing of twitch contraction.

E X E R C I S E 1 3 C O N T R A C T I O N O F S K E L E T A L M U S C L E 191

DISCUSSION QUESTIONS Control of Muscle Tension

1 Explain why you can maintain contraction of the ham- string muscles over time.

2 Explain why you can sustain the same contraction with a 5-lb weight attached to the ankle.

3 Explain why the hamstring muscles fatigue faster with the 5-lb ankle weight.

4 State the order of recruitment of muscle fiber types.

■

D. Isotonic and Isometric Contractions

Muscle contraction results in development of tension or force usually measured in grams. Muscles will shorten if they develop more force than the force that is opposing them. For example, contracting muscles in our arm will shorten and allow us to lift a book if the force developed by the muscles is greater than the weight (force) of the book. The weight of the book is also called load because it is a force against which the muscle is contracting. If a muscle is generating a constant force to move a load, that contraction is called an isotonic contraction. There are two types of isotonic contraction: concentric and eccentric isotonic contractions. In concentric isotonic contraction, the muscle is shortening while it is contract- ing. An example of this is using the biceps brachii (large anterior muscle of arm) to lift a book off the table. In eccen- tric isotonic contraction, the muscle is lengthening while it is contracting. This occurs when you slowly lower your arm to return the book to the table. The biceps brachii is still contracting, but it is lengthening while it is contracting. This enables you to lower the book in a controlled manner. Isometric contractions are contractions in which the muscle is developing force but not shortening and no vis- ible movement is seen. In this case, the force developed by the muscle equals the force (load) it is contracting against. An example of this would be holding a book in the same position. Isometric muscle contractions are maintaining the position against the weight (load) of the book, but the biceps

LAB ACTIVITY 4 Isotonic and Isometric Contractions

1 Recalling Lab Activity 3, in which the subject bent a knee and held it at 90 degrees, state which action was an iso- tonic contraction and which was an isometric contraction.

2 Is the isotonic contraction observed when the ham- strings contracted a concentric isotonic contraction or an eccentric isotonic contraction? What would you ask the subject to do to observe the other type of isotonic contraction?

3 Complete PowerPhys Experiment: Recruitment and Isometric and Isotonic Contractions

4 Complete the Biopac Laboratory Guide Experiment: Isometric and Isotonic Contractions. ■

E. Recording Force Generated by Skeletal Muscle

Polygraphs amplify and record physiological changes that are detected by various sensors. Examples of sensors in- clude those that detect changes in pH, force, temperature, and pressure. A myograph is a type of polygraph used to record the force generated by muscle contractions along with the following equipment: 1. A stimulator stimulates skeletal muscle fibers to

contract, and the stimulus strength is measured in volts. The frequency of stimulation is the number of stimuli per second. Increasing the frequency of stimulation increases the frequency of contractions.

2. A transducer, which is a sensor that converts the force generated by a contracting muscle into an electric signal (current), is attached to the muscle.

3. An amplifier increases the amplitude of the trans- ducer signal and transmits it to a recorder channel.

4. The recorder uses the electric signal from the trans- ducer to move a pen across a sheet of paper that is moving at preset speed. This allows students to ob- serve if the force changes over time. Computers can also act as recorders and display the pen deflections as lines moving across the computer screen. The visual displays can be saved and printed.

brachii muscle is not moving the book because it is not gen- erating a force greater than the weight (force) of the book.

192 E X E R C I S E 1 3 C O N T R A C T I O N O F S K E L E T A L M U S C L E

Recorders can have more than one channel, allowing several different measurements to be recorded at one time. For example, an electrode can be attached to the muscle and channel 1 of a recorder to record the electric signal or action potential of a stimulated muscle while a force transducer connected to channel 2 records the force of con- traction (myogram). Time and event markers of recorders are pens that mark the time when events occur, such as stimulation of a muscle. To calculate the force recorded from a contracting mus- cle, the transducer must be calibrated before it is attached to the muscle. Different gram weights are attached to the transducer to observe the electric signal or pen defl ection for each weight (or force). Pen defl ection is adjusted so that each gram of force will result in a pen defl ection of a known length. Figure 13.3 illustrates the use of equipment to record a myogram (recording of force generated by a frog gastroc- nemius muscle).

LAB ACTIVITY 5 Record Frog Gastrocnemius Muscle Contraction

1 Measure the force generated in grams and the length of the latent, contraction, and relaxation periods in milli- seconds on the myogram in Figure 13.4 and record your results on the figure.

2 With your group, discuss how you would measure threshold stimulus, maximal stimulus, and maximal force in the frog gastrocnemius preparation.

3 Record frog gastrocnemius muscle contractions. Follow the instructions supplied by your instructor to prepare and conduct the experiment.

FIGURE 13.3 Apparatus used to measure force generated in frog gastrocnemius muscle.

Calcaneal (Achilles) tendon

S-hook

Gastrocnemius muscle Femur clamp

Transducer

From stimulator

To amplifier

FIGURE 13.4 Myogram of frog gastrocnemius muscle contraction.

Latent period = msec

Contraction period msec

Force of contraction = g

Relaxation period msec

F or

ce (

gr am

Time (msec)

50 100 150 200 250

Stimulus

193

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

13 E X E R C I S E

A. Role of ATP in Contraction of Skeletal Muscle Fibers

Write T for true or F for false for the following statements.

____ 1. ATP causes the detachment of myosin from actin.

____ 2. Glycerinated skeletal muscle fibers need calcium in order to contract.

____ 3. Glycerinated skeletal muscle fibers need ATP in order to contract.

B. Influence of Muscle Fiber Type on Skeletal Muscle Contraction

Name the fiber type—slow oxidative (SO), fast oxidative-glycolytic (FOG), or fast glycolytic (FG)—that matches each fiber characteristic. Questions may have more than one answer.

______________________ 1. largest diameter

______________________ 2. is pink in color

______________________ 3. myoglobin content is low

______________________ 4. has the fastest contraction velocity

______________________ 5. has many capillaries

______________________ 6. is red in color

______________________ 7. generates ATP by aerobic respiration

______________________ 8. has the slowest myosin ATPase

______________________ 9. has glycogen stores

______________________ 10. smallest diameter

______________________ 11. recruited first

______________________ 12. recruited last

194 E X E R C I S E 1 3 C O N T R A C T I O N O F S K E L E T A L M U S C L E

C. Control of Muscle Tension

Name the term that matches each definition.

______________________ 1. Inability of muscle fibers to contract after a long period of contraction

______________________ 2. Time between muscle fiber stimulation and measurement of force generation

______________________ 3. Motor neuron and all the muscle fibers it innervates

______________________ 4. Period of force generation

______________________ 5. Type of wave summation with partial relaxation observed between twitches

______________________ 6. Increasing the number of motor units that are stimulated to contract

______________________ 7. Stimulus that results in maximal force generation

______________________ 8. Lowest stimulus that results in force generation

______________________ 9. Single contractile event in response to single action potential

______________________ 10. Period during which more crossbridges detach than reattach to thin filaments

______________________ 11. Type of wave summation with no observable relaxation between twitches

D. Isotonic and Isometric Contractions

Identify the following contractions of the biceps brachii muscle (large anterior muscle of forearm) as concentric isotonic, eccentric isotonic, or isometric.

______________________ 1. Lifting a glass off the table

______________________ 2. Holding a glass in the same position

______________________ 3. Lowering a glass to the table

E. Recording Force Generated by Skeletal Muscle Contractions

Name the equipment described.

______________________ 1. Increases the amplitude of the transducer signal and transmits it to a recorder channel

______________________ 2. Makes skeletal muscle fibers contract

______________________ 3. Machine that amplifies and records physiological changes detected by sensors

______________________ 4. Uses the electric signal from a transducer to make a tracing on moving paper

______________________ 5. Machine that records force generated by muscle contractions

______________________ 6. Sensor that converts force generated by a contracting muscle into an electric signal

195

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

13 E X E R C I S E

Answer the following questions with a short answer.

1. Explain why muscles are stiff (contracted) when rigor mortis occurs.

2. Large muscles, such as the muscles of the leg, have more muscle fibers than small muscles, such as the muscles of the finger. Explain why the muscles of the finger cannot develop as much force as the muscles of the leg.

3. Which type of muscle would fatigue faster, one that has many blood vessels or one that has fewer blood vessels? Explain.

Using your textbook or another reference, for each contraction below indicate whether it is an example of a muscle twitch, unfused tetanus, or fused tetanus.

______________________ 4. muscle spasm

______________________ 5. facial muscle tic

______________________ 6. cardiac fibrillation

______________________ 7. smiling

The percentage of each muscle fiber type in any given muscle of your body is genetically determined. Also, physical activity can cause slight changes in muscle fiber type. Discuss the relative amount of each muscle type in the thigh muscles of Olympic athletes participating in the following events:

8. marathon

9. weight lifting

10. 100-meter dash

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 197

There are approximately 700 skeletal muscles in the human body, and most of these originate and/or insert on an area of the skeleton. Because most muscles or their tendons cross a joint, muscle contractions cause skeletal movement at the joint.

A. Criteria for Naming Skeletal Muscle

Learning the criteria used to name skeletal muscles will assist you in identifying and learning the function of these muscles. Skeletal muscles are named for their orienta- tion relative to the midline of the body, size, shape, ac- tion, number of origins, location, or origin and insertion. The muscle attachment points, the origin and insertion, are usually skin or bone. The origin is the nonmoving point of attachment when a muscle contracts, and the insertion point moves toward the origin. The larger region of the muscle between the origin and the insertion is called the belly. For characteristics used to name skeletal muscles, refer to your textbook.

O B J E C T I V E S M A T E R I A L S

• muscle models, charts, cadaver photographs, or Real Anatomy (Muscular)

• colored pencils (for the review) • Cat Dissection: preserved cats, disposable gloves,

dissection equipment, safety glasses, and cat dissection manual

• Cadaver Dissection: Real Anatomy (Dissection)

Skeletal Muscles and Their Actions 14

E X E R C I S E

1 Identify major skeletal muscles on models or charts

2 Describe the action of major skeletal muscles

3 Identify antagonists to major agonists

197

B. Skeletal Muscle Identification and Action

When many skeletal muscles contract, they pull their point of insertion on a bone toward their point of origin. For the muscles of facial expression, this action moves the skin on the face and allows us to express emotion. In the appendages, muscles that perform similar functions are surrounded by fascia, forming compartments that are served by the same major blood vessels and nerves. Also, within a location some muscles are grouped according to whether they are superfi cial or deep. Sometimes muscles will work in groups when they are involved in multifaceted movements. Smaller muscles assist or enhance the action of larger muscles. Based on their function in a group, these muscles can be categorized as: an agonist (prime mover), an antagonist (working against the agonist), or a synergist (helps the agonist).

198 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

suprahyoid muscles are located superior to the hyoid bone and elevate the hyoid bone, fl oor of the oral cavity, and tongue while swallowing. The infrahyoid muscles are located inferior to the hyoid bone and depress the hyoid bone and larynx while swallowing and talking.

1. Muscles of the Head and Neck

Muscles of Facial Expression and Mastication Muscles located in the head include those involved in facial expression, mastication, blinking, and eye movements. Their origins are found in the superfi cial fascia beneath the skin and attached to skull bones, while their insertions are in the skin of the face. Muscles that insert on the exterior of the eyeball and move the eye will be studied in the exercise on Special Senses—The Eye.

Muscles That Move the Head and Neck Muscles that fl ex the head and neck are found in pairs on the anterior and lateral surface of the neck, while muscles that extend the head and neck are found on the posterior surface of the neck. However, the levator scapulae, a pos- terolateral neck muscle, elevates the scapula but does not move the neck. The sternocleidomastoid muscle, a muscle that runs diagonally from the sternum and the clavicle to the mas- toid process of the temporal bone, divides each side of the neck into an anterior and posterior triangle. The anterior triangle includes the carotid artery and the internal jugu- lar vein, while the posterior triangle includes the external jugular vein and part of the subclavian artery.

Muscles That Move the Hyoid Bone and Larynx Muscles that move the hyoid bone and larynx include the suprahyoid muscles and the infrahyoid muscles. The

Before Going to Lab

1 Label Figure 14.1(a), (b), and (c) and Figure 14.2(a), (b), and (c).

LAB ACTIVITY 1 Muscles of the Head and Neck

1 Use Figures 14.1 and 14.2 and Table 14.1 to identify the muscles on models, diagrams, cadaver photographs or use the search text box in Real Anatomy (Muscular) to find these structures.

2 Locate the superficial muscles on yourself and perform the action indicated in Table 14.1. Palpate each muscle while performing the action.

3 Use Appendix B to locate the origin and insertion on an articulated skeleton. Pull the insertion toward the origin to simulate muscle action. ■

TABLE 14 .1 Muscles of the Head and Neck

MUSCLE LOCAT ION AND ACT ION

MUSCLES OF FACIAL EXPRESSION Occipitofrontalis muscle Combination of frontalis and occipitalis muscles connected by an aponeurosis (a flat, broad tendon). Frontal belly Lies over frontal bone. Raises eyebrows and wrinkles forehead. Occipital belly Lies over occipital bone. Pulls scalp posteriorly. Orbicularis oculi (orbicularis � little Circular muscle that encircles the eye. circle; oculi � eye) Closes eye. Zygomaticus major (zygoma � bar) Between zygomatic bone and corner of mouth; inferior to zygomatic minor. Raises corners of mouth (smiling). Zygomaticus minor Between zygomatic bone and corner of mouth. Raises upper lips, exposing upper teeth. Orbicularis oris (oris � mouth) Circular muscle that encircles the mouth. Closes and purses lips. Platysma (platy � flat) Wide, flat muscle that covers lower mandible and entire anterior neck, and ends on chest. Tenses neck skin; depresses mandible (pouting).

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 199

FIGURE 14.1 Selected muscles of the head.

Frontalis

Orbicularis oculi

Zygomaticus major

Zygomaticus minor

Platysma

Orbicularis oris

Mentalis

Depressor anguli oris

Depressor labii inferioris

Risorius

Epicranial aponeurosis

Nasalis

Levator labii superioris

Trapezius

Sternocleidomastoid

Thyrohyoid

Depressor anguli oris

Epicranial aponeurosis

Levator labii superioris

Thyroid cartilage

(a) Anterior superficial view

• frontalis (fron-TA-lis) • orbicularis oculi (or-bi-

kyoo-LAR-is OC-yoo-lie) • orbicularis oris (OR-is) • platysma (pla-TIZ-ma) • zygomaticus (zy-go-

MAH-tu-kus) major • zygomaticus minor

1 _____________________________

2 _____________________________

3 _____________________________

4 _____________________________

5 _____________________________

6 _____________________________

200 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

TABLE 14 .1 Muscles of the Head and Neck (continued)

MUSCLE LOCAT ION AND ACT ION

MUSCLES OF MASTICATION Superficial Muscles Temporalis (tempora � temples) Lies over temporal bone. Elevates and retracts mandible. Masseter (maseter � chewer) Anterior to ear between zygomatic arch and posterior portion of mandible. Elevates and retracts mandible. Deep Muscles Buccinator (bucca � cheek) Deep to masseter. Fibers run transversely and form fleshy part of cheek. Presses cheeks inward to whistle, blow, and suck. Helps hold food between teeth while chewing. Lateral pterygoid (pterygoid � like Deep to masseter and superior to medial pterygoid. Transverse muscle fibers a wing) between pterygoid process of sphenoid and mandible. Protracts mandible, depresses mandible (opening mouth), and moves it sideways. Medial pterygoid Deep to masseter and inferior to lateral pterygoid. Vertical muscle fibers between pterygoid process of sphenoid and mandible. Elevates and protrudes mandible and moves it sideways.

Sternohyoid

Thyroid cartilage (Adam's apple)

Nasalis

8 Epicranial aponeurosis

Sternocleido- mastoid

Parotid gland

Trapezius

Orbicularis oris

Buccinator

Zygomaticus minor

Zygomaticus major

Orbicularis oculiOccipitalis

Masseter

Platysma

Frontalis

(b) Right lateral superficial view

FIGURE 14.1 Selected muscles of the head, continued.

• buccinator • frontalis • masseter

• occipitalis (ok-si-pi-TA-lis) • orbicularis oculi • orbicularis oris • zygomaticus major

7 ________________________

8 ________________________

9 ________________________

10 _______________________

11 _______________________

12 _______________________

13 _______________________

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 201

FIGURE 14.1 Selected muscles of the head, continued.

Medial pterygoid

Temporalis

Orbicularis oris

Buccinator

Lateral pterygoid

Mandible (cut)

• buccinator • lateral pterygoid (TER-ih-goid) • medial pterygoid • orbicularis oris • temporalis (tem-por-A-lis)

14 ___________________________________________

15 ___________________________________________

16 ___________________________________________

17 ___________________________________________

18 ___________________________________________

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TABLE 14 .1 Muscles of the Head and Neck (continued)

MUSCLE LOCAT ION AND ACT ION

MUSCLES THAT MOVE THE HEAD AND NECK Anterior and Lateral Muscles Sternocleidomastoid (sterno- � Strap-like muscle on anterior and lateral neck. Fibers run diagonally across breastbone; cleido � clavicle; the neck from the sternum and clavicle to the mastoid process. mastoid � mastoid process) Bilateral contraction flexes head (prayer muscle). Unilateral contraction laterally flexes head and rotates head to opposite side (as in saying no). Scalenes (scalenos � uneven) Three muscles—anterior, middle, and posterior scalenes—located in lateral neck deep to sternocleidomastoid muscle. Bilateral contraction flexes head and elevates 1st and 2nd ribs during deep inspiration. Unilateral contraction laterally flexes head and rotates head to opposite side (as in saying no). Posterior Muscles Splenius capitis Posterior neck deep to trapezius. Extends head when both muscles contract. Laterally flexes and rotates head to same side as contracting muscle when only one muscle contracts. Trapezius (superior portion) Superficial muscle of the upper back and posterior neck. Extends head and elevates scapula.

MUSCLE THAT MOVES ONLY THE SCAPULA Levator scapulae Posterior to sternocleidomastoid; runs diagonally from posterior head (levare � to raise) to scapula. Elevates scapula and rotates it downward; stabilizes scapula.

MUSCLES THAT MOVE HYOID BONE Suprahyoid Muscles Digastric (di- � two; gastric � belly) Anterior belly Strap-like muscle under chin that is parallel to midline of chin and extends from posterior belly. Elevates hyoid bone and depresses mandible (as in opening mouth). Posterior belly Runs along posterior border of chin. Elevates hyoid bone and depresses mandible (as in opening mouth). Stylohyoid Chin muscle, medial to posterior belly of digastric. Elevates hyoid bone and moves it posteriorly. Mylohyoid Deep muscle of chin extending from right side of mandible to left side. Elevates hyoid bone and floor of oral cavity and depresses mandible. Infrahyoid Muscles Omohyoid Lateral to sternohyoid. Depresses hyoid bone. Sternohyoid (sterno � sternum) Runs along midline of anterior neck. Depresses hyoid bone.

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 203

FIGURE 14.2 Selected muscles of the chin and neck.

Sternocleidomastoid

Splenius capitis

Scalene

Trapezius

Levator scapulae

Platysma

Sternohyoid

Thyroid cartilage

Buccinator

Zygomaticus major

Orbicularis oris

Levator labii superioris

Nasalis

Orbicularis oculi

Occipitofrontalis (frontal belly)Epicranial aponeurosis

Occipitofrontalis (occipital belly)

3 4 5

(a) Lateral superficial view

• levator scapulae (lee-VAY-tor SKA- pyoo-lee)

• scalene • splenius capitis • sternocleidomastoid

(ster-no-kli-do-MAS-toid) • trapezius (tra-PEE-

zee-us)

1 _______________________

2 _______________________

3 _______________________

4 _______________________

5 _______________________

204 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

FIGURE 14.2 Selected muscles of the chin and neck, continued.

Digastric:

Stylohyoid

Sternohyoid

Omohyoid

Sternocleidomastoid

Anterior belly

Posterior belly

(b) Anterior view with platysma removed

Mylohyoid

Masseter

Hyoid bone

Levator scapulae

Thyrohyoid

Sternothyroid

Cricothyroid

Scalene muscles

(2 of 3)

Mylohyoid

(b) • digastric, anterior belly • digastric, posterior belly • mylohyoid • omohyoid • sternocleidomastoid • sternohyoid • stylohyoid

6 _______________________

7 _______________________

8 _______________________

9 _______________________

10 _______________________

11 _______________________

12 _______________________

13 _______________________

14 _______________________

15 _______________________

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abdominis muscle runs horizontally it cannot fl ex the vertebral column.

Muscles Used in Breathing Muscles of inspiration increase the diameter or length of the thoracic cavity when they contract, while muscles of expiration decrease the diameter or length of the thoracic cavity. In this activity we will be examining the diaphragm, external intercostals, and internal intercostals. All muscles involved in breathing will be examined together when we study the respiratory system.

2. Muscles of the Trunk

Muscles That Move the Arm These muscles originate on the anterior or posterior trunk and insert on the humerus. Muscle contraction pulls the humerus toward the insertion, resulting in movement of the humerus at the shoulder joint. Because of the structure of the shoulder joint and the way these muscles surround the humerus, contraction can cause a full range of motion at a synovial joint—fl exion, extension, abduction, adduction, circumduction, and rotation. The rotator cuff muscles are deep muscles that move the arm and surround the shoulder joint like a sleeve cuff and help strengthen and stabilize the shoulder joint. They include the subscapularis, supraspinatus, infraspinatus, and teres minor.

Muscles That Move the Scapula Movements of the scapula include elevation, depression, abduction (protraction), adduction (retraction), and rota- tion. Shrugging the shoulders or lifting an object over the head elevates the scapula. Depression of the scapula occurs when doing a pullup. Performing a “pushup” abducts the scapula, and standing at attention adducts the scapula.

Muscles That Move the Abdominal Wall and Vertebral Column Muscles on the anterior surface of the abdomen (abdomi- nal muscles) fl ex the vertebral column, while the muscles of the back extend it. However, because the transversus

Before Going to Lab

1 Label Figure 14.3(a), (b), (c), (d), and (e) and Figure 14.4(a) and (b).

LAB ACTIVITY 2 Muscles of the Trunk

1 Use Figures 14.3 and 14.4 and Tables 14.2 and 14.3 to identify the muscles on models, charts, cadaver pho- tographs or use the search text box in Real Anatomy (Muscular) to find these structures.

2 Locate each muscle on yourself and perform the action indicated in Tables 14.2 and 14.3. Palpate each muscle while performing the action.

3 Identify the rotator cuff muscles on Figures 14.3 and 14.4. 4 Use Appendix B to locate the origin and insertion on an

articulated skeleton. Pull the insertion toward the origin to stimulate muscle action. ■

206 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

TABLE 14 .2 Muscles of the Anterior Trunk

MUSCLE LOCAT ION AND ACT ION

MUSCLES THAT MOVE THE ARM AT THE SHOULDER JOINT Superficial Muscles Deltoid (delta � triangle) Large, rounded, triangular shoulder muscle. Anterior fibers: flex and medially rotate arm. Lateral fibers: abduct arm. Posterior fibers: extend and laterally rotate arm. Pectoralis major (pectus � chest) Large muscles on superior, anterior chest between sternum and arm. Whole muscle adducts and medially rotates arm, clavicular head only flexes arm, and sternocostal head only extends arm. Deep Muscle Subscapularis On ventral side of the scapula in the subscapular fossa. Medially rotates arm.

MUSCLES THAT MOVE THE SCAPULA Serratus anterior (serratus � Serrated-looking muscles on the lateral trunk inferior to arms and rib. saw-toothed) Abducts scapula and rotates it upward. This occurs when throwing a punch and is often called the boxer’s muscle. Pectoralis minor Deep to pectoralis major attaching to 3rd through 5th ribs. Abducts scapula and rotates it downward; elevates 3rd through 5th ribs during forced inspiration.

MUSCLES THAT MOVE THE ABDOMINAL WALL Superficial Muscles Rectus abdominis (rectus � parallel Midline abdominal muscles located between sternum and inguinal ligament. fibers) Flexes vertebral column and compresses abdomen. Does not laterally flex vertebral column. External oblique Lateral and anterior sheet-like abdominal muscles whose fibers run obliquely down toward the midline (linea alba). Bilateral contraction flexes vertebral column and compresses abdomen. Unilateral contraction laterally flexes and rotates vertebral column to the opposite side. Deep Muscles Internal oblique Abdominal muscles deep to external oblique whose fibers run obliquely up toward linea alba. Bilateral contraction flexes vertebral column and compresses abdomen. Unilateral contraction laterally flexes and rotates vertebral column to the same side. Transversus abdominis Abdominal muscles deep to internal oblique whose fibers run transversely. Compresses abdomen and stabilizes trunk.

MUSCLES USED IN BREATHING Deep Muscles External intercostals (inter- � Oblique muscles located between ribs superficial to internal intercostals. between; costal � ribs) Fibers run obliquely down toward the midline. Increase thoracic diameter by elevating ribs during inspiration. Internal intercostals Oblique muscles located between ribs deep to external obliques. Fibers run obliquely up toward the midline. Decrease thoracic diameter by depressing ribs during forced expiration. Diaphragm Dome-shaped muscle that separates the thoracic and abdominal cavities. Contains openings for the esophagus, aorta, and vena cava. Flattens, increasing length of thoracic cage, during normal inspiration.

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 207

FIGURE 14.3 Muscles of the anterior trunk.

Sternocleidomastoid

Trapezius

Internal intercostals

Pectoralis minor

Rectus abdominis

Anterior superficial view Anterior deep view

Transverse abdominis

Internal oblique

External intercostals

Clavicle

Platysma

Pectoralis major

Serratus anterior

Linea alba

External oblique

Rectus sheath

Inguinal ligament

Inguinal ring (superficial)

Deltoid

Latissimus dorsi

Sternocleidomastoid

Clavicle

Third rib

(a) Anterior superficial view (b) Anterior deep view

Trapezius

• deltoid • external oblique • pectoralis (pek-tor-AL-lis) major • pectoralis minor • rectus abdominis (REK-tus

ab-DOM-in-is) • serratus (ser-RAY-tus) anterior

1 ______________________________

2 ______________________________

3 ______________________________

4 ______________________________

5 ______________________________

6 ______________________________

208 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

FIGURE 14.3 Muscles of the anterior trunk, continued.

Seventh rib

External intercostals

External oblique

Rectus abdominis

Internal intercostals

Internal oblique

(d) Right anterolateral deep view

Seventh rib

(e) Right anterolateral deeper view

Rectus abdominis

Transverse abdominis

TABLE 14 .3 Muscles of the Posterior Trunk

MUSCLE LOCAT ION AND ACT ION

MUSCLES THAT MOVE THE ARM AT THE SHOULDER JOINT Superficial muscles Deltoid (delta � triangle) Large, rounded, triangular shoulder muscle. Posterior portion of deltoid extends and laterally rotates arm. Infraspinatus (infra- � below; Located in infraspinous fossa (inferior to spine of scapula) and partially spinatus � spine of scapula covered by deltoid. Laterally rotates and adducts arm. Teres minor (teres � long and round) Inferior to infraspinatus and partially covered by deltoid. Laterally rotates, extends, and adducts arm. Teres major Inferior to teres minor and partially covered by deltoid. Extends, adducts, and medially rotates arm. Latissimus dorsi (latissimus � widest; Main large, flat muscle of middle and lower back that runs laterally and dorsum � back) attaches to superior portion of humerus. Extends, adducts, and medially rotates arm (if arm is elevated over head, it brings it down). Deep muscles Supraspinatus (supra- � above) Located in supraspinous fossa (superior to spine of scapula) and totally covered by deltoid. Assists deltoid muscle in abducting arm.

MUSCLES THAT MOVE THE SCAPULA Superficial muscle Trapezius (trapezoides � trapezoid Diamond-shaped muscle of posterior neck and upper back that extends from shape) the skull and vertebral column to spine of scapula and lateral clavicle. Superior portion elevates scapula and extends head, middle portion adducts scapula, inferior portion depresses scapula. Deep muscles Levator scapulae (levare � to raise) Posterior to sternocleidomastoid and runs diagonally from posterior head to scapula. Elevates scapula and rotates it downward. Rhomboid minor Deep to trapezius in upper back located between the vertebrae and scapula, and superior to rhomboid major. Elevates and adducts scapula and rotates it downward, stabilizes scapula. Rhomboid major Deep to trapezius in upper back located between the vertebrae and scapula, and inferior to rhomboid minor. Elevates and adducts scapula and rotates it downward, stabilizes scapula.

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 209

FIGURE 14.4 Muscles of the posterior trunk.

Levator scapulae

Rhomboid minor

Rhomboid major

Infraspinatus

Teres minor

Supraspinatus

Splenius capitis

Teres major

Sternocleidomastoid

Deltoid

Latissimus dorsi

External oblique

Anterior superficial view Anterior deep view

Infraspinatus

Teres minor

Teres major

Trapezius

Greater tubercle

of humerus

Acromion of scapula

Triceps brachii

10 Teres major

(a) Posterior superficial view (b) Posterior deep view

• deltoid • infraspinatus (in-fra-spi-NAY-tus) • latissimus dorsi (la-TIS-i-mus

DOR-sigh) • levator scapulae • rhomboid (ROM-boid) major • rhomboid minor • supraspinatus (soo-pra-spi-NAY-tus) • teres (TEH-rez) major • teres minor • trapezius (tra-PEE-zee-us)

1 ________________________________

2 ________________________________

3 ________________________________

4 ________________________________

5 ________________________________

6 ________________________________

7 ________________________________

8 ________________________________

9 ________________________________

10 ________________________________

210 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

FIGURE 14.4 Muscles of the posterior trunk, continued.

Longissimus capitis

Semispinalis capitis

Spinalis cervicis

Spinalis capitis

Splenius capitis

Semispinalis cervicis

Longissimus thoracis

Semispinalis thoracis

Longissimus cervicis

Iliocostalis thoracis

Iliocostalis lumborum

Spinalis thoracis

TABLE 14 .3 Muscles of the Posterior Trunk (continued)

MUSCLE LOCAT ION AND ACT ION

MUSCLES THAT MOVE THE VERTEBRAL COLUMN Erector spinae (erector � erect posture; Group of muscles next to the vertebral column deep to the trapezius, spinae � spine) latissimus dorsi, and scapula. consists of iliocostalis, longissimus, and Extend vertebral column and maintain erect posture when both muscles spinalis groups contract. Laterally flexes vertebral column when only one muscle.

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minimi, extensor digitorum, extensor carpi radialis brevis, and extensor carpi radialis longus. These muscles extend the hand and digits and originate on the lateral epicon- dyle of the humerus. Flexor and extensor muscles near the lateral surface of the forearm may also abduct the wrist, whereas those near the medial surface may adduct it. Other muscles located in the forearm include the brachioradialis, pronator teres, and supinator, which move the forearm at the radioulnar joint.

3. Muscles of the Arm

These muscles have their origin on the humerus or scapula, cross the elbow joint, and insert on the bones of the fore- arm. When these muscles contract, they fl ex or extend the forearm at the elbow joint or cause movement at the radio- ulnar joints. The muscles that have origins on the scapula can also move the arm at the shoulder joint. Muscles of the limbs that perform similar functions often are surrounded by fascia-forming compartments. Muscles in the anterior compartment of the arm, such as the biceps brachii and brachialis muscles, fl ex the forearm, whereas those in the posterior compartment, the triceps brachii, extend the forearm.

Muscles of the Forearm Muscles located in the forearm fl ex or extend the hand or cause movement at the radioulnar joint. The muscles that move the hand cross the wrist and insert on the carpals, metacarpals, or phalanges. These muscles are found in the anterior (fl exor) compartment and posterior (extensor) compartment of the forearm. The muscles of the superfi cial anterior compartment of the forearm from lateral to medial are: fl exor carpi radialis, palmaris longus, fl exor carpi ulna- ris, and fl exor digitorum superfi cialis. The fl exor digitorum superfi cialis is actually deep to the other three muscles. These muscles fl ex the hand or digits and originate on the medial epicondyle of the humerus. Muscles of the super- fi cial posterior compartment of the forearm from medial to lateral are: extensor carpi ulnaris, extensor digitorum

Before Going to Lab

1 Label Figure 14.5(a) and (b) and Figure 14.6(a), (b), (c), and (d).

LAB ACTIVITY 3 Muscles of the Arm and Forearm

1 Use Figures 14.5 and 14.6 and Tables 14.4 and 14.5A and B to identify the muscles on models, charts, cadaver photographs or use the search text box in Real Anatomy (Muscular) to find these structures.

2 Locate each muscle on yourself and perform the action indicated in Tables 14.4 and 14.5. Palpate each muscle while performing the action.

3 Use Appendix B to locate the origin and insertion on an articulated skeleton. Pull the insertion toward the origin to stimulate muscle action. ■

TABLE 14 .4 Muscles of the Arm

MUSCLE LOCAT ION AND ACT ION

ANTERIOR SURFACE Biceps brachii (biceps � 2 heads; Large muscle with 2 heads. brachii � arm) Flexes and supinates forearm, and flexes arm. Brachialis Deep to biceps brachii and anterior to humerus. Flexes forearm.

POSTERIOR SURFACE Triceps brachii Large muscle with three heads. Long head: Superficial muscle on medial side. Medial head: Deep muscle on medial side. Lateral head: Lateral side. All three heads extend forearm and help extend arm.

212 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

FIGURE 14.5 Muscles of the arm.

Biceps brachii

Brachialis

Subscapularis

Teres major

(a) Anterior view

Supraspinatus

Greater tubercle of humerus

Coracoid process of scapula

• biceps brachii (BI-ceps BRAY-key-eye) • subscapularis • teres major • brachialis (BRAY-key-AL-is)

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 213

FIGURE 14.5 Muscles of the arm, continued.

Triceps brachii long head

Triceps brachii lateral head

Triceps brachii medial head

(b) Posterior view

Teres minor

Olecranon of ulnaMedial epicondyle of humerus

Teres major

Infraspinatus

Spine of scapula

Greater tubercle of humerus

• triceps brachii, lateral head • triceps brachii, long head • triceps brachii, medial head

5 __________________________________________________

6 __________________________________________________

7 __________________________________________________

214 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

TABLE 14 .5A Muscles of the Anterior Forearm

MUSCLE LOCAT ION AND ACT ION

MUSCLES THAT MOVE THE RADIUS AND ULNA Superficial muscles Brachioradialis (brachi- � arm; Large, superficial lateral muscle. radialis � radius) Flexes forearm and pronates and supinates forearm to neutral position. Pronator teres (pronare � to bend Lateral to brachioradialis with oblique muscle fibers that cross antecubital forward; teres � long, cylindrical) fossa. Pronates and weakly flexes forearm. Deep muscle Supinator (supinate � supine; palm Anterior portion is deep to brachioradialis. upward) Supinates forearm.

MUSCLES THAT MOVE THE HAND Superficial muscles of anterior (flexor) compartment (Lateral to medial) Flexor carpi radialis (carpi- � wrist) Medial and inferior to pronator teres and medial to brachioradialis in forearm. Flexes and abducts hand. Palmaris longus (palma � palm) Medial to flexor carpi radialis. Weakly flexes wrist. Flexor carpi ulnaris Small part of muscle is seen anteriorly; most medial muscle of posterior forearm. Flexes and adducts hand. Flexor digitorum superficialis Deep to tendons of flexor carpi radialis, palmaris longus, and flexor carpi ulnaris. Flexes hand and proximal and middle phalanx of each finger. Deep muscle of anterior (flexor) compartment Flexor pollicis longus Inferior and lateral to flexor digitorum superficialis. Flexes distal phalanx of thumb.

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 215

FIGURE 14.6 Muscles of the forearm, wrist, and hands.

Biceps brachii

Brachialis

Medial epicondyle of humerus

Pronator teres

Brachioradialis

Palmaris longus

Flexor carpi radialis

Flexor digitorum superficialis

Flexor pollicis longus

Flexor carpi ulnaris

Abductor pollicis brevis

Flexor pollicis brevis

Adductor pollicis

Pisiform bone

Abductor digiti minimi

Flexor digiti minimi brevis

(a) Anterior superficial view

Supinator

Flexor digitorum profundus

Flexor pollicis longus

Dorsal interossei

Opponens digiti minimi

Carpal tunnel

(b) Anterior deep view

(a) • brachioradialis • flexor carpi (KAR-pee)

radialis • flexor carpi ulnaris • palmaris (pall-MARE-is)

longus • pronator (PRO-nay-tor)

teres

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

(b) • flexor digitorum

profundus • flexor pollicis (POL-ih-kis)

longus • supinator

6 ________________________

7 ________________________

8 ________________________

216 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

TABLE 14 .5B Muscles of the Posterior Forearm

MUSCLE LOCAT ION AND ACT ION

MUSCLE THAT MOVES THE RADIUS AND ULNA Supinator Posterior portion is deep to lateral muscles of posterior forearm. Supinates forearm.

MUSCLES THAT MOVE THE HAND Superficial muscles of posterior (extensor) compartment (Medial to lateral) Extensor carpi ulnaris Lateral to flexor carpi ulnaris. Extends and adducts hand. Extensor digitorum minimi Lateral to extensor carpi ulnaris. Extends hand and proximal phalanx of 5th digit. Extensor digitorum Lateral to extensor digitorum minimi. Extends hand and proximal, middle, and distal phalanges. Extensor carpi radialis brevis Lateral to extensor digitorum. Extends and abducts hand. Extensor carpi radialis longus Lateral to extensor radialis brevis. Extends and abducts hand. Deep muscle of posterior (extensor) compartment Extensor pollicis longus Deep to lateral extensor muscles on posterior forearm. Extends distal phalanx of thumb and first metacarpal of thumb and abducts hand.

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 217

FIGURE 14.6 Muscles of the forearm, wrist, and hands, continued.

Extensor carpi radialis longusMedial epicondyle

Extensor carpi ulnaris

Extensor digitorum

Extensor carpi radialis brevis

Extensor digiti minimi

Flexor carpi ulnaris

Abductor pollicis longus

Extensor pollicis brevis

Extensor retinaculum

Abductor pollicis longus

Extensor pollicis brevis

Supinator

Extensor pollicis longus

(d) Posterior deep view

(c) • extensor carpi radialis brevis • extensor carpi radialis longus • extensor carpi ulnaris • extensor digitorum • extensor digiti minimi • flexor carpi ulnaris

9 _________________________________

10 _________________________________

11 _________________________________

12 _________________________________

13 _________________________________

14 _________________________________

(d) • extensor pollicis longus • supinator (SOUP-ih-nay-tor)

15 _________________________________

16 _________________________________

218 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

4. Muscles of the Thigh

Muscles of the thigh fl ex, extend, abduct, adduct, circum- duct, and rotate the thigh. Muscles that move the thigh have origins on the pelvis or vertebrae and insertions on the femur or tibia. Those with origins on the pelvis move the thigh at the hip joint and the leg at the knee joint, whereas those with origins on the femur move only the leg at the knee joint. Muscles of the anterior compartment of the thigh, the quadriceps femoris group, extend the leg. The rec- tus femoris muscle of this group also fl exes the thigh. The sartorius, which runs diagonally from the hip to the medial tibia, marks the boundary between the anterior and medial compartments. Muscles of the medial compartment are pectineus, adductor magnus, adductor longus, adductor bre- vis, and gracilis. These muscles adduct and fl ex the thigh. Muscles of the posterior compartment are the hamstring muscle group, which fl ex the leg and extend the thigh.

Before Going to Lab

1 Label Figure 14.7(a), (b), and (e).

LAB ACTIVITY 4 Muscles of the Thigh

1 Use Figure 14.7 and Table 14.6 to identify the mus- cles on models, diagrams, cadaver photographs or use the search text box in Real Anatomy (Muscular) to find these structures.

2 Locate the muscles on yourself and perform the ac- tions indicated in Table 14.6. Palpate the muscles while performing the action.

3 Use Appendix B to locate the origin and insertion on an articulated skeleton. Pull the insertion toward the origin to simulate muscle action. ■

TABLE 14 .6 Muscles of the Thigh

MUSCLE LOCAT ION AND ACT ION

ANTERIOR SURFACE (Lateral to medial ) Tensor fasciae latae (tensor � to Small lateral hip muscle with fascia lata (deep fascia) that extends down thigh. stretch; fascia � band; latus � wide) Flexes and abducts thigh. Quadriceps femoris (quad- � four; Group of 4 muscles on anterior thigh. cep- � head or origins) Rectus femoris Located along midline of thigh. Extends leg and flexes thigh. Vastus lateralis Lateral to rectus femoris. Extends leg. Vastus medialis Medial to rectus femoris. Extends leg. Vastus intermedius Deep to rectus femoris and intermediate to vastus laterali and vastus medialis. Extends leg. Sartorius (sartor � tailor) Diagonal muscle. Extends from anterior superior iliac spine to medial surface of tibia. Flexes leg and flexes, abducts, and laterally rotates thigh (allows us to flex and cross our legs). Iliopsoas Combination of psoas major and iliacus. Psoas major (psoas � loin) A small portion of these muscles are observed in anterior/medial Iliacus (iliacus � ilium) compartment of thigh inferior to inguinal ligament. Together flex thigh, rotate thigh laterally, and flex trunk. Pectineus (pecten � comb) Medial to iliopsoas. Adducts and flexes thigh. Adductor longus Medial to pectineus. Adducts and flexes thigh and medially rotates thigh. Adductor magnus Observed medial and inferior to adductor longus. A larger portion of this muscle is deep to the adductor longus. Adducts and medially rotates thigh. Anterior portion flexes thigh and posterior portion extends thigh. Adductor brevis Deep to adductor longus, it is totally covered by superficial muscles in Figure 14.7. Adducts and flexes thigh and medially rotates thigh. Gracilis Medial to adductor magnus; straight muscle on inside of thigh. Adducts thigh and medially rotates thigh. Flexes leg.

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 219

(a) Anterior superficial view

Psoas major

Tensor fasciae latae Sartorius Rectus femoris (cut)

Vastus lateralis

Vastus medialis

Iliotibial tract

Vastus intermedius

Pectineus

Adductor longus

Gracilis

Adductor magnus

IliacusIliopsoas

Patella

1 2

Anterior superior iliac spine

Pubic symphysis

(a) • adductor longus • gracilis (grah-SIL-us) • iliacus (il-ee-AK-us) • pectineus (pek-tin-EE-us) • psoas (SO-us) major • rectus femoris (FEM-or-is) • sartorius (sar-TOR-ee-us) • tensor fasciae latae (FA-schee LA-tee) • vastus intermedius • vastus lateralis • vastus medialis

1 _________________________________

2 _________________________________

3 _________________________________

4 _________________________________

5 _________________________________

6 _________________________________

7 _________________________________

8 _________________________________

9 _________________________________

10 _________________________________

11 _________________________________

FIGURE 14.7 Muscles of the thigh.

(b) Anterior deep view

Inguinal ligament

Obturator externus

Adductor longus (cut)

Adductor brevis

Adductor magnus

Iliacus

Tensor fasciae latae

Vastus lateralis

Tendon of quadriceps femoris

Patella

Femur

Medial condyle of femur

Psoas major

Obturator externus

Gracilis

(b) • adductor brevis • adductor magnus • gracilis

12 _________________________________

13 _________________________________

14 _________________________________

220 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

TABLE 14 .6 Muscles of the Thigh (continued)

MUSCLE LOCAT ION AND ACT ION

POSTERIOR SURFACE Gluteus maximus Largest buttocks muscle. Extends and laterally rotates thigh. Gluteus medius Observed superior to gluteus maximus but is partially covered by it. Abducts and medially rotates thigh. Gluteus minimus Deep muscle covered by gluteus medius. Abducts and medially rotates thigh. Piriformis (pirum � pear; Deep muscle inferior to gluteus minimus; important landmark for sciatic -forma � shape) nerve, which passes deep to piriformis. Laterally rotates and abducts thigh. Hamstrings Three muscles on posterior thigh. Biceps femoris Most lateral hamstring. Flexes leg and extends thigh. Semitendinosus (semi- � half or Medial to biceps femoris and superficial to semimembranosus. part; tendinosus � long tendon) Flexes leg and extends thigh. Semimembranosus (membranosus Most medial of the hamstrings; (remember ‘m’ for medial). � partly membrane) Flexes leg and extends thigh.

Adductor magnus

Semitendinosus

Biceps femoris

Semimembranosus

Gluteus medius

Gluteus maximus

Long head

Short head

Gracilis

Iliotibial tract

Gluteus maximus (cut)

Sciatic nerve

Gluteus medius (cut)

Gluteus minimus

Piriformis

Greater trochanterCoccyx

Gluteus maximus (cut)

FIGURE 14.7 Muscles of the thigh, continued.

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 221

FIGURE 14.7 Muscles of the thigh, continued.

(e) Posterior view

Deep Superficial

Superior gemellus

Obturator internus

Inferior gemellus

Quadratus femoris

Adductor minimus

Popliteal fossa

Adductor magnus

Vastus lateralis (covered by iliotibial tract)

• biceps femoris • gluteus maximus • gluteus medius • piriformis • semimembranosus • semitendinosus

15 _________________________________

16 _________________________________

17 _________________________________

18 _________________________________

19 _________________________________

20 _________________________________

222 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

5. Muscles of the Leg and Foot

Palpate the tibia of your leg to fi nd the anterior crest and the lateral and medial borders of the tibia. Observe that the muscles on the anterior surface of the tibia are located lat- eral to the anterior crest of the tibia. The anterior and lateral superfi cial muscles are in order starting at the anterior crest just below the knee and moving laterally: tibialis anterior, extensor digitorum longus, and the fi bularis (peroneus) longus. The tibialis anterior and extensor digitorum are muscles of the anterior compartment of the leg. These muscles dorsifl ex the foot and also extend the toes if they insert on the phalanges. Muscles of the posterior compartment of the leg in- clude the gastrocnemius, soleus, and fl exor digitorum lon- gus. These muscles plantar fl ex the foot and also fl ex the toes if they insert on the phalanges. Eversion of the foot is due to contraction of muscles near the lateral surface of the leg, whereas inversion is due to contraction of muscles near the medial surface of the leg.

Before Going to Lab

1 Label Figure 14.8(a), (b), (c), and (d).

LAB ACTIVITY 5 Muscles of the Leg and Foot

1 Use Figure 14.8 and Table 14.7 to identify the muscles on models, diagrams, cadaver photographs or use the search text box in Real Anatomy (Muscular) to find these structures.

2 Locate each muscle on yourself and perform the action indicated in Table 14.7. Palpate each muscle while performing the action.

3 Use Appendix B to locate the origin and insertion on an articulated skeleton. Pull the insertion toward the origin to simulate muscle action. ■

TABLE 14 .7 Muscles of the Leg and Foot

MUSCLE LOCAT ION AND ACT ION

LATERAL AND ANTERIOR SURFACES (Superficial muscles) Tibialis anterior Lateral to the anterior crest of the tibia. Dorsiflexes and inverts foot. Extensor digitorum longus Lateral to tibialis anterior. Dorsiflexes foot and extends toes. Fibularis (peroneus) longus Lateral to the extensor digitorum longus. Plantar flexes and everts foot. POSTERIOR SURFACE (Superficial muscles) Gastrocnemius Large superficial muscle on posterior leg. Plantar flexes foot and flexes leg. Soleus Deep to gastrocnemius and posterior to fibularis (peroneus) longus. Plantar flexes foot only. (Deep muscles) Flexor digitorum longus Deep to soleus, medial muscle (not shown on Figure 14.8). Plantar flexes foot and flexes toes. Flexor hallucis longus Deep to soleus, lateral muscle. Plantar flexes foot and flexes great toe.

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 223

FIGURE 14.8 Muscles of the leg, ankle, and foot.

(a) • extensor digitorum longus • fibularis (peroneus) brevis • fibularis (peroneus) longus • tibialis anterior

1 ___________________________

2 ___________________________

3 ___________________________

4 ___________________________

(a) Anterior superficial view

Tibialis anterior

Extensor digitorum longus

Fibularis (peroneus) longus

Fibularis (peroneus) brevis

Gastrocnemius

Soleus

Flexor digitorum longus

Tendon of extensor hallucis longus

Fibularis tertius

Patellar ligament

Tibia

Patella

(b) Lateral superficial view

Tibialis anterior

Extensor digitorum longus

Fibularis (peroneus) longus

Gastrocnemius

Plantaris

Soleus

Extensor hallucis longus

Lateral malleolus of fibula

Calcaneal (Achilles) tendon

Fibularis tertius

Fibularis brevis

Patellar ligament

Patella

6 5

Lateral condyle of femur

(b) • extensor digitorum longus • fibularis (peroneus) longus • gastrocnemius

(gas-trok-NEE-mee-us) • soleus • tibialis anterior

5 ___________________________

6 ___________________________

7 ___________________________

8 ___________________________

9 ___________________________

224 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

10 ________________________________

11 ________________________________

(d) • flexor digitorum longus • flexor hallucis (HAL-a-kis) longus

12 ________________________________

13 ________________________________

Gastrocnemius

Plantaris

Fibularis (peroneus) longus

Flexor hallucis longus

Soleus

Calcaneal (Achilles) tendon

Tibialis posterior

Flexor digitorum longus

Flexor hallucis longus

(d) Posterior deep view

FIGURE 14.8 Muscles of the leg, ankle, and foot, continued.

C. Dissection of Skeletal Muscles

If you are dissecting a cat to observe skeletal muscles, refer to the appropriate accompanying dissection manual. Many skeletal muscles of the cat are similar to human muscles.

This dissection will reinforce your knowledge of human skeletal muscles and allow you to observe the fascia that surrounds, protects, and compartmentalizes these muscles. Real Anatomy (Dissection), a cadaver dissection, can be used to complement or substitute for animal dissection of skeletal muscles.

225

Name ___________________________________ Date _________________ Section ______________________________

Reviewing Your Knowledge

27 28

30 29

636

737

838

939

Abductor pollicis longus

Patellar tligament

Tibia

10 11 12

Extensor pollicis longus

13 14 15

17 18

23 Calcaneal (Achilles) tendon

(a) Anterior view

1 24

14 E X E R C I S E

FIGURE 14.9 Superficial skeletal muscles.

A. Anatomy Review

For Figures 14.9 (a) and 14.9 (b), write the name of the skeletal muscle next to the number. Color with colored pencils.

226 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

57 58 59 60

69 70

Flexor hallucis longus

Extensor digitorum longus

63 64 65

48 49

Abductor pollicis longus

Extensor pollicis brevis

(b) Posterior view

FIGURE 14.9 Superficial skeletal muscles, continued.

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 227

B. Muscle Function

Identify the muscles that perform each function.

Muscles of the Head and Neck a. masseter b. orbicularis oculi c. orbicularis oris d. sternocleidomastoid e. temporalis f. trapezius g. zygomaticus major

____ 1. Smiling muscle

____ 2. Kissing muscle

____ 3. Closes eyelid

____ 4. Two muscles that close mouth

____ 5.

____ 6. Paired muscle that flexes head and rotates head to side

____ 7. Extends head

Muscles of the Anterior Trunk a. deltoid b. external oblique c. internal oblique d. pectoralis major e. rectus abdominis f. serratus anterior g. transversus abdominis

____ 8. Adducts and flexes arm

____ 9. Anterior portion flexes arm; lateral portion abducts arm

____ 10. Abducts scapula and rotates it upward (boxer’s muscle)

____ 11. Flexes vertebral column and compresses abdomen

____ 12. Two muscle pairs that flex vertebral column, compress abdomen, and laterally flex vertebral column

____ 13.

____ 14. Only compresses abdomen

¯ ˘

˙ ¯

˘ ˙

228 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

Muscles of the Posterior Trunk a. deltoid b. erector spinae c. latissimus dorsi d. teres major e. trapezius

____ 15. Extends, adducts, and medially rotates arm

____ 16.

____ 17. Posterior portion extends arm; lateral portion abducts arm

____ 18. Superior portion elevates scapula, middle portion adducts scapula, inferior portion depresses scapula

____ 19. Paired muscle that extends vertebral column, maintains erect posture, and laterally flexes vertebral column

Muscles of the Arm and Forearm a. biceps brachii b. brachialis c. brachioradialis d. extensor carpi radialis e. extensor carpi ulnaris f. extensor digitorum g. flexor carpi radialis h. flexor carpi ulnaris i. palmaris longus j. triceps brachii

____ 20. Extends forearm at elbow and extends arm

____ 21. Flexes forearm at elbow and flexes arm

____ 22. Flexes forearm

____ 23. Flexes forearm and pronates and supinates forearm

____ 24. Flexes and abducts hand

____ 25. Flexes and adducts hand

____ 26. Weakly flexes hand

____ 27. Extends hand and extends phalanges

____ 28. Extends and adducts hand

____ 29. Extends and abducts hand

Muscles of the Thigh a. adductor magnus, longus, brevis b. biceps femoris c. gluteus maximus d. gluteus medius

¯ ˘

E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S 229

e. gracilis f. rectus femoris g. sartorius h. semimembranosus i. semitendinosus j. tensor fasciae latae k. vastus intermedius l. vastus lateralis m. vastus medialis

____ 30. Extends leg at knee and flexes thigh at hip

____ 31.

____ 32. Three muscles that extend leg only

____ 33.

____ 34. Flexes leg and flexes, abducts, and laterally rotates thigh (allows us to flex and cross our legs)

____ 35. Adducts thigh and flexes leg

____ 36. Group of muscles that adducts and flexes thigh

____ 37. Abducts thigh

____ 38. Flexes and abducts thigh

____ 39. Extends thigh

____ 40.

____ 41. Three muscles that flex leg and extend thigh

____ 42.

Muscles of the Leg a. extensor digitorum longus b. fibularis (peroneus) longus c. flexor digitorum longus d. gastrocnemius e. soleus f. tibialis anterior

____ 43. Plantar flexes and everts foot

____ 44. Plantar flexes foot and flexes toes

____ 45. Plantar flexes foot only

____ 46. Plantar flexes foot and flexes leg

____ 47. Dorsiflexes foot and extends toes

____ 48. Dorsiflexes and inverts foot

¯ ˚

˘ ˚

˙ ¯

˚ ˘

˚ ˙

231

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

14 E X E R C I S E

Identify the muscles and/or actions in the following questions.

1. Identify the muscles of the head that you use when you whistle.

2. Identify the muscles of the head used to blink.

3. Identify the major thigh and leg muscles you use when you kick a ball.

4. Give the action of each muscle listed in question 3.

5. Identify the forearm muscles you use when you turn a key in a lock.

6. Give the action of each muscle listed in question 5.

7. Identify the major arm muscles you use when you lift a glass to drink from it.

8. Give the action of each muscle listed in question 7.

9. Identify the neck muscles you use when you look both ways to cross a street.

10. Give the action of each muscle listed in question 9.

232 E X E R C I S E 1 4 S K E L E T A L M U S C L E S A N D T H E I R A C T I O N S

11. Identify the abdominal muscles you use when you do the dance called the “twist.”

12. Give the action of each muscle listed in question 11.

13. Identify the muscles used to move the upper limb when you do jumping jacks.

14. Give the action of each muscle listed in question 13.

15. Identify the muscles that move the lower limb when you do jumping jacks.

16. Give the action of each muscle listed in question 15.

17. Identify the muscles used to bend the trunk when you touch your toes.

18. Give the action of each muscle listed in question 17.

19. Identify the upper limb muscles used to play the cymbals in a band.

20. Give the action of each muscle listed in question 19.

O B J E C T I V E S M A T E R I A L S

• hand mirror • articulated skeleton • skeletal muscle models or charts

Surface Anatomy 15 E X E R C I S E

1 Define and describe the importance of surface anatomy

2 Locate by palpation and identify important anatomical landmarks on the external surface of the body

3 Identify the borders of the anterior and posterior triangles of the neck and the femoral triangle using anatomical landmarks on the external surface of the body

4 Identify organ location using anatomical landmarks on the external surface of the body

233

S urface anatomy is the study of anatomical landmarks observed on the external surface of the body. These landmarks can be used to locate underlying structures by palpation. Palpation (palpare � to touch gently) is a technique that uses the hands or fin- gers to locate internal body structures and to determine the size and texture of the structures. This exercise is a review and can be completed at home or in the lab.

LAB ACTIVITY 1 Surface Anatomy of the Head and Neck

1 Read the location and description of each structure. 2 Locate and label each structure in Figure 15.1(a),

(b), (c), and (d).

3 Palpate the designated structures on your body.

■

234 E X E R C I S E 1 5 S U R F A C E A N AT O M Y

• condylar process (mandibular condyle) [not shown on Figure 15.1(a)]—Rounded process at the poste- rior portion of the ramus. It articulates with the mandibular fossa of the temporal bone to form the TMJ.

• ramus of mandible—Vertical process of mandible. Palpate ramus inferior to the TMJ.

• mastoid process—Rounded projection on the inferior portion of the temporal bone posterior to the ear. Palpate area of the skull inferior and posterior to external auditory meatus of ear.

• external occipital protuberance—Rounded pro- jection superior to foramen magnum of the occipital bone. Palpate the base of the skull near the midline. Lateral to the external occipital protuberance are two curved ridges called the superior nuchal lines, which mark the boundary between the head and neck.

Skeletal Muscles • temporalis muscle—Located superior to the ear.

Palpate the temporalis muscle while closing the mouth and clenching your teeth.

• masseter muscle—Located anterior to ramus of the mandible. Palpate the masseter muscle while closing the mouth and clenching your teeth.

• occipitalis muscle—Lies over the inferior portion of the occipital bone. Firmly palpate the posterior surface of the skull immediately above the neck as you raise and lower eyebrows.

Other Structures • parotid gland—Located anterior and inferior to

the ears. The superior border is at the level of the zygomatic arch and the inferior border is at the angle formed by ramus and body of the mandible. The parotid gland covers the masseter muscle and is approximately 2 fingers wide.

A. Anterior Surface of the Head

Structures located in Figure 15.1(a).

Bones and Bone Surface Markings

• supraorbital margins—Superior borders of the frontal bone that border the eye orbits. Palpate the supraorbital margins.

• nasal bone—Forms the bridge of the nose. Place fingers along the bridge of the nose to feel nasal bones. Find the anterior border of the nasal bones and palpate the nasal cartilage inferior to nasal bones.

• body of mandible—Horizontal portion of the lower jawbone. Palpate this main part of the mandible that includes the chin.

• mental protuberance—Palpate this anterior tip of the chin.

Skeletal Muscles • frontalis muscle—Lies over the forehead. Palpate the

frontalis muscle with fingers while raising eyebrows. • zygomaticus major muscle—Originates on the

zygomatic bone and inserts on the corner of the mouth. Palpate this muscle near the zygomatic bone while smiling.

B. Lateral Surface of the Head

Structures located in Figure 15.1(b).

Bones and Bone Surface Markings • temporomandibular joint (TMJ)—Located anterior

to the external auditory meatus of the ear. Palpate the joint while opening and closing the mouth.

(b) Right lateral view of head • external occipital

protuberance • masseter muscle covered

by parotid gland • mastoid process • occipitalis muscle • ramus of mandible • temporalis muscle • temporomandibular joint

7 _______________________

8 _______________________

9 _______________________

10 _______________________

11 _______________________

12 _______________________

13 _______________________

(a) Anterior view of head • body of mandible • frontalis muscle • mental protuberance • nasal bone • supraorbital margin • zygomaticus major muscle

1 _______________________

2 _______________________

3 _______________________

4 _______________________

5 _______________________

6 _______________________

E X E R C I S E 1 5 S U R F A C E A N AT O M Y 235

Orbicularis oculi

muscle

Depressor labii

inferioris muscle

Orbicularis oris

muscle

(a) Anterior view of the head

Hyoid bone

(b) Right lateral view of the head

FIGURE 15.1 Surface anatomy of the head and neck.

236 E X E R C I S E 1 5 S U R F A C E A N AT O M Y

carotid arteries at the superior border of the larynx. Palpate the right common carotid artery by placing your fingers on the right side of the neck just lateral to the trachea.

• external jugular vein—Located lateral to the ster- nocleidomastoid muscle. To observe this vein, look in the mirror while clenching your teeth as in anger or placing fingers on the skin above the clavicle and pressing firmly to prevent blood from draining the external jugular vein.

• internal jugular vein—Located between the common carotid artery and external jugular vein [not shown on Figure 15.1(a)].

D. Lateral Surface of the Neck

Structures located in Figure15.1(d).

Skeletal Muscles • sternocleidomastoid muscle— A portion of this

muscle is look into a mirror while turning your head to the side. Observe the sternal and clavicular heads of the sternocleidomastoid muscle and palpate the muscle.

• scalenes—Located posterior-lateral to the sterno- cleidomastoid muscle, just superior to the clavicle.

• levator scapulae—Located superior to the scalenes. • trapezius muscle— A portion of this muscle is

located in the posterior and lateral neck. Inflammation of trapezius muscle may result in “stiff neck.” Place fingers on the posterior portion of the lateral neck and palpate while flexing and extending the neck.

Anterior and Posterior Triangles • anterior triangle [not shown in Figure 15.1(d)]—

Superiorly bounded by the inferior margin of the mandible, anteriorly by the midline of the neck, and posteriorly by the sternocleidomastoid. The common carotid artery and internal jugular vein are located in this triangle. Palpate to identify the triangle’s bor- ders and palpate your carotid pulse in the anterior triangle.

• posterior triangle [not shown in Figure 15.1(d)]— Anteriorly bordered by the sternocleidomastoid, posteriorly by the trapezius and inferiorly by the clavicle. Palpate to identify the triangle’s borders. The brachial plexus and external jugular vein are located in this triangle.

C. Anterior Surface of the Neck

Structures located in Figure 15.1(c).

Bones and Bone Surface Markings • hyoid bone—Located in the anterior neck between

the mandible and larynx. With the head in anatomi- cal position, palpate the hyoid bone by placing the thumb and middle finger of one hand on either side of the neck about 1 inch inferior to the mandible. This bone can be moved laterally from side to side.

• clavicle—Starting at the manubrium of the sternum, trace the clavicle’s S-shaped curvature laterally to its acromial end. Palpate the acromioclavicular joint just posterior to the acromial end of the clavicle as you thrust your shoulder joint anteriorly.

• suprasternal (jugular) notch—Located at the base of the neck between the sternal heads of the ster- nocleidomastoid muscles and just superior to the sternum. Palpate the sternum and move the fingers superiorly to feel the suprasternal notch.

Skeletal Muscles • sternocleidomastoid muscle—Originates on the

sternum and clavicle and inserts on the mastoid process of the temporal bone.

Other Structures

• thyroid cartilage of larynx—Largest cartilage of the larynx that has a prominence called the Adam’s apple. Located in anterior neck inferior to hyoid bone. Move fingers 1 inch inferiorly from the hyoid bone until a firm structure is reached. Swallow to feel this cartilage move superiorly.

• cricoid cartilage of larynx—Located inferior to the thyroid cartilage and used as a landmark when locating the trachea during a tracheostomy. Move your fingers down the thyroid cartilage. There is a depression between the thyroid cartilage and the cricoid cartilage. Palpate the cricoid cartilage inferior to this depression.

• thyroid gland—Located inferior to the larynx on either side of trachea. Palpate by placing fingers on neck inferior and lateral to the thyroid cartilage and feeling for a soft mass.

• common carotid arteries—Located in the lateral neck between the trachea and the sternocleidomastoid muscle. They branch into the external and internal

E X E R C I S E 1 5 S U R F A C E A N AT O M Y 237

(c) Anterior view of the neck • clavicle • common carotid artery • cricoid cartilage • hyoid bone • sternocleidomastoid muscle • suprasternal (jugular) notch • thyroid cartilage

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Thyroid gland

Subclavian artery

External jugular vein

(d) Lateral view of the neck • levator scapulae • scalenes • sternocleidomastoid • trapezius

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(d) Lateral view of the neck

FIGURE 15.1 Surface anatomy of the head and neck, continued.

238 E X E R C I S E 1 5 S U R F A C E A N AT O M Y

• xiphisternal joint—Joint between body of the sternum and xiphoid process of the sternum. Palpate the costal margin. Move fingers anteriorly along the costal margin until they reach the superior edge of the costal margin. Medial to this point is the xiphisternal joint.

• xiphoid process of sternum—Inferior portion of the sternum. Palpate the xiphoid process inferior to the xiphisternal joint.

Skeletal Muscles • pectoralis major muscle—Major muscle of the

chest. In males the inferior border can be observed as a curved line under the breasts. This line is at the level of the fifth rib. Bend over your lab bench and push yourself up with one limb. Use your opposite hand to palpate the pectoralis major muscle.

• serratus anterior muscle—Located on the lateral chest wall, extending from the ribs under the arm to the scapula. Flex your forearm and abduct your elbow. Use your opposite hand to palpate the serratus anterior muscle as it abducts the scapula. If you move too far posteriorly, you will be palpating the latissimus dorsi instead.

• diaphragm—Located between the fourth and fifth intercostal space. Position changes during inhalation and exhalation.

Other Structures [not shown in Figure 15.2(a)] • trachea—Located between cricoid cartilage of larynx

and sternal angle. The trachea is approximately 2 fingers in diameter.

• primary bronchi—The trachea divides into the right and left bronchi at the level of the sternal angle.

• lungs—Apex of lungs are slightly above the clavicle. The base of the lungs rests on the diaphragm.

• heart—Located between the second and sixth ribs. The heart rests on the diaphragm deep to the xiphisternal joint. The heart is about the size of your fist, and 2/3 of the heart lies to the left of the midline.

• aortic arch—Superior border of aortic arch is posterior to the sternal angle and anterior to the trachea.

E. Surface Anatomy of the Chest

Structures located in Figure 15.2(a).

Bones and Bone Surface Markings • suprasternal notch—Located at the base of the neck

between the sternal heads of the sternocleidomastoid muscles and just superior to the sternum. Palpate the sternum and move the fingers superiorly to feel the suprasternal notch.

• manubrium of the sternum—Superior part of the sternum between the suprasternal notch and body of the sternum. Palpate by placing fingers at suprasternal notch and moving them inferiorly until a ridge (sternal angle) is reached.

• body of sternum—Palpate area of the sternum inferior to the sternal angle.

• sternal angle— Slightly raised area that can be felt at border of manubrium and body of sternum.

• ribs—The ribs can be palpated lateral to the sternum. The second rib is located at the level of the sternal angle. Palpate the sternal angle and move fingers laterally until the second rib can be felt. Move the fingers inferiorly, counting each rib and each inter- costal space between the ribs.

• costal margin—Anterior edge of costal cartilage of ribs 7–10 that begins at the xiphisternal joint.

LAB ACTIVITY 2 Surface Anatomy of the Trunk

1 Read the location and description of each structure. 2 Locate and label each structure in Figure 15.2(a),

(b), (c), (d), (e), (f) and (g).

3 Palpate the designated structures on your body. ■

E X E R C I S E 1 5 S U R F A C E A N AT O M Y 239

(a) Anterior view of chest • body of sternum • costal margin • manubrium of sternum • pectoralis major muscle • ribs (deep to muscle) • second rib (deep to muscle) • serratus anterior muscle • sternal angle • xiphisternal joint • xiphoid process of sternum

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Suprasternal notch

(muscle)

Clavicle

(muscle) 3

(a) Anterior view of the chest

FIGURE 15.2 Surface anatomy of the trunk.

240 E X E R C I S E 1 5 S U R F A C E A N AT O M Y

Other Structures • linea alba—Tendinous raphe between the xiphoid

process and pubic symphysis forming a vertical groove along the midline. This is a common incision site because there is little damage to muscles and little bleeding.

• linea semilunaris—Lateral margin of rectus abdominis that is observable in lean people as a groove.

• tendinous intersection—Transverse grooves across rectus abdominis muscles that are observable in muscular individuals.

• umbilicus—Most notable feature of the abdomen and a common incision site. The umbilicus is located between L3 (3rd lumbar vertebra) and L4.

• liver [not shown on Figure 15.1(b) and (c)]—Inferior to the diaphragm. The position of the liver varies with body position, respiration, and degree of distension of the stomach and intestines.

• gallbladder [not shown on Figure 15.1(b) and (c)]— Located deep to the lateral margin of the rectus abdominis.

• appendix—Deep to McBurney’s point, which is located along the line between the umbilicus and the right anterior superior iliac spine, about 1 to 2 inches away from the latter. During appendicitis, pressure on McBurney’s point results in tenderness. This is the most common site of incision for an appendectomy.

• common iliac arteries [not shown on Figure 15.1(b) and (c)]—The abdominal aorta bifurcates into the common iliac arteries at the level of the anterior superior iliac spines.

F. Surface Anatomy of the Abdomen

Structures located in Figure 15.2(b) and (c). Bone and Bone Surface Structures

• anterior superior iliac spine—Located at the ante- rior end of the iliac crest. Palpate the iliac crest with your fingers and move your fingers medially until you feel the “bump” at the anterior end of the iliac crest.

• iliac crest—Marks the inferior border of the abdo- men. Palpate the iliac crest by placing your hands on your hips.

• pubic symphysis [not shown in Figure 15.2(b)]— Anterior joint between os coxae (hip bones). Palpate midline of the inferior pelvic area.

Skeletal Muscles • serratus anterior muscle—Located on the lateral

chest wall, extending from the ribs under the arm to the scapula. Flex your forearm and abduct your elbow. Use your opposite hand to palpate the serratus anterior muscle as it abducts the scapula. If you move too far posteriorly, you will be palpating the latissimus dorsi instead.

• external oblique muscle—Inferior to serratus anterior muscles. Palpate while twisting trunk toward the opposite side.

• rectus abdominis muscle—Longitudinal muscles lateral to the linea alba. Lie back in your chair and palpate these muscles as you sit up.

(b) Anterior view of abdomen • anterior superior iliac spine • external oblique muscle • iliac crest • linea alba • linea semilunaris • McBurney’s point • rectus abdominis muscle • tendinous intersection • umbilicus

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(c) Anteriolateral view of abdomen • anterior superior iliac spine • external oblique muscle • iliac crest • McBurney’s point • rectus abdominis muscle • serratus anterior muscle • tendinous intersection

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E X E R C I S E 1 5 S U R F A C E A N AT O M Y 241

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(b) Anterior view of abdomen

FIGURE 15.2 Surface anatomy of the trunk, continued.

242 E X E R C I S E 1 5 S U R F A C E A N AT O M Y

Skeletal Muscles • deltoid muscle—This large, triangular muscle forms

the rounded protrusion of the shoulder. It is used as a site for intramuscular injections. Palpate this muscle as you flex, abduct, and extend the arm to locate the deltoid’s anterior, lateral, and posterior portions.

• trapezius muscle—Large muscle of the posterior neck and middle of back.

• supraspinatus muscle—Located superior to the spine of the scapula. Palpate this muscle.

• infraspinatus muscle—Located inferior to the spine of the scapula. Palpate area inferior to the spine of the scapula to feel this muscle.

• teres major muscle—Located inferior to the infra- spinatus muscle.

• latissimus dorsi muscle—Broad muscle located between the lumbar region and axillary region. Together with teres major muscle forms the posterior axillary fold.

• erector spinae muscle—Large muscle of lower back. Bend over and palpate this muscle while extending the vertebral column.

Other • triangle of auscultation—Triangular region of

the back formed by the latissimus dorsi, trapezius, and vertebral border of scapula. This region is not covered by superficial muscles enabling respiratory sounds to be heard with a stethoscope.

G. Surface Anatomy of the Back

Structures located in Figure 15.2(d) and (e).

Bones and Bone Surface Markings • acromion—The flattened lateral end of the spine

of the scapula located at the peak of the shoulder. Palpate this prominent projection.

• spine of scapula [not shown in Figure 15.2(d) and (e)]—The ridge across the posterior surface of the scapula that extends from the acromion to the medial border of the scapula. Palpate this bone with your fingers. The spine is easier to palpate on a lean body.

• vertebral border of scapula—Draw left shoulder back and run the fingers of your right hand just lateral to the the midline to feel the vertebral border of the scapula.

• spinous processes of vertebrae—Located along the midline of the back. Run your fingers along midline to feel the spinous processes.

• vertebra prominens—Located at base of neck. Prominent single spinous process of C7 (7th cervical vertebra). The vertebra prominens, that can be seen as a bump at the base of the neck and palpated.

• T3—Tip of spinous process of 3rd thoracic vertebra is at the level of medial end of spine of scapula.

• L4—Tip of spinous process of 4th lumbar vertebra is at same level as highest point of iliac crest. Lumbar punctures to obtain CSF are usually done between L3 and L4.

(d) Posterior view of back • acromion • erector spinae muscle • infraspinatus muscle • latissimus dorsi muscle • spinous process of thoracic vertebrae • supraspinatus • teres major muscle • trapezius muscle • vertebral border of scapula

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(e) Posterior view of back with arms flexed • deltoid muscle , lateral fibers • deltoid muscle posterior fibers • latissimus dorsi muscle • spinous process of lumbar vertebra • spinous process of thoracic vertebra • teres major muscle • trapezius muscle • triangle of auscultation • vertebral border of scapula

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E X E R C I S E 1 5 S U R F A C E A N AT O M Y 243

Posterior axillary fold

Vertebra prominens

(d) Posterior view of the back

(e) Posterior view of the back with arms flexed

FIGURE 15.2 Surface anatomy of the trunk, continued.

244 E X E R C I S E 1 5 S U R F A C E A N AT O M Y

• greater trochanter—Palpate this bony landmark on the lateral side of your hip. Flex and extend your thigh to feel this structure move with the joint action.

Skeletal Muscles • gluteus maximus muscle—Most students are familiar

with these muscles that make up the largest portion of the buttocks. Palpate this prominent muscle as you extend your thigh.

• gluteus medius muscle—These muscles are inferior to the iliac crests in the upper, outer quadrant of the buttocks. Palpate this muscle as you shift your weight onto the palpated leg, causing the gluteus medius to contract. These muscles are the site of intramuscular (IM) injections.

Other Structures • gluteal (natal) cleft—A midline crevice between the

buttocks. • kidneys [not shown in Figure 15.2(f) and (g)]—

Place your hands on the iliac crest. Your thumbs land at the approximate location of the kidneys.

H. Surface Anatomy of the Posterior Pelvis and Gluteal Region

Structures located in Figure 15.2(f) and (g).

Bones and Bone Surface Markings • iliac crest—Superior boundary of the ileum. The

iliac crest can be palpated when you “put your hands on your hips.”

• posterior superior iliac spine—Located on posterior end of iliac crest. Locate the dimple in the skin located just lateral to sacrum.

• sacroiliac joint [not shown on Figure 15.2(f) and (g)]—Joint between sacrum and ilium. Middle of sacroiliac joint is deep to posterior superior iliac spine.

• sacrum—Superior to the gluteal cleft, palpate the medial sacral crest (fused spinous processes) portion of the buttocks.

• coccyx—The tip of the coccyx can be palpated in the superior portion of the gluteal cleft.

• ischial tuberosity—Sit down to palpate this structure that is near the gluteal folds of the inferior buttocks. This is the bony prominence of the hip bone that you sit upon.

(f) Surface anatomy of the posterior male pelvis and gluteal region

• coccyx • gluteus maximus muscle • gluteus medius muscle • greater trochanter • iliac crest • ischial tuberosity • posterior superior iliac spine • sacrum

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(g) Surface anatomy of the posterior female pelvis and gluteal region

• sacrum • greater trochanter of the femur • coccyx • gluteal cleft • iliac crest • posterior superior iliac spine • gluteus maximus muscle

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E X E R C I S E 1 5 S U R F A C E A N AT O M Y 245

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(f) Surface anatomy of the posterior male pelvis and gluteal region

FIGURE 15.2 Surface anatomy of the trunk, continued.

(g) Surface anatomy of posterior female pelvis and gluteal region

246 E X E R C I S E 1 5 S U R F A C E A N AT O M Y

lateral part of the shoulder. As you bend your fore- arm at the elbow and abduct your arm, move your fingers a little anteriorly to feel the intertubercular groove where the proximal tendon of the long head of the biceps traverses. The greater tubercle is just posterior to this groove.

Skeletal Muscles • deltoid muscle—This large, triangular muscle forms

J. Lateral Surface of Arm

Structures located in Figure 15.3(b).

Bones and Bone Surface Markings

• lateral epicondyle of humerus—Move your fingers lateral of the olecranon to palpate the lateral epicon- dyle of the humerus.

Skeletal Muscles • biceps brachii muscle—Flex your forearm and

tighten the biceps brachii as you palpate this muscle on the anterior surface of your arm.

• triceps brachii muscle—This muscle can be pal- pated on the posterior surface of the arm when the forearm is extended against resistance. If a person has a muscular arm with definition, all three heads of the triceps can be distinguished.

I. Surface Anatomy of the Shoulder

Structures located in Figure 15.3(a).

Bones and Bone Surface Markings • clavicle—Starting at the manubrium of the sternum,

trace the clavicle’s S-shaped curvature laterally to its acromial end.

• acromion—The flattened lateral end of the spine of the scapula located at the peak of the shoulder. Palpate this prominent projection.

• acromioclavicular joint—Palpate the acromio- clavicular joint just posterior to the acromial end of the clavicle as you thrust your shoulder joint anteriorly.

• spine of scapula—The ridge across the posterior surface of the scapula that extends from the acro- mion to the medial border of the scapula. Palpate this bone with your fingers. The spine is easier to palpate on a lean body.

• greater tubercle of humerus—This bony landmark can be palpated through the deltoid muscle on the

LAB ACTIVITY 3 Surface Anatomy of the Upper Limb

1 Read the location and description of each structure. 2 Locate and label each structure in Figure 15.3(a), (b),

(c), and (d).

3 Palpate the designated structures on your body. ■

(a) Right lateral view of shoulder • acromion • acromioclavicular joint • clavicle • deltoid muscle (lateral fibers) • greater tubercle of humerus • spine of scapula

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(b) Lateral surface of the arm • acromion • deltoid muscle (lateral fibers) • biceps brachii muscle • lateral epicondyle of humerus • triceps brachii muscle

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E X E R C I S E 1 5 S U R F A C E A N AT O M Y 247

(a) Right lateral view of shoulder

4 1

Coracoid process

(b) Lateral surface of the arm and elbow

Olecranon

process

FIGURE 15.3 Surface anatomy of the upper limb.

248 E X E R C I S E 1 5 S U R F A C E A N AT O M Y

of the anterior arm and runs from just proximal of the cubital fossa, through the cubital fossa, to insert on the radial tuberosity.

L. Surface Anatomy of the Antecubital Region

Structures located in Figure 15.3(d).

Skeletal Muscles • brachioradialis muscle—As its name indicates,

this muscle originates in the distal arm (brachium), borders the lateral side of the cubital fossa, and ex- tends to the proximal forearm to insert on the radius. Observe and palpate this muscle as you flex your forearm against resistance.

Other Structures • basilic vein—This superficial vein is seen on the

medial side of the anterior forearm and ascends to the arm. This vein is discernible under the skin of lean people.

• cephalic vein—This superficial vein can be viewed on the lateral side of the anterior forearm and ascends to the arm. This vein is discernible under the skin of lean people.

• cubital fossa (antecubital)—This triangular-shaped concavity is on the anterior surface of the elbow joint.

• median cubital vein—This superficial vein diagonally crosses the anterior surface of the elbow in the cubital (antecubital) fossa. This vein connects the lateral cephalic vein with the medial basilica vein. The median cubital vein is a typical site for drawing blood or for inserting an intravenous (IV) catheter.

K. Medial Surface of Arm and Elbow

Structures located in Figure 15.3(c).

Bones and Bone Surface Markings • medial epicondyle of humerus—Move your fingers

medially from the olecranon to feel the medial epi- condyle. The groove between the olecranon and the medial epicondyle has the ulnar nerve that you can palpate when the forearm is extended.

• olecranon of ulna—With the forearm flexed, pal- pate this prominent point at the elbow. Extend and flex the forearm as you feel this bony landmark.

Skeletal Muscles • biceps brachii muscle—Flex your forearm and

tighten the biceps brachii as you palpate this muscle on the anterior surface of your arm.

• triceps brachii muscle—This muscle can be palpated on the posterior surface of the arm when the forearm is flexed against resistance. If a person has a muscular arm with definition, all three heads of the triceps can be distinguished.

Other Structures • groove for brachial artery—Palpate the medial

border of the flexed biceps brachii muscle. You can feel your brachial pulse if you press into this groove with your fingers.

• tendon of biceps brachii muscle—The distal tendon of the biceps brachii can best be palpated with the forearm flexed. The tendon is located in the middle

(c) Medial view of the arm and elbow • biceps brachii muscle • groove for brachial artery • medial epicondyle of humerus • olecranon of ulna • tendon of biceps brachii muscle • triceps brachii muscle

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(d) Anterior view of antecubital region • basilic vein • biceps brachii muscle • brachioradialis muscle • cephalic vein • cubital fossa • median cubital vein

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E X E R C I S E 1 5 S U R F A C E A N AT O M Y 249

(d) Anterior view of cubital region

FIGURE 15.3 Surface anatomy of the upper limb, continued.

250 E X E R C I S E 1 5 S U R F A C E A N AT O M Y

N. Dorsum of Hand and Wrist

Structures located in Figure 15.3(f).

Bones and Bone Surface Markings • head of ulna—Palpate this distal end of the ulna on

the medial side of the wrist. • styloid process of ulna—Palpate just distal to the

head of the ulna. • styloid process of radius—Palpate this distal end of

the radius on the lateral side of wrist.

Other Structures • cephalic vein and dorsal venous arch—The dorsal

venous arch on the dorsum of the hand drains into the cephalic vein. The plexus of veins in the dorsal venous arch is also a site for drawing blood and inserting an IV catheter.

• anatomical snuffbox—Palpate this depression lo- cated on the dorsum of the hand between the tendon of the extensor pollicis longus muscle and the tendon of the extensor pollicis brevis muscle.

• tendons of extensor muscles—Extend the fingers and palpate the tendons of the extensor digitorum muscles.

M. Anterior Surface of the Wrist and Hand

Structures are located in Figure 15.3(e). The muscles of the forearm are diffi cult to differentiate

from surface anatomy, but four of the muscle tendons are readily discernible in the anterior forearm.

Tendons • flexor carpi radialis tendon—Make a fist to

observe and palpate this laterally located tendon. • flexor carpi ulnaris tendon—Make a fist to palpate

this most medially located tendon. Tendon is not readily apparent.

• flexor digitorum superficialis tendon—Make a fist to observe and palpate this tendon located medial to the palmaris longus tendon.

• palmaris longus tendon—Make a fist to observe and palpate this center-most tendon that is located just medial to the flexor radialis tendon.

Bone and Bone Surface Markings • pisiform bone—Located on the medial side just

distal to the wrist crease. Palpate this small bone that feels like a bump.

Other Structures • radial artery—Note the location of the radial artery

just lateral to the flexor carpi radialis tendon. With three fingers, press down on the radial artery and feel your pulse.

• hypothenar eminence—Palpate this small hand pad located medially just distal to the pisiform bone.

• thenar eminence—Palpate this larger elevation located between the wrist crease and the thumb.

E X E R C I S E 1 5 S U R F A C E A N AT O M Y 251

Tendon of palmaris longus muscle

Tendon of flexor carpi radialis muscle

Radial artery

Pisiform bone

Tendon of flexor carpi ulnaris muscle

Tendon of flexor digitorum superficialis muscle

Wrist crease

Thenar eminence

Hypothenar eminence

(e) Anterior right wrist and hand

(f) Dorsum of hand and wrist

Head of ulna

Styloid process of ulna

Cephalic vein

“Anatomical snuffbox”

Styloid process of radius

Tendon of extensor pollicis brevis muscleTendons of extensor

digitorum muscle

Dorsal venous arch

Tendon of extensor pollicis longus muscle

FIGURE 15.3 Surface anatomy of the upper limb, continued.

252 E X E R C I S E 1 5 S U R F A C E A N AT O M Y

Other Structures • patellar ligament—The quadriceps femoris tendon

extends beyond the patella as the patellar ligament and inserts on the tibial tuberosity. Press your fingers on the tendon between the patella and the tibial tuberosity to palpate the patellar ligament as you extend and flex the leg at the knee.

• femoral triangle [not shown on Figure 15.4(a)]— Triangle of the medial thigh bordered laterally by the sartorius and medially by the gracilis. The femoral artery, vein, and nerve traverse through this tri- angle. Palpate your femoral artery to feel your pulse.

2. Leg, Ankle, and Dorsum of Foot

Bones and Bone Surface Markings • lateral condyle of tibia—Palpate the bump or

projection on the proximal tibia lateral and inferior to the patella.

• medial condyle of tibia—Palpate the bump or projection on the proximal tibia medial and inferior to the patella.

• tibial tuberosity—Palpate this bump on the anterior surface of the proximal tibia just inferior to the patella.

• anterior border of tibia (shin)—With your fingers on the tibial tuberosity, slide down the anterior border of the tibia, better known as the shin.

• medial malleolus of tibia—Palpate the projection at the medial side of the ankle. This bump is formed by the medial malleolus of the tibia.

• lateral malleolus of fibula—Palpate the projection at the lateral side of the ankle. This bump is formed by the lateral malleolus of the fibula.

Skeletal Muscles • tibialis anterior muscle—Move your fingers laterally

from the anterior border of the tibia. Palpate this muscle as you dorsiflex your foot. Note the thick tendon of this muscle as it crosses medially at the ankle to insert on the medial cuneiform bone and the first metatarsal.

• extensor digitorum longus muscle—Palpate the ten- don as you dorsiflex your second through fifth toes.

• fibularis (peroneus) longus muscle—This lateral muscle of the leg is superficial to the fibula and can be palpated as you plantar flex the foot. Its tendon inserts on the plantar surface of the foot.

• extensor hallucis longus muscle—Palpate the tendon as you dorsiflex your great toes.

LAB ACTIVITY 4 Surface Anatomy of the Lower Limb

1 Read the location and description of each structure. 2 Locate and label each structure in Figure 15.4(a)

and (b).

3 Palpate the designated structures on your body. ■

O. Anterior Surface of the Lower Limb

Structures located in Figure 15.4(a).

1. Anterior Thigh

Bones and Bone Surface Markings • lateral condyle of femur—Palpate the bump or

projection on the distal femur lateral to the patella. • medial condyle of femur—Palpate the bump or

projection on the distal femur medial to the patella. • patella—The patella or kneecap is the most anterior

bone of the knee. Place your fingers on the patella and move it slightly.

Skeletal Muscles • adductor longus muscle—Located in the superior

part of the thigh in the femoral triangle, just medial to the sartorius.

• gracilis muscle—Located in the inner thigh region, medial to the femoral triangle. This muscle has fibers that run longitudinally from the pubic bone to the knee.

• sartorius muscle—Anteriorly located, this muscle diagonally spans the area between the anterior superior iliac spine laterally and the medial region of the knee. This muscle forms the lateral border of the femoral triangle.

• rectus femoris muscle—Located in the anterior compartment of the thigh, lateral to the sartorius. This muscle is in the midline and is the most superficial of the quadriceps femoris muscle group.

• vastus lateralis muscle—Large muscle of the quadriceps femoris group located on the lateral surface of the thigh.

• vastus medialis muscle—Large muscle of the quadriceps femoris group located on the medial surface of the thigh.

E X E R C I S E 1 5 S U R F A C E A N AT O M Y 253

4 5

7 10

11 8

(a) Anterior surface of the lower limb

FIGURE 15.4 Surface anatomy of the lower limb.

(a) Anterior surface of the lower limb • adductor longus muscle • gracilis muscle • rectus femoris muscle • sartorius muscle • vastus lateralis muscle • vastus medialis muscle

1 ____________________________________________________

2 ____________________________________________________

3 ____________________________________________________

4 ____________________________________________________

5 ____________________________________________________

6 ____________________________________________________

• lateral condyle of femur • lateral condyle of tibia • medial condyle of femur • medial condyle of tibia • patella • patellar ligament • tibial tuberosity

7 ____________________________________________________

8 ____________________________________________________

9 ____________________________________________________

10 ____________________________________________________

11 ____________________________________________________

12 ____________________________________________________

13 ____________________________________________________

• anterior border of tibia (shin) • lateral malleolus of fibula • fibularis (peroneus) longus muscle • medial malleolus of tibia • tendons of extensor digitorum longus muscle • tendon of extensor hallucis longus muscle • tibialis anterior muscle

14 ____________________________________________________

15 ____________________________________________________

16 ____________________________________________________

17 ____________________________________________________

18 ____________________________________________________

19 ____________________________________________________

20 ____________________________________________________

254 E X E R C I S E 1 5 S U R F A C E A N AT O M Y

P. Posterior Surface of Lower Limb

Structures located in Figure 15.4(b).

1. Posterior Thigh

Skeletal Muscles • biceps femoris muscle—Lateral hamstring muscle.

Palpate muscle while fl exing the knee. • biceps femoris tendon—Move your fingers inferi-

orly until you feel the rope-like that crosses the knee joint.

• semitendinosus and semimembranosus muscles— Medial hamstring muscles. Palpate these muscles while flexing the knee.

• tendon of semitendinosus muscle—Move your fin- gers inferiorly until you feel the tendons that crosses the knee joint.

2. Posterior Leg and Ankle

Bone and Bone Surface Markings • calcaneus—Heel bone of the foot.

Skeletal Muscles • gastrocnemius muscle (medial and lateral heads)—

Two large bellies of the calf muscles that form most of the superior portion of the calf. To palpate these two heads, extend the knee and place your fingers over the medial and lateral heads of the gastrocne- mius. Plantar flex the foot.

• soleus muscle—The flatter calf muscle that lies deep to the gastrocnemius. This muscle extends laterally from the gastrocnemius, and its tendon is in the mid to-distal portion of the calf. Palpate the soleus as you plantar flex the foot.

Other Structures • popliteal fossa—A depression located on the poste-

rior of the knee. • calcaneal (Achilles) tendon—The tendons of both the

gastrocnemius and the soleus merge to insert on the calcaneus bone of the foot. Palpate this thick tendon as you alternately plantar flex and dorsiflex the foot.

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

5 _____________________________________________________

6 _____________________________________________________

7 _____________________________________________________

(b) Posterior surface of the lower limb • biceps femoris muscle • biceps femoris tendon • calcaneus • gastrocnemius muscle (medial and lateral heads) • semitendinosus and semimembranosus muscles • soleus muscle • tendon of semitendinosus

Popliteal fossa

Calcaneal tendon

(b) Posterior surface of the lower limb

FIGURE 15.4 Surface anatomy of the lower limb, continued.

E X E R C I S E 1 6 N E R V O U S T I S S U E 255

Nervous tissue is found in the organs of the nervous system—the nerves, brain, and spinal cord—and contains cells that enable the nervous system to generate and transmit electrical signals called nerve impulses or action potentials.

A. Overview of Nervous System

The nervous system senses changes in our internal and ex- ternal environments, coordinates and integrates data, and initiates and transmits action potentials. It is organized into two basic components: the central nervous system

(CNS), which consists of the brain and spinal cord, and the peripheral nervous system (PNS). The PNS contains an afferent division composed of sensory receptors and sensory neurons, and an efferent division composed of motor neurons. Sensory receptors detect changes in the environment and transmit this information along sensory or afferent nerves to the CNS. The CNS coordinates and integrates information received from sensory receptors and initiates responses that are transmitted by neurons to effectors (neu- rons, muscle cells, or glands). Motor nerves transmit im- pulses from the CNS to effectors in the PNS. The nervous system is streamlined to send rapid signals from cell to cell to maintain homeostasis and coordinate body organs and functions.

O B J E C T I V E S M A T E R I A L S

• compound microscope, lens paper, prepared slides of astrocytes, motor neurons, dorsal root ganglia, cerebral cortex, and teased myelinated nerve fibers or use Real Anatomy (Histology)

• Simulation of Schwann Cell and Axon: zippered 1-quart plastic bag (1 per group), long pencil (1 per group), small smooth pebble or dry bean (1 per group)

• section of brain (human or animal) • section of spinal cord (human or animal) • PowerPhys Experiment: Graded and

Action Potentials

Nervous Tissue 16 E X E R C I S E

1 Describe the functions of the nervous system

2 Name the 2 major divisions of the nervous system and their organs

3 Explain the difference in function between neurons and neuroglia

4 Identify neuron structures and describe their functions

5 Describe how neurons are classified structurally and functionally

6 Identify unipolar, bipolar, and multipolar neurons

7 Describe the difference between myelinated and unmyelinated axons

8 Identify where the gray and white matter are located in the brain and spinal cord

255

256 E X E R C I S E 1 6 N E R V O U S T I S S U E

B. Structure of Nervous Tissue

Nervous tissue is located in the brain, spinal cord, ganglia, and nerves, and is composed of 2 types of cells: neurons and neuroglia. Neurons conduct action potentials and are the structural and functional units of nervous tissue. Neuroglia (neuro- � nerve; -glia � glue) are cells that support, protect, and furnish nutrients to neurons, and augment the speed of neuron transmission.

1. Neuroglia

Neuroglial cells are generally smaller and more abundant than neurons. Although they do not create action potentials, neuroglial cells have important roles in the nervous system. Of the 6 types of neuroglial cells, 4 are in the CNS and 2 are in the PNS. The 4 neuroglial cells in the CNS are astrocytes, oligodendrocytes, microglia, and ependymal cells. Astro- cytes (astro- � star; -cyte � cell) have many processes that make them look star-shaped. Their perivascular (peri- � around; vascular � vessel) feet wrap around and cover neu- rons and blood vessels to keep neurons in place. Astrocytes also guide neurons during development and control the composition of the chemical environment of the neurons by forming a blood–brain barrier. This barrier allows only certain substances to enter the nervous tissue at the blood vessel sites. Oligodendrocytes (oligo- � few; dendro- � tree) support the CNS neurons and have processes that form myelin sheaths around axons to increase the speed of nerve impulses. Microglia (micro- � small) are the phagocytes

(phago- � to eat) of the CNS that engulf debris, necrotic tissue, and invading bacteria or viruses. Ependymal cells (epen- � above; dym- � garment) line all 4 ventricles (spaces or cavities) of the brain, as well as the central canal of the spinal cord. These cells form cerebrospinal fl uid (CSF), and their cilia move the CSF through the ventricles. The 2 neuroglial cells in the PNS are Schwann cells and satellite cells. Schwann cells are fl attened cells that wrap around the axons in the PNS. Many Schwann cells form the myelin sheath around one axon. The myelin sheath increases nerve impulse speed and aids in the regeneration of PNS axons. Satellite cells have processes that are fl attened and surround the sensory neuron cell bodies located in ganglia in the PNS. They give support to these neurons and regulate their chemical environment.

TABLE 16 .1 Neuroglia

CELL TYPE LOCAT ION FUNCT ION

1. ____________________ CNS or PNS Entire cell forms myelin sheath around a segment of an axon; helps regeneration of axons.

2. ____________________ CNS or PNS Lines four brain ventricles; forms and circulates CSF. 3. ____________________ CNS or PNS Engulfs invading microbes; clears debris; migrates to injured nerves. 4. ____________________ CNS or PNS Maintains environment around neurons; forms blood–brain barrier. 5. ____________________ CNS or PNS Covers sensory neuron cell bodies; maintains neuron environment. 6. ____________________ CNS or PNS Processes from cell form myelin sheaths around axons of neurons.

Before Going to Lab

1 Complete Table 16.1 using the following list of cells. Under the “Location” heading, circle CNS or PNS. • astrocyte • ependymal cell • microglia • oligodendrocyte • satellite cell • Schwann cell

2 Label the neuroglial cells in Figure 16.1(a) and (b).

E X E R C I S E 1 6 N E R V O U S T I S S U E 257

• astrocytes (AS-troh-cytes) • ependymal (ee-PIN-dih-mahl) cell • microglial (my-CROG-lee-al) cell • oligodendrocyte

(OL-ih-go-DEN-droh-site) • satellite cell • Schwann (shh-WAN) cell

(a) CNS

(b) PNS

Cells of pia mater

Neuron

Blood capillary

Microvillus

Cilium

(a) CNS

Neurons

Node of Ranvier

Myelin sheath

Axon

(b) PNS

Axon

Neuron cell body in a ganglion

FIGURE 16.1 Neuroglia of the CNS and PNS.

258 E X E R C I S E 1 6 N E R V O U S T I S S U E

LAB ACTIVITY 1 Comparison of a Neuron and an Astrocyte

1 Examine a prepared slide of astrocytes. • Using the low-power objective, find an astrocyte and

center it in the field of view. • Using the high-power objective, identify the cell

body and processes. • Note the size of the astrocytes.

2 Examine a prepared slide of motor neurons or use Real Anatomy (Histology). • Using the low-power objective, find a large motor

neuron and center it in the field of view. • Using the high-power objective, identify the cell

body, nucleus, and dendrites. The axon is difficult to distinguish.

• Note the size of the motor neuron and the numerous small, dark-stained neuroglial cells near the neuron.

3 With your lab group compare the size of astrocytes and motor neurons. ■

Before Going to Lab

1 Label the structures in Figure 16.2(a) and (b). Note the magnification of the cells in these figures.

2 Label the structures in Figure 16.3.

Blood capillary

700�LM(a) Astrocyte

Neuroglia3 4 5 6 7

(b) Motor neuron 260�LM

(a) • cell body • processes

(b) • axon • axon hillock • cell body • dendrites • nucleus

FIGURE 16.2 Photomicrographs of nervous tissue cells.

2. Structure of a Neuron

The longest cells in the body are neurons, which can be over 3 feet long. Think about one neuron being long enough to reach from your spinal cord to the tips of your fi ngers or toes. There are 3 basic parts to any neuron: den- drites, a cell body, and an axon. Both the dendrites and the single axon are processes (extensions) of the neuron cell body. Dendrites receive information from receptors or other neurons and send it as a change in membrane potential to the neuron cell body or soma (soma � body). Neuron cell bodies have most of the organelles that are present in other types of cells. There is usually a triangu- lar or cone-shaped area of the cell body called the axon hillock (hillock � small hill). The axon (axon � axis), a longer process than the dendrites, extends from the axon hillock. Changes in membrane potential travel to the axon hillock where they are integrated to determine whether an action potential will be initiated in the axon. The fi rst part of the axon is known as the trigger area (initial segment), where the action potential begins. The axon may be a single process, or it may have side branches called axon collaterals. Axons and axon collaterals conduct action potentials along their full lengths to end at fi ne processes called axon terminals. Neurotransmitter molecules are released from axon terminals and transmit signals across a synapse to other neurons or to effectors such as muscles or glands.

E X E R C I S E 1 6 N E R V O U S T I S S U E 259

FIGURE 16.3 Parts of a motor neuron.

Mitochondrion

Cytoplasm

Nucleus

Nucleolus

Nucleus of Schwann cell

Synaptic end bulb

Neurolemma of Schwann cell

5 (yellow)

• axon (AX-on) • axon collateral • axon hillock (HILL-ock) • axon terminal • cell body or soma (SO-mah) • dendrites • myelin (MY-e-lin) sheath • node of Ranvier (RON-vee-ay) • Schwann cell • trigger zone (initial segment)

260 E X E R C I S E 1 6 N E R V O U S T I S S U E

spinal cord, the axon of the sensory neuron synapses with either a motor neuron or an interneuron. The interneuron (association neuron) is structurally a multipolar neuron and makes up about 90% of the neurons in the CNS. In the spinal cord, the interneuron can synapse with a chain of interneurons that sends the signal to the brain, and/or it can synapse with a motor (efferent) neuron that takes the impulse out of the spinal cord via a spinal nerve to an effector (muscle or gland). Motor neurons are structurally multipolar neurons.

C. Classification of Neurons

1. Structural Classification of Neurons

Neurons are classifi ed both structurally and functionally. The number of processes that project from the cell body of the neuron determine its structural classifi cation. The multipolar neurons have numerous processes, with many dendrites and one axon. Motor neurons and interneurons (association neurons) are multipolar neurons and com- pose most of the CNS neurons. Bipolar neurons have 2 processes—1 dendrite and 1 axon—on either side of the cell body and are found in the special senses like the retina of the eye, the olfactory cells of the nose, and the inner ear. Unipolar neurons have only 1 process, an axon, leading to and from the neuron cell body. The dendrites are small and attach to the axon instead of the neuron cell body. Unipolar neurons are sensory neurons that bring sensory information from the skin, muscles, and organs to the spinal cord.

2. Functional Classification of Neurons

There are 3 classifi cations of neurons based on their func- tions: sensory, interneuron (association neuron), and motor neuron. Changes in the environment produce a stimulus that is detected by the receptors associated with the den- drites of a sensory (afferent) neuron. This neuron changes the stimulation into an action potential or nervous impulse that travels along the axon to the spinal cord. General sensory neurons are structurally unipolar neurons. In the

1 2 3 4

300�LM(a) Dorsal root ganglia, unipolar neurons

5 6 7

(b) Cerebral cortex, multipolar neurons

(a) • neuron cell body • nucleus • process • satellite cells

(b) • axon • dendrites • neuron cell body

FIGURE 16.4 Sectional views of the dorsal root ganglion and cerebral cortex.

Before Going to Lab

1 Label the neurons in Figure 16.4(a) and (b). 2 Label the structures listed in Figure 16.5(a) and (b).

LAB ACTIVITY 2 Structural and Functional Classifications of Neurons

1 Examine prepared microscope slide of dorsal root ganglia. • Using the low-power objective, locate a neuron and

place it in the center of the field of view. • Identify the neuron cell body, nucleus, and processes.

2 Examine a prepared microscope slide of cerebral cortex. Follow the same steps as above. ■

E X E R C I S E 1 6 N E R V O U S T I S S U E 261

2 31

4 neurons conduct signals from receptors to the CNS

5 neurons are confined to CNS

6 neurons conduct signals from the CNS to effectors such as muscles and glands

Central nervous systemPeripheral nervous system

(a) Structural classification of neurons

(b) Functional classification of neurons

(a) Structural classifications • bipolar neuron • multipolar neuron • unipolar neuron

(b) Functional classifications • interneuron (association neuron) • motor neuron (efferent) • sensory neuron (afferent)

FIGURE 16.5 Structural and functional classifications of neurons.

262 E X E R C I S E 1 6 N E R V O U S T I S S U E

of the Schwann cell or oligodendrocyte plasma membrane covering the axons. Unmyelinated fi bers conduct impulses slower than myelinated fi bers.

D. Myelination of Axons

Two neuroglial cells, the oligodendrocytes (CNS) and the Schwann cells (PNS), form insulated wrappings called myelin sheaths around axons. As Schwann cells wrap around axons, their cytoplasm is pushed to the periphery and is called neurolemma. The multiple layers of my- elin that surround the axons are composed of lipoprotein (about 80% lipids and 20% protein), similar to the makeup of plasma membranes. The high amount of lipid in the myelin sheath gives the axons a whitish appearance. Be- cause babies and children do not have the complete myelin coverings encircling the axons, their need for dietary fat is different from that of an adult and is necessary for proper nervous system development. There is not a continuous myelin sheath around the axon, and gaps do exist between the cells. Gaps in the myelin sheaths are called nodes of Ranvier and are more numerous in the PNS than in the CNS. The myelin sheath provides protection and insulation for the axon, and also increases the speed of conductiv- ity of the nervous impulse (action potential). Myelinated axons are also called myelinated fi bers. The axons that are not myelinated are called unmyelinated fi bers. They still have neuroglial cells but possess only a thin coating

(a) __________________ (b) __________________

FIGURE 16.6 Myelinated and unmyelinated axons.

(a) • axon • myelin sheath • node of Ranvier • Schwann cell cytoplasm

(b) • axons • Schwann cell cytoplasm

LAB ACTIVITY 3 Myelination of Axons

1 Examine a microscope slide of a teased myelinated nerve fiber. • Using the low-power objective, locate a nerve fiber

and place it in the center of the field of view. • Using the high-power objective, identify the nodes

of Ranvier, myelin sheath, axon, and neurolemma.

2 Simulation of a Schwann cell and axon. • Obtain a 1-gallon zippered plastic bag (sandwich

size may be used) and a new pencil. • Add 15 ml (1 tablespoon) water to the bag and push

out all the air. • Add a small smooth pebble or dry bean to the bottom

of the bag and rezip the bag. • Starting at the bottom of the bag, wrap the plastic

bag around and around the pencil, watching the bean being pushed toward the zippered end.

3 Answer the Discussion Questions with your lab group.

DISCUSSION QUESTIONS Myelination of Axons

1 What do the bag and the pencil represent?

2 What do the water and bean represent?

3 Where do the water and the bean end up after the bag is totally wrapped around the pencil?

4 Why is it preferable to use a 1-gallon bag versus a sandwich- size plastic bag?

Before Going to Lab

1 Label the structures on Figure 16.6(a) and (b) and identify (a) and (b) as myelinated or unmyelinated axons.

2 Label the structures in the photomicrograph of a teased myelinated nerve fiber in Figure 16.7.

■

E X E R C I S E 1 6 N E R V O U S T I S S U E 263

1 2 3 4

• axon • myelin sheath (surrounding axon) • neurolemma (ner-oh-LEM-ma) • node of Ranvier

FIGURE 16.7 Teased myelinated nerve fiber.

Frontal plane

Transverse plane

(a) Sectional view of brain (b) Transverse view of spinal cord

FIGURE 16.8 Gray and white matter of brain and spinal cord.

• gray matter in brain and spinal cord • white matter in brain and spinal cord

E. Gray and White Matter in the CNS

Myelin sheaths are white in color, giving nervous tissue with many myelinated axons a white color. Nervous tissue with few myelinated axons appears gray, the color of ner- vous tissue cells. Groups of myelinated axons in the CNS form tracts and are called white matter, whereas unmy- elinated areas comprised of neuron cell bodies, dendrites, axon terminals, and neuroglia are called gray matter. In the brain, there is an outer area or cortex of gray matter, with an inner layer of white matter. There are also deeper areas within the brain that have isolated areas of gray matter; these are called nuclei of the brain and also contain neuron cell bodies and their dendrites. Unlike the brain, the spinal cord has an outer layer of white matter and a central H-shaped area of gray matter.

Before Going to Lab

1 Label gray and white matter in Figure 16.8(a) and (b).

LAB ACTIVITY 4 Gray and White Matter

1 Examine a section of brain and spinal cord, and identify the gray and white matter in each. ■

SAFETY NOTE: Wear safety glasses and gloves when handling preserved or fresh tissue. Always wash your hands thoroughly with soap and water when you are done.

264 E X E R C I S E 1 6 N E R V O U S T I S S U E

Cell body

Axon

Dendrites

6 5

FIGURE 16.9 Types of neuron-to-neuron synapses.

F. Synapses Between Neurons, Graded Potentials, and Action Potentials

We have previously discussed a type of chemical synapse at the neuromuscular junction where the synaptic end bulb released a neurotransmitter across the synaptic cleft to the receptors in the sarcolemma. Now we will study communi- cation between neurons at a chemical synapse that is sim- ilar, except the signal transmission is between two neurons. The neuron sending the neurotransmitter is the presynap- tic neuron, and the neuron receiving the chemical is the postsynaptic neuron. The postsynaptic neuron produces a type of graded potential called a postsynaptic potential. The postsynaptic neuron converts the postsynaptic poten- tial into an electrical signal. There are three types of neuron-to-neuron synapses that are named according to where the presynaptic neuron ana- tomically forms a synapse with the postsynaptic neuron. Most synapses are either axoaxonic (from axon to axon), axodendritic (from axon to dendrite), or axosomatic (from axon to the cell body).

LAB ACTIVITY 5 Graded and Action Potentials

1 Complete the PowerPhys Experiment: Graded and Action Potentials. ■

Before Going to Lab

1 Identify the type of synapse (#1 through 3) in Figure 16.9, using the bulleted list. • axosomatic 1.

• axoaxonic 2.

• axodendritic 3.

2 Write the numbers 4 through 8 shown in Figure 16.9 next to the phrase that describes the action that is occurring.

________ action potential started on postsynaptic neuron

________ graded potential sent toward trigger zone

________ action potential reaches axon terminal

________ action potential travels down axon

________ dendrites on postsynaptic neurons receive neurotransmitter at synapse

Name ___________________________________ Date _________________ Section ______________________________

265

16 E X E R C I S E

A. Organization of Nervous System

Fill in the blanks with the correct term chosen from the following:

afferent motor effectors peripheral efferent receptors

If you touch a hot stove with your hand, the sensory (1) ________________ in your hand send

a signal of pain to the CNS through the (2) ________________ nerve fibers of the

(3) _______________ nervous system. When the information

reaches the CNS and is processed, a(n) (4) ________________ response

is sent through the (5) ________________ nerve fibers of the

PNS system to skeletal muscles that are (6) ________________.

B. Nervous Tissue Cells

Write the name of the nervous tissue cell described.

1. Supporting cells of PNS

4. Supporting cells of CNS

7. Form myelin sheaths

9. Regulate chemical environment of neurons

10.

Reviewing Your Knowledge

¯ ˚

˚ ˘

˚ ˚

˙ ¯

˘ ˙

¯ ˘

˙ ¯

˘ ˙

266 E X E R C I S E 1 6 N E R V O U S T I S S U E

11. Generate and transmit nerve impulses

12. Line cavities of brain and spinal cord; form and move CSF

13. Phagocytes that destroy debris, dead tissue, and pathogens

C. Structural Classification of Neurons

Identify the neuron type described.

1. Many processes associated with the cell body

2. Has two cell processes

3. One short process extends from the cell body and divides

4. Neuron is rare and is the sensory neuron in the eye and nose

D. Functional Classification of Neurons

Identify the neuron type described.

1. Functional neuron types that are structurally multipolar neurons

3. Neuron types whose cell bodies are in the spinal cord (CNS)

5. Neuron type that is structurally either a unipolar neuron or bipolar neuron whose cell body is found in the PNS

6. Functional neuron type most prevalent in the CNS

E. Myelination of Axons and Gray and White Matter

¯ ˘

˙ ¯

˘ ˙

Match the description to the appropriate term.

a. gray matter b. white matter c. myelinated fibers d. unmyelinated fibers e. nodes of Ranvier

____ 1. Contains myelinated fibers

____ 2. Contains neuron cell bodies and unmyelinated fibers

____ 3. Nerve fibers that are white in color and conduct nerve impulses faster

____ 4. Nerve fibers that are gray in color

____ 5. Gaps in the myelin sheath

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Name ___________________________________ Date _________________ Section ______________________________

267

Using Your Knowledge

16 E X E R C I S E

A. Conduction of a Nervous Impulse

Reorder the following parts of a multipolar neuron in the correct order (1–8) of receiving and sending the nerve impulse. Start with the dendrites as number 1.

____ 1. axon

____ 2. axon hillock

____ 3. axon terminal

____ 4. cell body

____ 5. dendrites

____ 6. second neuron or effector

____ 7. synapse

____ 8. trigger zone

B. Nervous Tissue and Diseases

Using your textbook or other references, identify the nervous tissue cell(s) that is (are) involved in the following diseases:

9. Multiple sclerosis

10. Epilepsy

C. Overview of Communication within the Nervous System

Match the numbers in Figure 16.10 with the description of what is happening at that site. Start with number 1.

____1 Graded potential starts in a sensory receptor in the skin.

____ A synapse in the thalamus creates a graded potential followed by an action potential in a secondary interneuron, which reaches the cerebral cortex.

268 E X E R C I S E 1 6 N E R V O U S T I S S U E

____ The graded potential triggers an action potential in a sensory neuron.

____ The lower motor neuron forms a neuromuscular synapse with the hand muscles, which causes the muscles to contract as he writes the letter.

____ In another synapse, the neurotransmitter creates a graded potential, which triggers an action potential in the lower motor neuron.

____ A primary interneuron forms an action potential and crosses to the opposite side of the brain.

____ A stimulus from the brain causes a graded potential and then an action potential to form in an upper motor neuron (which crosses back to the original side of the body).

____ At a synapse, a presynaptic sensory neuron stimulates the postsynaptic interneuron to form a graded potential in its cell body.

Graded potential Nerve action potential Muscle action potential

Left side of brainRight side of brain

Cerebral cortex

Brain

Thalamus

Lower motor neuron

Skeletal muscles

Neuromuscular junction

Upper motor neuron

Interneuron

Spinal cord

Key:

Interneuron

Sensory neuron

Sensory receptor

6 4

FIGURE 16.10 Overview of nervous system communication.

E X E R C I S E 1 7 S P I N A L C O R D S T R U C T U R E A N D F U N C T I O N 269

O B J E C T I V E S M A T E R I A L S

• models or charts of the complete spinal cord, transverse section of the spinal cord, and verte- bral column with spinal cord or use Real Anatomy (Nervous)

• compound microscope, lens paper, and prepared microscope slides of spinal cord transverse section

• Dissection: preserved or fresh spinal cord with meninges, dissection equipment, disposable gloves, safety glasses

Spinal Cord Structure and Function

17 E X E R C I S E

1 Describe the protective structures of the spinal cord

2 Identify and describe the external features of the spinal cord

3 Identify and describe the anatomical features of a spinal cord transverse section

269

The spinal cord and the brain make up the central nervous system. Being continuous with the brain, the spinal cord begins at the foramen magnum and terminates between vertebrae L1 and L2. It is suspended within the vertebral canal, an area formed by the vertebral foramina of the cervical, thoracic, and lumbar ver- tebrae. The spinal cord has 2 functions: (1) it carries sensory information to the brain and motor output to nerves, and (2) it mediates spinal reflexes. Spinal reflexes process sen- sory input from and convey motor output to the spinal nerves.

A. Protective Structures and Spinal Meninges

The spinal cord is protected by the bony vertebrae, adi- pose tissue, spinal meninges, and cerebrospinal fl uid. Adi- pose tissue cushions the spinal cord and is found within the space between the vertebrae and the meninges known as the epidural space. The 3 meninges (meninx, sing.) or connective tissue membranes cover the spinal cord and are continuous with the cranial meninges that protect the brain. Dura mater, the outer meninx, is a tough, single-layered membrane that is deep to the epidural space and superfi cial to the spider web-like arachnoid mater. The inner me- ninx, the pia mater, is delicate and hugs the spinal cord. Denticulate ligaments are lateral extensions of pia mater that fuse with arachnoid mater and secure the spinal cord. Between the pia and arachnoid mater is the subarachnoid space that contains cerebrospinal fl uid, which also cush- ions the spinal cord.

270 E X E R C I S E 1 7 S P I N A L C O R D S T R U C T U R E A N D F U N C T I O N

The inferior lumbar enlargement is located at levels T9 through T12 and contains nuclei for the lower extremities. The spinal cord ends inferiorly as the conus medullaris between vertebral levels L1 and L2. Nerves arising from the inferior portion of the spinal cord continue inferiorly as a group called the cauda equina (cauda � tail; equin- � horse), or “horse’s tail.” An extension of the pia mater con- tinues past the conus medullaris as the fi lum terminale (fi lum � fi lament; termin- � terminal) and connects the inferior end of the spinal cord to the coccyx.

2 1

Spinous process of vertebra

POSTERIOR

Body of vertebraDenticulate ligament

FIGURE 17.1 Transverse section of spinal cord showing meninges.

• dura mater • epidural space • pia mater • subarachnoid space • web-like projection of arachnoic mater

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

Before Going to Lab

1 Label the meningeal structures in Figure 17.1.

Before Going to Lab

1 Label the spinal cord structures in Figure 17.2.

LAB ACTIVITY 1 Spinal Meninges

1 Identify the meningeal structures in Figure 17.1 on a spinal cord model, chart, or use the search text box in Real Anatomy (Nervous) to find these structures. ■

B. External Features of the Spinal Cord

The long, cylindrical spinal cord has 31 pairs of spinal nerves attached to it, with each pair of spinal nerves aris- ing from a different segment of the cord. The cord is wider in the cervical and lumbar regions, forming two enlarge- ments. The cervical enlargement is located at levels C3 or C4 through T1. This bulge designates the location of nuclei (collection of neuron cell bodies) for the upper extremities.

LAB ACTIVITY 2 External Features of the Spinal Cord

1 Identify the spinal cord structures in Figure 17.2 on a spinal cord model, chart, or use the search text box in Real Anatomy (Nervous) to find these structures. ■

E X E R C I S E 1 7 S P I N A L C O R D S T R U C T U R E A N D F U N C T I O N 271

Conus medullaris

Filum terminale

SUPERIOR

(b) Posterior view of inferior portion of spinal cord

INFERIOR

Posterior (dorsal) rami of spinal nerves

Cauda equina

Sacrum

Right coccygeal nerve

Dura mater

• cauda equina (CAU-da ee-QUI-na) • cervical enlargement • conus medullaris (CO-nus med-u-LAR-is) • filum terminale (FI-lum ter-min-AL-ee) • lumbar enlargement

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

5 _____________________________________________________

FIGURE 17.2 Posterior view of longitudinal spinal cord.

(a) Posterior view

272 E X E R C I S E 1 7 S P I N A L C O R D S T R U C T U R E A N D F U N C T I O N

sensory and motor roots merge to form the spinal nerve, these nerves are called mixed nerves. Near the spinal cord, there is a bulge in the posterior (dorsal) root called the pos- terior (dorsal) root ganglion. The posterior (dorsal) root ganglion consists of somatic sensory neuron cell bodies that synapse onto interneuron and/or motor neuron cell bodies in the spinal gray matter.

C. Transverse Section of the Spinal Cord

The most obvious parts of the spinal cord in cross-section are the anterior median fi ssure, the posterior median sul- cus, and the gray and white matter. The anterior median fi ssure is a wide, deep groove on the anterior surface of the spinal cord, and the posterior median sulcus is a narrow groove on the posterior surface. The gray matter looks like a butterfl y or a modifi ed “H” and is more centrally located than the white matter. The gray matter is divided into the anterior, lateral, and posterior gray horns and con- sists of nerve cell bodies and dendrites. Somatic motor neuron cell bodies are located in the anterior (ventral) gray horns, whereas the lateral gray horns (not present in cervical cord segments) contain cell bodies of autonomic motor neurons. The posterior (dorsal) gray horns con- tain neuron cell bodies that receive impulses from sensory neurons. The gray commissure is a narrow bridge of gray matter that connects the right and left sides of gray matter in the middle of the spinal cord. The central canal is in the center of the gray commissure and contains cerebrospinal fl uid. White matter surrounds the gray matter and forms the anterior, lateral, and posterior white columns. These columns or funiculi are made up of white, myelinated fi - bers (axons) that are either sensory or motor fi bers. A spinal nerve is formed from a posterior (dorsal) root and an anterior (ventral) root. Roots are collections of axons that are going to and leaving the spinal cord. The posterior (dorsal) root carries sensory fi bers, whereas the anterior (ventral) root carries motor fi bers. Because the

Before Going to Lab

1 Label Figures 17.3 and 17.4. 2 Label the photomicrograph of a transverse section of the

spinal cord in Figure 17.5.

LAB ACTIVITY 3 Transverse Section of Spinal Cord

1 Identify the spinal cord structures in Figures 17.3 and 17.4 on a transverse section model or chart of the spinal cord, or use the search text box in Real Anatomy (Nervous) to find these structures.

2 Examine a prepared microscope slide of a transverse section of the spinal cord. • Using the low-power objective lens, identify the

structures listed in Figure 17.5. • Using the high-power objective, observe myelin-

ated axons in the white matter and unmyelinated processes, neuron cell bodies, and neuroglia in the gray matter. ■

• anterior median fissure • anterior (ventral) root • central canal • posterior (dorsal) root • posterior (dorsal) root ganglion (GANG-li-on) • posterior median sulcus • spinal nerve

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

7 ________________________ANTERIOR

POSTERIOR

7 Gray matter

Anterior rootlets

White matter

FIGURE 17.3 Transverse section of spinal cord.

E X E R C I S E 1 7 S P I N A L C O R D S T R U C T U R E A N D F U N C T I O N 273

POSTERIOR

Transverse section of the thoracic spinal cord

• anterior gray horn • anterior white column • gray commissure (COM-mis-sure) • lateral gray horn • lateral white column • posterior gray horn • posterior white column

1 ___________________________________

2 ___________________________________

3 ___________________________________

4 ___________________________________

5 ___________________________________

6 ___________________________________

7___________________________________

FIGURE 17.4 Transverse section of spinal cord with areas of gray and white matter.

FIGURE 17.5 Photomicrograph of transverse section of spinal cord with spinal nerve.

• anterior gray horn • anterior median fissure • anterior (ventral) root • anterior white column • central canal • gray commissure • lateral white column • posterior (dorsal) root • posterior (dorsal) root

ganglion

• posterior gray horn • posterior white column • posterior median sulcus

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 _________________________

6 ________________________

7 _______________________

8 _______________________

9 _______________________

10 _______________________

11 _______________________

12 _______________________

7 8 9 10 11 12

1 3 52 4 6 POSTERIOR

274 E X E R C I S E 1 7 S P I N A L C O R D S T R U C T U R E A N D F U N C T I O N

D. Dissection of the Spinal Cord

Use either a preserved cow or sheep spinal cord or a fresh spinal cord from a butcher. Remember: If the specimen is preserved, it will be fi rmer and look different than a fresh specimen.

SAFETY NOTE: Use safety glasses and gloves when han- dling preserved or fresh tissue. Always wash your hands thoroughly with soap and water when you are done.

LAB ACTIVITY 4 Spinal Cord Dissection

1 Observe the posterior structures of the spinal cord in Figure 17.6(a) and then the anterior structures in Figure 17.6(b). • After putting on your gloves, place the spinal cord in

the dissection pan. • Use a blunt probe or forceps to separate the spinal

meninges. • Identify the dura and arachnoid mater. • Use a pointed dissection probe or pin to detach the

pia mater from the spinal cord. • Identify the denticulate ligaments. • Peel back the meninges to uncover the posterior

(dorsal) and anterior (ventral) roots of the spinal nerve. Locate the rootlets.

• Identify the anterior rami and posterior rami.

2 Observe transverse section structures. Refer to Figure 17.4 and Figure 17.5. • Cut a 1 � 4 inch to 1 � 2 inch section from your

spinal cord specimen. • Identify the anterior median fissure, posterior

median sulcus, central canal, gray commissure, gray horns, and white columns.

3 Clean up as directed by your instructor. ■

Fourth ventricle

Dura mater

SUPERIOR

INFERIOR (a) Posterior view

Cerebellum of brain (cut)

Occipital bone (cut)

Posterior median sulcus

Posterior rootlets

Denticulate ligaments

Vertebral artery

Posterior (dorsal) root

Anterior (ventral) root

Spinal nerve

Spinal nerve Anterior (ventral) ramus Posterior (dorsal) ramus

(b) Anterior view and oblique section of spinal cord

Denticulate ligament

Pedicle of vertebra (cut)

Dura mater and arachnoid mater

FIGURE 17.6 Spinal cord.

Name ___________________________________ Date _________________ Section ______________________________

275

Reviewing Your Knowledge

17 E X E R C I S E

A. Meninges

Write the name of the structure described.

1. Middle meninx; web-like

2. Tough, outer meninx

3. Space filled with adipose tissue

4. Thin meninx intimate with spinal cord

5. Contains cerebrospinal fluid

6. Extension of pia mater attaching to dura

B. Spinal Cord Structures

Write the terms that match the description.

1. Contains neuron cell bodies and unmyelinated processes

2. Shallow groove on dorsal side

3. Connects right and left halves of gray matter in spinal cord

4. Sensory branch of spinal nerve entering spinal cord

5. Tapered end of spinal cord

6. Motor branch of spinal nerve exiting spinal cord

7. Contains sensory neuron cell bodies

8. Collection of spinal nerves that arise from inferior end of spinal cord

9. Contains myelinated axons

276 E X E R C I S E 1 7 S P I N A L C O R D S T R U C T U R E A N D F U N C T I O N

10. Contains somatic motor neuron cell bodies

11. Space in center of spinal cord that contains cerebrospinal fluid

12. Bulge in spinal cord containing cell bodies of motor neurons supplying upper limb

13. Wide, deep groove on ventral side

14. Extension of pia mater that attaches spinal cord to coccyx

15. Bulge in spinal cord at T9–T12

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

277

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

17 E X E R C I S E

A. Spinal Cord Transverse Section

Label Figure 17.7.

FIGURE 17.7 Photographic cross-section of spinal cord and cervical vertebra.

Spinous process of vertebra

Transverse foramen

Body of vertebra

4 (Meninx)

Spinal cord

5 (Meninx)

Spinal nerve

Vertebral artery in transverse foramen

POSTERIOR

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

5 _____________________________________________________

6 _____________________________________________________

278 E X E R C I S E 1 7 S P I N A L C O R D S T R U C T U R E A N D F U N C T I O N

B. Spinal Cord Questions

7. The polio virus can cause skeletal muscle paralysis by destroying neuron cell bodies. Identify the area of the spinal cord that is destroyed.

8. Shingles is a condition characterized by pain, discoloration of the skin, and eruption of skin blisters along a sensory nerve. It is caused by the herpes zoster virus, the same virus that causes chicken pox. Using your textbook or another source, identify the spinal cord structure to which herpes virus retreats after chicken pox. The virus remains dormant there until it is activated and causes a shingles outbreak.

9. Identify the structural class(es) of neurons whose cell bodies are present in the spinal cord—unipolar, bipolar, or multipolar.

10. Nerve fibers are classified according to diameter and presence or absence of a myelin sheath. Using your textbook or another reference, name the nerve fiber types (Type A, B, C) present in the:

(a) anterior root (b) posterior root

11. When removing cerebrospinal fluid during a spinal tap, the needle is inserted below L2. Explain why spinal taps are not done above this level.

C. Pathway of Sensory and Motor Impulses

Numbering 1–5, indicate the order of structures through which sensory impulses pass as they enter the spinal cord and travel toward the brain.

____ 12. posterior (dorsal) root ganglion

____ 13. posterior (dorsal) root

____ 14. posterior gray horn

____ 15. white column

____ 16. spinal nerve

Numbering 1–4, indicate the order of structures through which motor impulses pass as they descend from the brain and leave the spinal cord.

____ 17. spinal nerve

____ 18. white column

____ 19. anterior (ventral) gray horn

____ 20. anterior (ventral) root

E X E R C I S E 1 8 SPINAL NERVES 279

Spinal Nerves 18 E X E R C I S E

279

Spinal nerves send information from periph-eral sensory receptors to the spinal cord and infor-mation from the spinal cord to effectors (muscles and glands). The 31 pairs of spinal nerves emerge from each side of the spinal cord through the intervertebral foramina and are named for the vertebral region and level from which they emerge. Spinal nerves connect to the spinal cord via a posterior (dorsal) root and an anterior (ventral) root and are called mixed nerves because each nerve contains sensory and motor axons.

A. Connective Tissue Coverings of Spinal Nerves

Each spinal nerve has 3 protective connective tissue layers: the epineurium (neuri- � nerve) that surrounds the whole nerve, the perineurium that encases each fascicle (fasciculus � little bundle), and the endoneurium that covers myelinated and unmyelinated axons.

O B J E C T I V E S M A T E R I A L S

• compound microscope, lens paper, prepared microscope slide of peripheral nerve cross-section, and prepared microscope slide of peripheral nerve longitudinal section

• model or chart of vertebral column with spinal cord and spinal nerves or use Real Anatomy (Nervous)

• model or chart with spinal nerves of the upper and lower extremities or use Real Anatomy (Nervous)

• Dissection: preserved cat or fetal pig, dissection equipment, dispoable gloves, safety glasses, and dissection manual

• Real Anatomy: Virtual Cadaver Dissection

1 Describe the connective tissue coverings of the spinal nerves

2 Identify the rami that carry impulses to and away from the spinal cord

3 Describe the organization and distribution of spinal nerve divisions and the formation of the spinal plexuses

4 Identify the 4 spinal plexuses and the major nerves arising from each plexus

280 E X E R C I S E 1 8 S P I N A L N E R V E S

B. Rami of the Spinal Nerves

The spinal nerves branch lateral to the intervertebral fora- men. These branches or rami (rami (pl.) � branches; ramus (sing.) � branch) are the posterior (dorsal) ramus, the anterior (ventral) ramus, the meningeal branch, and the rami communicantes. The posterior (dorsal) ramus curves around to the dorsal surface and innervates the skin and deep muscles of the back or trunk. The anterior (ven- tral) ramus supplies the muscles and skin of all four limbs, as well as the anterior and lateral parts of the body. The meningeal branch serves the vertebrae, vertebral liga- ments, blood vessels of the spinal cord, and the meninges. The 2 rami communicantes (communicans � communicating) connect to the sympathetic ganglion (sympathein � to feel with) of the autonomic nervous system.

Before Going to Lab

1 Label Figures 18.1 and 18.2.

LAB ACTIVITY 1 Connective Tissue Coverings of Spinal Nerves

1 Examine a prepared microscope slide of a cross-section of a spinal nerve. • Using the low-power objective lens, identify the

epineurium, fascicles, and perineurium. • Using the high-power objective lens, identify the

endoneurium, axons, and the myelin sheath of myelinated neurons. ■

• axon (AX-on) • endoneurium (endo-NEUR-i-um) • epineurium (epi-NEUR-i-um) • fascicle (FAS-i-cul) • myelin sheath • perineurium (peri-NEUR-i-um) • spinal nerve

7 _____________________________________________________ FIGURE 18.1 Transverse section showing the coverings of a spinal nerve.

FIGURE 18.2 Photomicrograph of a transverse section through a fascicle of a spinal nerve.

• axon • endoneurium • myelin sheath • perineurium

1 2 3 4

E X E R C I S E 1 8 SPINAL NERVES 281

Before Going to Lab

1 Label Figure 18.3.

LAB ACTIVITY 2 Rami of the Spinal Nerves

1 Identify the structures from Figure 18.3(a) and (b) on a model or chart. ■

• anterior (ventral) ramus (RAY-mus) • posterior (dorsal) ramus • rami communicantes

(RAY-my com-mun-i-CAHN-tayce) • spinal nerve

1 _______________________________________

2 _______________________________________

3 _______________________________________

4 _______________________________________

• anterior (ventral) ramus • intervertebral foramen • posterior (dorsal) ramus • rami communicantes • sympathetic ganglion

5 _______________________________________

6 _______________________________________

7 _______________________________________

8 _______________________________________

9 _______________________________________

FIGURE 18.3 Spinal cord with branches of a spinal nerve.

POSTERIOR

Posterior (dorsal) root

Meningeal branch

Anterior (ventral) root

Sympathetic ganglion

(b)

(a)

Transverse section

Lateral view

282 E X E R C I S E 1 8 S P I N A L N E R V E S

C. Spinal Nerve Divisions and the Four Spinal Plexuses

Of the 31 pairs of spinal nerves, there are 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. Many spi- nal nerves join with other spinal nerves to form a braided network or plexus before they innervate body structures. This occurs in 4 regions of the body where the networks form the cervical, brachial, lumbar, and sacral plexuses. The thoracic (intercostal) spinal nerves (T2–T12) do not form a plexus.

Before Going to Lab

1 Label the cervical, thoracic, lumbar, sacral, and coccy- geal nerves in Figure 18.4.

2 Label the 4 spinal plexuses also in Figure 18.4.

LAB ACTIVITY 3 Spinal Nerve Divisions and Spinal Plexuses

1 Identify the spinal nerve divisions and plexuses from Figure 18.4 on a model, chart, or use the search text box in Real Anatomy (Nervous) to find these structures. ■

• brachial plexus (PLEX-us)

• cervical nerves • cervical plexus • coccygeal

(cox-sih-GEAL) nerve • lumbar nerves • lumbar plexus • sacral nerves • sacral plexus • thoracic nerves

1 _______________________

2 _______________________

3 _______________________

4 _______________________

5 _______________________

6 _______________________

7 _______________________

8 _______________________

9 _______________________

Atlas (first cervical vertebra)

Medulla oblongata

C4 C5 C6 C7 C8 T1 T2 T3 T4 T5

T10

T11

T12

C2 C3

L1 L2

S2 S3 S4

FIGURE 18.4 Posterior view of the four spinal plexuses.

E X E R C I S E 1 8 SPINAL NERVES 283

D. Major Nerves from the Cervical and Brachial Plexuses

The cervical plexus is formed from the anterior (ventral) rami of C1–C5 on both the right and left sides of the spi- nal cord. An important paired nerve from this plexus is the phrenic nerve (phreni- � relating to the diaphragm), C3–C5, which innervates the diaphragm and is important for breath- ing. Remember the saying, “Cervical nerves 3, 4, and 5 keep the diaphragm alive.” Other cervical nerves mainly supply the scalp, neck, shoulders, and chest. The brachial plexus is formed from the ventral rami of C5–T1. This plexus serves the shoulders and upper limbs. The main nerves that arise from the brachial plexus are the axillary, median, musculocutane- ous (musculo- � muscle; cutan- � skin), radial, and ulnar.

Before Going to Lab

1 Label the spinal nerves in Figure 18.5.

LAB ACTIVITY 4 Major Nerves from the Cervical and Brachial Plexuses

1 Identify the nerves from Figure 18.5 on a model, chart, or use the search text box in Real Anatomy (Nervous) to find these structures.

2 Identify approximate location of nerves in Table 18.1 on yourself and demonstrate muscle action that occurs when each nerve is stimulated.

3 Test nerve conduction. • Flex your forearm to 90�. • Palpate a cord-like nerve between your medial

epicondyle and olecranon process. • Place pressure on the nerve with your fingers until you

feel a difference in your forearm, hand, and digits. • Describe what sensations you felt and what nerve

was compressed. • Describe what digits are involved and what produced

your symptoms.

4 Discuss your results with the class.

5 (Posterior to bone)

ANTERIOR VIEW

FIGURE 18.5 Major nerves from the cervical and brachial plexuses.

• axillary nerve • median nerve • musculocutaneous

(mus-cu-lo-cu-TAYN-e- ous) nerve

• phrenic (FREN-ic) nerve • radial nerve • ulnar nerve

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

TABLE 18.1 Motor Function of Major Nerves from Cervical and Brachial Plexuses

NER VE MUSCLES INNER VATED BY NER VE

Phrenic Diaphragm Axillary Deltoid and teres minor muscles Musculocutaneous Anterior muscles of the arm Ulnar Flexor carpi ulnaris, medial-half of flexor digitorum profundis, and most hand muscles Median Muscles of anterior forearm (excluding flexor carpi ulnaris and other muscles supplied by

ulnar nerve) and some of the muscles of the hand Radial Muscles of posterior arm and forearm

284 E X E R C I S E 1 8 S P I N A L N E R V E S

E. Major Nerves from the Lumbar and Sacral Plexuses

The lumbar plexus is made up of anterior (ventral) rami from L1–L4. The lumbar plexus supplies the skin and muscles of the abdominal wall, external genitalia, and part of the lower limbs. The major nerves are the femoral and obturator nerves. The sacral plexus is formed from the anterior (ven- tral) rami from L4–S4. This plexus supplies the buttocks, perineum, and most of the lower limbs. Its major nerves are the pudendal and sciatic. The sciatic is composed of the tibial and common fi bular (peroneal) nerves.

Before Going to Lab

1 Label the nerves listed in Figure 18.6.

LAB ACTIVITY 5 Major Nerves from the Lumbar and Sacral Plexuses

1 Identify the nerves from Figure 18.6 on models, charts, or use the search text box in Real Anatomy (Nervous) to find these structures.

2 Identify approximate location of nerves in Table 18.2 on yourself and demonstrate muscle action that occurs when each nerve is stimulated. ■

TABLE 18.2 Motor Function of Nerves from the Lumbar and Sacral Plexuses

NER VE MUSCLES INNER VATED BY NER VES

Femoral Iliacus, quadriceps femoris, sartorius, pectineus Obturator Adductor longus, adductor brevis, and part of adductor magnus, gracilis Common fibular Fibularis longus muscle, tibialis anterior, extensor digitorum longus Pudendal Muscles of perineum Sciatic Biceps femoris, semimembranosus, semitendinosus (hamstrings) Tibial Gastrocnemius, soleus, tibialis posterior, flexor digitorum longus, plantaris, flexor hallucis longus

ANTERIOR VIEW

(b) Distribution of nerves from the lumbar and sacral plexuses

POSTERIOR VIEW

FIGURE 18.6 Major nerves of the lumbar and sacral plexuses.

• femoral (FEM-o-rul) nerve • obturator (OB-tur-a-tor)

nerve • common fibular

(peroneal) • pudendal (pyoo-DEN-dal) • sciatic (sci-A-tic) • tibial

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

F. Dissection of Nerve Plexuses and Major Nerves

If you are dissecting an animal to observe nerves, refer to the dissection manual. Major nerves of animal plexuses are similar to human nerves and will reinforce your knowledge of human nerves. This dissection will allow you to observe the fascia that surrounds and protects the nerves as well as showing you how nerves dive between skeletal muscles to surface in other locations. Real Anatomy, a virtual cadaver dissection, can be used to complement or substitute for animal dissection of nerves.

SAFETY NOTE: Wear safety glasses and gloves when using fresh or preserved tissue. Wash hands thoroughly with soap and water when you are done.

Reviewing Your Knowledge

285

Name ___________________________________ Date _________________ Section ______________________________

18 E X E R C I S E

A. Connective Tissue Coverings

Identify the connective tissue covering.

______________________ 1. Covers unmyelinated or myelinated axons

______________________ 2. Covers fascicles

______________________ 3. Covers nerves

B. Rami of Spinal Nerves

Identify the spinal nerve ramus.

______________________ 1. Branch that serves the deep muscles and skin of the back

______________________ 2. Branches that belong to the sympathetic nervous system

______________________ 3. Branch that forms nerves serving the limbs

C. Major Nerves of the Nerve Plexuses

Identify the nerve plexus from which each nerve originates.

______________________ 1. femoral n.

______________________ 2. sciatic n.

______________________ 3. phrenic n.

______________________ 4. ulnar n.

______________________ 5. axillary n.

______________________ 6. tibial n.

______________________ 7. obturator n.

286 E X E R C I S E 1 8 S P I N A L N E R V E S

______________________ 8. radial n.

______________________ 9. common fibular n.

______________________ 10. pudendal n.

D. Spinal Nerves

Complete the sentences with the correct term about the spinal nerves.

1. The sciatic nerve is composed of two nerves, the _________________.

2. and the _________________.

3. There are ______ pairs of spinal nerves.

4. The nerve that supplies the posterior thigh _________________.

5. There is (are) ______ pair(s) of coccygeal nerves.

6. If the anterior (ventral) ramus of a spinal nerve is severed, there is a _________________ (motor and/or sensory) loss.

7. There is (are) ______ pair(s) of thoracic nerves.

8. The nerve that supplies the anterior thigh is the _________________.

9. There is (are) ______ pair(s) of sacral nerves.

10. There is (are) ______ pair(s) of lumbar nerves.

11. If the posterior (dorsal) ramus of a spinal nerve is severed, the functional loss is _________________ (motor and/or sensory).

12. There is (are) ______ pair(s) of cervical nerves.

13. The _________________ nerve supplies the deltoid and teres minor muscles.

14. The _________________ nerve supplies the triceps brachii muscles and the extensor digitorum longus.

15. The _________________ nerve supplies the biceps brachii muscles.

16. The _________________ nerve supplies the diaphragm.

17. The _________________ nerve supplies most hand muscles.

18. The _________________ nerve supplies the flexor carpi radialis.

¯ ˘ ˙

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

287

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

18 E X E R C I S E

Identify the correct nerve for each question.

_______________________ 1. A broken forearm resulted in an inability to pronate the forearm and loss of finger movement in digits 1–3. Name the nerve that was injured.

_______________________ 2. An injection into the shoulder results in an inability to extend the wrist and fingers. Name the nerve that was injured.

_______________________ 3. Health care professionals are taught how to properly administer gluteal injections to avoid pain and injury caused by inadvertently striking a major nerve. Name the nerve to avoid.

_______________________ 4. Hitting the medial epicondyle results in a tingling sensation in part of the hand. Name the nerve hit and the part of the hand that tingles.

_______________________ 5. John Jones injured his spinal cord. He has use of his serratus anterior muscle, biceps brachii, and deltoid. However, he does not have movement in most muscles of his hand and digits 4 and 5. Where is his spinal cord injury?

_______________________ 6. Following the birth of her daughter, Mary had trouble adducting her lower limbs. Which nerve was injured during childbirth?

_______________________ 7. Charles broke his leg playing softball. The fracture was a compound fracture of the fibula. After the cast was removed, he experienced difficulty dorsiflexing his foot. Which nerve was affected?

Identify the nerve that would carry pain impulses from each of the following injured areas.

_______________________ 8. Greenstick fracture of the tibia

_______________________ 9. Sunburn on the skin over deltoid muscles

_______________________ 10. Splinter in digit 5 of the hand

E X E R C I S E 1 9 S O M AT I C R E F L E X E S 289

Reflexes are rapid, involuntary motor responses to an environmental stimulus detected by sensory receptors. A nerve impulse travels from the receptor through a neural reflex arc pathway to an effector. If the motor response is contraction of skeletal muscle, the reflex is a somatic reflex. If the motor response involves cardiac muscle, smooth muscle, or glands, the reflex is an autonomic (visceral) reflex. Reflexes medi- ated by spinal nerves are called spinal reflexes, whereas reflexes mediated by cranial nerves are called cranial reflexes. Most reflexes help our bodies maintain homeo- stasis and therefore have a protective function.

O B J E C T I V E S M A T E R I A L S

• reflex hammer (with rubber head) • cross-section spinal cord model • • Biopac Laboratory Guide Experiments:

• Effect of Physical and Mental Distractions on Patellar Reflex (Knee Jerk) Response

Somatic Reflexes 19 E X E R C I S E

1 Identify and describe the five components of a somatic reflex arc

2 Describe how monosynaptic and polysynaptic reflex arcs differ

3 Test and describe somatic reflexes

4 Describe the effect of distractions on reflexes

289

A. Reflex Arcs

There are 5 components of a refl ex arc: 1. Sensory receptor. If the stimulus to the sensory recep-

tor is strong enough, an action potential is generated in the sensory neuron.

2. Sensory neuron. The sensory neuron propagates the action potential and synapses with neurons in the spinal cord or brain stem.

290 E X E R C I S E 1 9 S O M AT I C R E F L E X E S

DISCUSSION QUESTIONS Reflex Arc

1 Is the reflex arc in Figure 19.1 monosynaptic or poly- synaptic?

2 Is the reflex arc in Figure 19.1 ipsilateral or contralateral?

3. Integrating center. The integrating center is located within the gray matter of the central nervous system (CNS) and transfers information from the sensory neuron to the motor neuron. The integrating center of a monosynaptic reflex arc is a single synapse between a sensory and motor neuron. In a polysynaptic reflex arc, the integrating center consists of multiple synapses involving one or more interneurons (association neurons) between a sensory and a motor neuron.

4. Motor neuron. The motor neuron carries the action potential initiated by the integrating center to the effector.

5. Effector. An effector can be skeletal muscle (somatic reflex), cardiac muscle, smooth muscle, or glands (autonomic reflexes). A reflex is the response of the effector to stimulation by the motor neuron of the reflex arc.

Refl ex arcs that involve sensory receptors, sensory nerve fi bers, motor neurons, and effectors all on the same side of the body are ipsilateral. Contralateral refl ex arcs involve sensory receptors and neurons on one side of the body and motor neurons and effectors on the opposite side. Bilateral (consensual) refl exes involve both sides of the body simultaneously.

Before Going to Lab

1 Label Figure 19.1. 2 Identify whether the reflexes in Table 19.1 are somatic

reflexes or autonomic reflexes, and whether a spinal nerve or a cranial nerve mediates it.

LAB ACTIVITY 1 Reflexes

1 Using the cross-section spinal cord model or chart, trace the pathway of the reflex arc illustrated in Figure 19.1.

2 Answer the Discussion Questions with your lab group.

■

TABLE 19 .1 Types of Reflexes

SOMATIC OR SP INAL NER VE REFLEXES OR REFLEX ACT ION AUTONOMIC REFLEX CRANIAL NER VE REFLEXES

Plantar flexion of foot when Achilles tendon is stretched

Salivation in response to lemon juice on tongue

Blinking in response to touching the cornea

Flexing of arm in response to touching a hot object

E X E R C I S E 1 9 S O M AT I C R E F L E X E S 291

• Sensory neuron: Sensory axons carry nerve impulses to the integrating center (gray matter) in the spinal cord.

• Integrating center: The monosynaptic integrating center (two neurons, one synapse) is located in the anterior gray horn of the spinal cord. The sensory axon synapses with and initiates nerve impulses in the motor neuron that innervates the quadriceps femoris muscle group.

• Motor neuron: Axons of the motor neuron travel in the femoral nerve to the quadriceps femoris muscle group.

• Effector: Quadriceps femoris muscle group (ago- nists) contracts and extends the leg when stimulated. The sensory neuron associated with the monosyn- aptic stretch reflex arc is also a component of a polysynaptic reflex arc that has 3 neurons and 2 synapses. This reflex arc inhibits the motor neuron to the antagonist muscle group and results in its relax- ation. This is referred to as reciprocal innervation— stimulation of contraction in agonistic muscles with simultaneous inhibition of antagonistic muscles.

B. Reflex Testing

A series of refl ex tests are used clinically to evaluate the nervous system and to diagnose an abnormality or dys- function that may cause an inhibition, exaggeration, or ab- sence of refl exes.

1. Patellar Reflex (Knee Jerk)

The patellar refl ex is the extension of the knee that occurs when the quadriceps femoris tendon is stretched. A stretched tendon will stretch the muscle and cause it to con- tract. This refl ex helps prevent injury by preventing mus- cles from overstretching. The stretch refl ex helps maintain posture and equilibrium.

The components of the patellar refl ex arc are:

• Sensory receptors: Muscle spindles located in the quadriceps femoris muscle group. Tapping the quadriceps tendon stretches this muscle group and stimulates muscle spindles (stretch receptors), initiating nerve impulses in axons of sensory neurons.

FIGURE 19.1 Reflex arc components.

• effector • integrating center • motor neuron cell body • motor neuron axon • sensory neuron cell body • sensory neuron axon • sensory receptor

1 __________________________________

2 __________________________________

3 __________________________________

4 __________________________________

5 __________________________________

6 __________________________________

7 __________________________________

292 E X E R C I S E 1 9 S O M AT I C R E F L E X E S

• Although the grading is subjective, grade the exten- sion of the leg:

Results: ______________ 0 5 no response (hypo-reflexive) 11 5 little response (hypo-reflexive) 12 5 normal response 13 5 above normal response 14 5 exaggerated reflex (hyper-reflexive) • Now ask the subject to clasp both hands in front

of the chest and isometrically pull in opposite directions. This action leads to an enhancement of spinal reflexes causing a reinforced patellar reflex.

• While the subject is pulling, strike the patellar tendon again and observe the distance of leg movement this time.

• Reinforced patellar reflex results: ______________

2 Answer the Discussion Questions with your lab group. 3 Complete Biopac Laboratory Guide Experiment:

Effect of Physical and Mental Distraction on Patellar Reflex (Knee Jerk) Response.

LAB ACTIVITY 2 Testing the Patellar Reflex

1 Test the patellar reflex. • Have the subject sit on the edge of a table or a tall

lab chair with his/her knee off the table or chair and the leg dangling and relaxed.

• Palpate the patella and the tibial tuberosity; also palpate the patellar ligament located between these two structures.

• With the tapered end of a reflex hammer, gently but firmly tap the patellar ligament, which includes a portion of fibers of the quadriceps femoris tendon.

Before Going to Lab

1 Label the patellar reflex arc and reciprocal innervation in Figure 19.2.

FIGURE 19.2 Patellar reflex arc.

+ –

• effector for patellar reflex arc • effector for reciprocal innervation • integrating center for patellar reflex arc • integrating center for reciprocal innervation • motor neuron for patellar reflex arc • motor neuron for reciprocal innervation • receptor • sensory neuron

1 ___________________________________________

2 ___________________________________________

3 ___________________________________________

4 ___________________________________________

5 ___________________________________________

6 ___________________________________________

7 ___________________________________________

8 ___________________________________________

E X E R C I S E 1 9 S O M AT I C R E F L E X E S 293

DISCUSSION QUESTIONS Biceps Reflex

1 Name the nerve that carries the sensory and motor axons for this reflex arc.

2 Name the antagonistic muscles that are inhibited by reciprocal innervation.

3. Triceps Reflex (Triceps Jerk)

The triceps refl ex is the contraction of the triceps brachii muscle that occurs when the triceps brachii tendon is stretched.

DISCUSSION QUESTIONS Patellar Reflex

1 Is the patellar reflex ipsilateral or contralateral?

2 During the patellar reflex, are the motor neurons sup- plying the hamstrings stimulated or inhibited?

3 Describe the effect that clasping and pulling the hands has on the patellar reflex compared with the first patel- lar reflex.

2. Biceps Reflex (Biceps Jerk)

The biceps refl ex is the contraction of the biceps brachii muscle that occurs when the biceps tendon is stretched. Although the biceps brachii fl exes the forearm, in this test you may only see the contraction or tension in the biceps brachii muscle because the forearm is resting on the table.

■

LAB ACTIVITY 3 Testing the Biceps Reflex (Biceps Jerk)

1 Test the biceps reflex. • Have the subject stand with an arm completely

relaxed and hanging down at the side. • Ask the subject to isometrically contract the biceps

brachii so you can palpate the tendon in the antecu- bital fossa.

• After locating the tendon, have the subject relax and place your thumb over the tendon.

• Gently but firmly tap your thumb with the tapered end of the reflex hammer.

• Biceps reflex results: ____________ 0 5 no response 11 5 little response 12 5 normal response 13 5 above normal response 14 5 exaggerated reflex • If the reflex is absent, have the subject clench his/her

teeth and try the reflex test again. • Reinforced biceps reflex results: ____________

2 Answer the Discussion Questions with your lab group.

LAB ACTIVITY 4 Triceps Reflex (Triceps Jerk)

1 Test the triceps reflex. • Have the subject stand with an arm completely

relaxed and hanging down at the side. • Palpate the triceps tendon (proximal to olecranon

process) as the subject isometrically contracts the triceps muscles.

• Keep your finger on the tendon and have the subject bend the arm across the front of the body.

• Have the subject support the arm by holding it in his/her other hand.

• Use the tapered end of the reflex hammer to tap the triceps tendon.

• Triceps tendon reflex results: ____________ 0 5 no response 11 5 little response 12 5 normal response 13 5 above normal response 14 5 exaggerated reflex • If the reflex is absent, have the subject clench his/her

teeth and try the reflex again. • Reinforced triceps tendon results: ____________

2 Answer the Discussion Questions with your lab group.

294 E X E R C I S E 1 9 S O M AT I C R E F L E X E S

DISCUSSION QUESTIONS Achilles Reflex

1 Name the nerve that carries the sensory and motor neurons for this reflex arc.

2 Name the antagonistic muscles that are inhibited by reciprocal innervation.

5. Plantar Flexion

Plantar fl exion is a superfi cial cord refl ex that is an impor- tant neurological test. This test stimulates the cutaneous receptors and involves the brain in addition to the spinal cord. In adults, plantar fl exion and fl exed (curled) toes occurs when the plantar surface of the foot is stroked. A re- action of dorsifl exion with extended fl ared toes (Babinski’s sign) is seen in infants because all the nerve fi bers are not myelinated. The Babinski’s sign is abnormal in adults.

DISCUSSION QUESTIONS Triceps Reflex

1 Name the nerve that carries the sensory and motor axons for this reflex arc.

2 Name the antagonistic muscles that are inhibited by reciprocal innervation.

4. Achilles Reflex (Ankle Jerk)

The response of this refl ex is plantar fl exion when the Achilles (calcaneal) tendon is tapped with the refl ex hammer.

■ ■

LAB ACTIVITY 5 Achilles Reflex (Ankle Jerk)

1 Test the Achilles reflex. • Have the subject keep one foot on the floor and place

the knee of the other leg on a chair with the foot dan- gling over the edge.

• Ask the subject to slightly dorsiflex the foot to stretch the tendon a little, but be relaxed.

• Tap the calcaneal tendon with the tapered end of a reflex hammer and observe the response of the foot.

• Calcaneal reflex results: _____________ 0 5 no response 11 5 little response 12 5 normal response 13 5 above normal response 14 5 exaggerated reflex

2 Answer the Discussion Questions with your lab group.

LAB ACTIVITY 6 Plantar Flexion

1 Test the plantar flexion reflex. • Have the subject seated with a foot propped up and

relaxed. • Using the metal end of the reflex hammer, stroke

the plantar surface of the foot starting at the heel, extending up the lateral side of the foot, and crossing over to the great toe area.

• Plantar flexion results: ______________ 0 5 no response 11 5 little response 12 5 normal response 13 5 above normal response 14 5 exaggerated reflex

2 Answer Discussion Questions with your lab group.

DISCUSSION QUESTIONS Plantar Flexion

1 Name the nerve that carries the sensory and motor neurons for this reflex arc.

2 Name the antagonistic muscles that are inhibited by reciprocal innervation.

■

295

A. Reflex Arc

1. Name the 5 components of a reflex arc in order.

a. ______________________

b. ______________________

c. ______________________

d. ______________________

e. ______________________

2. How many neurons are in a monosynaptic reflex arc? _______ How many synapses are in the integrating center? _______

3. How many neurons are in a polysynaptic reflex arc? _______ How many synapses are in a polysynaptic reflex arc containing two interneurons in the integrating center? _______

4. Which type of neuron does the sensory neuron synapse with in a monosynaptic reflex arc? ______________________

5. Which type of neuron does the sensory neuron synapse with in a polysynaptic reflex arc? _______________________

B. Reflex Tests

Name the nerve that is tested in each of the following reflexes.

1. Achilles reflex ______________________

2. Biceps reflex ______________________

3. Patellar reflex ______________________

4. Plantar flexion reflex ______________________

5. Triceps reflex ______________________

6. Is a Babinski’s sign normal in adults? ______________________

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

19 E X E R C I S E

296 E X E R C I S E 1 9 S O M AT I C R E F L E X E S

C. Reflexes

1. Define reflex.

2. Describe the difference between a somatic and visceral reflex.

3. Describe the difference between a cranial and spinal reflex.

4. Describe the difference between an ipsilateral and contralateral reflex arc.

5. Define reciprocal innervation.

297

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

19 E X E R C I S E

A. Flexor and Crossed Extensor Reflex

You are walking along the beach barefoot and step on a sharp object with your right foot. You immediately flex the right leg and balance yourself by extending the left leg. Label the following neurons in Figure 19.3.

1. Sensory neuron

2. Interneuron sending impulses up and down the spinal cord

3. Interneuron synapsing with motor neurons

4. Motor neuron causing flexion

5. Motor neuron causing extension

FIGURE 19.3 Flexor and crossed extensor reflex arc.

Right leg

Left leg

298 E X E R C I S E 1 9 S O M AT I C R E F L E X E S

For the reflex arc in Figure 19.3, name the:

______________________ 6. Nerve carrying motor information causing right leg flexion

______________________ 7. Nerve carrying motor information causing left leg extension

______________________ 8. Agonistic muscles for right leg flexion

______________________ 9. Agonistic muscles for left leg extension

B. Modification of Reflex Activity

10. Reflex activity can be modified by the cerebral cortex. For example, you are baking a roast in the oven. As you are moving the roast from the oven to the counter, hot juices splash you. Reflex activity would cause you to drop the pan, but you hold on to it. Explain how the cerebral cortex overrides the reflex.

E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N 299

Brain Structure and Function 20

E X E R C I S E

299

The human brain simultaneously conducts and coordinates a variety of incredible processes with which no computer is presently able to com- pete. The expansive development of the human brain dis- tinguishes it from that of all other creatures. One of the largest organs in the human body, our brain is responsible for our memory, intellect, ideas, and behavior. The brain is the center for cataloging sensory information, integrating this information with previously recorded information, and producing actions based on the results of the information synthesis. The brain is well protected, located within the cranium of the skull. During development, the brain and skull are growing simultaneously, so the shape of the cranial cavity mirrors the shape of the brain.

A. Major Brain Regions

The brain is composed of 4 main regions: the brain stem, cerebellum (cerebel- � little brain), diencephalons (di- � through; encephal- � brain), and cerebrum (cerebr- � brain). The brain stem is connected to the superior part of the spinal cord, the cerebellum is posterior to the brain stem, and the diencephalon is superior to the brain stem in the center of the brain. The large cerebrum is the dominant brain structure, with many folds and crevices enveloping the diencephalon.

O B J E C T I V E S M A T E R I A L S

• human brain models, charts, or use Real Anatomy (Nervous)

• preserved human brain, skull • ventricular system model • Dissection: preserved sheep brains, dissection

equipment, disposable gloves, safety glasses

• • Biopac Laboratory Guide Experiment: • The Effect of Mental and Sensory

Stimulations on Brain Wave Patterns

1 Identify the major external and internal structures of the brain

2 Describe the basic functions of the principal structures of the brain

3 Identify brain waves and describe the effect of stimulation on brain wave patterns

4 Identify the 3 main cranial fossae

5 Name the 3 meninges and describe their similarities and differences

6 Identify the 4 ventricles of the brain and describe their function

7 Trace the cerebrospinal fluid circulation

8 Compare the anatomy of the sheep brain with that of the human brain

300 E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N

Before Going to Lab

1 Label the major brain regions in Figure 20.1.

LAB ACTIVITY 1 Identification of Major Brain Regions

1 Identify the major brain regions on human brain models, charts, or use the search text box in Real Anatomy (Nervous) to find these structures. ■

CEREBRUMSagittal plane

Thalamus DIENCEPHALON:

Hypothalamus Epithalamus Pineal gland

Midbrain BRAIN STEM:

CEREBELLUM

Spinal cord

POSTERIOR

Sagittal section of brain, medial view

Pons Medulla oblongata Infundibulum

Pituitary gland

Fornix

Corpus callosum

• brain stem • cerebellum (cer-e-BELL-um) • cerebrum (ce-REE-brum) • diencephalon

1 _________________________

2 _________________________

3 _________________________

4 _________________________

Spinal cord

INFERIOR

SUPERIOR

POSTERIOR ANTERIOR

FIGURE 20.1 Four major brain regions.

E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N 301

3. The Midbrain

The midbrain is a smaller area superior to the pons and in- ferior to the diencephalon, consisting of cerebral peduncles (ped- � foot) and the corpora quadrigemina (corpora � body; quad- � four; gemin- � twin; i.e., 4 twin bodies). The cerebral peduncles are white fi bers that connect the upper and lower brain areas, and the corpora quadrige- mina are composed of 2 superior colliculi (colliculus � small mound) and 2 inferior colliculi. The superior col- liculi have refl ex centers involved in eye, head, and neck movements with visual stimulation, whereas the inferior colliculi have refl ex centers involved in auditory stimuli that result in head and trunk movements. The midbrain is observed best from a sagittal section, medial view. It spans from the dorsal to the ventral side of the brain stem.

B. The Brain Stem

The brain stem is composed of 3 structures: the medulla (medull- � marrow) oblongata, the pons, and the midbrain.

1. The Medulla Oblongata

The fi rst brain structure, the medulla oblongata, is immediately superior to the spinal cord and is the most vital part of the brain because it houses the respiratory and cardiovascular control centers. The respiratory center con- trols the rate and depth of breathing, and the cardiovascular center is responsible for the rate and force of the heart- beat and blood pressure refl exes. Other refl ex centers in the medulla are for coughing, vomiting, and sneezing.

2. The Pons

The pons (pons � bridge) is an expanded structure located superior to the medulla oblongata and anterior to the cer- ebellum, and has respiratory centers that assist the medulla oblongata in controlling breathing. The pons also relays in- formation to the diencephalon and the cerebellum.

Before Going to Lab

1 Label the brain stem structures on Figure 20.2(a) and (b).

LAB ACTIVITY 2 The Brain Stem

1 Identify the brain stem structures on a human brain model, chart, or use the search text box in Real Anatomy (Nervous) to find these structures. ■

Spinal cord

(a) Sagittal section, medial view

INFERIOR

SUPERIOR

ANTERIORPOSTERIOR

2 3 4

Superior colliculus

Inferior colliculus

• cerebral peduncle • corpora quadrigemina (cor-POR-a quad-ri-GEM-i-na) • medulla oblongata • midbrain • pons

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

5 _____________________________________________________

FIGURE 20.2 Brain stem.

302 E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N

Midbrain

POSTERIOR

Medulla oblongata

Middle cerebellar peduncle

Spinal cord

Pons Brain stem

Middle cerebellar peduncle

(b) Inferior aspect of brain

• medulla oblongata (meh-DEW-la ob-lon-GAH-tah) • midbrain • pons • spinal cord

6 ________________________________________

7 ________________________________________

8 ________________________________________

9 ________________________________________

FIGURE 20.2 Brain stem, continued.

E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N 303

addition, smoothes and coordinates skilled skeletal muscle movements. The cerebellum is connected to the brain stem by the superior, middle, and inferior cerebellar peduncles. Do not confuse them with the cerebral peduncles.

C. The Cerebellum

The cerebellum (cerebellum � little brain) is second in size to the cerebrum and is located inferior to it and poste- rior to the medulla and pons. There are 2 cerebellar hemi- spheres, with a central area, the vermis, connecting them. When cut in sagittal section, gray matter can be observed on the exterior, with deeper white matter called the arbor vitae (arbor � tree; vitae � living) appearing as branches of a tree. The outer layer of gray matter is called the cere- bellar cortex. Like the cerebral cortex, the cerebellar cortex has folds that increase the surface area allowing for more neuron cell bodies. The cerebellar folds are slender, pleated gyri or folia (folia � leaves) that look similar to pages in a book. The cerebellum regulates posture and balance and, in

Before Going to Lab

1 Label the structures of the cerebellum in Figure 20.3(a) and (b).

LAB ACTIVITY 3 Cerebellum

1 Identify the structures of the cerebellum on a human brain model, chart, or use the search text box in Real Anatomy (Nervous) to find these structures. ■

(a) Posterior view • cerebellar (cer-e-BELL-ar) hemispheres • folia (FO-lia) • vermis (VER-mis)

1 __________________________________

2 __________________________________

3 __________________________________

(b) Sagittal view • arbor vitae (white matter) • cerebellar cortex (gray matter) • inferior colliculus • medulla oblongata • pons • superior colliculus

4 __________________________________

5 __________________________________

6 __________________________________

7 __________________________________

8 __________________________________

9 __________________________________

POSTERIOR

(a) Superior view

Cerebellum:

(b) Midsagittal section

Cerebral peduncle Mammillary body

Fourth ventricle

FIGURE 20.3 The cerebellum.

304 E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N

The hypothalamus includes the infundibulum and mammillary bodies. The infundibulum (infundibulum � funnel) is a stalk that connects the pituitary gland to the hypothalamus. The mammillary bodies (mammilla � nipple)—two small, round masses located just posterior to the infundibulum—are relay stations for smell and taste refl exes. Other structures that are observed in this area are the optic chiasm and the pituitary gland. The optic chiasm (chi � �, Greek letter chi, a crossing over), the area where the optic nerves cross, is anterior to the infundibulum. The pituitary gland looks like a large pea and is attached to the end of the infundibulum. The hypothalamus controls the pituitary gland.

3. The Epithalamus

The epithalamus (epi- � above) is superior and poste- rior to the thalamus and includes the pineal (pineas � pinecone) gland or body, a small endocrine gland that secretes the hormone melatonin.

D. The Diencephalon

The diencephalon (di- � two; -cephalon � brain) is located in the brain’s central area and has 3 main regions: the thalamus, the hypothalamus, and the epithalamus.

1. The Thalamus

The thalamus (thala- � inner chamber) is composed of paired, egg-shaped bodies centrally located in the dienceph- alon and makes up approximately 80% of this structure. Each cerebral hemisphere contains half of the thalamus, which is connected by a small bridge called the intermedi- ate mass. The thalamus is the brain’s “Grand Central relay station” because it is the principal relay station for sensory fi bers and some somatic motor fi bers. Sensory fi bers that synapse in the thalamus are relayed to a particular area of the cerebral cortex to be interpreted, and other fi bers relay messages to the somatic motor cortex. The thalamus also fi lters out unnecessary sensory information and is involved in consciousness, emotions, learning, and memory.

2. The Hypothalamus

The hypothalamus (hypo- � below) is located below the thalamus and is a quadrangular-shaped structure. The hypothalamus has important nuclei (a group of nerve cell bodies) that control many body functions and homeostasis. Some of the major functions include integrat- ing and controlling the pituitary gland and hormonal func- tions, autonomic functions, emotions and behavior, body temperature, eating, and drinking.

Before Going to Lab

1 Label the diencephalon structures in Figure 20.4(a), (b), and (c). Refer to Figure 20.1 if necessary.

LAB ACTIVITY 4 The Diencephalon

1 Identify the diencephalon structures listed on the human brain model, chart, or use the search text box in Real Anatomy (Nervous) to find these structures. ■

CEREBRUM

CEREBELLUM

Spinal cord

(a) Sagittal section, medial view

BRAIN STEM: Midbrain

Pons

Medulla oblongata

2 4

FIGURE 20.4 The diencephalon.

(a) • diencephalon • hypothalamus

(hypo-THAL-a-mus) • pineal (pi-NEE-al) gland

(part of epithalamus) • thalamus

1 ________________________

2 ________________________

3 ________________________

4 ________________________

E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N 305

Optic chiasm 10

(b) Sagittal section, magnified

Longitudinal fissure

Cerebral cortex (gray matter)

Optic tract

FIGURE 20.4 The diencephalon, continued.

(b) • hypothalamus • infundibulum

(in-fun-DIB-u-lum) • intermediate mass of

thalamus • mammillary (MAM-mil-lary)

body • pineal gland • pituitary gland • thalamus (THAL-a-mus)

5 ________________________

6 ________________________

7 ________________________

8 ________________________

9 ________________________

10 ________________________

11 ________________________

12 ________________________

13 ________________________

14 ________________________

15 ________________________

306 E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N

kinds of fi ber tracts in the cerebrum that are named ac- cording to the direction of the fi bers [Figure 20.5(a)]. As- sociation fi bers transmit nerve impulses within the same hemisphere, whereas commissural (commisura � connec- tion) fi bers transmit nerve impulses between the two hemi- spheres. Projection fi bers are ascending and descending tracts that project nervous impulses from inferior to supe- rior brain areas or vice versa. The corpus callosum (corpus � body; callosus � hard), a prominent commissural fi ber tract that is readily observable in midsagittal sections of the brain, connects the two cerebral hemispheres. The fornix looks like a group of commissural fi bers but is actually a tract of arched association fi bers. The internal capsule, a large group of projection fi bers, contains sensory and mo- tor tracts that connect the cerebral cortex to the brain stem and spinal cord.

E. The Cerebrum

The cerebrum is made up of right and left cerebral hemi- spheres and is the largest and most complex division of the brain. The cerebrum is superior to and surrounds the diencephalon and part of the brain stem. The cerebrum is the center of higher mental processes such as intelligence, communication, learning and memory, reasoning, and emotions. In addition, it interprets sensory input and initi- ates skeletal muscle contraction.

1. Organization of Cerebral Gray and White Matter

The 3 main regions of the cerebrum are the cerebral cortex (cortex � bark), white matter, and the deep basal nuclei. The cerebral cortex (also known as the cortical area) is the superfi cial cerebral gray matter on the exterior of the cerebrum composed of nerve cell bodies and dendrites. The cerebral cortex integrates sensory information, initi- ates motor output, and is also involved in emotions and intellectual processes. Basal nuclei (ganglia � knot) are areas of cerebral gray matter composed of paired nuclei (clusters of neuron cell bodies in the CNS) that are found deep within each cerebral hemisphere. The basal nuclei control automatic skeletal muscle movement and are in- volved with the limbic system or emotional brain. Cerebral white matter lies deep to the outer cortex and is composed mostly of myelinated axons that give it the white appearance. These axons are organized into three

Before Going to Lab

1 Label the gray and white matter in Figure 20.5(b).

LAB ACTIVITY 5 Organization of Gray and White Matter in Cerebrum

1 Identify the cerebral gray and white matter on a human coronal section of brain, brain model, chart, or use the search text box in Real Anatomy (Nervous) to find these structures. ■

Association fibers

Third ventricle

Lateral ventricles

Commissural fibers (Corpus callosum)

Projection fibers

Cerebellum

(a) Frontal section

FIGURE 20.5 Gray and white matter in the cerebrum.

E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N 307

Longitudinal fissure

Thalamus

Hypothalamus

Cerebral cortex (gray matter)

Corpus callosum (white matter)

Globus pallidus

Frontal section

Basal nuclei (deep grey matter)

Caudate nucleus

Cerebral (white matter)

Internal capsule (white matter)

Fornix (white matter)

Putamen

5 6

Third ventricle

Choroid plexus

Lateral ventricles

SUPERIOR

INFERIOR

(b) Frontal section

Frontal plane through brain

Superior

FIGURE 20.5 Gray and white matter in the cerebrum, continued.

(b) • basal nuclei (gray matter) • cerebral cortex (gray matter) • cerebral white matter • corpus callosum (commissural fibers) • fornix (association fibers) • internal capsule (projection fibers)

1 __________________________________

2 __________________________________

3 __________________________________

4 __________________________________

5 __________________________________

6 __________________________________

308 E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N

• lateral cerebral sulcus—shallow groove separating frontal and temporal lobes

• parieto-occipital sulcus—shallow groove separating parietal and occipital lobes

• longitudinal fissure—deep groove separating the 2 cerebral hemispheres at the midline

• transverse fissure—deep groove separating the cerebrum from the cerebellum in the posterior/infe- rior part of the brain

2. Surface Features of the Cerebrum

There are 4 lobes that compose the exterior of the cere- brum, which are mainly named for the overlying cranial bones. These lobes are the frontal, parietal, occipital, and temporal lobes. An inner lobe, the insula, lies deep to the lateral cerebral fi ssure and is not visible from the exterior. Other obvious external anatomical features of the cerebrum include the following:

• gyrus (gyros � circle; gyri, pl.)—elevation or fold in the cerebral cortex; increases the surface area for neuron cell bodies

• sulcus (sulcus � furrow; sulci, pl.)—shallow groove between elevations

• central sulcus—shallow groove separating frontal lobe from parietal lobe

• precentral gyrus—elevation located just anterior to the central sulcus

• postcentral gyrus—elevation located just posterior to the central sulcus

Before Going to Lab

1 Label the structures listed for Figure 20.6 and locate the longitudinal fissure on Figures 20.2(b) and 20.5(a).

LAB ACTIVITY 6 External Features of the Cerebrum

1 Identify the external features of the cerebrum on a brain model, chart, or use the search text box in Real Anatomy (Nervous) to find these structures. ■

• central sulcus • frontal lobe • insula • occipital lobe • parietal lobe • postcentral gyrus • precentral gyrus • temporal lobe (cut) • transverse fissure

1 __________________________________

2 __________________________________

3 __________________________________

4 __________________________________

5 __________________________________

6 __________________________________

7 __________________________________

8 __________________________________

9 __________________________________

Right lateral view

Frontal lobe

Insula (gold area)

Temporal lobe

Parieto-occipital sulcus

Occipital lobe

Cerebellum

Transverse fissure

Central sulcus

Lateral cerebral sulcus

Parietal lobe (blue area)

Postcentral gyrus Precentral gyrus

ANTERIORPOSTERIOR

Right lateral view with temporal lobe cut away

7 (lobe)

8 (lobe)

9 (lobe)

1 (space) 2

3 (lobe)

4 (lobe)

5 (space)

Cerebellum

FIGURE 20.6 External features of the cerebrum.

E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N 309

• primary gustatory area—in each postcentral gyrus, just superior to the lateral sulcus; receives impulses when the taste buds are stimulated

• primary olfactory area—located on the medial side of each temporal lobe; cannot be seen from the lateral view; receives impulses when the olfactory receptors of the nose are stimulated

• primary visual area—in the posterior occipital lobe; receives impulses from the thalamus when the retina is stimulated

Selected Association Areas • Wernicke’s area—located in left temporal and

parietal lobes; recognizes spoken words, translates words into thoughts, and possibly helps us sound out strange or new words

• somatosensory, visual, and auditory association areas—larger areas adjacent to the corresponding sensory cortex; integrate sensory information from the sensory cortex with past experiences allowing us, for example, to identify objects by touch or to identify sound as music or speech

3. Functional Areas of the Cerebral Cortex

The cerebral cortex is composed of 3 types of functional areas: motor, sensory, and association areas. Sensory areas receive and interpret impulses from sensory receptors, while motor areas initiate impulses to skeletal muscles. Association areas, which perform complex integrative functions, receive and send information to multiple areas of the cortex via association fi bers. The majority of the cortex is composed of association areas.

Motor Areas • primary motor area—located in the precentral

gyrus of each frontal lobe; initiates impulses to skeletal muscles

• Broca’s speech area—located superior to the lat- eral sulcus and anterior to the primary motor cortex, usually in the left hemisphere; initiates impulses that result in speech

Sensory Areas • primary somatosensory area—located in the

postcentral gyrus of each parietal lobe; receives nerve impulses for touch, proprioception, pain, and temperature

• primary auditory area—located in each temporal lobe across the lateral sulcus from the gustatory area; receives impulses when the auditory receptors of the ear are stimulated

• Broca’s speech area (dotted area) • central sulcus • primary auditory area • primary gustatory (GUS-tah-tory) area • primary motor area • primary somatosensory (so-ma-to-SEN-

sory) area • primary visual area • Wernicke’s area (dotted area)

1 ______________________________________

2 ______________________________________

3 ______________________________________

4 ______________________________________

5 ______________________________________

6 ______________________________________

7 ______________________________________

8 ______________________________________

Before Going to Lab

1 Label the functional areas of the cortex in Figure 20.7.

LAB ACTIVITY 7 Functional Areas of Cerebral Cortex

1 Identify functional areas of the cerebral cortex on a brain model or chart. ■

FIGURE 20.7 Functional areas of the cerebral cortex.

Left lateral view POSTERIORANTERIOR 8

3 4 5

310 E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N

F. Protection of the Brain

The brain is protected both physically and chemically by cranial bones, the blood-brain barrier, the cranial menin- ges, and cerebrospinal fl uid.

1. Cranial Bones

The cranial bones form a vault called the cranium, which surrounds and protects the brain. The fl oor of the cranium contains depressions—the anterior, middle, and poste- rior cranial fossae—which support parts of the brain. The

4. Encephalography

Millions of brain neurons close to the surface of the cerebral cortex collectively create action potentials (nerve impulses or electrical currents) that can be detected by electrodes positioned on the scalp. The electrodes are con- nected with wires to a computer, and the electrical currents are displayed on a screen as brain waves. The record of brain waves is called an electroencephalogram (EEG). The four main types of brain waves in an EEG, Alpha, Beta, Theta, and Delta, can be recognized by their char- acteristic patterns (Figure 21.8). These brain waves differ in frequency (cycles per second) in the various areas of the brain. Neurologists use EEGs diagnostically for many situ- ations, including epilepsy, coma, brain disease, dementia, brain death, and to study sleep disorders and monitor brain activity during general anesthesia.

LAB ACTIVITY 8 Encephalography

1 Complete Biopac Laboratory Guide Experiment: The Effect of Mental and Sensory Stimulation on Brain Wave Patterns. ■

Alpha

Beta

Theta

Delta

1 sec

FIGURE 20.8 Types of brain waves recorded in an electroencephalogram (EEG).

Before Going to Lab

1 Observe the cranial meninges in Figure 20.9(a). 2 Label the structures in Figure 20.9(b).

LAB ACTIVITY 9 Cranial Bones and Cranial Meninges

1 Identify the cranial fossae in the cranial floor of the skull.

2 Using a preserved human brain or the search text box in Real Anatomy (Nervous), identify the meninges.

3 Using a brain model, preserved human brain, or the search text box in Real Anatomy (Nervous), show where the falx cerebri and tentorium cerebelli would be found. ■

anterior cranial fossae support the frontal lobes of the cerebrum; the middle cranial fossae support portions of the temporal and parietal lobes of the cerebrum and the diencephalon; the posterior cranial fossae support por- tions of the temporal, parietal, and occipital lobes of the cerebrum, the cerebellum, and the brain stem.

2. Cranial Meninges

There are 3 cranial meninges (connective tissue membranes): the dura mater, arachnoid mater, and pia ma- ter. The dura mater (dura � hard; mater � mother) is the fi rst meninx (sing.) located deep to the cranial bones. It is composed of 2 layers: the periosteal layer, which is a tough membrane attached to the cranial bones, and the meningeal layer, which is exterior to the arachnoid mater. The 2 dural layers split to form the dural sinuses that eventually drain cranial blood into the jugular veins. The superior sagittal sinus, located superior to the longitudinal fi ssure, is one of the main dural sinuses. The double-layered dura mater extends deep into the longitudinal fi ssure forming the falx ( falx � sickle-shaped) cerebri, into the transverse fi ssure forming the tentorium (tent) cerebelli, and between the cerebellar hemispheres forming the falx cerebelli. The arachnoid (arachnoid � spider-like) mater is the 2nd meninx located deep to the dura mater. Projections of the arachnoid mater into the dural sinuses are called arachnoid villi (villi � tiny projections). The pia (pia � delicate) mater is the thin, inner meninx. It hugs and over- lays the cerebral cortex, following each gyrus and sulcus. Between the arachnoid and pia is the subarachnoid space.

E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N 311

Falx cerebri

Subarachnoid space

(a) Frontal section

Skin Parietal bone of cranium

Arachnoid mater

Pia mater

Cerebral cortex

Superior sagittal sinus

CRANIAL MENINGES:

Dura mater

Frontal plane

• arachnoid mater (a-RAK-noid MAH-ter)

• arachnoid villus (VIL-us)

• cerebral (ce-REE-bral) cortex

• dura mater • falx cerebri (falks

ce-REE-bree)

• parietal bone • pia (PEE-ah) mater • subarachnoid (sub-a-

RAK-noid) space • superior sagittal

(SA-jih-tahl) sinus • white matter

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

7 ________________________

8 ________________________

9 ________________________

10 ________________________

FIGURE 20.9 Cranial meninges.

Skin

Frontal plane

(b) Frontal section through skull.

312 E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N

pons and the cerebellum. Lateral and median apertures or openings allow the CSF to fl ow from the fourth ventricle into the subarachnoid space surrounding the brain and the spinal cord. CSF also fl ows through the central canal of the spinal cord and back out into the subarachnoid space. Just as CSF enters the brain ventricles from the bloodstream, it is returned to the blood by reabsorption through the arach- noid villi (tiny projections) located in the dural sinuses, especially the superior sagittal sinus.

3. Cerebrospinal Fluid and Ventricles of the Brain

Cerebrospinal fl uid (CSF) constantly bathes the brain and spinal cord with oxygen, nutrients, and vital chemi- cals. Although different in content, CSF is made from blood plasma that leaks out of specialized, tiny blood ves- sels (capillaries) called the choroid plexus (choroid � membrane-like; plexus � pleated) and passes through ependymal cells into 4 small brain cavities or ventricles. The ependymal cells have cilia that move the CSF in one direction. There are choroid plexuses in the roof of all four ventricles. A lateral ventricle is located in each cerebral hemisphere with a thin membrane, the septum pellucidum (septum � partition; pellucid � transparent), separating the 2 ventricles anteriorly. Each arched lateral ventricle has an interventricular foramen that opens me- dially into the third ventricle. The third ventricle is medi- ally located between the paired masses of the thalamus and is narrower and smaller than the other ventricles. Connect- ing the third ventricle to the fourth ventricle is a thin tube, the cerebral aqueduct (aqua � water; duct � way; i.e., waterway). The fourth ventricle is located between the

Before Going to Lab

1 Label the structures in Figure 20.10(a), (b), and (c).

LAB ACTIVITY 10 CSF Circulation

1 Identify these structures on a human brain model, chart, or use the search text box in Real Anatomy (Nervous) to find these structures.

2 With your laboratory partner, trace a drop of CSF from its origin in a lateral ventricle through the other ven- tricles and subarachnoid space, and follow it until it is reabsorbed into the bloodstream (Figure 20.10c). ■

Cerebrum

Cerebellum

Superior sagittal sinus (blue)

Falx cerebri

Corpus callosum

Septum pellucidum 2

Tentorium cerebelli

LATERAL APERTURE

MEDIAN APERTURE

SPINAL CORD

SUBARACHNOID SPACE

(surrounding spinal cord)

(a) Frontal section of brain and spinal cord

View

Frontal

plane

FIGURE 20.10 Ventricles of the brain and cerebral spinal fluid.

• cerebral aqueduct • arachnoid villus • choroid plexus • fourth ventricle • lateral ventricle • subarachnoid space • third ventricle

1 ______________________________________

2 ______________________________________

3 ______________________________________

4 ______________________________________

5 ______________________________________

6 ______________________________________

7 ______________________________________

E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N 313

(b) Right lateral view (ventricles superimposed)

13 Spinal cord

FIGURE 20.10 Ventricles of the brain and cerebrospinal fluid, continued.

• central canal of the spinal cord • cerebral aqueduct (AH-que-duct) • fourth ventricle • interventricular (in-ter-ven-TRIK-u-lar)

foramen • lateral ventricles • third ventricle

8 ______________________________________

9 ______________________________________

10 ______________________________________

11 ______________________________________

12 ______________________________________

13 ______________________________________

• arachnoid villus (a-RACH-noid VIL-us) • central canal • cerebral aqueduct • choroid plexus (CHOR-oid PLEX-us) • fourth ventricle • lateral ventricle • subarachnoid (sub-ah-RAK-noid) space • superior sagittal sinus • third ventricle

14 ______________________________________

15 ______________________________________

16 ______________________________________

17 ______________________________________

18 ______________________________________

19 ______________________________________

20 ______________________________________

21 ______________________________________

22 ______________________________________

314 E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N

• The small abducens nerves (VI) are found medial and slightly posterior to the trigeminal nerves, aris- ing from the pons.

5 Identify midbrain structures (Figure 20.13). • Carefully pull the cerebellum away from the cere-

brum. Identify the pineal body, superior colliculi, and inferior colliculi.

6 Identify midsagittal section structures (Figure 20.14). • Using a sharp knife or scalpel, carefully make a

midsagittal section. • Locate the brain stem components: the medulla

oblongata, the pons, and the midbrain. Compare this with your human brain model.

• Identify the arbor vitae in the cerebellum. • Note the cerebral aqueduct and the fourth

ventricle. • Identify the thalamus, corpus collosum, septum

pellucidum, fornix, and lateral ventricles.

7 Observe a coronal section. • Observe the coronal section your instructor may have

as a demonstration. Note the gray matter, white matter, longitudinal fissure, corpus callosum, thalamus, lateral ventricles, and third ventricle.

• Observe the transverse or horizontal section your instructor may have as a demonstration. Identify the gray matter, white matter, and ventricles.

8 Clean up as directed by your instructor. 9 Answer Discussion Questions with your lab group.

DISCUSSION QUESTIONS Sheep Brain Dissections

1 Why are the olfactory tracts not called olfactory nerves?

2 How does the human mammillary body look different from the sheep?

3 How do the three parts of the sheep brain stem compare to the human brain stem?

4 Does the arbor vitae in the cerebellum of the sheep brain look similar or different from the arbor vitae of the hu- man brain?

Remember that preserved material does not look like a fresh specimen. Usually more detail may be observed in a preserved brain because the tissue is fi rmer.

SAFETY NOTE: Use disposable gloves, safety glasses, and a lab coat when handling preserved material.

G. Sheep Brain Dissection

LAB ACTIVITY 11 Dissection of Sheep Brain

1 Rinse the sheep brain to remove preservative. 2 Observe meninges and main brain regions.

• Examine the brain to see if the tough, outer dura mater is present. If present, note the falx cerebri and tentorium cerebelli. Carefully remove the dura mater.

• Now look for the stringy, web-like arachnoid mater beneath and adhering to the dura mater. Deep to this membrane is the very thin pia mater that follows the contours of the gyri and sulci.

• Compare the sheep brain with the main external regions of the human brain. Identify the cerebrum, brain stem (medulla and pons), and cerebellum.

3 Identify dorsal structures (Figure 20.11). • With the dorsal side up, identify the cerebral hemi-

spheres, gyri, sulci, longitudinal fissure, and transverse fissure.

• Identify the 4 main lobes of the brain—frontal, parietal, occipital, and temporal.

• At the longitudinal fissure, gently separate the 2 parts and look down between them for the thick band of white fibers, the corpus callosum.

4 Identify ventral structures (Figure 20.12). • Place the sheep brain ventral side up. • Identify the olfactory bulb, olfactory tract, optic

nerve, optic chiasm, and optic tract. • Posterior to these structures, locate the one large

mammillary body. • If present, identify the infundibulum and pituitary

gland. • Look at the three parts of the brain stem—the

midbrain, pons, and medulla oblongata. • The large trigeminal nerves (V) are located laterally

at the junction of the pons and medulla. ■

E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N 315

FIGURE 20.11 Dorsal view of the sheep brain.

Left cerebral hemisphere

Parietal lobe

Longitudinal fissure

Occipital lobe

Cerebellar hemispheres

Medulla oblongata

Spinal cord

Frontal lobe

Right cerebral hemisphere

Sulci

Gyri

Vermis of cerebellum

FIGURE 20.12 Ventral view of the sheep brain.

Olfactory bulb

Olfactory tract

Optic chiasm

Optic tract

Cerebral peduncle

Trigeminal nerve (V)

Optic (II) nerve

Infundibulum (pituitary gland removed)

Mammillary body

Pons

Medulla oblongata

Spinal cord

Abducens nerve (VI)

316 E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N

FIGURE 20.13 Posterior view of the midbrain structures of the sheep brain.

Occipital lobe

Pineal body

Superior colliculi

Cerebrum

Inferior colliculi

Cerebellum

FIGURE 20.14 Midsagittal section of the sheep brain.

Cerebrum

Pineal body Thalamus

FornixLateral ventricle

Corpus collosum

Optic chiasm

Pituitary gland

Transverse fissure

Corpora quadrigemina

Cerebellum

Fourth ventricle

Pons

Medulla oblongataMammillary body

317

A. Brain Structure

Label the structures in Figures 20.15(a) and (b).

FIGURE 20.15 Brain structure.

POSTERIOR

1 24

8 12

7 9

(a) Sagittal section, medial view ANTERIOR

POSTERIOR

(b) Inferior aspect of brain

(a)

1 ______________________________________

2 ______________________________________

3 ______________________________________

4 ______________________________________

5 ______________________________________

6 ______________________________________

7 ______________________________________

8 ______________________________________

9 ______________________________________

10 ______________________________________

11 ______________________________________

12 ______________________________________

(b)

13 ______________________________________

14 ______________________________________

15 ______________________________________

16 ______________________________________

17 ______________________________________

18 ______________________________________

19 ______________________________________

20 ______________________________________

21 ______________________________________

22 ______________________________________

Name ___________________________________ Date _________________ Section ______________________________

20 E X E R C I S EReviewing Your Knowledge

318 E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N

B. Functions of Brain Regions

Give the brain region for the functions described.

1. Contains vital centers that regulate heartbeat, breathing, blood pressure, vomiting, coughing

2. Smoothes and coordinates skilled skeletal muscle movement; also posture and balance or equilibrium

3. Secretes melatonin that controls the sleep-wake cycle

4. Controls and integrates the autonomic nervous system; regulates hormones, emotional behavior, temperature, eating, and drinking behavior

5. Interprets sensory input, controls skilled skeletal muscle movements, and is involved in emotional and intellectual processes

6. Helps control breathing; conducts impulses to and from the cerebellum, midbrain, and medulla

7. Relays all sensory input to the cerebral cortex; involved in skeletal muscle actions and memory processing

8. Coordinates visual and auditory reflexes

9. Coordinates gross, automatic muscle movements; also involved with the limbic system

10. White fiber tracts communicating between hemispheres

C. Flow of Cerebrospinal Fluid

Fill in the numbered blanks with the name of the structure that corresponds with the number in the following paragraph. Fluid for the CSF is derived from the bloodstream. The sites of CSF formation are the (1), special tiny capillaries located in the walls of (2), (3), and (4). Cells that line the ventricles have cilia that move the CSF and are called (5). The two lateral ventricles are separated by a thin membrane called the (6). CSF flows by cilia movement from the two lateral ventricles through the interventricular foramen to the (7). From here, the CSF flows through the (8) into the fourth ventri- cle. The CSF leaves the fourth ventricle through three openings: the median aperture and two lateral apertures. CSF is now located in the (9) space around the brain, and circulates all around the cerebrum and cerebellum. CSF continues to flow into the inner part of the spinal cord by flowing through the tiny (10) of the spinal cord, as well as around the exterior of the spinal cord in the (11) space. Because CSF is continually being made at the rate of about 20 mL/hr, it has to exit back into the bloodstream by being reabsorbed through the (12) that protrude into the dural venous sinuses. The venous sinus that overlies the brain superiorly is called the (13).

1. ____________________________

2. ____________________________

3. ____________________________

4. ____________________________

5. ____________________________

6. ____________________________

7. ____________________________

8. ____________________________

9. ____________________________

10. ____________________________

11. ____________________________

12. ____________________________

13. ____________________________

319

A. MRI Scan of the Human Brain

Identify the structures in Figure 20.16, midsagittal view.

1. ___________________________________________

2. ___________________________________________

3. ___________________________________________

4. ___________________________________________

5. ___________________________________________

FIGURE 20.16 Midsagittal section of the human brain MRI.

1 2

4 3

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Name ___________________________________ Date _________________ Section ______________________________

Using Your Knowledge

20 E X E R C I S E

320 E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N

B. Transverse Section of a Human Brain

Identify the structures in Figure 20.17, a transverse section.

6. ___________________________________________

7. ___________________________________________

8. ___________________________________________

9. ___________________________________________

10. ___________________________________________

POSTERIOR

Superior Transverse plane through brain

FIGURE 20.17 Human brain, transverse section.

E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N 321

C. Sagittal Section of Human Brain

Identify the structures in Figure 20.18, sagittal section.

11. ___________________________________________

12. ___________________________________________

13. ___________________________________________

14. ___________________________________________

15. ___________________________________________

FIGURE 20.18 Human brain, sagittal section.

POSTERIOR ANTERIOR

SUPERIOR

INFERIOR

12 13

Sagittal plane through brain

Superior

322 E X E R C I S E 2 0 B R A I N S T R U C T U R E A N D F U N C T I O N

D. Brain Injury

Match the brain injury to the appropriate change in function. Use Figure 20.19 to locate the area injured. a. cessation of breathing b. loss of equilibrium c. loss of use of left arm d. loss of vision e. loss of pain localization in the shoulder

________ 16. The effect of a blow to the back of the head that damages this area.

________ 17. The effect of alcohol on this area.

________ 18. The effect of a head injury (i.e., from diving into a pool) that forces the dens into this area.

________ 19. The effect of a stroke that damages this area.

________ 20. The effect of a stroke that damages this area.

FIGURE 20.19 Human brain, lateral view.

SUPERIOR

POSTERIOR ANTERIOR

INFERIOR

Right lateral view

Spinal cord

Body of cervical vertebra

The 12 pairs of cranial nerves are part of the peripheral nervous system. They are numbered from anterior to posterior with Roman numerals I–XII. Cranial nerves originate from various ventral areas of the brain and exit the cranial cavity through foramina to reach their destinations, which are primarily in the head and neck.

A. Name and Location of Cranial Nerves

The cranial nerve’s name sometimes indicates the struc- ture it innervates or its function. The names of the cranial nerves I–XII are in order as follows: olfactory (olfactus �

O B J E C T I V E S M A T E R I A L S

• human brain models, charts, or use Real Anatomy (Nervous)

• skull with or without cranial nerves • preserved human brain (if available) • Testing Cranial Nerve Function: spice or aromatic

oil, penlight, cotton, ice water, sugar, quinine or bitter food (vinegar, turmeric, unsweetened cocoa powder, coffee), tuning fork, tongue depressors

1 Identify the 12 pairs of cranial nerves by name and Roman numeral on brain models and/or preserved human brains

2 State the function of the 12 pairs of cranial nerves

3 Test cranial nerve function

4 Identify specific cranial nerves on the sheep brain

323

sense of smell), optic, oculomotor (oculo- � eye; motor � mover), trochlear (trochlea � pulley), trigeminal (tri- � three; -gemini � twins), abducens (ab- � away; -ducens � to lead), facial, vestibulocochlear (vestibulo- � vestibule of ear/equilibrium; -cochlear � cochlea of ear/hear- ing), glossopharyngeal (glosso- � tongue; -pharyngeal � throat), vagus (vagus � wandering), accessory, and hypoglossal (hypo- � below; -glossal � tongue). The vagus nerve has the distinction of being different from the other 11 cranial nerves in its distribution. As its word derivative states, it is the “wandering nerve” that branches extensively and innervates the viscera of the thoracic and abdominopelvic cavities.

Cranial Nerves 21 E X E R C I S E

324 E X E R C I S E 2 1 C R A N I A L N E R V E S

You may want to use the following mnemonic device to help remember the names of the cranial nerves in or- der: “On Old Olympus’ Towering Top A Friendly Viking Grew Vines And Hops.” The bold fi rst letter of each word matches with the fi rst letter in the name of the cranial nerve. The olfactory nerves are very small and will not be seen in Figure 21.1. The olfactory bulbs and tracts can be observed and are marked instead. When locating the foramen for the cranial nerves, note that cranial nerves III, IV, VI, and the ophthalmic divi- sion of V, all exit the same foramen, the superior orbital fi ssure. Cranial nerves IX, X, and XI all exit the jugular foramen. Each of the other 7 foramina has one cranial nerve exiting.

Before Going to Lab

1 Learn the mnemonic for recalling the names of the cra- nial nerves.

2 Label the cranial nerves on Figure 21.1. 3 In Figure 21.2, identify the cranial nerve(s) that exit

each foramen by writing the name(s) in the blank.

4 Learn the Roman numeral, name, and function of each cranial nerve.

LAB ACTIVITY 1 Name and Location of Cranial Nerves

1 Identify each cranial nerve on a preserved human brain, human brain model, chart, or use the search text box in Real Anatomy (Nervous) to locate these structures.

2 Locate the foramen for each cranial nerve on a skull with or without cranial nerves. Refer to Table 21.1 and Figure 21.2.

3 Quiz your lab partner on cranial nerve names and functions. ■

TABLE 21 .1 Foramen of Cranial Nerves

NUMBER NAME FORAMEN

I Olfactory Olfactory foramina of cribriform plate II Optic Optic foramen III Oculomotor Superior orbital fissure IV Trochlear Superior orbital fissure V Trigeminal Ophthalmic—Superior orbital fissure Maxillary—Foramen rotundum Mandibular—Foramen ovale VI Abducens Superior orbital fissure VII Facial Stylomastoid foramen VIII Vestibulocochlear Internal auditory meatus IX Glossopharyngeal Jugular foramen X Vagus Jugular foramen XI Accessory Jugular foramen XII Hypoglossal Hypoglossal canal

E X E R C I S E 2 1 C R A N I A L N E R V E S 325

Olfactory bulb

Olfactory tract

Oculomotor nerve

Trigeminal nerve

Facial nerve

Glossopharyngeal nerve Hypoglossal nerve

Optic nerve

Trochlear nerve

Abducens nerve

Vestibulo- cochlear nerve

Vagus nerve

Accessory nerve

View

POSTERIOR

CRANIAL NERVES:

Inferior aspect of brain

• abducens (ab-DUE-senz) • accessory • facial • glossopharyngeal

(gloss-oh-fah-RIN-jeal) • hypoglossal (hypo-GLOSS-al) • oculomotor (ok-u-low-MO-tor) • olfactory (OHL-fac-tory) tract • optic • trigeminal (tri-GEM-i-nal) • trochlear (TROH-klee-ur) • vagus (VAY-gus) • vestibulocochlear

(ves-tib-u-lo-COKE-lee-ur)

1 _________________________________

2 _________________________________

3 _________________________________

4 _________________________________

5 _________________________________

6 _________________________________

7 _________________________________

8 _________________________________

9 _________________________________

10 _________________________________

11 _________________________________

12 _________________________________

FIGURE 21.1 Cranial nerves of the human brain.

326 E X E R C I S E 2 1 C R A N I A L N E R V E S

Foramen rotundum

Stylomas foramen

Int au

Axons pass through olfactory foramina

Location of optic foramen

Location of superior orbital fissure

Foramen ovale

Cerebellum

Posterolateral view of dissected brain with cranial nerves

Hypoglossal canal

FIGURE 21.2 Cranial nerves and foramina.

• abducens • accessory • facial • glossopharyngeal • hypoglossal • oculomotor • olfactory • optic • trigeminal • trochlear • vagus • vestibulocochlear

1. foramen ovale _____________________________________________________________________________

2. foramen rotundum ________________________________________________________________________

3. hypoglossal canal __________________________________________________________________________

4. internal auditory meatus ___________________________________________________________________

5. jugular foramen ___________________________________________________________________________

6. axons pass through olfactory foramina ______________________________________________________

7. optic foramen _____________________________________________________________________________

8. stylomastoid foramen ______________________________________________________________________

9. superior orbital fissure _____________________________________________________________________

E X E R C I S E 2 1 C R A N I A L N E R V E S 327

shown to have some motor activity, but its main function is sensory. Two of the cranial nerves have branches. The tri- geminal nerve (V) has 3 branches: ophthalmic, maxillary, and mandibular. The accessory nerve (XI) has a cranial portion and spinal portion. In addition to somatic motor fi bers, cranial nerves III, VII, IX, and X also have parasym- pathetic motor fi bers. An easy way to remember the names of the cranial nerves that innervate the eyeball is by using the following formula: LR6SO4 � the lateral rectus muscle (LR) is in- nervated by cranial nerve VI; the superior oblique muscle (SO) is innervated by cranial nerve IV; the other 4 external muscles of the eyeball are innervated by cranial nerve III.

B. Testing Cranial Nerve Function

Not all cranial nerves function in the same way. Some cra- nial nerves are primarily special sensory in function, others are primarily motor in function, and still others have both sensory and motor fi bers. A mnemonic device for recalling the function of cranial nerves is: “Some Say Marry Money But My Brother Says Bad Business Marry Money.” The 3 types are: S � sensory; M � motor; B � both sensory and motor (mixed nerve). Motor nerves also have sensory proprioceptors located in the muscles they innervate, but their main function is motor. Cranial nerve VIII has been

TABLE 21 .2 Cranial Nerve Function, Distribution, and Action

NUMBER AND NAME D ISTR IBUT ION ACT ION

I Olfactory Nasal mucosa Smell II Optic Eye Vision III Oculomotor Levator palpebrae superioris; four extrinsic eye Movement of eyelid; movement of muscles (inferior oblique, superior rectus, eyeball; accommodation of lens; medial rectus, inferior rectus); ciliary muscle pupillary constriction (intrinsic eye muscle); iris muscles of eye (intrinsic eye muscles) IV Trochlear Superior oblique muscle of eyeball Movement of eyeball V Trigeminal Ophthalmic branch (eye and forehead) Cutaneous sensations from ophthalmic, Maxillary branch maxillary, and mandibular areas; Mandibular branch chewing VI Abducens Lateral rectus muscle of eyeball Movement of eyeball VII Facial Anterior 2/3 of tongue; facial, scalp, and neck Taste; facial expression; secretion muscles; lacrimal glands; salivary glands of tears; salivation VIII Vestibulocochlear Semicircular canals and cochlea of ear Equilibrium and hearing IX Glossopharyngeal Posterior 1/3 of tongue; pharyngeal muscles; Taste; swallowing and speech; secretion parotid gland of saliva X Vagus Pharyngeal muscles and epiglottis; smooth Taste and somatic sensation from muscles of thorax and GI tract; cardiac pharynx and epiglottis; swallowing, muscle; glands of GI tract coughing, and voice production; smooth

muscle contraction of GI tract; slows heart rate; secretion by digestive glands

XI Accessory Cranial portion—muscles of pharynx, larynx, and Swallowing soft palate Spinal portion—sternocleidomastoid and Movement of head and shoulders trapezius muscles XII Hypoglossal Tongue muscles Speech and swallowing

328 E X E R C I S E 2 1 C R A N I A L N E R V E S

LAB ACTIVITY 2 Testing Cranial Nerve Function

1 Perform the cranial nerve tests to determine if function is normal, consulting Table 21.2 for each nerve action. Record results in Table 21.3 by circling either normal (N) or abnormal (A) for each nerve.

2 Clean up as directed by your instructor. ■

TABLE 21 .3 Testing Cranial Nerve Function

NUMBER CRANIAL NER VE QUICK TEST RESULTS

I • Sniff aromatic oil, spice, or coffee grounds (ability to smell is normal) N A II • Read a Snellen eye chart at 20 ft. (ability to read is normal) N A III, IV, VI • Observe eyelids (eyelid not drooping is normal) N A • Look up, down, medially, laterally, upper lateral, lower lateral (ability to move eyeball is normal) N A • Shine penlight on pupils (constriction is normal) N A V • Lightly touch the cornea of the subject with a wisp of cotton (blinking is normal) N A • Subject bites down on tongue depressor; try to pull it out (good resistance to pulling is normal) N A VII • Have subject smile, raise eyebrows, whistle, and close the eyes (ability to do these actions is normal) N A • Check tip of tongue for taste with sugar (ability to taste is normal) N A VIII • Use a tuning fork to check hearing in each ear (ability to hear is normal) N A • Have the subject stand straight with eyes closed (absence of swaying is normal) N A IX, X • Have subject say, “Ah”; check uvula position with mouth open (midline is normal) N A • Using a cotton-tipped applicator, gently touch the subject’s uvula to elicit a gag reflex (gag response is normal) N A • The posterior 1/3 of tongue can be tested with cotton applicator dipped in quinine (taste is normal) N A XI • Have subject shrug shoulders against resistance as you are holding them down (both sides having equal strength is normal) N A XII • Ask your lab partner to stick out and retract his/her tongue (tongue not deviating to one side is normal) N A

SAFETY NOTE: INSTRUCTIONS FOR TESTING CRANIAL NERVE FUNCTION Anything that was used in the mouth (tongue depressor or cotton-tipped swab or applicator) needs to be im- mediately placed in an autoclavable bag after use. Do not place these used items on your lab bench.

329

A. Cranial Nerve Numbers

Give the Roman numeral for the 12 pairs of cranial nerves.

____ 1. Abducens ____ 2. Accessory ____ 3. Facial

____ 4. Glossopharyngeal ____ 5. Hypoglossal ____ 6. Oculomotor

____ 7. Olfactory ____ 8. Optic ____ 9. Trigeminal

____ 10. Trochlear ____ 11. Vagus ____ 12. Vestibulocochlear

Identify the cranial nerves by writing the name in the blank. ANTERIOR

POSTERIOR

CRANIAL NERVES:

1 _________________________________

2 _________________________________

3 _________________________________

4 _________________________________

5 _________________________________

6 _________________________________

7 _________________________________

8 _________________________________

9 _________________________________

10 _________________________________

11 _________________________________

12 _________________________________

FIGURE 21.3 Cranial nerves.

Name ___________________________________ Date _________________ Section ______________________________

21 E X E R C I S EReviewing Your Knowledge

330 E X E R C I S E 2 1 C R A N I A L N E R V E S

B. Cranial Nerve Function

Identify if each cranial nerve is mainly sensory, motor, or both. S � sensory M � motor B � both sensory and motor

____ 1. Olfactory

____ 2. Optic

____ 3. Oculomotor

____ 4. Trochlear

____ 5. Trigeminal

____ 6. Abducens

____ 7. Facial

____ 8. Vestibulocochlear

____ 9. Glossopharyngeal

____ 10. Vagus

____ 11. Accessory

____ 12. Hypoglossal

C. Cranial Nerve Action—Matching

Choose the action of the cranial nerve and write the letter next to the cranial number.

____ I. A. Movement of lateral rectus muscle

____ II. B. Speech and swallowing—tongue muscles

____ III. C. Taste; facial expression; tears; salivation

____ IV. D. Equilibrium and hearing

____ V. E. Smell

____ VI. F. Movement of superior oblique muscle

____ VII. G. Movement of head and shoulders—sternocleidomastoid and trapezius muscles

____ VIII. H. Vision

____ IX. I. Posterior 1/3 of tongue; taste, swallowing and speech; secretion of saliva

____ X. J. Cutaneous sensations from ophthalmic, maxillary, and mandibular areas; chewing

____ XI. K. Taste; pharynx and epiglottis sensations; swallowing, coughing; voice production; smooth muscle of GI tract; secretion of digestive glands; slows heart rate

____ XII. L. Movement of 4 extrinsic eye muscles; accommodation of lens; pupillary constriction

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Name ___________________________________ Date _________________ Section ______________________________

Using Your Knowledge

21 E X E R C I S E

331

A. Normal Cranial Nerve Function

Give the Roman numeral of the cranial nerve(s) involved with the following functions or activities.

_______________ 1. Hearing the crack of a bat hitting a baseball

_______________ 2. Smelling dinner cooking

_______________ 3. Being dizzy after going on a Tilt-a-Whirl ride at the fair

_______________ 4. Lifting your shoulders while doing warm-up exercises

_______________ 5. Chewing a tender steak

_______________ 6. Swallowing the tender steak

_______________ 7. Salivation and crying

_______________ 8. Reading a book

_______________ 9. Seeing a sunset

_______________ 10. Looking cross-eyed

_______________ 11. Smiling

_______________ 12. Moving your head from side to side

_______________ 13. Feeling a hot curling iron touching the forehead

_______________ 14. Decreased heart rate

_______________ 15. Rolling your eyes

_______________ 16. All of the cranial nerves that are involved with the digestive system in some way, starting with the mouth

_______________ 17. Speaking

332 E X E R C I S E 2 1 C R A N I A L N E R V E S

B. Cranial Nerve Injury

Write the name of the cranial nerve(s) involved.

18. Injury to this cranial nerve causes Bell’s palsy—a loss of taste, decreased salivation, and loss of the ability to close the eyes, even during sleep. Name this nerve.

19. Injury to this cranial nerve causes a loss of taste sensation, decreased salivation, and difficulty in swallowing. Name this nerve.

20. Injury to this cranial nerve causes paralysis of the vocal cords, interferes with swallowing, interrupts sensations from many organs, and causes the heart rate to increase. Name this nerve.

E X E R C I S E 2 2 A U T O N O M I C N E R V O U S S Y S T E M S T R U C T U R E A N D F U N C T I O N 333

The autonomic nervous system (ANS) is the division of the peripheral nervous system that op-erates without conscious control in most individu- als. The ANS has autonomic sensory neurons that carry nerve impulses from sensory receptors in visceral organs and blood vessels to the central nervous system (CNS), and autonomic motor neurons that carry nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands (effectors). There are 2 autonomic motor neurons between the spinal cord and the effectors. The first motor neuron (preganglionic) synapses with the second motor neuron (postganglionic) in ANS ganglia.

Autonomic Nervous System Structure and Function

22 E X E R C I S E

333

The ANS has 2 different motor divisions, the sympa- thetic division and the parasympathetic division. Most ANS effectors are innervated by both the sympathetic and parasympathetic divisions, which have opposing actions. Activation of the sympathetic division occurs during exercise, emergencies, excitement, and embarrassment and results in a series of physiological responses that together are called the fi ght-or-fl ight response. The fi ght-or-fl ight response includes activities that promote mental alertness, vision, and skeletal muscle activity. Activation of the parasympathetic division promotes rest, reading, restoration, and repair.

O B J E C T I V E S M A T E R I A L S

• spinal cord model or chart with autonomic ganglia

• brain model or chart showing the cranial nerves • transverse section model or chart of the spinal

cord with white and gray rami communicantes

• Pupillary Light Reflex: penlight • Lie Detector Test: millimeter rulers, temperature

strips (forehead) or temple temperature thermometer, stopwatch

• Stress and Relaxation: blood pressure cuff, stopwatch

• • Biopac Laboratory Guide Experiments: • Observing ANS Responses to Lying • Observing ANS Responses Following

Meditation

1 Compare and contrast the anatomical components of the sympathetic and parasympathetic divisions of the autonomic nervous system (ANS)

2 Name and locate the ganglia of the sympathetic and parasympathetic nervous systems

3 Compare somatic and autonomic reflexes

4 Describe the pupillary light reflex

5 Describe ANS reponses as observed in a lie detector test

334 E X E R C I S E 2 2 A U T O N O M I C N E R V O U S S Y S T E M S T R U C T U R E A N D F U N C T I O N

A. Anatomy of the Sympathetic Division

1. Preganglionic and Postganglionic Motor Neurons

Cell bodies of preganglionic neurons are located in the gray matter of the lateral horn of spinal cord segments T1–L2. Because the nerve impulses from the sympathetic preganglionic neuron originate in the thoracic and lumbar segments of the spinal cord, the sympathetic division is also called the thoracolumbar division. Axons of the fi rst motor neurons of this division, pre- ganglionic neurons, exit the spinal cord in the anterior (ventral) root of the spinal nerves and travel with somatic motor neurons in the spinal nerves a short distance. These myelinated preganglionic axons quickly leave the spinal nerve as white rami communicantes that connect with sympathetic trunk ganglia, paired chains of ganglia that lie parallel to the spinal cord. In these ganglia, the axons either synapse with postganglionic cell bodies, or they pass through the sympathetic trunk ganglia without synapsing, emerging to form splanchnic nerves (splanchnic � viscera) in the abdominopelvic region. Nerve cell bodies of the second motor neuron, the post- ganglionic neuron, are located in the sympathetic ganglia. Preganglionic axons synapse with postganglionic neuron cell bodies in the ganglia. Some of the axons of postgan- glionic neurons return to the spinal nerve at the same level via the gray rami communicantes. Postganglionic axons are longer than preganglionic axons because they travel a greater distance to innervate the effectors.

2. Sympathetic Ganglia

The sympathetic division has 2 groups of ganglia: the sym- pathetic trunk (chain) ganglia and the prevertebral (collat- eral) ganglia.

• sympathetic trunk (chain) ganglia—These paired ganglia chains lie parallel to the spinal cord. Postganglionic neurons from these ganglia innervate organs superior to the diaphragm.

• prevertebral (collateral) ganglia: celiac, superior mesenteric, and inferior mesenteric—These 3 single ganglia lie anterior to the abdominal aorta, and their postganglionic neurons innervate organs inferior to the diaphragm. Preganglionic axons traveling in splanchnic nerves synapse with postsynaptic neuron cell bodies in the prevertebral ganglia or in the adrenal medullae.

Before Going to Lab

1 Label the structures in Figure 22.1. 2 Identify the following structures on a chart showing

the sympathetic nervous system: right and left sympa- thetic trunk ganglia, prevertebral ganglia, splanch- nic nerves, and preganglionic and postganglionic motor neurons.

LAB ACTIVITY 1 Anatomy of the Sympathetic Division

1 Identify the sympathetic trunk ganglia on a longitudi- nal spinal cord model.

2 Identify the rami communicantes and the sympathetic trunk ganglia on a transverse section spinal cord model or chart. ■

E X E R C I S E 2 2 A U T O N O M I C N E R V O U S S Y S T E M S T R U C T U R E A N D F U N C T I O N 335

• left sympathetic trunk ganglia • prevertebral ganglia • right sympathetic trunk ganglia • splanchnic nerves

1 ___________________________________________

2 ___________________________________________

3 ___________________________________________

4 ___________________________________________

Trachea

Arch of aorta

Left primary bronchus

Esophagus

Thoracic aorta

Diaphragm

Left kidney

Abdominal aorta

Anterior view

FIGURE 22.1 Location of sympathetic motor ganglia and nerves.

336 E X E R C I S E 2 2 A U T O N O M I C N E R V O U S S Y S T E M S T R U C T U R E A N D F U N C T I O N

Nerve cell bodies of postganglionic neurons (2nd motor neurons) are in the terminal ganglia. Axons of postgangli- onic neurons are short because they travel a short distance to their effectors.

B. Anatomy of the Parasympathetic Division

Cell bodies of the preganglionic motor neurons of this divi- sion are located in the nuclei of 4 cranial nerves in the brain stem and in the lateral horns of spinal cord segments S2–S4. Because the outfl ow is from these areas, this division is also known as the craniosacral division. Axons of the cranial preganglionic neurons exit the brain in cranial nerves III, VII, IX, and X and synapse with postganglionic neurons in terminal (intramural) ganglia located near their target organs in the head region. The major terminal ganglia in the head region are: ciliary, pterygo- palatine, submandibular, and otic ganglia. Axons of the sacral preganglionic neurons leave the spinal cord in the anterior (ventral) roots, form nerves called pelvic splanchnic nerves, and synapse with post- ganglionic neurons in terminal ganglia that are within the wall of the target organ.

Before Going to Lab

1 Label the terminal ganglia in Figure 22.2. Use the name of the ganglia to find the location.

LAB ACTIVITY 2 Anatomy of the Parasympathetic Division

1 Identify the following structures on a model or chart showing the parasympathetic nervous system: terminal ganglia, pelvic splanchnic nerves, and preganglionic and postganglionic motor neurons. ■

• ciliary ganglion • otic ganglion • pterygopalatine ganglion • submandibular ganglion

Oculomotor nerve (III)

Facial nerve (VII) Vestibulocochlear nerve (VIII) Glossopharyngeal nerve (IX)

Vagus nerve (X)

Trigeminal nerve (V) (mandibular branch)

Superior cervical sympathetic ganglion

Cervical sympathetic trunk

1 ___________________________________

2 ___________________________________

3 ___________________________________

4 ___________________________________

FIGURE 22.2 Parasympathetic nerves and ganglia.

E X E R C I S E 2 2 A U T O N O M I C N E R V O U S S Y S T E M S T R U C T U R E A N D F U N C T I O N 337

1. Pupillary Light Reflex

When photoreceptors in the retina of the eye are stimu- lated by light, nerve impulses are sent via the optic nerve to integrating centers in the brain. Interneurons from the integrating centers send impulses to motor neurons in the midbrain. Axons from these preganglionic motor neurons travel along cranial nerve III (oculomotor nerve) to the cili- ary ganglion where they synapse with the postganglionic motor neuron. The postganglionic axons travel a short dis- tance to smooth muscles in the iris of the eye. When these muscles contract, the pupil constricts.

C. Autonomic Reflexes

Autonomic refl exes control many body functions such as blood pressure, respiration, and digestion. The autonomic refl ex arc contains the same components as the somatic re- fl ex arc: receptor, sensory neuron, integrating center, motor neurons, and effector. Although most autonomic sensory receptors are located in visceral organs, some autonomic refl exes are responses to changes in the external environ- ment. Autonomic integrating centers are polysynaptic and most are located in the hypothalamus and brain stem. However, the autonomic refl ex arcs that control urination and defecation have integrating centers in the spinal cord. ANS refl ex arcs have 2 motor neurons—preganglionic and postganglionic neurons—which synapse in the autonomic ganglia. ANS effectors are cardiac muscle, smooth muscle, and glands. Most ANS effectors receive motor neurons from both the sympathetic and the parasympathetic branches of the ANS. Since sympathetic and parasympathetic responses usually oppose each other, the hypothalamic integrating center determines which response is appropriate.

Before Going to Lab

1 Label the parts of the autonomic reflex arc in Figure 22.3.

3 Stimulus2

5 6 7

Response Central nervous system (brain or spinal cord)

• autonomic ganglion (sympathetic or parasympathetic)

• axon of postganglionic motor neuron • axon of preganglionic motor neuron • axon of sensory neuron (afferent) • interneuron • sensory receptor • visceral effector

1 ___________________________________

2 ___________________________________

3 ___________________________________

4 ___________________________________

5 ___________________________________

6 ___________________________________

7 ___________________________________

FIGURE 22.3 Autonomic reflex arc.

LAB ACTIVITY 3 Pupillary Light Reflex

1 Test the pupillary light reflex. • This experiment works best if conducted in a dimly

lit room using a subject with light-colored eyes. • Have the subject cover his or her right eye by holding

a hand over the eye. • Using a penlight, shine a light into the subject’s left

eye. Observe the pupil and describe the change in the pupil size. _______________

• While shining a light into the subject’s left eye, uncover the right eye and immediately observe the size of the right pupil. Is the right pupil the same size as the left pupil? _______________

• Shut off the penlight and observe the change in size of the subject’s pupils. _______________

2 Answer the Discussion Questions with your lab group.

338 E X E R C I S E 2 2 A U T O N O M I C N E R V O U S S Y S T E M S T R U C T U R E A N D F U N C T I O N

2. The Effect of Higher Brain Centers on ANS Functions

The cerebral cortex, limbic system (emotional brain), and thalamus can also alter the ANS responses. For example, when some people tell a lie, the limbic system causes the following sympathetic ANS responses: dilation of the blood vessels in the face and neck area resulting in red- ness, dilation of the pupils, and an increase in breathing rate, heart rate, and/or blood pressure. However, detection of autonomic changes by observation is a subjective exer- cise. Also, some people can lie without feeling emotion, avoiding ANS responses.

DISCUSSION QUESTIONS Pupillary Light Reflex

1 Is this reflex a somatic or autonomic reflex?

2 Identify the nerve that is carrying the sensory informa- tion from the eye to the brain.

3 Identify the cranial nerve carrying the preganglionic parasympathetic axons to the ciliary ganglia.

4 Is this a monosynaptic or polysynaptic reflex?

5 Is the pupillary light reflex ipsilateral, contralateral, or both?

■

LAB ACTIVITY 4 Lie Detector Test and the ANS

1 Decide who will be the subject, the interrogator, the observer, and the pulse-taker.

2 Use 10 of the questions below or other questions that the group devises and has the instructor’s approval. Assign each question a number (1–10) indicating the order in which the questions are to be asked.

How old are you? _______ You were born in what city and state? _______ How many brothers and sisters do you have? _______ When driving a car, do you purposely exceed the speed

limit over twice a week? _______ Have you ever flunked a college or university class?

_______ Are you single or married? _______ Do you like this anatomy and physiology class? _______ Do you study for this class as much as you should?

_______ Are you getting the grade in this class that you want?

_______ What is your major? _______ Have you ever cheated on your income taxes? _______ What is your weight? _______ What is your height? _______ Have you ever cheated on an exam? _______ 3 Have the subject privately write down which three ques-

tions are going to be lies. In a real polygraph test, the subject sees all questions before the test commences.

4 Perform the lie detector test. • Have the observer obtain baseline information on:

the subject’s redness of face and neck, pupil size, pulse rate in 15 seconds, nervousness of hands or fingers, or any other nervous changes that might indicate lying. You may take the temperature on the forehead with temperature strips, if available. Record the results in Table 22.1.

• Have the interrogator ask the 10 chosen questions. • Observe ANS changes after each question and record

in Table 22.1 before continuing to the next question.

5 Based on the collected data, have the experimenters privately predict which three questions the subject lied about, and then ask the subject to give the answers that were lies. • Question numbers that experimenters predict the

subject is lying about. _______________ • Actual question numbers the subject did lie about.

_______________ • Number of correct predictions chosen by

experimenters in your group. _______________ • Pool your data with all the lab groups. What is the

average number of correct predictions? _______________

6 Answer Discussion Questions with your lab group. 7 Discuss your results with the class. 8 Complete the Biopac Laboratory Guide Experiment:

Observing ANS Responses to Lying.

E X E R C I S E 2 2 A U T O N O M I C N E R V O U S S Y S T E M S T R U C T U R E A N D F U N C T I O N 339

DISCUSSION QUESTIONS Lie Detector Test

1 Based on the pooled class data, give reasons why using this type of lie detector test to solve a crime may or may not be advantageous.

2 A professional polygraph test is administered by someone who is trained to perform the test and lasts 2–3 hours, with additional time to analyze the results. Four reactions are recorded by four sensors attached to a person’s body that record chest movement during res- piration, abdominal movement during respiration, skin conductance (sweating), and heart rate/blood pressure (Figure 22.4). Note the response (truthful answer) on the left side of the figure, compared with the response (lie) on the right side.

3 Give reasons why the use of a polygraph test given by a professional may or may not reveal if the person is tell- ing the truth.

■

TABLE 22 .1 ANS Responses and Lie Detector Test

PRE -QUEST ION ANS RESPONSES FOR QUEST ION OBSER VAT IONS ANS RESPONSES 1 2 3 4 5 6 7 8 9 10

Color Color ______________ No Change (N) or Redness (R)

Pupil Size Pupil Size (mm) No Change (N), Increased (I), _______ or Decreased (D)

Pulse Rate Pulse Rate (beats/15 sec) (beats/15 sec) _______ N, I, or D

Temperature Temperature (�F or �C) (�F or �C) _______ N, I, or D

Nervousness Yes (Y) or No (N)

Prediction: Was the answer the Truth (T) or a Lie (L)?

FIGURE 22.4 Polygraph test reactions.

Chest movement during respiration

Abdominal movement during respiration

Skin conductance

Heart rate and blood pressure

340 E X E R C I S E 2 2 A U T O N O M I C N E R V O U S S Y S T E M S T R U C T U R E A N D F U N C T I O N

3. The Effect of Stress and Relaxation on ANS Functions

Breathing rate is an ANS response that can be controlled. Decreasing breathing rate and increasing depth of breath- ing can cause a person to relax. This state of relaxation is characterized by diminished sympathetic stimulation and increased parasympathetic stimulation. Alternately, increasing breathing rate can lead to arousal caused by in- creased sympathetic stimulation.

LAB ACTIVITY 5 Effect of Relaxation on ANS Functions

1 Decide who will be the subject and who will measure and record pulse rate and blood pressure.

2 Have the subject sit down and measure resting pulse rate and blood pressure after 2 minutes. Record measure- ments in Table 22.2.

3 Give the subject a series of multiplication questions that the subject must answer in a short period of time.

4 Measure pulse rate and blood pressure immediately after doing the math problems and record in Table 22.2.

5 Have subject take deep slow breaths (8 breaths/min) for 10 minutes.

6 Measure pulse rate and blood pressure and record in Table 22.2.

7 Answer Discussion Questions with your lab group.

TABLE 22 .2 Effect of Stress and Relaxation on Pulse and Blood Pressure

PULSE BLOOD ACT IV ITY RATE PRESSURE

Resting

Stress

Deep, slow breathing

DISCUSSION QUESTIONS Effect of Stress and Relaxation on Pulse and Blood Pressure

1 State whether stress increased or decreased blood pres- sure and pulse rate. Which division of the ANS caused this change?

2 State whether relaxation increased or decreased blood pressure and pulse rate. Which division of the ANS caused this change?

3 The ANS regulation of blood pressure is involuntary, yet biofeedback techniques enable individuals to reduce their pulse rate and blood pressure. Explain how this occurs.

■

341

Name ___________________________________ Date _________________ Section ______________________________

22 E X E R C I S EReviewing Your Knowledge

A. Comparison of Somatic and Autonomic Nervous Systems

Answer each of the following questions:

1. Compare the number of motor neurons in a somatic and autonomic reflex arc.

2. Compare the effectors of the somatic and autonomic nervous systems.

B. Comparison of Sympathetic and Parasympathetic Divisions

Match the terms with the appropriate ANS division: P � parasympathetic division; S � sympathetic division. Use one or both choices to answer the question.

1. two motor neurons

2. short preganglionic axons

3. long preganglionic axons

4. innervates adrenal medullae

5. terminal ganglia

6. trunk or chain ganglia

7. prevertebral ganglia

8. craniosacral division

9. thoracolumbar division

342 E X E R C I S E 2 2 A U T O N O M I C N E R V O U S S Y S T E M S T R U C T U R E A N D F U N C T I O N

10. activated during exercise, fighting, or fleeing

11. rami communicantes

12. promotes digestion

13. short postganglionic axons

14. long postganglionic axons

C. Autonomic Reflex Arc

Answer each of the following questions:

1. List the components of the autonomic reflex arc. Compare with somatic reflex arc.

2. Where are autonomic integrating centers located?

3. Are the autonomic integrating centers monosynaptic or polysynaptic?

4. Can the autonomic integrating centers be influenced by higher brain area?

343

A. Sympathetic Division

Refer to a sympathetic nervous system chart (or textbook) to answer questions 1–6.

Brittany was visibly upset that a class she needed to take was cancelled because of low enrollment. Jim observed that her eyes were dilated. Trace the sympathetic pathway from the lateral gray horn of the spinal cord to the iris of her eye.

1. Identify the spinal cord area (cervical or thoracic) that the preganglionic axons exit in the anterior (ventral) root.

2. Name the sympathetic ganglia in which the preganglionic and postganglionic neurons synapse.

Paul ate a big lunch and then decided to jog a mile, which was not a very good idea. His digestive system was put “on hold” while his sympathetic nervous system was stimulated to run. Trace the sympathetic pathway from the lateral gray horn of the spinal cord to the stomach.

3. Identify the nerve that the preganglionic axons form.

4. Name the effector (the tissue within the organ that is innervated by the postganglionic neuron).

Burke is in the final 100 yards of a race with an opponent at his heels. His sympathetic nervous system is stimulating his adrenal medullae. Trace the sympathetic pathway from the lateral gray horn of the spinal cord to the adrenal medulla.

5. Name the sympathetic ganglia in which the preganglionic axons synapse.

6. What is different about these postganglionic cells?

Name ___________________________________ Date _________________ Section ______________________________

Using Your Knowledge

22 E X E R C I S E

344 E X E R C I S E 2 2 A U T O N O M I C N E R V O U S S Y S T E M S T R U C T U R E A N D F U N C T I O N

B. Parasympathetic Division

Refer to parasympathetic nervous system chart (or textbook) to answer questions 7–10.

Tom had anesthesia for surgery and was unable to void for a short time after awakening. Trace the normal parasympathetic pathway from the lateral gray horn of the spinal cord to the urinary bladder.

7. Name the spinal cord segments that the preganglionic axons exit in the anterior (ventral) root.

8. Name the effector (the tissue within the organ that is innervated by the postganglionic neuron).

Michael just ate lunch and his salivary glands are responding with secretions. Trace the parasympathetic pathway from the medulla oblongata to the salivary glands.

9. Name the two nerves that carry the preganglionic axons to the parasympathetic ganglia.

10. Name the parasympathetic ganglia in which the preganglionic and postganglionic neurons synapse.

C. Functions of the Sympathetic and Parasympathetic Nervous Systems

Choose the correct division of the ANS that generates the following results: S � sympathetic; P � parasympathetic.

11. sweaty palms

12. blushing

13. urination

14. stomach churning

15. salivary gland secretion

16. constriction of pupils

17. increased blood pressure

18. increased respiration

19. decreased heart rate

20. digestive enzyme secretions

E X E R C I S E 2 3 G E N E R A L S E N S E S 345

Sensory receptors provide information about the environment outside and within our body. General sensory information originates either from somatic sensory receptors (skin and skeletal muscle) or visceral sensory receptors (visceral organs). Special sensory information originates from special sense organs (eye, inner ear, nasal mucosae, or taste buds).

General Senses 23 E X E R C I S E

345

A. Sensory Receptors

Structural classes of general sensory receptors include: free nerve endings, encapsulated nerve endings, or specialized receptor cells. Free nerve endings are dendrites of sensory nerves that convey to the brain the general sensations of pain, temperature, tickle, itch, and some touch sensations. Encapsulated nerve endings are dendrites of sensory neu- rons enclosed by a connective tissue capsule that convey the general sensations of touch and pressure to the brain. Sensory receptors of special sense organs are receptor cells that form synapses with sensory neurons.

O B J E C T I V E S M A T E R I A L S

• skin model • compound microscope, lens paper, prepared

microscopic slides of corpuscles of touch (Meissner’s corpuscles) and lamellated (Pacinian) corpuscles

• cross-section model or chart of spinal cord • Tactile Sensitivity: toothpicks or calipers

or aesthesiometer, millimeter rulers, sandpaper, velvet or synthetic fur, smooth surface such as glass

• Adaptation of Temperature Receptors: 3 fingerbowls or 1,000-mL beakers, water (10�C, 25�C, 45�C), thermometer

• Adaptation to Light Pressure: 4 pennies per group • Referred Pain: bowl of ice water

1 Differentiate between free and capsulated nerve endings and receptor cells

2 Describe the pathway from the sensory receptor to the cerebral cortex

3 Identify areas of the body that have the greatest tactile discrimination

4 Observe adaptation of sensory receptors

5 Observe the phenomenon of referred pain

346 E X E R C I S E 2 3 G E N E R A L S E N S E S

Before Going to Lab

1 Label the somatic sensory receptors in Figure 23.1(a) and (b). Figure 23.1(a) shows somatic sensory receptors found in hairless skin and skin with hair follicles. Refer to Table 23.1, which identifies location, structure (free or encapsulated nerve ending), and stimuli of somatic sensory receptors.

Epidermis

Dermis

Subcutaneous layer

Nociceptor (pain receptor)

Connective tissue capsule

(b) Proprioceptors(a) Sensory receptors in the skin

Connective tissue capsule

(a) • corpuscle of touch

(Meissner’s) • hair root plexus • lamellated corpuscle

(Pacinian) • type I cutaneous

mechanoreceptor • type II cutaneous

mechanoreceptor

1 ___________________________

2 ___________________________

3 ___________________________

4 ___________________________

5 ___________________________

(b) • muscle spindle • tendon organ

6 ___________________________

7 ___________________________

FIGURE 23.1 Somatic sensory receptors.

LAB ACTIVITY 1 General Sensory Receptors

1 Point to the sensory receptors identified in Figure 23.1(a) on a skin model or anatomical chart.

2 Examine prepared microscope slides of cutaneous sen- sory receptors. ■

E X E R C I S E 2 3 G E N E R A L S E N S E S 347

TABLE 23 .1 Somatic Sensory Receptors

RECEPTOR LOCAT ION STRUCTURE ST IMUL I

Corpuscles of touch Dermal papillae of hair- Encapsulated nerve Touch and pressure (Meissner’s corpuscles) less skin endings

Hair root plexuses Surrounds hair follicles Free nerve endings Touching hair

Lamellated corpuscles Subcutaneous and sub- Encapsulated nerve Touch and pressure (Pacinian corpuscles) mucosal tissue, joints, endings tendons, and muscles

Type I cutaneous Associated with Merkel Free nerve endings Touch and pressure mechanoreceptors cells in stratum basale (Merkel discs) layer of epidermis

Type II cutaneous Dermis, ligaments, and Encapsulated nerve Stretching of digits and limbs mechanoreceptors tendons endings (Ruffini’s corpuscles)

Muscle spindles Found within most Encapsulated nerve Respond to changes in skeletal muscles endings muscle length

Tendon organs Found at junction of Encapsulated nerve Respond to changes in joint tendons and muscles endings position and movement

Warm receptors Dermis Free nerve endings Thermoreceptor; responds to temperatures between 32� and 48�C (90�–118�F)

Cold receptors Stratum basale of Free nerve endings Thermoreceptor; responds to epidermis temperatures between 10� and 40�C (50�–105�F)

Nociceptors Every body tissue Free nerve endings Pain receptors; respond to harmful stimuli

348 E X E R C I S E 2 3 G E N E R A L S E N S E S

2 a. Where are the cell bodies for the sensory neurons (first-order neurons) located?

b. Where are their axon terminals located?

3 a. Where are the cell bodies for the second-order neu- rons located?

b. Where are their axon terminals located?

4 a. Where are the cell bodies for the third-order neurons located?

b. Where are their axon terminals located?

5 Where does the posterior column-medial lemniscus pathway cross the opposite side of the CNS?

6 Where does the anteriolateral (spinothalamic) pathway cross to the opposite side of the CNS?

■

B. Sensory Pathways

Sensations that are consciously perceived include touch, pressure, pain, temperature, and some proprioception. These sensations have sensory pathways consisting of a chain of 3 neurons (fi rst-, second-, and third-order neurons) that terminate in the cerebral cortex. Sensory neurons (fi rst-order neurons) located in the peripheral nervous system synapse with an association neuron (second- order neuron) in the spinal cord or brain. Second-order neurons synapse with third-order neurons in the thalamus. Third-order neurons transmit information to the primary somatosensory area of the cerebral cortex. These sensory pathways cross to the opposite side of the CNS somewhere during their ascent. Sensations that do not reach the cerebral cortex are not consciously perceived and include some proprioception and information from visceral sensory receptors. These pathways do not contain third-order neurons.

Before Going to Lab

1 Label the sensory pathways in Figure 23.2(a) and (b).

LAB ACTIVITY 2 Sensory Pathways

1 Point out the pathway of the first- and second-order neurons in Figure 23.2(a) and (b) on a cross-section spinal cord model or chart.

2 Answer Discussion Questions with your lab group.

DISCUSSION QUESTIONS Sensory Pathways

Refer to Exercise 16: Nervous Tissue, if necessary.

1 Are sensory neurons from general sensory receptors unipolar, bipolar, or multipolar neurons?

E X E R C I S E 2 3 G E N E R A L S E N S E S 349

Posterior column

(a) Anterolateral (spinothalamic) pathway (b) Posterior column-medial lemniscus pathway

Corpuscle of touch

Cold receptor

Anterolateral (spinothalmic) tract

Dorsal root ganglion

Medulla

Midbrain

Primary somatosensory cortex

FIGURE 23.2 Selected sensory pathways.

(a) • first-order neuron • second-order neuron • third-order neuron

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

(b) • first-order neuron • second-order neuron • third-order neuron

4 _____________________________________________________

5 _____________________________________________________

6 _____________________________________________________

350 E X E R C I S E 2 3 G E N E R A L S E N S E S

2 Materials: Obtain materials for the tactile sensitivity experiment.

3 Data Collection: Perform the two-point discrimination test on the different body areas and record your results in Table 23.2. • Decide who will be the activity coordinator, subject,

data collector, and data recorder. • Have the subject’s eyes closed during the

experiment. • Put the 2 caliper points (or toothpicks) together. • Place caliper points on skin area to be tested. Touch

both caliper points to the skin at the same time. • Ask the subject if 1 or 2 points of the caliper can be

felt. • Increase the distance between caliper points. For the

fingertip and palm, increase the distance 1 mm. For the cheek, forearm, and back of leg, increase the distance by 2 mm.

• Continue to increase the distance between the caliper points until the subject can feel 2 points. This distance is the two-point discrimination distance and is to be measured with a millimeter ruler. Record this value in Table 23.2.

4 With eyes closed, have the subject feel objects of differ- ent textures (sandpaper, velvet or synthetic fur, smooth surface such as glass) with fingertips, posterior surface of forearm, and side of leg.

5 Clean up as directed by your instructor.

C. Tactile Sensitivity of Different Body Areas

Some areas of the skin have greater tactile sensitivity than others. The greater the number of cutaneous receptors in an area (touch receptor density), the greater the tactile sensitiv- ity of that area. The size of the somatosensory cortex area receiving sensory information from a specifi c body area is directly proportional to the cutaneous receptor density. The two-point discrimination test is an indirect mea- sure of cutaneous touch receptor density. A subject is touched by 2 closely spaced points and asked if he or she can feel both points. The objects are moved farther apart until 2 points can be felt. An area of skin with a greater density of touch receptors is more sensitive to touch and can discriminate between 2 points closer together than an area with a lower density of touch receptors.

LAB ACTIVITY 3 Experiment: Tactile Sensitivity: Two-Point Discrimination

1 Prediction: List the cutaneous receptor density of the following body areas (cheek, fingertip, palm, forearm, back of leg) from the greatest to the least. • ________________ (greatest) • ________________ • ________________ • ________________ • ________________ (least)

TABLE 23 .2 Tactile Sensitivity: Two-Point Discrimination

CLASS AVERAGE TWO-POINT TWO-POINT D ISCR IMINAT ION D ISCR IMINAT ION CLASS AVERAGE AREA TESTED D ISTANCE (mm) REC IPROCAL (mm) D ISTANCE (mm) REC IPROCAL (mm)

Cheek

Fingertip

Palm

Forearm

Back of leg

E X E R C I S E 2 3 G E N E R A L S E N S E S 351

• State which body area tested had the least and most sensitivity to different textures.

Discussion: • Which body area tested was represented by the larg-

est area of cerebral cortex? Discuss the reason for your conclusion.

• Which body area tested was represented by the smallest area of cerebral cortex? Discuss the reason for your conclusion.

• Discuss why cutaneous receptor density varied or did not vary among individuals.

Conclusion: • Write a sentence that postulates a correlation be-

tween the average two-point discrimination and the number of cutaneous receptors (receptor density) in a body area.

• Write a sentence that states which body area has the greatest and the least density of cutaneous receptors.

■

6 Data Analysis: • Calculate the reciprocal 1

two-point distance( ) of the two-point discrimination distance for each area

and record the value in Table 23.2. The reciprocal represents the portion of the somatosensory cortex that receives information from sensory receptors for a given body area. Areas with high sensory receptor density are represented by a corresponding greater area of cerebral cortex.

• Collect the individual two-point discrimination distance and reciprocal values for each body area from each lab group.

• Calculate the average two-point discrimination distance and reciprocal for each body area and record in Table 23.2.

• Create a bar graph with the body areas on the X axis and the class averages of the reciprocals on the Y axis. Use the graph in Figure 23.3.

7 Complete the Experimental Report with your lab group.

EXPERIMENTAL REPORT Tactile Sensitivity

Results: • State which body area tested has the highest average of

cutaneous receptor density and which has the lowest.

• State whether variation in tactile sensitivity per body area was observed among subjects.

FIGURE 23.3 Tactile sensitivity of different body areas.

352 E X E R C I S E 2 3 G E N E R A L S E N S E S

• Have the subject immerse the left hand into the water and record the immediate sensations in Table 23.3.

• Keep the left hand immersed for 1 minute; then also immerse the right hand into the same water. Now record the temperature sensation of both hands in Table 23.3.

• In which hand did adaptation occur? ________ • Have the subject wash hands in room temperature

water and then wait for 5 minutes before beginning the next procedure.

2 Part 2: Observe adaptation for warm and cold tempera- ture receptors. • Obtain 3 bowls or 1,000-mL beakers of water: one

room temperature (25�C), one warm (45�C), and one ice water (10�C).

• Have the subject place the left hand in 45�C warm water and the right hand in 10�C ice water simultane- ously. Record the immediate temperature sensation of each hand (hot, cold, or no change) in Table 23.3.

• Record the sensations of each hand after 1 minute. • Have the subject simultaneously put both hands into

the room-temperature (25�C) bowl. Record the imme- diate temperature sensation of each hand in Table 23.3.

3 Clean up as directed by your instructor. 4 Answer the Discussion Questions with your lab group.

D. Adaptation of Sensory Receptors

Adaptation (or fatigue) occurs when the continued stimu- lus of sensory receptors results in a decrease in nerve im- pulse generation in the sensory neuron(s) associated with the receptors. This phenomenon may occur with the length of time a stimulus is given and with the stimulus inten- sity. Receptors may adapt rapidly or slowly to continued stimulation. During this adaptation, conscious awareness dissipates. In this exercise, we will examine adaptation of temperature receptors that are initially rapidly adapting but maintain some response to stimuli.

LAB ACTIVITY 4 Adaptation of Temperature Receptors

1 Part 1: Observe adaptation for warm temperature receptors. • Decide who will be the subject, the timer, and the

data collector and recorder. • Obtain a bowl or 1,000-mL beaker of 45�C warm

water.

TABLE 23 .3 Adaptation of Temperature Receptors

BODY AREA T IME TEMPERATURE SENSAT ION

Part 1 Left hand Immediate (45�C)

1 minute (45�C)

Right hand Immediate (45�C)

Part 2 Left hand Immediate (45�C)

1 minute (45�C)

Immediate (25�C)

Right hand Immediate (10�C)

1 minute (10�C)

Immediate (25�C)

E X E R C I S E 2 3 G E N E R A L S E N S E S 353

DISCUSSION QUESTIONS Adaptation of Temperature Receptors

1 How long did it take for the cold and warm temperature receptors to adapt for the subject in your group?

2 When sensory receptors adapt, does the cerebral cortex receive an increased or decreased number of sensory nerve impulses?

3 Indicate whether each of the following general sensory receptors adapt quickly, slowly, or not at all. Use your own experience.

a. Cutaneous touch receptors (stimulated when skin is touched by an object, for example, when clothes touch the skin).

b. Cutaneous pressure receptors (stimulated when pres- sure is applied to skin).

c. Proprioceptors associated with skeletal muscles and tendons that are important for balance (propriocep- tors maintain muscle contraction needed for stand- ing erect and keeping head erect).

d. Pain receptors.

■

DISCUSSION QUESTIONS Adaptation of Light Pressure

1 How long did it take for the light pressure receptors to adapt to one penny versus 4 pennies on the forearm of your subject?

2 How did the results differ among members of your lab group? Was there a very large difference in adaptation time?

3 Discuss what the difference is between the stimulation of one penny versus the stimulation of 4 pennies. What do you conclude from the results?

■

LAB ACTIVITY 5 Adaptation to Light Pressure

1 Observe adaptation for light pressure receptors. • Rest your forearm on the desk and close your eyes.

Your lab partner will place one penny on the anterior surface of your forearm. Determine the length of time that the pressure sensation persists and record.

• Duration of pressure sensation � ________ sec • Your lab partner will now stack 3 more pennies on

top of the first penny. • Does the pressure sensation return? ________

Determine the length of time that this new pressure sensation persists and record.

• Duration of pressure sensation � ________ sec

2 Repeat the activity for each member of your lab group. 3 Answer the Discussion Questions with your lab group.

354 E X E R C I S E 2 3 G E N E R A L S E N S E S

E. Referred Pain

Pain that is felt in areas that are not injured or stimulated is called referred pain. Sometimes this pain originates in visceral organs and is perceived in the skin that is inner- vated by the same spinal segments. The pain of a heart at- tack is usually felt in the skin over the heart and down the left arm.

LAB ACTIVITY 6 Referred Pain

1 Observe referred pain in the elbow. • Choose a subject, a timer, and a data collector and

recorder. This experiment works best on a subject who has thin arms. The subject will be asked to immerse his/her elbow in ice water and describe the sensation (pain, discomfort, or tingling) and where the sensation is located.

• Obtain a bowl of ice water (10�C). • Have the subject immerse an elbow in ice water

and immediately describe the sensation and where it is located. Record results in Table 23.4. Have the subject keep the elbow in the water until directions indicate to remove it.

DISCUSSION QUESTIONS Referred Pain

1 The location of the sensation changed over time. Name the areas in order where the sensation was felt.

2 Which nerve supplies the areas where the sensation occurred?

■

• After 1 minute, ask the subject to describe the sensation and where it is located. Record results in Table 23.4.

• After 2 minutes, ask the subject to describe the sensa- tion and where it is located. Have the subject remove elbow from water. Record results in Table 23.4.

2 Clean up as directed by your instructor. 3 Answer the Discussion Questions with your lab group.

TABLE 23 .4 Referred Pain

TIME (min ) SENSAT ION LOCAT ION OF SENSAT ION

Immersion of elbow (0 min)

1 minute after immersion

2 minutes after immersion

355

A. Sensory Receptors

1. Describe the function of sensory receptors.

2. Name the general sensory receptors that belong to each structural class.

(a) Free nerve endings

(b) Encapsulated nerve endings

B. Sensory Pathways

Match each term to the correct numbered phrase.

cerebral cortex first-order neuron posterior (dorsal) root ganglion second-order neuron thalamus third-order neuron

______________________ 1. Receives input from third-order neurons; sensory information is consciously perceived.

______________________ 2. Cell body located in spinal cord or brain stem.

______________________ 3. Gateway to cerebral cortex; location of synapse between second- and third-order neurons.

______________________ 4. Neuron associated with sensory receptor.

______________________ 5. Relays sensory nerve impulses from thalamus to cerebral cortex.

______________________ 6. Cell body for first-order neuron located here.

Reviewing Your Knowledge

23 E X E R C I S E

Name ___________________________________ Date _________________ Section ______________________________

356 E X E R C I S E 2 3 G E N E R A L S E N S E S

C. Tactile Sensitivity

1. Describe correlation between tactile density of a body area and the size of the cerebral cortex receiving information from those receptors.

D. Adaptation

1. Define adaptation.

2. Do warm receptors adapt quickly?

3. Do cold receptors adapt quickly?

E. Referred Pain

1. Define referred pain.

2. After the subject’s elbow had been immersed in water for 2 minutes, where was the referred pain located? Explain.

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

357

Questions 1–3. Figure 23.4 shows a map of the specific areas of the primary somatosensory cortex that represent areas of the body. The cerebral cortex localizes the precise area of the body that sends sensory nerve impulses. Based on the size of the area represented on the cortex and the size of the body area, circle which body area has the greatest density of receptors:

1. The lips or the hip

2. The tongue or the toes

3. The foot or the hand

23 E X E R C I S E

Intra -

abdo mina

l Pha

ryn x

Tongue

Teeth, gums, and jaw

Lower lip

Upper lip

Face

Nose

Eye

Thumb

Index

Middle

Ring

Little

Hand

Wrist

Fo re

ar m

E lb

ow H ea

d N

ec k

Tr un

k H

Leg Foot Toes

Genitals

A rm

S ho

ul de

Lips

FIGURE 23.4 Somatosensory cortex.

358 E X E R C I S E 2 3 G E N E R A L S E N S E S

Answer the following questions.

4. Using your knowledge, compare the size of the somatosensory cortex representing the fingertips for a visually impaired person who reads Braille (increased tactile sensitivity) to that of someone with normal vision who has normal tactile sensitivity.

5. Leprosy often results in loss of pain to infected body areas. Describe the hazards of this.

6. When a hair on your head is moved, the hair follicle touch receptors are stimulated. If a person put his or her hair in a ponytail, what would be the result if there was no adaptation to these touch receptors?

7. When you hit your funny bone (olecranon), where do you experience referred pain? Hint: What nerve would you hit?

8. (a) When a person experiences a heart attack, why is there pain down the left arm?

(b) Why would pain persist even after the stimulus is removed?

Using your textbook or other reference, trace the sensory pathway from proprioceptors located in the quadriceps muscle to the spinocerebellar tract traveling to the cerebellum.

9. Identify the nerve carrying the axon of the first-order neuron and the levels where the first-order neuron enters the spinal cord.

10. (a) Do the cerebellar hemispheres receive proprioceptive nerve impulses ipsilaterally or contralaterally?

(b) Using your knowledge, is proprioception consciously perceived by the cerebellum?

Special Senses 24 E X E R C I S E

O B J E C T I V E S M A T E R I A L S The Eye and Vision

• eye models or charts • Dissection: cow eyes, dissection equipment,

disposable gloves, safety glasses

• compound microscope, lens paper, prepared slides of an eyeball

• ophthalmoscope • metric ruler, Snellen eye chart The Ear, Hearing, and Equilibrium

• ear models or charts, skull • compound microscope, lens paper, prepared

slides of the cochlea, macula, and crista

• tuning forks, cotton balls • swivel chair or stool The Nose and Olfaction

• skull • stopwatch; cotton balls; clove oil, peppermint oil,

cinnamon oil, or any three aromatic substances

The Taste Buds and Gustation

• compound microscope, lens paper, prepared slides of taste buds

• mirror • 1/2-inch cubes of apple, banana, cheese, carrot,

and raw potato

The Eye and Vision

1 Identify the accessory structures of the eye and the structures of the eyeball

2 Identify the 3 principal layers of the retina

3 Perform visual tests that are used to determine visual acuity, near point of vision, astigmatism, location of blind spot, and presence of red-green color blindness

The Ear, Hearing, and Equilibrium

1 Identify the structures of the external, middle, and internal ear

2 Identify the major structures of the cochlea, vestibule, and semicircular canals

3 Perform tests that are used in determining the cause of hearing loss

4 Perform tests that exhibit the function of the receptors for dynamic and static equilibrium

The Nose and Olfaction

1 Identify the location of receptors for olfaction

2 Identify olfactory receptor structures

3 Determine time of adaptation for olfactory receptors

The Taste Buds and Gustation

1 Identify the type of taste buds and their location

2 Identify gustatory structures

3 Observe the influence of smell and texture on taste

359

360 E X E R C I S E 2 4 S P E C I A L S E N S E S

A. Structure of the Eye and Vision

1. Accessory Eye Structures

Accessory structures of the eye include the eyebrows, eye- lids or palpabrae, eyelashes, conjunctiva, lacrimal appara- tus, and the extrinsic eye muscles. The conjunctiva is the thin, protective mucous membrane that covers the anterior eye and folds to cover the inner eyelid. The conjunctival fold forms a pocket that keeps contacts from moving toward the posterior part of the eyeball. The palpebral conjunctiva covers the interior of the eyelid, and the bulbar conjunctiva covers the anterior part of the white of the eye, but not the cornea. The lacrimal apparatus (lacrim- � tears) is a group of structures involved in producing and draining tears. The lacrimal gland produces and secretes tears onto the eye

surface, and the lacrimal canals drain the tears from the eyes into the enlarged lacrimal sac. The enlarged nasolac- rimal duct receives tears from the lacrimal sac and drains the tears into the nasal cavity. The extrinsic eye muscles are six skeletal muscles that insert on the exterior of the eyeball to move the eyeball in all directions. The superior, inferior, medial, and lateral rectus muscles are parallel to the long axis of the eyeball. The superior and inferior oblique muscles attach to the eyeball at an angle.

Before Going to Lab

1 Label the parts of the conjunctiva in Figure 24.1(a) and structures of the lacrimal apparatus in (b).

2 Label the extrinsic eye muscles in Figure 24.2(a) and (b).

(a) Lateral view of eyeball

(b) Lacrimal apparatus

(a) • bulbar conjunctiva

(con-junk-TIE-va) • conjunctival fold • palpebral (PAL-pub-bral)

conjunctiva

• lacrimal (LAK-rih-mal) canals

• lacrimal gland • lacrimal sac • nasolacrimal duct

1 __________________________

2 __________________________

3 __________________________

4 __________________________

5 __________________________

6 __________________________

7 __________________________

FIGURE 24.1 Accessory structures of the eye.

(b)

E X E R C I S E 2 4 S P E C I A L S E N S E S 361

LAB ACTIVITY 1 Accessory Structures of the Eye

1 Identify all the accessory structures of the eye, includ- ing all parts of the lacrimal apparatus, on an eye model or chart.

2 Identify the extrinsic eye muscles on an eye model. 3 Determine how each muscle moves the eye by observ-

ing where it inserts on the eye and how the eye would move if the insertion is moved toward the origin.

4 Write the function of each extrinsic eye muscle in Table 24.1. Choose one of the following eye movements for each muscle: moves eye superiorly, inferiorly, medi- ally, laterally, superiorly and laterally, or inferiorly and laterally. ■

Levator palpebrae superioris

Optic nerve

Trochlea

Annular ring

(a) Lateral view of right eyeball (b) Superior view of left eyeball

FIGURE 24.2 Extrinsic eye muscles.

• inferior oblique • inferior rectus • lateral rectus • medial rectus • superior oblique • superior rectus

1 ___________________________________

2 ___________________________________

3 ___________________________________

4 ___________________________________

5 ___________________________________

6 ___________________________________

TABLE 24 .1 Function of the Extrinsic Eye Muscles

EXTR INS IC EYE MUSCLE FUNCT ION

Inferior oblique

Inferior rectus

Lateral rectus

Medial rectus

Superior oblique

Superior rectus

362 E X E R C I S E 2 4 S P E C I A L S E N S E S

and sclera and consists of the ciliary muscle and ciliary processes. The ciliary muscle is a circular smooth mus- cle that contracts to control the shape of the lens. Ciliary processes are folds that protrude from the ciliary body to- ward the lens. They contain capillaries that secrete aque- ous humor, the fl uid in the anterior chamber of the eyeball. Suspensory ligaments (zonular fi bers) are thin fi bers that attach the lens to these processes. The choroid is the most posterior part of the vascular tunic that lines most of the interior of the sclera. It contains many blood vessels that nourish the retina. The retina (sensory tunic) is the inner coat that begins at the ora serrata, the serrated boundary between the ciliary muscle and the retina. The retina continues posteriorly, lin- ing the interior of the choroid. The pigmented layer of the retina is the outer portion, and the neural layer is the inner portion that contains photoreceptors and associated neurons.

2. Structure of the Eyeball

The wall of the eyeball has 3 layers: the outer fi brous tunic, the middle vascular tunic, and the inner retina. The fi brous tunic is composed of the cornea and sclera. The cornea is the transparent anterior portion that covers the iris and pupil, and the sclera (scler- � hard) is the tough, white part of the eye that forms the majority of the eyeball. The scleral venous sinus (canal of Schlemm) is an opening found at the junction of the cornea and the sclera. The middle vascular tunic is composed of the iris, cili- ary body, and choroid. The iris is the most anterior portion of the vascular tunic and contains pigmented cells. It is made of circular and radial smooth muscle and controls the pupil size. The pupil is the opening in the middle of the iris that allows light to enter the eyeball and changes size in response to the intensity of light. The ciliary body begins posterior to the iris at the junction of the cornea

3 4

Lens 11

9 8

FIGURE 24.3 Structure of the eyeball.

• choroid • ciliary (SIL-ee-air-ee) body • ciliary muscle • ciliary process • cornea (KOR-nee-ah) • iris • ora serrata (ser-RAH-tah) • pupil • retina • sclera (SKLER-ah) • scleral venous sinus • suspensory ligament (zonular fibers)

1 __________________________________

2 __________________________________

3 __________________________________

4 __________________________________

5 __________________________________

6 __________________________________

7 __________________________________

8 __________________________________

9 __________________________________

10 __________________________________

11 __________________________________

12 __________________________________

E X E R C I S E 2 4 S P E C I A L S E N S E S 363

between the lens and the retina. This cavity is fi lled with a gel-like substance called the vitreous body (humor) that holds the retina fl at against the choroid.

3. Interior of the Eyeball

The interior of the eyeball contains the lens, anterior cav- ity, and vitreous chamber. The lens divides the interior of the eyeball into an anterior cavity and a vitreous chamber (posterior cavity). The anterior cavity is a space between the cornea and the lens that is fi lled with watery aqueous humor (aqua � water; humor � moist). This cavity is sub- divided into an anterior chamber (between the cornea and the iris) and a posterior chamber (between the iris and the lens). The scleral venous sinus (canal of Schlemm) is an opening found at the junction of the cornea and sclera that drains aqueous humor back into the bloodstream. The vitreous chamber is the larger, posterior cavity located

4 6

3 2

FIGURE 24.4 Anterior and posterior cavities of the eyeball.

• anterior cavity • anterior chamber • lens • posterior chamber • scleral venous sinus • vitreous chamber

1 ___________________________________

2 ___________________________________

3 ___________________________________

4 ___________________________________

5 ___________________________________

6 ___________________________________

Before Going to Lab

1 Label the eyeball structures in Figure 24.3.

LAB ACTIVITY 2 Structure of the Eyeball

1 Identify these structures on an eye model or chart. ■

Before Going to Lab

1 Label the interior spaces and structures of the eyeball in Figure 24.4.

LAB ACTIVITY 3 Anterior and Posterior Cavities of the Eye

1 Identify these spaces and structures on a model or chart. ■

CLINICAL NOTE: Glaucoma is caused by an increase in pressure within the eye called intraocular pressure. Block- age of the scleral venous sinus prevents drainage of aqueous humor, increasing the amount in the anterior cavity that causes increased intraocular pressure.

364 E X E R C I S E 2 4 S P E C I A L S E N S E S

7 Using Figure 24.5(b), identify the following structures in the anterior portion of the eyeball: pupil, iris, and ciliary muscle.

8 Carefully remove the vitreous body from the poste- rior portion of the eyeball. Refer to Figure 24.5(b) to identify the structures in the posterior portion of the eyeball. The retina, a thin beige layer, will probably separate from the choroid. The only point of attach- ment of the retina to the wall of the eyeball is at the optic disc.

9 Pull the retina away from the choroid, the dark middle layer of the eyeball that contains the pigment melanin. The choroid of the cow’s eye has an iridescent reflect- ing surface called the tapetum lucidum that is not found in humans. The tapetum lucidum reflects light within the eye and enables animals to see in low-light conditions.

10 Separate the choroid from the sclera. Observe how the three coats or tunics—the retina, choroid, and sclera—form the wall of the eyeball.

11 Clean up as directed by your instructor. ■

1 Using gloves, obtain a cow eye and rinse it to remove excess preservative.

2 The posterior portion of the eye may be encased in adipose tissue. Carefully remove the adipose tissue protecting the optic nerve.

3 Identify the external eye structures: cornea, sclera, optic nerve, and extrinsic eye muscles. Refer to Figure 24.5(a). The preservative causes the cornea to change from being transparent and smooth to opaque and wrinkled.

4 Using the point of a scalpel, punch an opening ¼-inch posterior to the cornea through the very tough sclera. Be careful not to squeeze the eyeball too tightly or liquid may squirt out. Use the scissors to cut an incision all the way around the eyeball, separating it into two parts.

5 Carefully separate the anterior and posterior parts of the eyeball so the vitreous body remains in the poste- rior part of the eyeball and the lens in the anterior part.

6 Carefully remove the lens, noting the transparent suspensory ligaments that are attached to the lens.

LAB ACTIVITY 4 Dissection of Cow Eye

SAFETY NOTE: Wear safety glasses and gloves when using preserved or fresh tissue. Wash hands thoroughly with soap and water when you are done.

FIGURE 24.5 Cow eye dissection.

Extrinsic eye muscles

Optic nerve

Cornea

Sclera

Iris

Pupil

Ciliary muscle

Choroid

Optic disc

Retina

(a) External structures (b) Anterior and posterior sections

E X E R C I S E 2 4 S P E C I A L S E N S E S 365

4. Anatomy of the Retina

The neural portion of the retina is an outgrowth of the brain and contains three layers of neurons: the photoreceptor layer (deepest cell layer), the bipolar cell layer (middle layer), and the ganglion cell layer (the superfi cial cell layer). The photoreceptor cell layer contains the rods and cones. Rods are used in night vision and respond to low levels of light, allowing us to perceive shades of gray, black, and white. Visual acuity with rods is low. Cones require brighter light for stimulation, but allow us to see color and provide high visual acuity. The rods and cones synapse with the bipolar neurons in the bipolar cell layer, which synapses on the ganglion cells in the ganglion cell layer. Axons from the ganglion cells extend through the optic disc and leave the eyeball as the optic nerve. The optic disc does not con- tain photoreceptors and forms the blind spot of the retina. It is also the site where the central retinal artery and vein enter and leave the retina, and the only place where the retina is secured to the other layers of the eyeball. The macula lutea (macula � fl at spot; lutea � yellow), the site of macular degeneration, is in the center of the neural portion of the retina. In the middle of the macula lutea is the central fovea (fovea centralis). This area of the retina has the highest density of cones of any area of the retina and is not covered by ganglion and bipolar cell layers. Therefore, this area has the highest visual acuity (sharpness of vision) of any area of the retina. When we look at an object, the light rays refl ected from the object are focused onto the central fovea. The retina can be viewed with an ophthalmoscope. The ophthalmoscope illuminates the interior of the eye, and the retina appears red from the many blood vessels. Blood vessels

can be seen branching from the optic disc while the cir- cular macula lutea appears dark because of the absence of blood vessels. The central fovea is in the middle of the macula lutea.

1 2 3 4

FIGURE 24.6 Normal retina viewed with an ophthalmoscope.

• blood vessel • central fovea • macula lutea • optic disc

LAB ACTIVITY 5 Anatomy of the Retina

1 Examine a prepared microscope slide of a cross-section through an eyeball. • Using the low-power objective lens, find the poste-

rior surface of the eyeball and identify the sclera, choroid, and retina. Place the retina in the center of the field of view and switch to the high-power objective lens.

• Using the high-power objective lens, identify the pigmented epithelium of the retina and the neural layer of the retina. Within the neural layer of the retina, identify the ganglion layer, the bipolar layer, and the photoreceptor layer.

2 View the retina with an ophthalmoscope. Instructions will be provided by your instructor. ■

Before Going to Lab

1 Label the structures of the retina as observed with an ophthalmoscope in Figure 24.6.

2 Label the structures of the eyeball in Figure 24.7(a), and (b).

3 Label the structures of the retina in Figure 24.8(a) and (b).

366 E X E R C I S E 2 4 S P E C I A L S E N S E S

1 2

3 4 5

(a) Transverse section of eyeball

(a) • central fovea • central retinal artery • central retinal vein • optic disc • optic nerve

7 8 9 10 11

13 14

(b) Photomicrograph of eyeball, 5�

(b) • choroid • ciliary body • cornea • iris • lens • optic disc • optic nerve • pupil • retina • sclera

FIGURE 24.7 Section of eyeball.

E X E R C I S E 2 4 S P E C I A L S E N S E S 367

(a) • bipolar cell layer • ganglion cell layer • neural portion of retina • optic nerve fibers (axons) • photoreceptor layer • pigmented epithelium of retina

6 6

Microscopic structure of retina(a)

(b) Photomicrograph of retina

Choroid

Sclera

450�

FIGURE 24.8 Microscopic anatomy of the retina.

(b) • bipolar cell layer • ganglion cell layer • neural portion of retina • photoreceptor layer • pigmented epithelium of retina

368 E X E R C I S E 2 4 S P E C I A L S E N S E S

vision is 10 cm for young adults, 20 cm for adults in their 40s, and 80 cm for people in their 60s. Astigmatism is caused by irregularities in the curvature of the cornea or lens. This causes parts of an image to be blurry.

LAB ACTIVITY 7 Visual Acuity Tests

1 Distance visual acuity is measured using a Snellen eye chart (provided by your instructor). If you wear eyeglasses or contact lenses, remove them to determine visual acuity without correction or wear them to deter- mine visual acuity with correction. • Have the subject stand 20 feet from the Snellen eye

chart that is placed in a well-lighted area and cover the left eye with a hand.

• Have the subject read the smallest line of letters they can see clearly without squinting. If the subject can correctly read half of the letters or more, then ask the subject to read the letters on the next, smaller line.

• Record the number of the line with the smallest size letters read with half or greater accuracy in Table 24.2.

• Have the subject cover the right eye and repeat the procedure.

• A value of 20/20 indicates that the subject has normal vision. A value of 20/40 indicates that the subject sees at 20 feet what a person who has normal vision sees at 40 feet. This is not as good as normal vision. A value of 20/15 indicates that the subject sees at 20 feet what a person with normal vision sees at 15 feet. This is better than normal vision.

2 Near visual acuity is measured using a Snellen acuity card (Fig. 24.10). • Have the subject hold the Snellen acuity card 14 inches

from his or her face. The card should be illuminated with the light source either behind or above the sub- ject. Instruct the subject to cover the left eye with his or her hand.

• Repeat the steps used to measure distance visual acuity. Start with the second bulleted step.

LAB ACTIVITY 6 Locating Blind Spot

1 Looking at Figure 24.9, hold the lab manual in both hands and extend both arms in front of you. Close your left eye. Keep your right eye open and focus on the dot. Slowly move the figure toward you. The X will disap- pear when it crosses your blind spot, but if you move the figure too fast, you will miss it.

2 Have a lab partner measure in centimeters the distance the book is from your face when this happens. Then move the figure closer to your face, and the X will reappear.

Blind spot distance for right eye: _________ 3 Close your right eye. Keep your left eye open and focus

on the X. Slowly move the figure toward you until the dot disappears. Measure the distance in centimeters. Then move the figure closer to your face, and the dot will reappear.

Blind spot distance for left eye: _________ 4 Explain why the X and the dot disappear and reappear.

■

FIGURE 24.9 Blind spot test.

5. Visual Acuity Tests

Visual acuity tests measure the ability of the lens to fo- cus light refl ected from an object on the central fovea of the retina. The lens can accommodate or change shape to bend light rays to focus them on the central fovea. At 20 feet, light rays from an object are nearly parallel and do not have to bend as much to focus on the central fovea. At this distance, the lens is fl attened and the refractive power (ability to bend light rays) of the lens is lowest. To observe objects closer than 20 feet, the lens must change shape or accommodate to focus the light rays on the central fovea. The lens bulges to increase the refractive power. Individu- als who have normal distance vision and near vision are emmetropic, individuals who have normal distance vision but blurry near vision are hyperopic (farsighted), and in- dividuals who have blurry distance vision but normal near vision are myopic (nearsighted). As we age, the ability of the lens to accommodate diminishes and the ability to focus on very close objects decreases, a condition called presbyopia (presby- � old). The near point of vision is the closest distance that a person can focus on an object. The average near point of

CLINICAL NOTE: To obtain an accurate acuity test, pro- fessionals also count the number of letters a patient missed on the line recorded as the best vision. For example, if the best vision was 20/40, and the patient missed two letters on that line, it would be recorded as 20/40 (�2). If a patient read two letters on the 20/15 line, it would be recorded as 20/15 (�2).

3 Measure the near point of vision and compare it with the average for the age of your subject. • Have the subject hold the Snellen visual acuity card

(Figure 24.10) 14 inches from his or her face. • Have the subject cover the left eye and read letters

from a line above his or her near visual acuity.

E X E R C I S E 2 4 S P E C I A L S E N S E S 369

4 Determine whether you have astigmatism. • Remove corrective lenses. • Cover the right eye and look at the center of the

astigmatism chart in Figure 24.11. • If all the radiating lines are equally sharp and dark,

you do not have astigmatism. However, if some lines are lighter or less distinct than others, you have astigmatism.

• Cover the left eye and repeat the procedure.

5 Answer the Discussion Questions with your lab group.

• Instruct the subject to slowly move the chart closer to his or her face until the letters are blurry.

• Measure the distance from the card to the subject’s eye in centimeters.

• Record the value in Table 24.2.

TABLE 24 .2 Visual Test Results

RESULTS

TEST LEFT EYE R IGHT EYE

Distance visual acuity

Near visual acuity

Near point of vision

Astigmatism Yes or No Yes or No

FIGURE 24.10 Snellen acuity card.

FIGURE 24.11 Astigmatism chart.

10 2

11 1

DISCUSSION QUESTIONS Visual Tests

1 Why must the subject stand 20 feet from the Snellen eye chart to test distance vision?

2 Why must the subject hold the Snellen acuity card close to his or her eyes to test near vision?

■

370 E X E R C I S E 2 4 S P E C I A L S E N S E S

LAB ACTIVITY 8 Red-Green Color Blindness Tests

1 Look at Figure 24.12(a) and (b) to see if you may have red-green color blindness.

2 Record the number of students in your class that have: • normal color vision ________ • red color blindness ________ • green color blindness ________ • total color blindness ________ ■

6. Red-Green Color Blindness

Red-green color blindness in an inherited disorder and is the most common form of color blindness. This form of color blindness is due to the absence of either red or green cones. There are 3 types of cones in the human retina, and these cones differ in the type of photopigment present. The approximate distribution of cones are 64% red, 34% green, and 2% blue. Perception of different colors occurs when different wave lengths of color selectively activate differ- ent photopigments. In order to differentiate between red and green, both red and green cones must be present.

FIGURE 24.12 Red-Green Color Blindness Test.

(a) Ishihara Color Blindness Test Plate 7

(b) Ishihara Color Blindness Test Plate 16

What did you see?

Those with normal color vision see a 74.

Those with red-green color blindness see a 21.

Those with total color blindness see spots.

What did you see?

Those with normal color vision should see a 26.

Red color blind people will see a 6.

Green color blind people will see a 2.

E X E R C I S E 2 4 S P E C I A L S E N S E S 371

B. The Ear, Hearing, and Equilibrium

1. Anatomy of the Ear

The ear is divided into 3 regions: the external (outer) ear, the middle ear, and the internal (inner) ear. The external ear, consisting of the auricle, external auditory canal, and tympanic membrane, extends from the auricle to the tym- panic membrane. The auricle, the fl exible external struc- ture that is commonly called the ear, collects sound waves and directs them toward the external auditory canal. The rim of the auricle is called the helix and the fl eshy, inferior portion is the lobule. The external auditory canal con- ducts sound waves from the auricle to the tympanic mem- brane. The tympanic membrane (tympan- � drum) or eardrum converts sound waves to vibrations that are trans- ferred to middle ear structures. The middle ear is an air-fi lled cavity within the temporal bone that extends from the tympanic membrane to the oval window. Middle ear structures include auditory ossicles, oval window, round window, and auditory tube. Auditory ossicles are small bones within the cavity that are connected by synovial joints. These bones transfer vibrations from the tympanic membrane to the oval window. The malleus is the

outermost bone and is attached to the tympanic membrane. The incus is the middle bone and connects to the stapes. The innermost bone is the stapes, which connects to the incus and oval window. The oval window is the membrane- covered opening that separates the middle and inner ear and transfers vibrations to the inner ear. The round window is a membrane-covered opening between the middle ear and cochlea. The auditory tube (pharyngotympanic or Eusta- chian tube) connects the middle ear to the nasopharynx (part of the throat near the nasal cavity) and equalizes the air pressure of the middle ear with atmospheric air.

4 3

• auditory tube • auricle • external auditory canal • external ear • helix (HEE-liks) • incus (INK-us) • internal ear • lobule • malleus (MAL-ee-us) • middle ear • stapes (STAY-peez) attached to oval window • tympanic (tim-PAN-ik) membrane

FIGURE 24.13 Anatomy of the external and middle ear.

Before Going to Lab

1 Label the structures of the external and middle ear in Figure 24.13.

LAB ACTIVITY 9 Anatomy of the External and Middle Ear

1 Identify the external and middle ear structures on a model or chart.

2 Identify the area of the temporal bone that houses the middle and internal ear on the skull. ■

372 E X E R C I S E 2 4 S P E C I A L S E N S E S

The internal ear is housed within the temporal bone. It consists of cavities within the bone called the bony laby- rinth that encloses a series of connected membranous sacs, the membranous labyrinth. The bony labyrinth contains a fl uid called perilymph that surrounds the membranous labyrinth. Endolymph is the fl uid within the membranous labyrinth. The bony labyrinth has 3 main regions: the vestibule, the semicircular canals, and the cochlea. The vestibule is the middle area of the bony labyrinth that encircles 2 sections of membranous labyrinth, the utri- cle and the saccule. The utricle (utricle � little bag) is the posterior section of the membranous labyrinth within the vestibule, and it houses equilibrium receptors. The saccule (saccule � little sac) is the anterior section of the membra- nous labyrinth within the vestibule. The saccule is continu- ous with the utricle and also houses equilibrium receptors. Semicircular canals are 3 bony canals posterior to the vestibule that project posteriorly, laterally, and superiorly from the vestibule. Each canal is at right angles to the other two. Semicircular ducts are sections of membranous laby- rinth within the semicircular canals that contain equilib- rium receptors and connect with the utricle. The ampulla is the widened end of each semicircular canal and duct.

The cochlea is the spiral area of the bony labyrinth an- terior to the vestibule. The cochlear duct is the section of membranous labyrinth within the cochlea. The cochlear duct contains the hearing receptors and is connected to the saccule. Hearing and equilibrium receptors initiate nerve im- pulses that are carried by the vestibulocochlear nerve (cranial nerve VIII) to the brain. The vestibulocochlear nerve has two branches: the vestibular branch that carries nerve impulses generated by equilibrium receptors and the cochlear branch that carries nerve impulses generated by the hearing receptors.

Before Going to Lab

1 Label the structures of the internal ear in Figure 24.14.

LAB ACTIVITY 10 Anatomy of the Internal (Inner) Ear

1 Identify the internal ear structures on a model or chart. ■

FIGURE 24.14 Anatomy of the internal ear.

4 5 6 7

9 12

Vestibulocochlear nerve

• ampulla of semicircular canal and duct • anterior semicircular canal • cochlea (COKE-lee-uh) • cochlear duct • lateral semicircular canal • membranous semicircular duct • oval window • posterior semicircular duct • round window • saccule (SAK-yool) • utricle (YOU-trih-cul) • vestibule

E X E R C I S E 2 4 S P E C I A L S E N S E S 373

2. Microscopic Anatomy of the Cochlea and the Spiral Organ of Corti

The cochlea is a spiral cavity that resembles the space within a snail shell. The cochlea makes 3 turns around a bony core. A section through the cochlea shows 3 channels: the scala vestibuli, the cochlear duct (scala media), and the scala tym- pani. The scala vestibuli is part of the cochlea and is superior to the cochlear duct. It is separated from the cochlear duct by the vestibular membrane. The scala tympani is also part of the cochlea and is posterior to the cochlear duct. It is sepa- rated from the cochlear duct by the basilar membrane. The scala vestibuli and scala tympani are continuous with one another and are fi lled with perilymph. The cochlear duct, part of the membranous labyrinth, houses the spiral organ of Corti and is fi lled with endolymph. The spiral organ of Corti sits on the basilar membrane. It contains hair cells (receptors for hearing) and supporting cells. The hair cells have a hair bundle composed of stereocilia at their apical end. Superior to and in contact with the stereocilia is the tectorial membrane (tector � covering). The basal end of the hair cells synapse with sensory and motor neurons from the cochlear branch of the vestibulocochlear nerve.

(b) • basilar membrane • cochlear duct • hair cells • tectorial membrane • vestibular membrane

5 6

(a) Cross-section through cochlea

20�

7 8 9 10 11

(b) Cross-section through spiral organ of Corti

110�

(a) • basilar (BAY-sih-lur) membrane • cochlear duct • scala (SCAY-lah) tympani • scala vestibuli • spiral organ of Corti • vestibular membrane

FIGURE 24.15 Photomicrographs of the cochlea and spiral organ of Corti.

Movement of the basilar membrane, caused by peri- lymph movement, forces the hair bundle into the tectorial membrane and bends the stereocilia. This results in a gen- eration of nerve impulses in the sensory neurons.

Before Going to Lab

1 Label the structures of the cochlea and spiral organ of Corti in Figure 24.15(a) and (b).

LAB ACTIVITY 11 Microscopic Anatomy of the Cochlea and Spiral Organ of Corti

1 Identify the cochlear structures on a model or chart. 2 Examine a prepared microscope slide showing a cross-

section through the cochlea. • Using the low-power objective, identify the basilar

membrane, cochlear duct, spiral organ of Corti, scala tympani, scala vestibuli, and vestibular membrane.

• Using the high-power objective, identify the basilar membrane, hair bundle, hair cells, and tectorial membrane. ■

374 E X E R C I S E 2 4 S P E C I A L S E N S E S

3. Microscopic Anatomy of the Equilibrium Receptors of the Internal Ear

There are 2 types of equilibrium receptors: the maculae (macula, sing.) located in the utricle and saccule, and the cristae (crista, sing.) located in the membranous semicircular ducts within the ampullae. The maculae provide informa- tion on head position (static equilibrium), as well as linear acceleration and deceleration, a type of dynamic equilibrium. The maculae consist of hair cells with hair bundles and supporting cells. The hair bundles are in contact with a gelatinous membrane, the otolithic membrane (oto � stone), which contains calcium carbonate crystals called otoliths. Movement of the head causes movement of the otoliths and otolithic membrane, which bends the hair bundles. The direction

of movement will determine if the hair cells release more or less neurotransmitter to the associated sensory neurons. The crista (ampullaris) detects rotational acceleration and deceleration, a type of dynamic equilibrium. Each crista consists of hair cells and supporting cells. The hair bundles of the hair cells are covered by a gelatinous structure called the cupula. When the head moves, movement of endolymph pushes the cupula causing the hair cells to bend. Bending of the hair bundles results in generation of nerve impulses in the vestibular branch of the vestibulocochlear nerve.

Before Going to Lab

1 Label the structures of the macula and crista in Fig- ure 24.16(a) and (b).

LAB ACTIVITY 12 Microscopic Anatomy of the Macula and Crista

1 Identify macula and crista structures on a model or chart. 2 Examine a prepared microscope slide showing a cross-

section through the crista with the high-power objective lens. Identify the cupula and hair cells. ■

(a) Macula

(b) Crista

Flow of endolymph

Nerve fibers

Direction of body movement

(a) • hair cell • otoliths (OH-toe-liths) • otolithic membrane • stereocilium in hair bundle • vestibular branches of vestibulocochlear nerve

(b) • cupula (KYou-pyul-uh) • hair bundle • hair cell

FIGURE 24.16 Microscopic anatomy of the macula and crista.

E X E R C I S E 2 4 S P E C I A L S E N S E S 375

4. Auditory and Equilibrium Tests

Hearing loss can be described as either conduction deafness or sensorineural deafness. Conduction deafness occurs when there is a decreased ability to conduct the energy of sound waves through the external and middle ear to hear- ing receptors in the inner ear. Ear wax buildup, damage to the tympanic membrane, or fusion of auditory ossicles may cause conduction deafness. Sensorineural deafness is caused by damage to hearing receptors, damage to the cochlear branch of the vestibulocochlear nerve, or damage of the neural pathways to the auditory cortex. Equilibrium receptors provide information that enables the body to maintain balance. There are two types of equi- librium receptors, static and dynamic. Static equilibrium receptors provide information about body position relative to the force of gravity (standing upright vs. being upside down). Dynamic equilibrium receptors provide informa- tion about body position in response to sudden movement such as rotation, acceleration, and deceleration (spinning, going faster, stopping). Infl ammation of or injury to equilib- rium receptors results in an inability to maintain body posi- tion, vertigo, and/or dizziness. Vertigo is the sensation of circular motion either of oneself or external objects, while dizziness is often used to describe faintness, unsteadiness, or lightheadedness. Severe vertigo may be accompanied by nystagmus—rapid, involuntary movement of eyeballs.

NOTE: In the Weber test, sound is louder in the ear with con- duction deafness. This is not a typo error. Research this and you will find several explanations from simple to complex. This simplest explanation is that bone conducts sound better than air. The ear with conduction deafness hears only sound con- ducted through bone, whereas the normal ear hears sound conducted through air in the external ear canal and sound conducted through bone. In the normal ear, the sound conducted through air in the external ear canal acts like background noise.

LAB ACTIVITY 13 Auditory and Equilibrium Tests

1 Test for unilateral (one side only) deafness using the Weber test. • Choose a subject from your group. Have the subject

sit with the head erect and facing forward. • Strike a tuning fork (middle C preferably) and place it

medially on the subject’s forehead (bone conduction). • Ask the subject if the sound is equally loud in both ears

or louder in one ear. Circle the result in Table 24.3. • If the sound is equally loud in both ears, the subject

either has normal hearing or bilateral deafness (equal hearing loss in both ears). If the subject hears the sound louder in one ear, then the subject may have unilateral deafness (either conduction deafness in that ear or sensorineural deafness in the opposite ear).

• If the subject has unilateral deafness, conduct the Rinne test to determine if hearing loss is conduction deafness.

• Mimic unilateral conduction deafness by placing a cotton ball (or finger) in one external auditory canal and repeat the Weber test.

TABLE 24 .3 Results of Weber, Rinne, and Barany Tests

TEST RESULTS (C IRCLE YOUR RESULTS )

Weber test Equal loudness in both ears � normal hearing or equal hearing loss in both ears or Sound is louder in right ear � conduction deafness in right ear or sensorineural deafness in left ear or Sound is louder in left ear � conduction deafness in left ear or sensorineural deafness in right ear

Rinne test Conduction deafness or no conduction deafness

Balance test Static equilibrium receptors: functioning or not functioning

Direction of Name semicircular eye movement canal stimulated Barany test Head slightly forward: lateral or vertical or rotational lateral or anterior or posterior Head toward shoulder: lateral or vertical or rotational lateral or anterior or posterior Head on chin: lateral or vertical or rotational lateral or anterior or posterior

376 E X E R C I S E 2 4 S P E C I A L S E N S E S

the subject will not be able to maintain posture and will exhibit large swaying movements or will fall. Be prepared to support the subject if necessary.

• Record the results in Table 24.3.

4 Conduct the Barany test to evaluate function of semi- circular canals and dynamic equilibrium receptors. • Choose a subject from your lab group who does not

readily experience dizziness or become nauseated when rotated. If the subject experiences nausea dur- ing the demonstration, immediately stop rotation.

• Provide the subject with a chair or stool that can be rotated. Have the subject sit on the chair and hold on to the arms or seat for safety. Decide how the subject will position his or her legs during rotation to ensure safety and prevent interference. Position 3 to 4 stu- dents around the chair with their feet firmly against the legs of the chair to prevent the chair from tipping over or the subject from falling off.

• Tell the subject to slightly tilt his or her head forward, focus on a distant object, and keep both eyes open during the rotation.

• Carefully turn the chair or stool clockwise (to the right). Complete 10 turns, one turn per 2 seconds, and stop suddenly. Be prepared to support the subject until vertigo and/or dizziness has passed. The subject will still experience rotation, indicating that the semicircular canals are functioning. Endo- lymph continues to move within the membranous semicircular ducts for a short time after rotation has stopped.

• Observe which way the subject’s eyeballs are mov- ing immediately after stopping rotation. Record direction in Table 24.3.

• Lateral movement of the eyes indicates stimulation of the dynamic equilibrium receptors in the lateral semicircular canals.

• Vertical movement of the eyes indicates stimulation of the dynamic equilibrium receptors in the anterior semicircular canals.

• Rotational movement of the eyes indicates stimula- tion of the dynamic equilibrium receptors in the posterior semicircular canals.

• Repeat the demonstration with the subject’s head tilted toward one shoulder, and then again with the subject’s chin resting on his or her chest. ■

2 Test for conduction deafness using the Rinne test. • This test will be conducted on the ear that may have

conduction deafness as indicated by the Weber test. • Have the subject sit with head erect and facing

forward. • Strike a tuning fork and place it on the subject’s mas-

toid process to test hearing by bone conduction. • Ask the subject to tell you when the sound can no

longer be heard. Immediately place the still-vibrating tuning fork close to the subject’s ear to test hearing by air conduction. If the subject can hear the tuning fork again when it is placed next to his or her ear, the subject does not have conduction deafness in that ear. If the subject cannot hear the tuning fork again, then the subject may have conduction deafness in that ear.

• Circle the results in Table 24.3. If the subject does not have conduction deafness, the test is complete.

• To verify conduction deafness, test the same ear again. This time you are testing hearing by air conduction first.

• Strike the tuning fork again and place the tuning fork close to the subject’s ear.

• Ask the subject to tell you when the sound can no longer be heard, then place the tuning fork on the subject’s mastoid process (bone conduction). If the subject hears the sound again, there is conduction deafness in that ear. Record whether the subject has conduction deafness or no conduction deafness in that ear by circling the results in Table 24.3.

3 Conduct a balance test to evaluate static equilibrium receptors. • Have the subject stand in front of a whiteboard or

chalkboard with arms at the sides. The subject may not lean against the wall or support him- or herself in any manner.

• Tell the subject to stand perfectly still. Mark the outline of the shoulders to help determine when he or she sways.

• Tell the subject to close his or her eyes. Observe movement in the subject’s shoulders. Notice that, although the subject may sway slightly, posture is always corrected. Signals from the static equilibrium receptors are helping the subject to maintain posture. If the static equilibrium receptors are not functioning,

E X E R C I S E 2 4 S P E C I A L S E N S E S 377

C. The Nose and Olfaction

The nose contains the receptors for the sense of smell or olfaction (olfact- � smell). Olfactory receptors are found within the olfactory epithelium, a specialized area of the epithelium lining the nasal cavity. The olfactory epithe- lium covers the inferior surface of the cribriform plate, the superior nasal concha, and the upper part of the middle nasal concha. The olfactory epithelium contains olfactory receptor cells, supporting cells, basal stem cells, and ducts of olfac- tory glands. The olfactory receptor cells are bipolar neu- rons whose dendritic end is embedded in the mucus layer covering the surface of the olfactory epithelium and whose axons form the olfactory nerves. The olfactory receptors are located on olfactory hairs that project from the den- drites of the olfactory receptor cells. Olfactory nerves pass through olfactory foramina in the cribriform plate and synapse on neurons in the olfactory bulb. Nerve impulses then travel along the olfactory tract

to the lateral olfactory area of the cerebral cortex. Olfac- tory receptors adapt to odors very quickly. This explains why when we are trying to determine the source of an odor we often lose the smell before we fi nd it. If we leave the area and return, we can smell the odor again.

Before Going to Lab

1 Label the structures of the olfactory epithelium in Figure 24.17(a) and (b).

LAB ACTIVITY 14 Structure of the Olfactory Epithelium

1 Identify the following areas on a skull: location of olfactory epithelium and the olfactory foramina in the cribriform plate. ■

(a) • cribriform (CRIB-ri-form) plate • olfactory (OHL-fak-tore-ee) bulb • olfactory tract

(b) • olfactory hair • olfactory nerve • olfactory receptor cell

FIGURE 24.17 Olfactory structures.

2 4

Mucus layer

(a) Sagittal section through head showing olfactory structures

(b) Olfactory epithelium

378 E X E R C I S E 2 4 S P E C I A L S E N S E S

D. Taste Buds and Gustation

Taste buds, which are found on the tongue, soft palate, pharynx (throat), and larynx, are microscopic, onion- shaped structures that contain gustatory cells, gustatory hairs, and supporting cells. Each gustatory (gust- � taste) cell has one gustatory hair that projects through an open- ing, the taste pore, on the apical end of the taste bud. Gus- tatory receptors are located on the gustatory hairs. The basal end of gustatory cells synapse onto the dendritic end of sensory neurons. Axons from the sensory neurons con- tribute fi bers to the facial nerve (cranial nerve VII), glos- sopharyngeal nerve (IX), or vagus nerve (X), depending on the location of the taste bud. Taste buds on the tongue are located in papillae, elevated structures that give the tongue its rough appearance. There are 4 types of papillae: vallate (circumvallate), fungiform, foliate, and fi liform. Vallate (circumvallate) papillae are the largest papillae and form an inverted V at the posterior of the tongue. Fungiform papillae are mushroom-shaped and are scattered over the surface of the tongue. Foliate papillae are present mostly in children and are located in lateral margins of the tongue. Filiform papillae are slen- der, pointed projections that cover the surface of the tongue and give the tongue a rough texture. These papillae have tactile receptors but no taste buds. Taste buds are found in vallate, fungiform, and foliate papillae.

LAB ACTIVITY 15 Olfactory Adaptation

1 Choose a subject, a timer, an experimenter (holds vial under subject’s nose), and a recorder.

2 Have the subject plug one nostril with cotton and close both eyes.

3 Noting the time, hold a container of cloves (or another aromatic substance) just under the open nostril and ask the subject to inhale through the open nostril and exhale through the mouth.

4 Ask the subject to tell you when the odor has disap- peared, note the time, and record in Table 24.4. Instruct the subject to immediately pull out the cotton in the other nostril and inhale (vial still under nose).

5 Ask the subject if he or she can smell the odor. Record the result in Table 24.4.

6 Repeat the experiment with two distinct smells, such as peppermint or cinnamon. Avoid irritating odors.

7 Clean up as directed by your instructor. 8 Answer the Discussion Questions with your lab group.

DISCUSSION QUESTIONS Olfactory Adaptation

1 Is the time of adaptation the same for all odors?

2 After the nostril was unplugged, explain why the sub- ject was able to smell the odor again.

■

TABLE 24 .4 Results of Olfactory Adaptation Experiment

CAN SUBJECT SMELL ODOR AFTER ODOR T IME TO ADAPTAT ION ( sec ) NOSTR IL UNPLUGGED?

E X E R C I S E 2 4 S P E C I A L S E N S E S 379

Epiglottis

Palatine tonsil

Lingual tonsil

(a) Dorsum of tongue showing location of papillae

Stratified squamous epithelium

Connective tissue

Details of papillae

(b)

(a) • filiform papilla • foliate papilla • fungiform papilla • vallate (circumvallate) papilla

1 ________________________________

2 ________________________________

3 ________________________________

4 ________________________________

(b) • filiform papilla • fungiform papilla • taste bud • vallate papilla

5 ________________________________

6 ________________________________

7 ________________________________

8 ________________________________

9 ________________________________

10 ________________________________

11 ________________________________

12 ________________________________

FIGURE 24.18 Gustatory structures.

There are 4 primary taste sensations: sweet, bitter, salty, and sour, and a possible fi fth, MSG (monosodium gluta- mate). Gustatory receptors most sensitive to sweet and salty sensations are found on the tip of the tongue, while bitter sensations are in the back and sour sensations are on the sides of the tongue. Other taste sensations are a mix- ture of these four. Smell, temperature, and texture (tactile sensation) contribute to our sense of taste. A person with a cold often has a loss of taste due to a loss of smell. Cold French fries are not as tasty as hot ones, and mushy apples are not as good as crisp ones.

LAB ACTIVITY 16 Gustatory Structures and Sensations

1 Examine a prepared microscope slide of a vallate papilla. • Using the low-power objective lens, identify the taste

bud in the wall of the papilla. • Using the high-power objective lens, identify the

taste pore, gustatory hairs, and gustatory receptor cells forming the wall of the taste bud.

Before Going to Lab

1 Label the gustatory structures in Figure 24.18(a), (b), and (c).

380 E X E R C I S E 2 4 S P E C I A L S E N S E S

2 Use a mirror to identify fungiform and filiform papillae on your tongue. Try to see vallate papillae on the back of the tongue.

3 Examine the contribution of texture and smell to the sense of taste. Since many labs do not allow eating or drinking, this activity may need to be done in another area or at home. • Choose a subject, an experimenter (who will give

the food cubes to the subject), and a recorder. The subject will first try to identify food by texture only (rolling food on surface of tongue), then by taste (chewing food increases the amount of chemicals dissolved in saliva and capable of interacting with taste receptors), and finally with the addition of smell.

• Place ½-inch cubes of carrot, banana, apple, raw potato, and cheese on a plate.

• Have the subject pinch both nostrils, close both eyes, and open his or her mouth. Randomly choose one of the cubes and place it in the subject’s mouth.

• Instruct the subject to roll the food around the sur- face of the tongue and attempt to identify the food. If identification is correct, check the “texture only” column next to the food in Table 24.5.

• Instruct the subject to chew the food and attempt to identify the food. If identification is correct, check “texture and taste” column in Table 24.5.

• Instruct the subject to open both nostrils and attempt to identify the food. If identification is correct, check the “texture, taste, and smell” column in Table 24.5.

• Repeat procedure with the other food cubes.

4 Clean up as directed by your instructor. 5 Answer the Discussion Questions with your lab group.

DISCUSSION QUESTION Gustatory Structures and Sensations

1 Compare the number of foods identified by texture, identified by taste, and identified by the sense of smell.

■

TABLE 24 .5 Results of Experiment: Contribution of Texture and Smell to Taste

FOOD TEXTURE ONLY TEXTURE AND TASTE TEXTURE , TASTE , AND SMELL

Carrot

Banana

Apple

Raw potato

Cheese

381

A. Accessory Eye Structures

Name the structure that corresponds to each statement.

______________________ 1. drains tears into nasal cavity

______________________ 2. produces tears

______________________ 3. membrane that covers the inner surface of eyelid

______________________ 4. tears from surface of eye drain into here

______________________ 5. membrane that covers the anterior surface of the sclera

______________________ 6. drains tears into the nasolacrimal duct

B. Extrinsic Eye Muscles

Name the muscle that applies to each statement.

______________________ 1. moves eyeball superiorly

______________________ 2. moves eyeball laterally

______________________ 3. moves eyeball inferiorly

______________________ 4. moves eyeball medially

______________________ 5. moves eyeball laterally and inferiorly

______________________ 6. moves eyeball laterally and superiorly

Reviewing Your Knowledge

24 E X E R C I S E

Name ___________________________________ Date _________________ Section ______________________________

382 E X E R C I S E 2 4 S P E C I A L S E N S E S

C. Eye Structures

Choose the structure that applies to each statement. More than one structure may apply to a statement, and a structure may be used more than once.

a. anterior cavity j. ora serrata b. anterior chamber k. posterior chamber c. choroid l. pupil d. ciliary body m. retina e. ciliary muscle n. sclera f. ciliary process o. scleral venous sinus g. cornea p. suspensory ligaments h. iris i. lens

1. produces aqueous humor

2. structures that are part of vascular tunic

3. contains photoreceptors

4. controls the size of the pupil

5. drains aqueous humor from the anterior chamber

6. structures that are part of the fibrous tunic

7. most anterior part of the eyeball

8. anterior boundary of retina

9. attaches lens to ciliary body

10. changes shape to focus light on retina

11. location of aqueous humor

12. white, tough outer layer of eyeball

Answer the following questions:

13. Why can the retina pull away from the back of the eyeball?

14. Name the instrument used to view the retina during a physical exam.

15. Name the two layers of the retina.

E X E R C I S E 2 4 S P E C I A L S E N S E S 383

D. Anatomy of the Retina

Choose the structure that corresponds to each statement.

a. bipolar cell layer e. macula lutea b. central fovea f. optic disc c. cones g. photoreceptor layer d. ganglion cell layer h. rods

1. has the highest density of cones in the retina

2. axons form optic nerve

3. does not contain photoreceptors; blind spot

4. photoreceptor that allows us to see color

5. contains rods and cones

6. the center of the neural portion of the retina

7. photoreceptor used in night vision

8. rods and cones synapse on these cells

E. Visual Acuity Tests

Answer the following questions:

1. Define accommodation.

2. A 10-year-old patient’s distance visual acuity was tested and determined to be 20/80. (a) Explain what that means.

(b) Is 20/80 better or worse than 20/20? Explain.

3. A 60-year-old man has to hold his newspaper at arm’s length to read it. What condition does he have?

4. A person with _________ has blurry near vision but normal distance vision.

5. A person with _________ does not see everything within a visual field clearly; some parts are blurry.

6. A person with _________ has normal near vision but blurry distance vision.

384 E X E R C I S E 2 4 S P E C I A L S E N S E S

F. External and Middle Ear Structures

Choose the structure that applies to each statement. More than one structure may apply to a statement, and a structure may be used more than once.

a. auditory tube h. malleus b. auricle i. middle ear c. external auditory canal j. oval window d. external ear k. stapes e. helix l. tympanic membrane f. incus g. lobule

1. auditory ossicle attached to tympanic membrane

2. equalizes air pressure in middle ear with external air pressure

3. external ear structures

4. ear drum

5. external feature of ear that contains the helix and lobule

6. stapes is attached to this membrane-covered opening

7. middle auditory ossicle

8. small bones of middle ear that are connected by synovial joints

G. Internal Ear Structures

Choose the structure that applies to each statement. More than one structure may apply to a statement, and a structure may be used more than once.

a. ampulla f. semicircular canals b. cochlea g. semicircular ducts c. cochlear duct h. utricle d. perilymph i. vestibule e. saccule

1. interconnected components of membranous labyrinth

2. fluid found within all bony labyrinth structures

3. sections of the membranous labyrinth found within vestibule

4. section of the membranous labyrinth that contains hearing receptors

5. sections of the membranous labyrinth that contain equilibrium receptors

6. interconnected components of bony labyrinth

E X E R C I S E 2 4 S P E C I A L S E N S E S 385

H. Microscopic Anatomy of the Cochlea, Spiral Organ of Corti, Macula, and Crista

Choose the structure that applies to each statement. More than one structure may apply to a statement, and a structure may be used more than once.

a. basilar membrane f. hair cells k. spiral organ of Corti b. cochlear duct g. macula l. supporting cells c. crista h. otolithic membrane m. tectorial membrane d. cupula i. scala tympani n. vestibular membrane e. hair bundle j. scala vestibuli

1. receptor for hearing

2. receptor(s) that contain(s) hair bundles, hair cells, and supporting cells

3. components of macula

4. membrane separating the superior chamber of cochlea from cochlear duct

5. structure(s) that bend(s) stereocilia of hair cells

6. spiral organ of Corti sits on this membrane

7. equilibrium receptors

8. contains endolymph

9. contains perilymph

10. equilibrium receptor found within ampullae of semicircular canals

I. Auditory and Equilibrium Tests

Answer the following questions:

1. What causes nystagmus?

2. What causes conduction deafness?

3. What causes sensorineural deafness?

4. If a vibrating tuning fork is placed on the mastoid process, who would “hear” the sound—someone with normal hearing, someone with conduction deafness, or someone with sensorineural deafness? Circle all that apply.

5. Inability to maintain posture while standing still would indicate a problem with which equilibrium receptor?

386 E X E R C I S E 2 4 S P E C I A L S E N S E S

J. Olfaction

Choose the structure that applies to each statement.

a. cribriform plate b. superior portion of nasal cavity c. olfactory hair d. olfactory nerve e. olfactory receptor cells

1. bipolar neurons

2. part of olfactory receptor cell that contains the olfactory receptors

3. formed of bipolar neuron axons

4. olfactory nerves pass through this structure before synapsing onto olfactory bulb

5. location of the olfactory epithelium

K. Taste

Choose the structure that applies to each statement. More than one structure may apply to a statement, and a structure may be used more than once.

a. filiform papillae f. gustatory hair b. fungiform papillae g. supporting cell c. pharynx h. taste buds d. soft palate i. taste pore e. gustatory cell j. vallate papillae

1. contain taste buds

2. part of gustatory cell that contains gustatory receptor

3. opening in taste bud through which gustatory hair projects

4. components of taste bud

5. mushroom-shaped projections on tongue

6. projections that form inverted V on back of tongue

Answer the following questions:

7. Identify where on the tongue the receptors most sensitive to each of the four taste sensations usually are located.

8. What other sensations contribute to the sensation of taste?

387

A. The Eye and Vision

1. Strabismus, a misalignment of the eyeball caused by an imbalance in the extrinsic eye muscles, is also called lazy eye or wandering eye. Identify the extrinsic eye muscle that would cause lateral strabismus of the right eye.

2. Why do photographers use a red light in the darkroom when developing black and white film?

3–4. Name all the accessory eyeball structures, fluids, and retinal layers that light passes through before it hits the photoreceptors.

5. Explain why the retina can detach from the eyeball with just a blow to the back of the head.

6. Is the retinal area in Figure 24.19 the macula lutea, fovea centralis, or optic disc? Explain your choice.

24 E X E R C I S E

Choroid Sclera

Retina

FIGURE 24.19 Retinal area.

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

388 E X E R C I S E 2 4 S P E C I A L S E N S E S

7. Explain why a pituitary tumor may affect vision.

8. A 10-year-old boy has 20/20 distance vision and 20/60 near vision. What refraction abnormality does he have?

9. Using your textbook or another source, research how and why glaucoma and macular degeneration affect vision. Compare Figure 24.20(a) and (b) and identify whether the visual field in (b) is representative of a person with macu- lar degeneration or glaucoma.

10. Explain why the condition represented in Figure 24.20(b) causes loss of vision in the center of the field of vision and blurriness in the periphery.

11. What structure keeps a contact lens on the cornea and prevents it from becoming lodged on the posterior surface of the eyeball?

FIGURE 24.20 Visual fields.

(a) Normal (b) Abnormal

E X E R C I S E 2 4 S P E C I A L S E N S E S 389

B. The Ear, Hearing, and Balance

12–13. Sound waves enter the external auditory canal and cause vibrations in structures and fluids of the ear. Identify in order the structures and fluids that vibrate in the pathway from the external auditory canal to the spiral organ of Corti.

14. Diving to the bottom of a deep pool will sometimes cause discomfort in the middle ear. Explain the cause of this discomfort.

15. What do the receptor cells for hearing, static equilibrium, and dynamic equilibrium have in common?

16. Would the receptors for equilibrium work in space at zero gravity?

17. Describe a series of movements that would stimulate all semicircular duct receptors and if repeated may cause vertigo. (Hint: Think of a carnival ride that causes vertigo.)

C. Olfaction and Gustation

18. Why do we sniff when we wish to smell something better?

19. When you lick ice cream off an ice cream cone, which papillae are involved in scraping the ice cream off the cone?

20. Licking cold ice cream off an ice cream cone stimulates a variety of sensory receptors associated with the tongue. Name all the sensory receptors involved.

The endocrine system (endo- � within; krinein � to secrete) has many glands that secrete hormones into the bloodstream. These chemicals are trans- ported throughout the body in blood and bind to target cells that have cell membrane receptors for a specific hormone. Hormones cause changes in activity in these target cells and direct a variety of cellular activities to keep the body in homeostasis.

A. Identification of Major Endocrine Glands

The selected, major endocrine glands that we study in this exercise are shown in Figure 25.1. From the head inferi- orly, they are the pineal gland (body), hypothalamus,

O B J E C T I V E S M A T E R I A L S

• human torso, brain model, endocrine chart, or use Real Anatomy (Endocrine)

• compound microscope, lens paper, prepared slides of selected endocrine glands: hypothalamus, pituitary gland, thyroid gland, parathyroid gland, adrenal gland, pancreas, or use Real Anatomy (Histology)

• Measurement of Blood Glucose: glucometer, alcohol wipes, lancet, test strips, other material specified by lab group’s experimental protocol

• Dissection: preserved cats or fetal pigs, dissecting equipment, disposable gloves, safety glasses, dis- section manual

• Real Anatomy: Virtual Cadaver Dissection • PowerPhys Experiments: • Blood Glucose Regulation • Thyroid Function

Endocrine Structure and Function

25 E X E R C I S E

1 Identify major endocrine glands

2 Name the main hormones secreted by each major endocrine gland

3 Identify microscopic structures of endocrine glands

4 Describe the function of each major hormone

391

Before Going To Lab

1 Use your textbook to label the major endocrine glands in Figure 25.1.

LAB ACTIVITY 1 Identification of the Major Endocrine Glands

1 Identify the major endocrine glands on a human torso, brain model, endocrine chart, or use the search text box in Real Anatomy (Endocrine) to locate these structures. ■

pituitary gland, thyroid gland, parathyroid glands, thymus, adrenal glands, pancreas, ovaries, and testes.

392 E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N

atrophies during fetal development. The infundibulum is the stalk that connects the hypothalamus to the pituitary gland and contains a direct blood supply to the pituitary. The anterior pituitary is composed of glandular epithelial tissue that makes and secretes seven hormones: human growth hormone (hGH) or somatotropin, thyroid- stimulating hormone (TSH), follicle-stimulating hor- mone (FSH), luteinizing hormone (LH), prolactin (PRL), adrenocorticotropic hormone (ACTH), and melanocyte- stimulating hormone (MSH). Secretory or inhibitory hormones secreted by the hypothalamus either stimulate or inhibit secretion of anterior pituitary hormones. The posterior pituitary is composed of nervous tissue that stores and releases into the blood two hormones that are not synthesized in the posterior pituitary: antidiuretic hormone (ADH) and oxytocin (OT). These two hormones are synthesized within cell bodies of hypothalamic neurons, are packaged into vesicles, and travel down axons that pass through the infundibulum to the posterior pituitary gland.

B. Hypothalamus and Pituitary Gland

Located inferior to the thalamus in the brain, the hypo- thalamus is an important component of both the nervous and endocrine systems and couples these two regulatory systems together. Although in the past the pituitary gland was called the “master gland,” it is now known that the hormones produced by the hypothalamus regulate the pitu- itary gland. The hypothalamic hormones and several of the anterior pituitary hormones are called tropic hormones because they target another endocrine gland. The pituitary gland is also called the hypophysis (hypo- � under; phyein � to grow; translated as “to grow under the hypothalamus”) and is composed of the ante- rior pituitary or adenohypophysis (adeno- � gland) and the posterior pituitary or neurohypophysis (neuro- � nerves). An intermediate lobe is present in the fetus but

Anterior view

9 (in female)

10 (in male)

2 (behind #7)

FIGURE 25.1 Major endocrine glands.

• adrenal (a-DREE-nul) glands • hypothalamus (hypo-THAL-a-mus) • ovaries • pancreas • parathyroid (para-THY-roid) glands • pineal (pie-NEE-ul) gland • pituitary gland or hypophysis (hy-POF-ih-sis) • testes (TES-teez) • thymus (THY-mus) • thyroid gland

E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N 393

Before Going to Lab

1 Label the drawing and photomicrographs of the pituitary gland in Figure 25.2(a), (b), and (c).

LAB ACTIVITY 2 Pituitary Gland

1 Examine a prepared microscope slide of the anterior and posterior pituitary with a compound microscope and identify the structures listed with Figure 25.2(c). ■

(b) Survey photomicrograph of infundibulum and pituitary

10�

109

90�

Sphenoid bone (sella turcica)

Mammillary body

Optic chiasm

(a) Hypothalamus and pituitary gland

• anterior pituitary or adenohypophysis (a-den-oh-hy-POF-ih-sis)

• hypothalamus (hypo-THAL-uh-mus) • infundibulum (in-fun-DIB-u-lum) • posterior pituitary or neurohypophysis

(neur-oh-hy-POF-ih-sis)

• anterior pituitary • hypothalamus • infundibulum • posterior pituitary

• anterior pituitary • posterior pituitary

FIGURE 25.2 The pituitary gland.

394 E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N

C. Thyroid and Parathyroid Glands

The thyroid gland has two lobes with a connecting isthmus and lies on both sides of the trachea near the thyroid carti- lage (Adam’s apple) of the larynx. The thyroid gland has a striking microscopic structure with large follicles that are fi lled with a protein colloid (large insoluble molecules). Simple cuboidal or simple columnar cells called follicu- lar cells form the follicular walls. Follicle cells synthe- size thyroglobulin, a thyroid hormone precursor stored in colloid. Two thyroid hormones (TH), thyroxine (T4) or tetraiodothyronine (tetra- � four; iodo- � iodine) and triiodothyronine (T3), are produced from thyroglobulin. Located between the follicles are parafollicular cells or C cells, which synthesize and secrete calcitonin. Embedded in the posterior surface of the thyroid gland are typically four small, round parathyroid glands. Two types of epithelial cells are found in the parathyroid glands: the principal cells and the oxyphil cells. The principal cells, which produce parathyroid hormone (PTH), are more numerous and smaller than the oxyphil cells, whose function is unknown.

Thyroid glandTrachea

5 1

(a) Anterior view of thyroid gland

FIGURE 25.3 The thyroid and parathyroid glands.

(a) • isthmus of thyroid gland • left lobe of thyroid gland • right lobe of thyroid gland • thyroid cartilage of larynx • trachea

Before Going to Lab

1 Label the structures of the thyroid and parathyroid glands in Figure 25.3(a) and (b).

2 Label the photomicrographs of the sections of thyroid and parathyroid glands in Figure 25.4(a) and (b).

LAB ACTIVITY 3 Thyroid and Parathyroid Glands

1 Place your fingers on each side of the trachea, three fingers’ breadth superior to the suprasternal (jugular) notch, and feel the thyroid gland move upward as you swallow.

2 Examine a prepared microscope slide of the thyroid and parathyroid glands, and identify the structures listed in Figure 25.4(a) and (b), or identify the structures using Real Anatomy (Histology).

3 Answer the Discussion Question with your lab group.

DISCUSSION QUESTION Thyroid and Parathyroid Glands

1 Examine Figure 25.4. Thyroglobulin is stored in the colloid, and calcitonin and PTH are stored in the para- follicular cells and principal cells, respectively. Compare the storage space for thyroglobulin (TH precursor) to the storage space for calcitonin and PTH.

■

E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N 395

(b) Posterior view

6 Trachea

Parathyroid glands (behind thyroid gland)

(b) • isthmus of thyroid gland • left lobe of thyroid gland • left parathyroid glands • right lobe of thyroid gland • right parathyroid glands • trachea

FIGURE 25.3 The thyroid and parathyroid glands, continued.

FIGURE 25.4 Sectional views of the thyroid and parathyroid glands.

1 2

(a) Survey photomicrograph of thyroid and

parathyroid glands

3 4 5

(b) Photomicrograph of thyroid gland

(a) • parathyroid gland • thyroid gland

(b) • colloid (COL-oid)-filled

follicle • follicular (fohl-LIK-u-lar) cell • parafollicular

(para-fohl-LIK-u-lar) cell or C cell

396 E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N

D. Adrenal Glands

The adrenal glands (ad- � addition to; renal � kidneys) are also known as the suprarenal glands because of their location on the superior part of the kidneys. Each adrenal gland is surrounded by a capsule and is composed of an outer cortex and a central medulla. The cortex and medulla are formed of different tissue types, and therefore produce and secrete different types of hormones. The adrenal cortex is glandular and can be divided his- tologically into three layers, each layer secreting a different hormone. The zona glomerulosa (zona � belt; glomeru- losa � little ball) is the outermost layer whose cells are arranged in little columns. The middle layer, the zona fas- ciculata (fasciculata � little bundle), has long cords and is the largest layer. The zona reticularis (reticul- � network) is the innermost layer and has branching cords. Hormones secreted by the adrenal cortex are mineral- corticoids, glucocorticoids, and androgens (gonadocorti- coids). The zona glomerulosa secretes mineralcorticoids, with aldosterone being the main hormone secreted. The zona fasciculata secretes glucocorticoids, with cortisol being the main hormone secreted. In males and females, the zona reticularis mainly secretes a small amount of the male androgen DHEA (dehydroepiandrosterone), which has weak hormonal effects. Androgens (andros � man) are

hormones that increase male characteristics. Some of the peripheral target tissues of DHEA convert this hormone to a more powerful hormone, testosterone, while other pe- ripheral target tissues convert DHEA into estrogen. The adrenal medulla is made up of nervous tissue that is stimulated by the sympathetic nervous system to secrete two hormones: epinephrine and norepinephrine (NE). Like the posterior pituitary gland, the chemicals secreted by this nervous tissue are called hormones because they are secreted into the blood and travel to another part of the body to target cells.

Diaphragm

Adrenal glands

Inferior vena cava

Descending aorta

FIGURE 25.5 The adrenal glands.

LAB ACTIVITY 4 Adrenal Glands

1 Examine a prepared microscope slide of the adrenal cortex and medulla and identify the structures listed with Figure 25.6(c), or identify the structures using Real Anatomy (Histology). ■

Before Going to Lab

1 Observe the location of the adrenal glands in the ca- daver photos in Figure 25.5.

2 Label the terms in Figure 25.6(a), (b), and (c).

E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N 397

Adrenal glands

Kidney

(a) Anterior view

(a) • kidney • left adrenal gland • right adrenal gland

(b) Section through left adrenal gland

65�

FIGURE 25.6 The adrenal glands.

(b) • adrenal cortex • adrenal medulla • capsule (c) • adrenal cortex • adrenal medulla • capsule • zona fasciculata (ZOH-na

fah-sick-you-LAH-ta) • zona glomerulosa

(glow-mare-you-LOH-sa) • zona reticularis

(reh-tik-you-LAIR-is)

398 E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N

E. Pancreas

The pancreas is composed of a head, body, and tail. Its head is cradled in the curvature of the duodenum, and the body and tail are inferior and posterior to the stomach near the spleen. The pancreas has both endocrine and exocrine (exo- � outside; literally “to secrete outside”) functions. The exocrine or acini (acinus � grape-like) cells vastly outnumber the endocrine cells. Exocrine enzymes are se- creted into the duodenum of the small intestine through a duct called the pancreatic duct and function in digestion. Endocrine cells, called pancreatic islets (islets of Lang- erhans), are located as little islands among the clusters of acini cells. The alpha or A cells in the pancreatic islets secrete glucagon, and the beta or B cells secrete insulin.

Before Going to Lab

1 Observe the location of the pancreas in the cadaver photo in Figure 25.7.

2 Label the structures on the drawing in Figure 25.8(a). 3 Using the labeled line drawing in Figure 25.8(b), label

the structures in (c).

Diaphragm

Spleen

Tail of pancreas

Pancreatic duct

Body of pancreas

Head of pancreas

Liver

Gallbladder

Duodenum (cut open)

Anterior view

FIGURE 25.7 The pancreas.

LAB ACTIVITY 5 Pancreas

1 Examine a prepared microscope slide of the pancreas and identify the structures listed in Figure 25.8(c), or identify the structures using Real Anatomy (Histology). ■

E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N 399

(a) Anterior view

Spleen (elevated)

Duodenum

(a) • body of pancreas • head of pancreas • tail of pancreas

the microscopic anatomy of the testes will be studied in Exercise 38. The pineal gland (pinea- � pinecone) or pineal body is a small, cone-shaped gland that is located in the brain posterior to the thalamus and superior to the cerebellum. This gland secretes melatonin in darkness and, to a lesser degree in daytime, helps set the body’s biological clock. The thymus plays a role in immune function and is lo- cated anterior and superior to the heart (Figure 25.9). This gland is much larger in babies and children and regresses in size as a person ages. The main hormone produced by this gland is thymosin.

F. Ovaries, Testes, Pineal Gland, and Thymus

Ovaries are female gonads that not only produce and house the ova as they mature but are also endocrine organs that produce two major hormones: estrogen and progesterone. These two hormones and the micro- scopic anatomy of the ovary will be studied further in the Exercise 39. The testes are male gonads that not only produce sperm but also produce and secrete an- drogens, primarily testosterone. These hormones and

(b) Pancreatic islet and surrounding acini

Blood capillary

Exocrine acinus

Alpha cell (secretes glucagon)

Beta cell (secretes insulin)

4 5

450�

FIGURE 25.8 The pancreas.

400 E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N

G. Hormone Functions

Hormones act by changing target cell activity. Changes in target cell activity include:

• Synthesis of molecules within the cell (example: estrogen)

• Changing plasma membrane permeability (example: aldosterone)

• Altering cellular metabolism (example: thyroxin) • Secretion of cell products (example: thyroid-

stimulating hormone) • Contraction of smooth muscle (example: oxytocin) • Contraction of cardiac muscle (example:

epinephrine)

TABLE 25 .1 Endocrine Glands, Hormones, Target Cells, and Hormone Function

GLAND HORMONE LOCAT ION OF TARGET CELLS HORMONE FUNCT ION

Anterior pituitary 1. Cartilage, bone, skeletal Stimulates secretion of hormones muscle, liver, and other body that stimulate body growth and tissues metabolism. 2. Thyroid gland Stimulates growth of thyroid gland and secretion of its hormones. 3. Testes Stimulates sperm production. Ovaries Stimulates oocyte production and estrogen secretion. 4. Testes Stimulates secretion of testosterone. Ovaries Triggers ovulation and stimulates secretion of estrogen and progesterone. 5. Mammary gland Stimulates production and secretion of milk. 6. Adrenal cortex Stimulates secretion of hormones by adrenal cortex. 7. Skin Darkens skin pigmentation.

Posterior pituitary 1. Kidneys Decreases water lost in urine by returning water to the blood. 2. Uterus and mammary glands Stimulates uterine contractions and milk ejection during suckling. Thyroid gland 1.

Most body cells

Increases metabolism and basal metabolic rate (BMR). 2.

3. Osteoclast cells in bones Decreases blood calcium levels by inhibiting osteoclasts. Parathyroid glands Osteoclast cells in bones Increases blood calcium levels by stimulating osteoclasts to break down bone matrix. Adrenal cortex 1. Kidneys Decreases sodium and water loss in urine by returning sodium and water to the blood. 2. Liver, muscle, and cells involved Increases resistance to stress, in body defenses increases blood glucose levels, and decreases inflammation. 3. Uterus, mammary glands, and Insignificant in males; increases sex other body cells involved in drive in females. secondary sex characteristics

LAB ACTIVITY 6 Hormone Functions

1 In Table 25.1, identify the hormone(s) produced by each gland and review the target cells and function of each hormone.

2 Using a human torso, brain model, endocrine chart, or the search text box in Real Anatomy (Endocrine), locate each endocrine gland and name the hormone(s) it secretes.

3 For each hormone, point to and name its target cells on a torso model, and describe how the hormone stimulates target cell activity.

4 Complete PowerPhys Experiments: • Blood Glucose Regulation • Thyroid Function

■

}

E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N 401

TABLE 25 .1 Endocrine Glands, Hormones, Target Cells, and Hormone Function (Continued)

GLAND HORMONE LOCAT ION OF TARGET CELLS HORMONE FUNCT ION

Adrenal medulla 1. Body cells involved in fight-or- Promotes fight-or-flight response.

flight response 2.

Pancreas 1. Most body cells Decreases blood glucose levels by transporting glucose into body cells. 2. Liver Increases blood glucose levels by stimulating liver to break down glycogen into glucose. Ovaries 1.

Uterus, mammary glands, and Stimulates development of female other body cells involved in sex characteristics; helps regulate female sexual characteristics menstrual cycle. 2.

Testes Testes, muscle, and other body Stimulates development of male sex cells involved in male sexual characteristics; stimulates male characteristics sex drive; regulates sperm production. Pineal gland Brain Helps to set biological clock.

Thymus T cells (type of white blood cell Promotes the maturation of T cells involved in immune response) for the immune response.

LAB ACTIVITY 7 Measurement of Blood Glucose

1 Devise an experiment with your group or with the whole class that will show a change in blood glucose levels.

2 Things to consider: • Amount of class time available to complete the

experiment • Time since last meal or snack • Relative amount of carbohydrate, fat, and protein in

last meal or snack • Variable that can be changed in lab that will either

increase or decrease blood glucose • Time required for variable to change blood glucose • When and how often blood glucose should be measured

3 Decide who will be the subjects and who will record the data.

4 Read the instructions for your glucometer. 5 Take baseline blood glucose measurement. 6 Take a glucometer, a test strip, a lancet, and an alcohol

wipe to your lab area. • Wash your hands thoroughly to prevent infection. • Decide which finger you will use to obtain blood. • Turn on the glucometer. When the glucometer is

ready, insert the test strip.

• Watch the indicator for placing the blood to the strip. • Wipe the fingertip you will pierce with an alcohol wipe. • Using the lancet, pierce your fingertip. • Apply blood to the test strip according to the instruc-

tions for your glucometer. • Record the blood glucose reading when it appears.

7 Clean up as directed by your instructor. 8 Discuss your experiment and results with the class. ■

SAFETY NOTE: Use safety glasses and gloves when han- dling preserved or fresh tissue. Always wash your hands thoroughly with soap and water when you are done.

H. Dissection of Endocrine Glands

If you are dissecting a cat or fetal pig to observe endocrine organs, refer to the dissection manual. The major endo- crine organs of the cat and fetal pig have a similar location and structure compared with humans. Real Anatomy, a virtual cadaver dissection, can be used to complement or substitute for animal dissection of endocrine glands.

}

Name ___________________________________ Date _________________ Section ______________________________

25 E X E R C I S EReviewing Your Knowledge

403

A. Hormone Abbreviations

Write the name of the hormone next to the abbreviation.

1. ACTH

2. ADH

3. DHEA

4. FSH

5. hGH

6. LH

7. NE

8. OT

9. PRL

10. PTH

11. T3

12. T4

13. TSH

14. MSH

15. TH

404 E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N

B. Main Endocrine Glands and Their Hormones

Write the name of the endocrine gland that secretes the following hormones.

Hormone Endocrine Gland

1. ACTH

2. ADH

3. aldosterone

4. androgens (DHEA)

5. calcitonin

6. cortisol; cortisone

7. epinephrine/NE

8. estrogen; progesterone

9. FSH

10. glucagon

11. hGH

12. insulin

13. LH

14. melatonin

15. OT

16. PRL

17. PTH

18. T3 and T4

19. testosterone

20. TSH

21. thymosin

22. MSH

E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N 405

C. Hormone Function

Write the name of the hormone that matches its function.

ACTH glucagons progesterone ADH hGH PTH aldosterone insulin T3 androgens LH T4 calcitonin melatonin testosterone cortisol MSH thymosin epinephrine NE TSH estrogen OT FSH PRL

Hormone Function

1. Stimulates uterine contractions and milk ejection during suckling.

2. Stimulates secretion of hormones by the adrenal cortex.

3. Decreases water loss by increasing reabsorption of water into blood and decreasing urine production.

4. Increases sex drive in females.

5. Increases metabolism and BMR.

7. Triggers ovulation and stimulates secretion of estrogen and progesterone.

8. Increases blood calcium levels by stimulating osteoclast activity.

9. Promotes fight-or-flight response.

10.

11. Stimulates production and secretion of milk.

12. Increases resistance to stress, increases blood glucose levels, and decreases inflammation.

13. Helps to set the biological clock.

14. Darkens skin pigmentation.

15. Stimulates secretion of hormones that stimulate body growth and metabolism.

16. Decreases blood calcium levels by inhibiting osteoclasts.

17. Promotes the maturation of T cells for the immune response.

18. Stimulates oocyte production and estrogen secretion.

19. Decreases blood glucose levels by transporting glucose into body cells.

}

406 E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N

20. Increases blood glucose levels by stimulating the liver to break down glycogen into glucose.

21. Stimulates development of female sex characteristics and helps regulate menstrual cycle. 22.

23. Regulates sperm development, stimulates development of male sex characteristics, and stimulates male sex drive.

24. Stimulates secretion of testosterone.

25. Stimulates secretion of thyroid hormones.

26. Stimulates sperm production.

27. Increases reabsorption of sodium and water into blood and decreases urine output.

}

Name ___________________________________ Date _________________ Section ______________________________

Using Your Knowledge

25 E X E R C I S E

407

A. Endocrine Glands of the Thorax

Label the structures in Figure 25.9. For question 3, name the hormone secreted by the endocrine gland named in question 2.

B. Hormone Imbalances

Using your textbook or another reference book, identify the gland and hormone(s) affected by each of the following opera- tions or conditions.

4. Oophorectomy

5. Orchiectomy

6. Cushing’s disease

INFERIOR

SUPERIOR

FIGURE 25.9 Neck and thorax region, anterior view.

408 E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N

C. Hormones

Answer the following questions:

7. Name two hormones that are also neurotransmitters.

8. Explain why hormones are able to affect only certain cells and not other cells.

Sometimes more than one tropic hormone is involved in a cascade of events involved in negative feedback regulation. In Figures 25.10 and 25.11, a stimulus disrupts homeostasis and initiates release of hormones in a specific order to return to homeostasis. Answer the questions associated with each figure.

FIGURE 25.10 Hypothalamus and tropic hormones.

Hypothalamus (endocrine gland 1)

Endocrine gland 2

Corticotropin releasing hormone

(hormone 1)

Stress causes low levels of glucocorticoids (mainly cortisol) to stimulate the release of

Increases glucose metabolism and stress resistance

CRH.

Hormone 2

Endocrine gland 3

(hormone 3)

9. Identify endocrine gland 2.

10. Identify hormone 2.

11. Identify endocrine gland 3.

12. Identify hormone 3.

13.

14. Name the 2 tropic hormones}

E X E R C I S E 2 5 E N D O C R I N E S T R U C T U R E A N D F U N C T I O N 409

15. Identify endocrine gland 2.

16. Identify hormone 2.

17. Identify endocrine gland 3.

18. Identify hormone 3.

19.

20.

Hypothalamus (endocrine gland 1)

Gonadotropin- releasing hormone

(hormone 1)

Low metabolic rate stimulates the release of

Increases metabolic rate

TRH.

Endocrine gland 2

Hormone 2

Endocrine gland 3

hormone 3

FIGURE 25.11 Hypothalamus and tropic hormones.

Name the 2 tropic hormones}

The adult cardiovascular system contains approximately 5.5 liters (1.5 gallons) of blood. Blood transports oxygen, nutrients, and hormones to body tissues and transports carbon dioxide, heat, and

Blood Components and Blood Tests 26

E X E R C I S E

411

metabolic wastes away from body tissues. It regulates pH, body temperature, and cell water content and also provides protection from blood loss through clotting and against dis- ease through phagocytic white blood cells and antibodies.

O B J E C T I V E S M A T E R I A L S • WBC Identification and Differential WBC

Count: compound microscopes, lens paper, hand counter, prepared slides of normal human blood (with Wright’s stain), prepared slides of abnormal blood (allergies or infections), or Virtual Differen- tial WBC Count Activity (Instructors: download from Wiley Instructors’ Companion Site)

• materials needed if using human or animal blood: biohazardous waste container; sharps container; safety glasses; disposable gloves; 10% bleach so- lution in spray bottle; sterile, disposable lancets or Autolets; alcohol swabs; cotton balls

• Hematocrit: human or animal blood, heparinized capillary tubes, sealing clay, microcentrifuge, mm rulers (or hematocrit reader)

• Hemoglobin: human or animal blood, Tallquist paper or hemoglobinometers

• Coagulation Time: human or animal blood, nonheparinized capillary tubes, small metal file

• Blood Typing: blood typing kit or antisera (anti-A; anti-B; anti-D), new test cards or glass slides (two per student), toothpicks, wax marking pencil, Rh warming tray

• PowerPhys Experiment: Hematocrit and Hemoglobin Concentration and Blood Typing

1 Describe the functions of blood

2 Name the components of blood

3 Describe the structure, characteristics, and function of red blood cells (RBCs), each type of white blood cell (WBC), and platelets

4 Identify RBCs, each type of WBC, and platelets

5 Describe the importance of and perform the following blood tests: differential WBC count, hematocrit, hemoglobin, and coagulation time

6 Describe how blood is typed and perform ABO and Rh blood typing

412 E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S

A. Components of Blood

When centrifuged, blood in a heparinized tube separates visually into two main components: plasma and formed elements. The clear, straw-colored liquid is called plasma and the dark-red and buff-colored portions are the formed elements (Figure 26.1). The formed ele- ments include red blood cells (RBCs), white blood cells (WBCs), and platelets (cell fragments). RBCs are also called erythrocytes (erythro- � red; -cytes � cells), WBCs are known as leukocytes (leuko- � white), and platelets are known as thrombocytes (thrombo- � clot). The formed elements constitute approximately 45% of whole blood volume, and plasma composes about 55%. Plasma is about 91.5% water and 8.5% solutes. The solutes are mostly plasma proteins but also include nutrients (glucose, amino acids, and lipids), blood gases (oxygen and carbon dioxide), electrolytes, hormones, enzymes, and waste materials. Serum is plasma minus clotting proteins. It is the watery fl uid created when blood is allowed to sit and clot in an unheparinized tube.

B. The Structure and Function of Red Blood Cells, White Blood Cells, and Platelets

1. Red Blood Cells (Erythrocytes or RBCs)

Erythrocytes are small, anucleate (without a nucleus) biconcave cells that contain hemoglobin, a large molecule used to transport oxygen and carbon dioxide in the blood. About 33% of the total weight of RBCs is composed of hemoglobin. Hemoglobin contains a red pigment called heme that gives blood its red color. Blood is bright red when oxygen-rich and darker red when oxygen-poor. Characteristics of RBCs are given in Table 26.1. There are approximately 4.5 to 5 million RBCs per microliter of blood; females have lower amounts and males have higher amounts. An abnormally high number of RBCs is called polycythemia (poly- � many; cyto- � cells; -emia � blood), and an unusually low number of RBCs is one type of anemia.

2. White Blood Cells (Leukocytes or WBCs)

WBCs, nucleated cells that are typically larger than RBCs, attack pathogens and other foreign substances in the body. There are fi ve kinds of leukocytes that are divided into two categories: granular and agranular. Granular leukocytes have discernible vesicles (granules) in the cytoplasm that can be seen after staining, and agranular leukocytes also have granules, but they cannot be observed with the light microscope. These WBCs were named agranular because the microscopes that were used at that time were not power- ful enough to distinguish the granules. Granular leukocytes include neutrophils, eosinophils, and basophils. Agranu- lar leukocytes include lymphocytes and monocytes. Char- acteristics of WBCs are given in Table 26.1. There are normally 5,000 to 10,000 WBCs per micro- liter of blood. An abnormally high number of WBCs is called leukocytosis (-osis � an increase in a pathological condition), and a decrease in the number of WBCs is called leukopenia (-penia � defi ciency).

3. Platelets (Thrombocytes)

Platelets are formed in red bone marrow from large, mul- tinuclear cells called megakaryocytes (mega- � large; karyo- � nucleus). Large megakaryocytes break into tiny cytoplasmic fragments called platelets that do not have nuclei and are not considered to be cells. Characteristics of platelets are given in Table 26.1. These special cell fragments protect the body by forming a platelet plug to stop bleeding when blood vessels rupture and by secreting chemicals that aid in blood clotting. Thrombocytopenia (thrombo- � clot; -penia � defi ciency) is a defi ciency in the number of circulating platelets.

FIGURE 26.1 Components of blood in a normal adult.

(a) Plasma and formed elements

Uncentrifuged Centrifuged (b) Serum and formed elements

E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S 413

(60 to 70% of WBCs). Lymphocytes make up 20 to 25% of WBCs, monocytes 3 to 8%, eosinophils 2 to 4%, and basophils 0.5 to 1%. Often it is diffi cult to fi nd basophils in normal blood smears. The platelets, which are much smaller than RBCs, stain dark purple and may just look like an extra stain on the slide. Keep in mind that blood cells and their nuclei have a three-dimensional spherical shape. You will not always fi nd the nucleus appearing as described or as seen in pho- tomicrographs because of the various views that are pos- sible. Figure 26.2 depicts the three-dimensional structure of RBCs, WBCs, and platelets.

C. Microscopic Examination of the Formed Elements

Blood cells are diffi cult to see at low magnifi cations be- cause the cells are so small. The erythrocytes are the most numerous (700:35:1 ratio of RBCs:platelets:WBCs) and are small, pinkish cells. The WBCs are conspicuous because their nuclei stain dark blue to dark purple with Wright’s stain. The majority of WBCs are larger than the RBCs. RBCs are used as a standard to compare the size of WBCs. When looking at WBCs in normal blood cells, the majority of WBCs that you will see are neutrophils

TABLE 26 .1 Characteristics of RBCs, WBCs, and Platelets (Wright’s Stain)

FORMED COLOR OF ELEMENT S IZE NUCLEUS GRANULES CYTOPLASM

RBCs 7–8 micrometer (�m) No nucleus No granules Light pinkish-red diameter

Neutrophils 10–12 �m Multilobed nucleus Small, nondistinct Usually pink but, (neutr � neutral; diameter with 2–5 or more pale lilac to depending on the -phil � loving) lobes connected neutral-staining stain used, by threads. granules sometimes has a reddish tinge that makes students mistake these cells for eosinophils

Eosinophils 10–12 �m in Bi-lobed nucleus Many medium, Pink (eosin- � red, diameter (occasionally 3 red-orange acidic dye) lobes) granules (some stains make them look very dark brownish-red-orange)

Basophils (baso- � 8–10 �m in Nucleus is large, Large, dark blue- Purple dark blue, diameter varied in shape; purple granules basic dye) generally obscured by large granules

Lymphocytes Small lymphocyte: Large, round, or Granules not Light sky-blue (lymph cell) 6–9 �m in diameter; slightly indented obvious with light cytoplasm; small cells large lymphocyte: nucleus that stains microscope have only a rim of 10–14 �m in very dark purple cytoplasm; more diameter cytoplasm in larger lymphocytes

Monocytes (mono- Very large cell; Large kidney bean or Granules not Light blue-gray � one; pertains 12–20 �m in horseshoe-shaped obvious with light to having only diameter lacy nucleus; microscope one nucleus) sometimes oval and indented

Platelets 2–4 �m in diameter; No nucleus Dark purple granules Difficult to see because small cell fragments of dark purple granules

414 E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S

LAB ACTIVITY 1 Identification of RBCs, WBCs, and Platelets

1 Examine a prepared blood slide using the low-power lens to locate RBCs and WBCs. The tiny RBCs are difficult to see at first and will look like tiny dots. You may see the blue/purple colored nuclei of the WBCs. See Figure 26.3.

2 Using the high-power or oil immersion lens, locate RBCs, WBCs, and platelets. • When you begin your identification, the obvious thing

you will notice is there are many, many RBCs found everywhere. Then you will notice the most numerous of the WBCs, the neutrophils. The next prevalent WBC type is the lymphocyte. In fact, you may tire of seeing so many of these two types of WBCs; but the other three types of WBCs are a little more elusive and can be found with diligent searching. The numbers below indicate the percentages each specific WBC represents out of the total WBCs present. Use the size of the RBCs (7–8 �m) to estimate the size of the WBCs.

Step 1 Identify the most numerous WBC—the neutrophil—60–70% of WBCs (multi- lobed nucleus; neutral to pink granules; 10–12 �m)

CLINICAL NOTE: Neutrophils have a multilobed nucleus that gives them the nickname polymorphonuclear leukocytes, or PMNs. Neutrophils are also called “segs” because of the segmented look of the nucleus.

FIGURE 26.2 Photomicrographs of variations of white blood cells.

(e) Monocytes(d) Lymphocytes

(a) Neutrophils (b) Eosinophils (c) Basophils

LM all 1000�

Step 2 Identify the next most numerous WBC—the lymphocyte—20–25% of WBCs (smallest WBC; nucleus is 90% of cell; small lymphocyte is 6–9 �m)

Step 3 Identify the largest WBC—the monocyte—3–8% of WBCs (horseshoe-shaped nucleus; light blue cytoplasm; 12–20 �m)

Step 4 Identify the red granular WBC—the eosinophil—2–4% of WBCs (small red granules; bilobed nucleus; 10–12 �m)

Step 5 Identify the blue granular WBC—the basophil—0.5–1% of WBCs (large blue-purple droplets; nucleus is obscured by granules; 8-10 �m)

3 Clean up as directed by your instructor. ■

E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S 415

higher-power objective lens as directed by your instructor.

• To avoid recounting any WBCs, begin at one end of the slide that has a good separation of cells and slowly scan systematically, moving the slide down and over, then up and over, and repeat as seen in Figure 26.3.

• If you encounter a cell that you cannot identify or are not sure of, do not count it and continue on.

• Continue this pattern until you have found and re- corded 100 WBCs in Table 26.2.

• Because you are counting 100 cells, the total number of each type of WBC counted is its percentage in the blood sample (i.e., 26 lymphocytes means 26% of the WBCs are lymphocytes).

• Write your results on the board to pool class data.

2 Complete a differential WBC count using a prepared microscope slide of abnormal blood, if available, or use the Virtual Differential WBC Count Activity. • Follow the instructions for a differential WBC using

normal blood (listed above). • Record your tally counts and totals in Table 26.2. • Determine the disorder by consulting Table 26.3 and

record at the bottom of Table 26.2. • Write your results on the board to pool class data for

comparison.

3 Clean up as directed by your instructor. ■

D. Differential White Blood Cell Count

A differential WBC count is performed to determine the percentage of each of the fi ve types of WBCs in a blood sample. When attempting to learn which WBCs are nor- mally present from the greatest to least percentages, it is helpful to remember the following mnemonic: “Never Let Monkeys Eat Bananas” (N � neutrophils; L � lympho- cytes; M � monocytes; E � eosinophils; and B � baso- phils). Because the normal percentage of each WBC type is known, any signifi cant abnormality in these percentages, elevated or depressed, can be indicative of particular disor- ders. Numerical values for the normal range of WBCs may vary depending on the reference source.

SAFETY NOTE: When using human or animal blood samples, you must protect yourself from any blood-borne in- fectious disease (hepatitis, HIV, etc.). Wear gloves and safety goggles while performing blood tests. If a blood spill occurs, cover the spill with paper towels soaked in 10% bleach solu- tion and immediately inform your instructor.

LAB ACTIVITY 2 Differential WBC Count

1 Complete a differential WBC count using a prepared microscope slide of normal blood, or use the Virtual Differential WBC Count Activity supplied by your instructor. INSTRUCTORS: Download Activity from Wiley Instructor Companion Site. • Complete this activity individually or with a lab part-

ner as your instructor directs. If done together, one person will identify each WBC with the microscope and call out the type to the lab partner. The other per- son will mark the type of cells encountered by using tally marks (|||| ||) and also keep track of the total number of cells.

• Using a prepared, normal blood slide, focus using the low-power objective lens and then switch to a

FIGURE 26.3 Procedure for scanning WBC differential count.

416 E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S

TABLE 26 .2 Results of Differential WBC Count

A. Normal Differential WBC Count

% OF TOTAL CLASS AVERAGE NORMAL PERCENTAGE TYPE OF WBC OBSER VAT ION TALLY WBCs (% OF TOTAL WBCs ) OF WBCs

Neutrophil 60–70%

Lymphocyte 20–25%

Monocyte 3–8%

Eosinophil 2–4%

Basophil 0.5–1%

Total WBCs

B. Pathological Differential WBC Count

Neutrophil 60–70%

Lymphocyte 20–25%

Monocyte 3–8%

Eosinophil 2–4%

Basophil 0.5–1%

Total WBCs

Type of Disorder

TABLE 26 .3 Significance of Elevated and Depressed WBC Counts

WBC TYPE H IGH COUNT MAY INDICATE LOW COUNT MAY INDICATE

Neutrophils Bacterial infection, burns, stress, inflammation Radiation exposure, drug toxicity, vitamin B12 deficiency, systemic lupus erythematosus Lymphocytes Viral infections, some leukemias Prolonged illness, immunosuppression, treatment with cortisol Monocytes Viral or fungal infections, tuberculosis, some Bone marrow depression, treatment with cortisol leukemias, other chronic diseases Eosinophils Allergic reactions, parasitic infections, Drug toxicity, stress autoimmune diseases Basophils Allergic reactions, leukemias, cancers, Pregnancy, ovulation, stress, hyperthyroidism hypothyroidism

E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S 417

discard the lancet in the sharps container for biohaz- ardous material only.

• Touch the red-lined end of a heparinized (prevents blood from coagulating) capillary tube to the blood and hold the tube at a downward angle. Taking care that no air is allowed to enter while the tube fills by capillary action, fill the capillary tube about three- fourths full if possible.

• Hold a finger over the end of the tube so blood can- not drain out. Place the blood end of the tube into sealing clay to plug the end.

• Place the sealed tube in a microhematocrit centrifuge with the sealed end on the rubber gasket pointing outward and away from the center.

• Prepare a second tube in the same manner. • Place the second sealed tube in the centrifuge oppo-

site the first tube for balance. Always keep the centrifuge balanced.

• If others are using the centrifuge, make a note of the groove numbers of your tubes.

• Secure the inside and outside covers of the centrifuge and set the timer for 4 to 5 minutes.

• After the centrifuge has stopped, remove your tubes. Note that the RBCs are packed at the bottom near the sealing clay, the WBCs (and platelets) are buff col- ored next to them, and the clear plasma is on the top.

• Use a microhematocrit reader or a millimeter ruler to measure the length of the whole column, the length of the packed RBCs, WBCs, and plasma in millime- ters (Figure 26.4).

• Record the whole column length (in mm) and the RBC length (in mm) in Table 26.4.

• Use the following formula to calculate the percent- age of RBCs (the hematocrit) in whole blood:

Length of RBCs in mm Length of the whole column in mm( ) � 100

• Record the hematocrit in Table 26.4.

3 Clean up as directed by your instructor. 4 Answer Discussion Questions with your lab group.

E. Hematocrit (Packed Red Cell Volume)

A hematocrit determines the volume of RBCs described as the percentage of RBCs in a whole blood sample. A capillary tube of blood is centrifuged to pack the red cells at the outer end of the tube, separating them from the WBCs, platelets, and plasma. After measuring the length of the RBC column and the total length of the blood column, the percentage of RBCs can be calculated. The normal hema- tocrit range for females is approximately 38 to 46% and for males it is 40 to 54%. An abnormally high hematocrit (gen- erally 65% or above) is indicative of polycythemia, and a hematocrit with RBCs below the normal level indicates a type of anemia.

FIGURE 26.4 Capillary tubes for calculating a hematocrit.

Air Plasma Buffy coat Red blood cells Clay

(a)

(b)

LAB ACTIVITY 3 Hematocrit

1 Calculate the hematocrit for blood in the capillary tubes in Figure 26.4. • Use a millimeter ruler to measure (in mm) the length

of the whole column (the length of packed RBCs, WBCs, and plasma) and record it in Table 26.4.

• Measure the length (in mm) of the RBCs and record in Table 26.4.

• Use the following formula to calculate the percent- age of RBCs (the hematocrit) in whole blood:

Length of RBCs in mm Length of the whole column in mm( ) � 100

• Record the hematocrit in Table 26.4.

2 Calculate the hematocrit on a blood sample if equip- ment is available. • If using your own blood, clean your finger with an

alcohol wipe, lance it with a new, sterile lancet, and

418 E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S

LAB ACTIVITY 4 Determining Hemoglobin Content of Blood

1 Follow the Tallquist procedure for determining hemo- globin content, or if using a hemoglobinometer, follow the procedure given in its instruction booklet. • After reviewing the Safety Note before Lab Activity 3

on using blood, obtain a blood sample provided by your instructor or your own blood using methods described previously.

• Place one drop of blood on the absorbent Tallquist paper. Be sure the blood spot is large enough to be seen in all the chart holes simultaneously.

• Allow blood to dry until it is no longer shiny but not so dry as to turn brownish. Match its color with the color scale provided.

• Record the results as grams of hemoglobin/100 mL of blood in Table 26.5.

2 Clean up as directed by your instructor. 3 Answer Discussion Questions with your lab group.

DISCUSSION QUESTIONS Hematocrit

1 For the capillary tubes in Figure 26.4, is the hematocrit normal, low, or high? If abnormal, do values indicate anemia or polycythemia?

2 Is the class average hematocrit for males higher than females?

3 How does your class compare with the national averages?

■

F. Determining Hemoglobin Content of Blood

Hemoglobin (Hb) is a protein that carries oxygen in the RBCs. Therefore, hemoglobin concentration in blood deter- mines the oxygen-carrying capacity of the blood. It is possi- ble for you to have a normal hematocrit or RBC volume and still be anemic due to low hemoglobin concentration. Normal values are 12 to 15 g hemoglobin/100 mL blood in females and 13 to 16 g/100 mL in males. In severe anemia, the hemo- globin content can be less than 7 g/100 mL. Clinically, the relationship of the hematocrit (%) is compared with the he- moglobin reading (g/100 mL) and is generally a ratio of 3:1. Two of the several techniques for determining the hemo- globin content of blood are discussed here. The Tallquist measurement is the simpler but older method that does not always produce accurate results. Hemoglobinometers are accurately calibrated instruments but are more expensive.

TABLE 26 .4 Hematocrit Results

HEMATOCRIT CAP ILLARY RBC COLUMN WHOLE COLUMN HEMATOCRIT (PERCENTAGE TUBES (mm) (mm) OF RBCs / TOTAL BLOOD)

Hematocrit a

Hematocrit b

Hematocrit (your blood)

MALE CLASS FEMALE CLASS NAT IONAL AVERAGE NAT IONAL AVERAGE FOR AVERAGE AVERAGE FOR MALES FEMALES

40–54% 38–46%

TABLE 26 .5 Hemoglobin Content

HEMOGLOBIN CONTENT

Tallquist method: ______ g/100 mL Hemoglobinometer: ______ g/100 mL

E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S 419

• If using your own blood, use an alcohol swab on a clean finger and prick the finger with a clean, sterile lancet. Have a free flow of blood.

• Hold the nonheparinized capillary tube at an angle to collect the blood and put the upper end in the drop of blood.

• Fill the tube a minimum of two-thirds full and record the time started. Time: __________

• Lay the tube on a paper towel. • After 30 seconds, scratch the glass with the metal file

close to an end of the tube. Holding the tube close to each side of the scratch, gently break the tube away from you.

• Gently pull the tube apart and observe the blood to see if a fibrin thread is present.

• Repeat this process every 30 seconds until fibrin occurs. Record the amount of time required for coagulation in Table 26.6.

• Write results on the board to pool class data. Calculate average coagulation time for your class and record in Table 26.6.

3 Clean up as directed by your instructor. 4 Answer Discussion Questions with your lab group.

DISCUSSION QUESTIONS Coagulation Time

1 Would a person with hemophilia have higher or lower than normal clotting times? Explain.

2 How would coagulation time be affected if a heparin- ized capillary tube was used? Explain.

■

DISCUSSION QUESTIONS Hemoglobin Content of Blood

1 Compare your hematocrit results with your grams of hemoglobin/100 mL. Calculate the ratio. _________Is this close to the normal ratio? (yes/no)

2 To measure the hemoglobin content, RBCs are hemo- lyzed. How would the results be different if you did not completely hemolyze the RBCs? Would the hemoglo- bin concentration be higher or lower?

3 Within your class, are there any students who have the same hematocrit but different hemoglobin concentra- tions? Explain why this can occur.

■

G. Coagulation Time

The process of blood clotting or coagulation prevents excessive blood loss. There are many blood clotting factors present in the plasma. Other factors are released by injured tissues and platelets to initiate the chemical chain reaction that forms a blood clot. Fibrin is a long, insoluble thread- like protein strand that forms a mesh to trap platelets. Fibrin is formed from soluble fi brinogen molecules during clotting. The coagulation time is the time it takes for clotting to take place when blood is removed from the body. Normal clotting time is within 2 to 6 minutes.

TABLE 26 .6 Coagulation Time

YOUR COAGULAT ION CLASS AVERAGE OF T IME COAGULAT ION T IMES

LAB ACTIVITY 5 Coagulation Time

1 Observe the demonstration of clotting blood. • Your instructor will place animal or sterile human

blood into two test tubes, one with and one without an anticoagulant.

• Observe the clot form and settle to the bottom of the tube without anticoagulant. Observe the straw- colored serum above the clot.

• Compare the tube with the blood clot to the blood in the test tube with an anticoagulant.

2 Determine coagulation time. • If using human blood, review the Safety Note before

Lab Activity 3.

420 E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S

attaches to the recipient’s RBCs and hemolyzes or bursts them, releasing hemoglobin that can cause kidney damage. A and B antibodies do not cross the placenta because of their large size. The Rh blood system is different from the ABO system but has some similarities. If you have the Rh antigen as a surface membrane molecule on your RBCs, you are Rh�. If you do not have the Rh antigen, you are Rh�. An Rh� person does not spontaneously develop the anti-Rh anti- body (as in the ABO system) and does not produce this antibody until the person is exposed to the Rh antigen from Rh� blood. This can happen through a blood transfusion, by sharing hypodermic needles, or by an Rh� mother car- rying an Rh� child. During delivery, the baby’s blood can leak from the placenta into the mother’s bloodstream, causing the mother’s body to make Rh antibodies. The fi rst baby would not be affected, but subsequent pregnan- cies with Rh� fetuses can result in the small Rh antibodies crossing the placenta and causing hemolysis in the fetuses’ blood. This condition is called hemolytic disease of the newborn. Rh� mothers are typically given RhoGAM so they will not make Rh antibodies. The following activity will use antisera (antiserum, sing.), which can be artifi cial serum or serum from an animal or human containing antibodies against A, B, or D (Rh) antigens. Serum is blood plasma without clotting proteins. If anti-A serum clumps a particular blood sample, the blood is type A because of an antibody-antigen com- plex formed with the A antigens on the RBCs.

H. ABO and Rh Blood Typing

Blood typing is critical for blood transfusions, transplanta- tions, and maternal-fetal compatibility, but is also used in genetic studies, forensic studies, legal medicine, and an- thropology. Although there are many different systems for classifying human blood, we will be studying the ABO and Rh systems because they are most commonly used. Blood typing is based on the antigenic (agglutinogens) molecules that are on the surface of the RBC membranes. An antigen is a substance that is able to produce an immune response and will react with a specifi c antibody. Antibodies are plasma proteins that combine with a specifi c antigen to inhibit or destroy it. In the ABO system, there are two types of antigens (A and B) that can be present as surface membrane molecules on RBCs. If the plasma membranes of your RBCs have only the A antigen present, you have type A blood; correspondingly, if you have only B antigens present, you have type B blood. If you have both antigens A and B present you have type AB blood, and if you do not have either A or B antigen present, you have type O blood (Figure 26.5). A or B antibodies appear in babies’ blood a few months after birth. If you have type A blood, you do not have its cor- responding anti-A antibody. If the two are mixed, they will form a detrimental antigen-antibody complex and cause clumping. People with type A blood have anti-B antibodies that will become cross-linked and agglutinate (clump) if type B blood is given to them (Figure 26.6). Agglutination is followed by the activation of another plasma protein that

FIGURE 26.5 Antigens and antibodies of the ABO blood types.

Red blood cells

Plasma

TYPE B

B antigen

TYPE A

A antigen

TYPE O

Neither A nor B antigen

TYPE AB

Both A and B antigens

Both anti-A and anti-B antibodies

Neither antibody

Anti-A antibody

Anti-B antibody

BLOOD TYPE

E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S 421

Before Going to Lab

1 Complete Table 26.7 by writing in the antigen present on the RBCs and the antibody present in plasma for each blood type. Also, determine each compatible and incompatible donor for each blood type.

TABLE 26 .7 Summary of ABO Blood Group Interactions

BLOOD TYPE A B AB O

Antigen on RBCs

Antibody in plasma

Compatible donor blood types (no hemolysis)

Incompatible donor blood types (hemolysis)

LAB ACTIVITY 6 ABO and Rh Blood Typing

1 Your instructor will tell you whether you will be using sterile blood, your own blood, or simulated blood.

2 Procedure for obtaining blood sample. • Thoroughly wash hands with soap and dry with a

clean paper towel. • Thoroughly clean the tip of index finger with an

alcohol swab. • Open a new, sterile blood lancet exposing the sharp

tip only (or use an Autolet). Lance just to the side of

the finger pad with the new lancet. Never reuse a lancet, even your own.

• Deposit the used lancet in the sharps container for biohazardous materials only.

• Wipe away the first drop of blood with cotton ball and dispose in biohazard waste container. Gently squeeze one drop of blood on each side of a clean prepared slide.

3 Perform ABO blood typing according to the procedure below, using Figure 26.6 as a guide. • Obtain a clean glass slide (test cards if using a typing

kit), two new toothpicks, a wax marking pencil, and anti-A and anti-B sera.

• Divide the glass slide in half with a wax pencil. Mark A on the left side and B on the right side. Place one drop of anti-A serum on the left side and one drop of anti-B serum on the right side.

• Place one drop of blood on sides A and B of slide. • Using separate new toothpicks, mix each sample of

blood with the corresponding antiserum. • Results may take up to 2 minutes. Observe each sam-

ple for agglutination or the appearance of granulation (Figure 26.6); interpret the results.

• Record your results in Table 26.8 by writing “Yes” if clumping occurs and “No” if clumping does not occur.

• Write your results on the board to pool class data for comparison.

• Record percentage of ABO blood types for your class in Table 26.8.

422 E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S

4 Perform Rh blood typing according to the procedure below. • Obtain a clean glass slide and antiserum D (Rh). • Place one drop of anti-D on the glass slide and add a

drop of blood. • Mix the two liquids with a new toothpick. • Place slide on the warm Rh typing box and rock gently

to mix. Rh typing requires a higher temperature than ABO typing does.

• Results may take up to 2 minutes. Observe your sample for clumping or the appearance of granula- tion (Figure 26.6); interpret the results.

• Sometimes, it is more difficult to obtain positive results with the anti-Rh serum, depending on the supply and delivery situations.

• Record your results in Table 26.8 for each sample you tested.

• Write your results on the board to pool class data for comparison.

• Record percentage of Rh blood types for your class in Table 26.8.

5 Clean up as directed by your instructor. ■

FIGURE 26.6 Serum agglutination results.

B lo

od o

nl y

LAB ACTIVITY 7 Hematocrit and Hemoglobin Concentration and Blood Typing

1 Complete PowerPhys Experiments: Hematocrit and Hemoglobin Concentration and Blood Typing. • Effect of Altitude on Hematocrit and Hemoglobin. • ABO and Rh Blood Typing. ■

TABLE 26 .8 Blood Typing Results

STUDENT UNKNOWN UNKNOWN UNKNOWN UNKNOWN SERUM AGGLUT INAT ION RESULTS BLOOD SAMPLE 1 2 3 4

Clumping with anti-A

Clumping with anti-B

Clumping with anti-D (Rh)

ABO blood type

Rh type

CLASS BLOOD TYPES BLOOD TYPES (PERCENTAGE)

Rh�

E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S 423

I. Complete Blood Count (CBC)

A complete blood count (CBC), a vital diagnostic tool, screens for abnormalities in the number or structure of formed elements. The CBC includes: a total RBC count,

total WBC count, platelet count, differential WBC count, hematocrit, and hemoglobin concentration. The CBC is used along with a battery of blood chemistry tests to put to- gether a comprehensive profi le of a person’s general level of health based on blood values. Examine Exhibit 26.1 to observe the complexity of a CBC.

WBC � white blood cell; RBC � red blood cell; HGB � hemoglobin; HCT � hematocrit; MCV � mean corpuscular volume; MCH � mean corpuscular hemoglobin; MCHC � mean corpuscular hemoglobin concentration; RDW � red blood cell distribution index; PLT � platelet; MPV � mean platelet volume; NEUT% � neutrophil percent; LYMPH% � lymphocyte percent; MONO% � monocyte percent; EO% � eosinophil percent; BASO% � basophil percent; NEUT# � neutrophil number; LYMPH# � lymphocyte number; MONO# � monocyte number; EO# � eosinophil number; BASO# � basophil number; L � low; H � high; PTT � partial thromboplastin time.

EXHIB IT 26 .1 Complete Blood Count Results

PAT IENT: DOCTOR : ACCOUNT NO: REPORT FOR LOCAT ION: MEDICAL RECORD NO. :

HEMATOLOGY

DAY: � 1 DATE : AUG 20 13 T IME : 1000 REFERENCE UNITS

WBC 8.0 4.5–11.0 �103/�L RBC 4.12 L 4.70–6.10 �106/�L HGB 14.4 14.0–18.0 g/dL HCT 41.6 L 42.0–52.0 % MCV 101 H 83–99 fL MCH 34.8 H 28–34 pg MCHC 34.5 31.0–37.0 % RDW 13.1 11.0–15.5 % PLT 265 150–450 �103/�L MPV 8.2 7.4–10.4 fL NEUT% 47.7 L 49.0–90.0 % LYMPH% 41.0 22.0–51.1 % MONO% 6.5 0.0–13.0 % EO% 4.3 0.0–7.0 % BASO% 0.5 0.0–3.0 % NEUT# 3.90 1.50–7.06 �103/�L LYMPH# 3.30 H 0.70–3.00 �103/�L MONO# 0.5 0.0–1.4 �103/�L EO# 0.3 0.0–0.8 �103/�L BASO# 0.0 0.0–0.3 �103/�L

COAGULAT ION

DAY: � 1 DATE : AUG 20 13 T IME : 1000 REFERENCE UNITS

PROTIME: 11.4 10.9–13.3 sec PTT: 28.3 25.9–35.3 sec

425

Name ___________________________________ Date _________________ Section ______________________________

26 E X E R C I S EReviewing Your Knowledge

A. Characteristics of the Formed Elements and Blood Abnormalities

Fill in the blank with the term that fits the description.

______________________ 1. The oxygen and carbon dioxide carrying cell

______________________ 2. Help the body fight infections and foreign substances

______________________ 3. Form a clot to help the body stop bleeding

______________________ 4. Another name for red blood cells

______________________ 5. Another name for platelets

______________________ 6. Another name for white blood cells

______________________ 7. Large cells that develop into platelets

______________________ 8. A deficiency in number of RBCs or decreased hemoglobin content of blood

______________________ 9. An abnormal increase in RBCs

______________________ 10. An abnormal increase in WBCs

______________________ 11. A deficiency in WBCs

______________________ 12. A deficiency in platelets

426 E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S

B. White Blood Cell Structure and Characteristics

Fill in the blank with the term that fits the description. Terms may be used more than once.

______________________ 1. 60–70% of all WBCs

______________________ 2. 2–4% of all WBCs

______________________ 3. 0.5–1% of all WBCs

______________________ 4. 20–25% of all WBCs

______________________ 5. 3–8% of all WBCs

______________________ 6. 10–12 �m; nucleus with 2–5 connected lobes; pale lilac granules

______________________ 7. 10–12 �m; nucleus with 2 or 3 lobes; red-orange granules

______________________ 8. 8–10 �m; nucleus difficult to see; large deep blue-purple granules

______________________ 9. 6–9 �m; round nucleus that is dark purple; sky blue cytoplasm, no visible granules

______________________ 10. 12–20 �m; kidney-shaped nucleus; blue-gray cytoplasm, no visible granules

______________________ 11. Abbreviation for polymorphonuclear leukocytes

______________________ 12. General name for all of the WBCs

______________________ 13. Nicknames for neutrophils

______________________ 14.

C. White Blood Cells

Write the name of the white blood cell that matches the description. Terms may be used more than once.

______________________ 1.

______________________ 2. granulocytes

______________________ 3.

______________________ 4. agranulocytes

______________________ 5.

______________________ 6. most numerous leukocyte

______________________ 7. least numerous leukocyte

}

} }

E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S 427

D. ABO and Rh Blood Typing

Name the antigens present on the RBCs and the antibodies present in plasma of each blood type.

Antigens on RBCs Antibodies in Plasma

1. O� ____________ ____________

2. A� ____________ ____________

3. B� ____________ ____________

4. AB� ____________ ____________

5. Based on what you know about antigens and antibodies, what blood type is the universal donor? ____________ Explain.

6. What blood type is the universal recipient? ____________ Explain.

E. Hematocrit

1. Define hematocrit.

2. What is the anticoagulant used in this type of blood test? __________

3. Ron has a hematocrit of 47%. Is this within the normal range? (yes/no)

4. Janey has a hematocrit of 58%. Is this within the normal range? (yes/no)

F. Hemoglobin Content and Coagulation Time

1. Do the hematocrit and hemoglobin content of blood measure the same thing? _________________ Explain.

2. What is the importance of coagulation time?

3. Would a hemophiliac have an above or below normal coagulation time?

429

Name ___________________________________ Date _________________ Section ______________________________

Using Your Knowledge

26 E X E R C I S E

A. Formed Elements of Blood

Identify the formed elements in Figure 26.7.

FIGURE 26.7 Scanning electron micrograph of the formed elements of blood.

SEM about 3000�

Platelet

Red blood cell

White blood cell

1. ___________________________

2. ___________________________

3. ___________________________

B. White Blood Cell Functions

4. Ken has a bacterial infection with inflammation. What type of WBC increases in number first to help him fight the infection? Which WBC arrives second to help?

430 E X E R C I S E 2 6 B L O O D C O M P O N E N T S A N D B L O O D T E S T S

C. Differential White Blood Cell Count

5. Lindsey had a differential WBC count that showed 60% neutrophils, 10% eosinophils, 1% basophils, 22% lympho- cytes, and 7% monocytes. What could have caused this?

D. Hematocrit

6. Michaela is an athlete who has been training for several years only in Florida. She had an annual physical, and the doctor read her hematocrit as 59%. What could this reading potentially tell the doctor?

E. Hemoglobin

7. Using your textbook or another reference, determine what type of anemia could cause a reduced hemoglobin level while the person still has a normal hematocrit.

F. Blood Typing

8. Blake’s doctor found out that, although Blake is Rh�, he received Rh� blood for the first time. Will he have a transfu- sion reaction? Explain.

9. Jim has type AB� blood. What type(s) of blood can he receive in a transfusion?

10. If Brittany is blood type O� and her husband is blood type AB�, what effect can the Rh factor have on their second child?

11. Michael is type O�. He is donating blood today and wants to know what blood types can accept his blood. What would you tell him?

12. Staci has antibody A in her blood with no Rh antibody. What blood type does she have?

13. Leslie has AB� blood and had a blood transfusion with AB� blood. Could this be a life-threatening situation? Why or why not?

O B J E C T I V E S M A T E R I A L S

• human heart model or use Real Anatomy (Cardiovascular)

• Location of Heart: skeleton, small removable labels

• human torso or chart showing the heart/ pulmonary/systemic circulations, colored pencils (red, blue, purple), index cards

• model or chart of the coronary circulation • compound microscope, lens paper, prepared

microscope slides of cardiac muscle, or Real Anatomy (Histology)

• Simulated Pericardium: gallon plastic zip bags (one per group)

• Dissection: preserved sheep heart (or other mammalian heart), dissecting instruments, 5-inch blade knife, disposable gloves, safety glasses

Heart Structure and Function 27

E X E R C I S E

1 Identify and describe the functions of the major heart structures

2 Explain the differences in structure and function of the two types of heart valves

3 Describe the changes that take place in the heart after birth

4 Trace the flow of a drop of blood through the pulmonary and systemic circulations, listing the vessels, chambers, and valves

5 Identify the major vessels involved in coronary circulation

6 Describe and identify the microscopic structures of cardiac muscle

7 Describe and identify the two layers of the pericardium and the three layers of the heart wall

8 Dissect a sheep heart and identify selected heart structures

431

The heart is a small double pump that simultane-ously pumps blood to and from body cells through the systemic circulation and to and from the lungs through the pulmonary circulation. The blood vessels that carry blood from the heart are called arteries and the blood vessels that carry blood to the heart are called veins.

432 E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N

surface for protection and padding, most heart models do not show this. The coronary sulcus is a deep sulcus that externally shows the separation of the atria and the ven- tricles. The anterior interventricular sulcus and the pos- terior interventricular sulcus are shallow grooves that depict the surface boundaries between the two ventricles.

Before Going to Lab

1 Label the heart structures in Figure 27.2(a) and (b).

A. Location and Surface Features of the Heart

Like all mammalian hearts, the human heart has four cham- bers and is divided into right and left sides. Each side has an upper chamber called an atrium and a lower chamber called a ventricle. The atria have pouch-like extensions called auricles. From the exterior, the auricles look like fl aps with wrinkled edges. The heart is about the size of a fi st and is shaped like a cone. In situ, it lies on its side in the thoracic cavity within the mediastinum. The mediastinum is an area bounded by the lungs laterally, the sternum and ribs anteriorly, the thoracic vertebrae posteriorly, and the diaphragm inferi- orly. Approximately two-thirds of the heart lies to the left of the thoracic midline. The right ventricle forms most of the anterior surface of the heart. The left ventricle is also observed on the anterior surface of the heart. The apex of the heart is the inferior pointed end of the left ventricle and is located in the 5th intercostal space. The inferior surface of the heart lies primary on the diaphragm between the apex and right lung and is attached to the diaphragm by dense fi brous connective tissue. Both atria and the left ventricle are observed on the posterior surface of the heart. The right and left atria form the base of the heart, and the base faces the right shoulder while the apex points to the left hip (see Figure 27.1). Coronary blood vessels and adipose tissue are found in the sulci or grooves that externally mark the boundaries between the four heart chambers. Although a considerable amount of external adipose tissue is present on the heart

LAB ACTIVITY 1 Location and Surface Features of the Heart

1 Identify each structure in Figure 27.2(a) and (b) on a model, chart, or use the search text box in Real Anatomy (Cardiovascular) to locate these structures.

2 Locate the 4 points that form the outline of the heart by placing small removable labels on the following loca- tions on a skeleton. Refer to Figure 27.1. • Superior right point: about 3 cm to the right of

the midline on the superior border of the 3rd costal cartilage

• Superior left point: about 3 cm to the left of the midline in the 2nd intercostal space

• Inferior left point: about 9 cm to the left of the midline in the 5th intercostal space

• Inferior right point: about 3 cm to the right of the midline at the 6th right costal cartilage ■

Inferior left point Inferior right point

Superior right point Superior left point

Midline

FIGURE 27.1 Location of heart.

E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N 433

• anterior interventricular sulcus • apex of heart • coronary sulcus • left auricle • left ventricle • right auricle • right ventricle

1 ___________________________________

2 ___________________________________

3 ___________________________________

4 ___________________________________

5 ___________________________________

6 ___________________________________

7 ___________________________________

5 (groove)

2 (groove)

(a) Anterior view

FIGURE 27.2 Surface features of the heart.

(b) Posterior view

9 (groove)

12 (groove)

• adipose tissue • coronary sulcus • left auricle • left ventricle • posterior interventricular sulcus • right auricle • right ventricle

8 ___________________________________

9 ___________________________________

10 ___________________________________

11 ___________________________________

12 ___________________________________

13 ___________________________________

14 ___________________________________

434 E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N

The fetal heart contains a short, temporary vascular chan- nel, the ductus arteriosus (ductus � duct; arteriosus � artery), which connects the pulmonary trunk and the aorta. This right heart to left heart shunt re-routes some of the blood destined for the lungs to the systemic circulation via the aorta. In fetal life, oxygen is obtained through the pla- centa from the mother and not from the lungs. Therefore, it is not detrimental to the baby’s health for blood to bypass the lungs. The ductus arteriosus changes into a ligament after birth and remains as the ligamentum arteriosum.

B. Great Vessels of the Heart

The great vessels of the heart either return blood to the atria or carry blood away from the ventricles. The superior vena cava, inferior vena cava, and coronary sinus return oxygen-poor blood to the right atrium. The superior vena cava returns blood from the head, neck, and arms; the infe- rior vena cava returns blood from the body inferior to the heart; and the coronary sinus is a smaller vein that returns blood from the coronary circulation. Blood leaves the right atrium to enter the right ventricle. From here, blood enters the pulmonary trunk, the only vessel that removes blood from the right ventricle. This large artery divides into the right and left pulmonary arteries, which carry blood to the lungs, where it is oxygenated. Oxygen-rich blood returns to the left atrium through two right and two left pulmonary veins. The blood then passes into the left ven- tricle, which pumps blood into the large aorta. The aorta distributes blood to the systemic circulation. The aorta be- gins as a short ascending aorta, curves to the left to form the aortic arch, descends posteriorly, and continues as the descending aorta.

LAB ACTIVITY 2 Great Vessels of the Heart

1 Identify each great vessel on a model, chart, or use the search text box in Real Anatomy (Cardiovascular) to locate these structures. ■

Before Going to Lab

1 Label the great vessels of the heart in Figure 27.3(b) and (c).

Brachiocephalic trunk

Ascending aorta

Ligamentum arteriosum Superior vena cava

RIGHT AURICLE OF RIGHT ATRIUM

RIGHT VENTRICLE

Left subclavian artery

LEFT AURICLE OF LEFT ATRIUM

Pulmonary trunk

Left pulmonary artery

Arch of aorta

Left common carotid artery

ANTERIOR INTERVENTRICULAR SULCUS

LEFT VENTRICLE

(a) Anterior external view

CORONARY SULCUS

RIGHT ATRIUM

Right pulmonary veins

Left pulmonary veins

FIGURE 27.3 Great vessels of the heart.

E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N 435

• aortic arch • ascending aorta • descending aorta • inferior vena cava • left pulmonary artery • left pulmonary veins • ligamentum arteriosum • pulmonary trunk • right pulmonary artery • right pulmonary veins • superior vena cava

1 ______________________________________

2 ______________________________________

3 ______________________________________

4 ______________________________________

5 ______________________________________

6 ______________________________________

7 ______________________________________

8 ______________________________________

9 ______________________________________

10 ______________________________________

11 ______________________________________

• aortic arch • ascending aorta • coronary sinus • inferior vena cava • left pulmonary artery • left pulmonary veins • ligamentum arteriosum • right pulmonary artery • right pulmonary veins • superior vena cava

12 ______________________________________

13 ______________________________________

14 ______________________________________

15 ______________________________________

16 ______________________________________

17 ______________________________________

18 ______________________________________

19 ______________________________________

20 ______________________________________

21 ______________________________________

10 11

(b) Anterior view

FIGURE 27.3 Great vessels of the heart, continued.

436 E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N

Blood in the right ventricle goes through the pulmonary (semilunar) valve to enter the pulmonary trunk (artery). The aortic (semilunar) valve is located between the left ventricle and the aorta. These two semilunar valves are identical, with each having three pockets that fi ll with blood, preventing blood from fl owing back into the ventricles when the valves are closed. The thinner-walled atria receive the blood returning to the heart from veins. The pressure of blood in the atria opens the AV valves, and most of the blood fl ows into the ventricles. Both atria then contract simultaneously to pump the remaining blood into the ventricles. The larger, thick ventricular walls are double pumps that also contract si- multaneously. When the ventricles contract, the papillary muscles contract and tighten the chordae tendineae. The chordae tendineae prevent the AV valve fl aps from opening into the atria. During ventricular contraction, the force of blood in the ventricles pushes the semilunar valves open. Once the semilunar valves open, blood from the right ven- tricle fl ows into the pulmonary circulation as blood from the left ventricle simultaneously fl ows into the systemic circulation. As the ventricles relax, some blood fl ows back toward the ventricle, causing the semilunar valves to close. The wall of the left ventricle is thicker than the wall of the right ventricle because the left side requires more force to pump blood throughout the systemic circulation.

C. Internal Features of the Heart

The myocardium of the anterior wall of the right atrium has a honeycombed appearance, and these myocardial ridges, called pectinate muscles (pecten � comb-like), continue into the auricles. The walls of the right and left atria are separated by the thin interatrial septum. In the fetus, there is a hole in the interatrial septum called the foramen ovale. The foramen ovale allows blood to bypass the lungs and go from the right atrium to the left atrium, forming another right-heart to left-heart shunt. The fossa ovalis, a connective tissue membrane, forms over and closes the fetal foramen ovale after birth. The ventricles have ridges of muscles called trabeculae carneae (trabecula � little beam; carnea � fl esh). The larger of these muscles, the papillary muscles, have string- like cords attached to them called the chordae tendineae (tendinous strands). The opposite ends of these cords are attached to the valves between the atria and ventricles (atrio-ventricular valves). The interventricular septum is a thick wall that separates the right and left ventricles. The heart has four valves that control the one-way fl ow of blood through the heart: two atrioventricular (AV) valves and two semilunar valves (semi- � half; lunar � moon). Blood passing between the right atrium and the right ventricle goes through the right AV valve, the tricus- pid valve (tri- � three; cusp � fl ap). The left AV valve, the bicuspid valve, is between the left atrium and the left ventricle. This valve clinically is called the mitral valve (miter � tall, liturgical headdress) because the open valve resembles a bishop’s headdress. The two AV valves are structurally similar, except the tricuspid valve has three cusps or fl aps and the bicuspid valve has two cusps or fl aps that prevent blood from fl owing back into the atria when the valves are closed.

LAB ACTIVITY 3 Internal Features of the Heart

1 Identify each structure on a model, chart, or use the search text box in Real Anatomy (Cardiovascular) to locate these structures. ■

Before Going to Lab

1 Label the internal heart structures in Figure 27.4(b).

FIGURE 27.4 Internal features of the heart.

• aortic (semilunar) valve • bicuspid valve (mitral) • chordae tendineae

(CHOR-dee ten-DIN-ee) • coronary sinus opening • inferior vena cava opening • interventricular (inter-ven-

TRIC-u-lar) septum • left atrium • left ventricle • left pulmonary vein

openings

• papillary (PAP-ih-lary) muscle

• pulmonary (semilunar) valve

• right atrium • right ventricle • superior vena cava

opening • trabeculae carneae

(tra-BEC-u-lee CAR-nee) • tricuspid valve

1 ______________________

2 ______________________

3 ______________________

4 ______________________

5 ______________________

6 ______________________

7 ______________________

8 ______________________

9 ______________________

10 ______________________

11 ______________________

12 ______________________

13 ______________________

14 ______________________

15 ______________________

16 ______________________

E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N 437

FIGURE 27.4 Internal features of the heart, continued.

Arch of aorta

Pulmonary trunk

LEFT AURICLE

TRABECULAE CARNEAE

LEFT VENTRICLE

INTERVENTRICULAR SEPTUM

Pectinate muscles

RIGHT ATRIUM

RIGHT AURICLE (cut open)

Cusp of tricuspid valve

Right pulmonary vein

Ascending aorta

Chordae tendineae

Papillary muscle

RIGHT VENTRICLE

(a) Anterior view of partially sectioned heart

Superior vena cava

Brachiocephalic trunk

Left common carotid artery

Left subclavian artery

Left pulmonary vein

Ligamentum arteriosum

Frontal plane

Fossa ovalis

(b) Frontal section

438 E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N

D. Systemic and Pulmonary Circulations

As you trace a drop of blood through the heart to the lungs and then to the rest of the body, you will be examining the pulmonary and systemic circulations. The pulmonary cir- culation takes blood from the right ventricle to the lungs and back to the left atrium. The systemic circulation takes blood from the left ventricle to the body tissues and back to the right atrium. Note that each circulation begins and ends at the heart, and each circulation is composed of arteries, capillaries, and veins.

LAB ACTIVITY 4 Systemic and Pulmonary Circulations

1 Make flash cards from the list of structures given in Before Going to Lab 4.

2 Mix up all the cards and assemble them in order, tracing a drop of blood through the heart and lungs and then out the systemic circulation. Start and end with the right atrium.

3 Check your answers with the class. ■

Before Going to Lab

1 In Figure 27.5, color the vessels that are carrying oxygen-poor blood blue and the vessels carrying oxygen- rich blood red, being careful to note the color switch in the pulmonary vessels. Color the four capillary beds purple.

2 Trace the pathway of blood in Figure 27.5 through the pulmonary circulation with arrows of one color and the systemic circulation with arrows of another color, start- ing and ending with the right atrium.

3 Write the names of the blood vessels in the blanks under the appropriate headings. • aorta • pulmonary arteries • pulmonary trunk • pulmonary veins • venae cavae

Blood vessels with oxygen-poor blood

a. _________________________________________

b. _________________________________________

c. _________________________________________

Blood vessels with oxygen-rich blood

d. _________________________________________

e. _________________________________________

4 Trace a drop of blood through the heart and lung by list- ing in order in blanks 2–18 all vessels, heart chambers, and valves through which the blood passes, starting and ending with the right atrium: • aorta • aortic (semilunar) valve • bicuspid (mitral) valve • left atrium • left ventricle • pulmonary arteries

• pulmonary capillaries • pulmonary (semilunar) valve • pulmonary trunk • pulmonary veins • right atrium • right ventricle • systemic arteries • systemic capillaries • systemic veins • tricuspid valve • venae cavae and coronary sinus

1. ________________________________________

2. ________________________________________

3. ________________________________________

4. ________________________________________

5. ________________________________________

6. ________________________________________

7. ________________________________________

8. ________________________________________

9. ________________________________________

10. ________________________________________

11. ________________________________________

12. ________________________________________

13. ________________________________________

14. ________________________________________

15. ________________________________________

16. ________________________________________

17. ________________________________________

18. ________________________________________

right atrium

E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N 439

FIGURE 27.5 Systemic and pulmonary circulations.

Systemic capillaries of upper body

Pulmonary capillaries of left lung

Systemic capillaries of lower body

Pulmonary capillaries of right lung

Right pulmonary artery

Systemic arteries to upper body

Systemic veins from upper body

Systemic arteries to lower body

Systemic veins from lower body

Left pulmonary veins

440 E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N

The right coronary artery, located in the coronary sulcus, continues inferiorly to the right and branches into the marginal branch and posterior interventricular branch. The marginal branch supplies the anterior right side of the right ventricle. The posterior interventricular branch lies in the posterior interventricular sulcus on the posterior surface of the heart, supplying oxygen-rich blood to both ventricles. Arteries branch into smaller vessels, called arterioles, which penetrate the heart muscle and divide into narrower vessels, called capillaries, which deliver oxygen to the car- diac muscle. Capillaries drain into venules, which exit the heart muscle and connect to veins that receive oxygen-poor blood, returning it to the right atrium. The great cardiac vein is the principal vein of the coronary circulation, draining the left anterior portion of the heart. It lies near the anterior interventricular branch in the interventricular sulcus. The small cardiac vein drains the right anterior portion of the heart. The middle cardiac vein, which lies next to the pos- terior interventricular branch of the right coronary artery in the posterior interventricular sulcus, drains the posterior portion of the heart. Both of these veins empty into a large, thin-walled venous sinus called the coronary sinus, which is located on the posterior surface of the heart. The coronary sinus empties its oxygen-poor blood into the right atrium.

E. Coronary Circulation

The walls of the heart have their own blood supply and circulation, the coronary (corona � crown) circulation. These vessels encompass the heart similar to a crown. The endothelium lining the heart chambers is too thick for blood in the chambers to supply nutrients to cardiac muscle tissue. Coronary blood vessels supply blood to cardiac muscle tissue. On the anterior surface of the heart, the right and left coronary arteries branch off the base of the ascending aorta just superior to the aortic semilunar valve. These small arteries are supplied with blood when the ventricles are resting. When the ventricles contract, the cusps of the aortic valve open to cover the openings to the coronary ar- teries. If the coronary arteries were not covered, they would not be able to withstand the blood pressure and would burst like an overinfl ated balloon. The left coronary artery is shorter than the right coro- nary artery. As the left coronary artery passes the base of the left auricle, it branches into the anterior interventricular branch (left anterior descending branch, or LAD) and the circumfl ex branch. The anterior interventricular branch (LAD) supplies both ventricles with oxygen-rich blood and lies within the anterior interventricular sulcus, a shallow depression between the two ventricles. The anterior interventricular branch is commonly occluded, which can result in a myo- cardial infarct and at times death. The circumfl ex branch continues around the left side of the heart, lying within the coronary sulcus (atrioventricular sulcus), and supplies blood to the left ventricle and left atrium. The circumfl ex branch forms anastomoses (connections) with the posterior interventricular branch near the posterior interventricular sulcus.

LAB ACTIVITY 5 Coronary Circulation

1 Identify each vessel on a model, chart, or use the search text box in Real Anatomy (Cardiovascular) to locate these structures. ■

Before Going to Lab

1 Label the coronary vessels in Figure 27.6(c) and (d).

Pulmonary trunk

Left pulmonary artery

Arch of aorta

Left coronary artery

Circumflex branch Left marginal branch

Tributary to great cardiac vein

Left auricle

Ascending aorta

Anterior interventricular branch

Right auricle

Right coronary artery

Marginal branch

(a) Anterior view

Anterior cardiac vein

Right ventricle Left ventricle

Great cardiac vein

FIGURE 27.6 Coronary circulation.

E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N 441

Right ventricle

Inferior vena cava

Right pulmonary artery

Right pulmonary veins

Right atrium

Superior vena cava

Posterior interventricular branch

Middle cardiac vein

Left atrium

Left pulmonary artery

Left pulmonary veins

Oblique vein

Circumflex branch of left coronary artery

Coronary sinus

Left ventricle

Posterior veins of the left ventricle

(b) Posterior view

3 6

(d) Coronary blood vessels, posterior view

• anterior interventricular branch (LAD) • circumflex branch • coronary sinus • great cardiac vein • left coronary artery • marginal branch • middle cardiac vein • posterior interventricular branch • right coronary artery • small cardiac vein

FIGURE 27.6 Coronary circulation, continued.

1 _______________________________

2 _______________________________

3 _______________________________

4 _______________________________

5 _______________________________

6 _______________________________

7 _______________________________

8 _______________________________

9 _______________________________

10 _______________________________

442 E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N

myocardium or cardiac muscle tissue. The endocardium is a thin layer of endothelium deep to the myocardium that lines the inside chambers of the heart and the valves.

F. Pericardium and Layers of the Heart Wall

In the mediastinum, the heart is surrounded and protected by the pericardium (peri- � around). The pericardium con- sists of an outer, tough, fi brous pericardium and an inner, delicate, serous pericardium. The fi brous pericardium attaches to the diaphragm and also to the great vessels of the heart, securing the heart in the mediastinum. Like all serous membranes, the serous pericardium is a double membrane composed of an outer parietal layer and an inner visceral layer. Between these two layers is the pericardial cavity fi lled with serous fl uid. The serous fl uid reduces friction as the heart moves. The outer parietal (paries � wall) pericardium is attached to the fi brous pericardium, and the inner visceral (viscera � internal organs) pericar- dium covers the cardiac muscle. The wall of the heart has three layers: the outer epicar- dium (epi- � on, upon; cardia � heart), the middle myo- cardium (myo- � muscle), and the inner endocardium (endo- � within, inward). The epicardium is the visceral layer of the pericardium. The majority of the heart is the

LAB ACTIVITY 6 Pericardium and Layers of the Heart Wall

1 Simulate the formation of the pericardium using a 1-gallon zippered plastic bag. • Figure 27.8 shows the heart and its relationship to the

pericardium. In this activity, your fist represents the heart, and the plastic bag represents the pericardium.

• Add a small amount of water to the bag and push out the extra air before sealing the bag.

• Have a lab partner place a fist (simulating the heart) at the bottom of the bag and push the fist into the bag so the bag surrounds the fist.

• Discuss with your lab group what the outer layer of the bag and the water represent. ■

Before Going to Lab

1 Label the structures in Figures 27.7(a) and (b).

(a) Heart in the mediastinum, anterior view

Trabeculae carneae

PERICARDIUM

Heart wall

Coronary blood vessels

(b) Pericardium and layers of heart wall

(space)

• endocardium • fibrous pericardium • myocardium • parietal layer of serous

pericardium • pericardial cavity • visceral layer of serous

pericardium (epicardium)

3 ________________________

4 ________________________

5 ________________________

6 ________________________

7 ________________________

8 ________________________

FIGURE 27.7 Pericardium and layers of the heart wall.

• diaphragm • fibrous pericardium

(peri-CAR-dee-um)

1 _______________________

2 _______________________

E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N 443

G. Histology of Cardiac Muscle

Cardiac muscle fi bers in the myocardium are striated, branching cells with one or two nuclei. The ends of adja- cent cardiac muscle fi bers are connected by intercalated discs. The intercalated discs contain desmosomes that hold cardiac fi bers together and gap junctions. Gap junctions enable action potentials to spread quickly from cell to cell, allowing cardiac muscle to contract as a unit.

FIGURE 27.8 Simplified relationship of serous pericardium to heart.

Heart

Serous pericardium

Pericardial cavity Visceral layer

of serous pericardium

Parietal layer of serous pericardium

Pericardial cavity

LAB ACTIVITY 7 Histology of Cardiac Muscle

1 Examine a prepared microscope slide of cardiac tissue or use Real Anatomy (Histology).

2 Draw the tissue in the space provided, and label your drawing. ■

Before Going to Lab

1 Label the photomicrograph of cardiac muscle fibers in Figure 27.9.

FIGURE 27.9 Photomicrograph of cardiac muscle fibers.

1 ______________________________________________

2 ______________________________________________

3 ______________________________________________

4 ______________________________________________

LM 700�

1 2 3 4

Student drawing

• branching cardiac fibers • cardiac muscle fiber • intercalated (in-TER-cal-ated) discs • nucleus

444 E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N

4 Examine the anterior surface of the heart. Great vessels are often cut close to the base of the heart and may be difficult to find. Refer to Figure 27.10(a) and (c) and a heart model to identify the following structures: • epicardium • base • apex • right auricle • left auricle • right ventricle • left ventricle • pulmonary trunk

5 Examine the posterior surface of the heart using Figure 27.10(b) and (d) and identify the following structures: • coronary sulcus • left auricle • left ventricle • right auricle • right ventricle

6 Insert a blunt probe into the collapsed superior vena cava and into the right atrium. Maneuver the probe to find the interior opening of the inferior vena cava in the right atrium and push the probe out into this vessel.

H. Dissection of a Sheep Heart

The sheep heart is similar to the human heart in both struc- ture and size. It provides students the opportunity to observe the fl exibility of the valves and tissues.

SAFETY NOTE: Wear safety glasses and gloves when using preserved tissue. Wash hands thoroughly with soap and water when you are done.

LAB ACTIVITY 8 Dissection of a Sheep Heart

1 Observe the pericardial sac surrounding the sheep heart. The outer surface of the pericardium is the fi- brous pericardium. Carefully cut through the pericar- dial sac and remove the outer fibrous pericardium. The parietal layer of the serous pericardium lines the fibrous pericardium. The visceral layer of the serous pericardium (epicardium) will remain on the surface of the heart. Identify the fibrous pericardium, parietal layer of serous pericardium, and the epicardium.

2 Carefully remove adipose tissue so you can identify surface features of the heart.

3 Identify the anterior and posterior surfaces of the sheep heart.

FIGURE 27.10 Sheep heart.

Apex

Left ventricle

Left auricle

Left pulmonary artery

Left pulmonary veins

Pulmonary trunk

Aorta

Right ventricle

Right auricle

Opening of superior vena cava

Superior vena cava

Opening of inferior vena cava

Right ventricle

Coronary vessels in anterior interventricular sulcus

Right auricle

Ligamentum arteriosum

(a) Anterior view (b) Posterior view

E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N 445

FIGURE 27.10 Sheep heart, continued.

Right auricle

Adipose tissue

Right ventricle

Pulmonary trunk

Left auricle

Anterior interventricular sulcus

Left ventricle

Apex of heart

(d) Posterior view

Aortic arch

Right auricle

Right ventricle

Left atrium

Coronary sulcus

Adipose tissue

Left ventricle

7 Examine the interior of the heart by making a coro- nal section of the heart. Using a knife with about a 5-inch blade, make a coronal cut of the sheep heart starting at the apex and cutting toward the base [Fig- ure 27.10(e)]. Cut through both auricles (to ensure cutting through both atria) but not all the way through

the base and the great vessels, so the two halves do not get separated. This cut allows you to observe both atria and both ventricles simultaneously (similar to a heart model) and easily compare the size of the walls of the right and left ventricles.

446 E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N

8 Using Figure 27.10(e), identify the following interior structures on the right side of the heart: • myocardium • endocardium • right atrium • right auricle • pectinate muscle • opening of superior and inferior vena cava • opening of the coronary sinus • tricuspid valve • right ventricle • chordae tendinae • papillary muscles • moderator band (cord between the two walls of the

right ventricle) • interventricular septum • pulmonary trunk • pulmonary semilunar valve

9 In the right atrium, insert a blunt probe in the small open- ing of the coronary sinus that is inferior to the opening of the inferior vena cava. Observe the movement of the probe in the coronary sinus from the posterior view of the heart.

10 In the right ventricle, insert a blunt probe into the open- ing of the pulmonary trunk and push it through to the superior end of the vessel. Remove the probe and take

a scalpel to cut the wall of the pulmonary trunk longi- tudinally to expose the pulmonary semilunar valve. Count the three cusps. How does this valve differ from the tricuspid valve?

11 Continue identifying structures on the left side of the heart: • left atrium • left auricle • bicuspid valve • left ventricle • aortic semilunar valve • aorta

12 How many cusps does the bicuspid valve have? ______ Does this valve look similar otherwise to the other AV valve? ______ Are there chordae tendineae and papillary muscles? ______ Does the left ventricle have a greater or smaller number of papillary muscles compared with the right side? ______ Compare the thickness of the right and left ventricles. Which one is thicker?______ Why? ____________________

13 Look just above the cusps of the aortic valve for the openings to the right and left coronary arter- ies. Use the blunt probe to push into these small vessels.

14 Clean up as directed by your instructor. ■

Right atrium

Left atrium

Tricuspid valve

Wall of left ventricle

Wall of right ventricle

Right auricle

Ascending aorta

Aortic valve

Bicuspid valve

Chordae tendineae

Papillary muscle

Interventricular septum Trabeculae carneae

Apex

(e) Coronal section

FIGURE 27.10 Sheep heart, continued.

447

Name ___________________________________ Date _________________ Section ______________________________

Reviewing Your Knowledge

27 E X E R C I S E

A. Major Heart Structures and Great Vessels

Fill in the blank with the term that fits the description.

1. Arteries that supply blood to cardiac muscle

2. Layer of heart wall containing cardiac muscle

3. Extensions of the atria

4. Heart is located here (area between the lungs)

5. Lines the heart chambers

6. Pointed inferior part of the heart

7. Two heart pumps; lower heart chambers

8. Superior heart chambers

9. Another name for visceral pericardium

10. Atria compose this on the posterior surface of heart

11. Blood pumped by right ventricle (oxygen-rich or oxygen-poor)

12. Blood pumped by left ventricle (oxygen-rich or oxygen-poor)

13. Enlarged muscles in ventricles attached to chordae tendinae

14. Muscle ridges in ventricles

15. Ridges in anterior wall of right atrium

16. Strings attached to AV cusps

17. Blood vessel that returns blood from the body inferior to the heart

18. The valve located between the left ventricle and the aorta

19. A membrane between the atria that closes after birth

20. The valve located between the right atrium and right ventricle

448 E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N

B. Coronary Circulation

After reviewing the coronary circulation in Figure 27.5, fill in the blank with the word that fits the description.

1. Anterior branch of the left coronary artery; lies in anterior interventricular sulcus

2. Posterior branch of the right coronary artery; lies in posterior interventricular sulcus

3. Branch of the left coronary artery that curves around left side and lies in the coronary sulcus

4. Branch of right coronary artery that supplies the anterior right ventricle

5. Branch of left coronary artery that supplies both ventricles

6. Shorter coronary artery that is hidden anteriorly by pulmonary trunk

7. Vein that drains coronary circulation into right atrium

8. Vein that drains most of anterior ventricles

9. Vein that drains the posterior ventricles

10. Vein that drains the right anterior side

C. The Heart and Pulmonary Circulation

Place the following structures in order, tracing the blood flow from the superior vena cava to the heart, to the pulmonary circulation, and out of the heart to the systemic circulation. Start with superior vena cava as number 1.

• aorta • aortic valve • bicuspid valve • left atrium • left ventricle

• pulmonary capillaries • right atrium • right ventricle • pulmonary arteries • pulmonary trunk

• pulmonary valve • pulmonary veins • superior vena cava • tricuspid valve

1. ___________________________________________

2. ___________________________________________

3. ___________________________________________

4. ___________________________________________

5. ___________________________________________

6. ___________________________________________

7. ___________________________________________

8. ___________________________________________

9. ___________________________________________

10. ___________________________________________

11. ___________________________________________

12. ___________________________________________

13. ___________________________________________

14. ___________________________________________

449

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

27 A. The Heart

1. What is the function of the pericardial fluid?

2. If a person has pulmonary valve stenosis, which circulation is affected the most: pulmonary, systemic, or cardiac circulation?

3. A blood clot (thrombus) in which artery of the coronary circulation would be more likely to cause sudden death? (Circle your answer.) Explain your choice.

a. right coronary artery b. posterior interventricular branches

c. circumflex branch d. anterior interventricular branch

4. The pulmonary trunk and pulmonary arteries are colored blue in all of the figures. Why are they colored blue like most veins?

5. If the foramen ovale does not fully close after birth, what will happen?

6. If a person has endocarditis, myocarditis, or pericarditis, what areas (in order) are infected?

a. b. c.

7. Athletes have thicker heart walls than non-athletes. Which layer of the heart enlarges? Explain.

8. Atrioventricular valves and semilunar valves have different structures. Explain if high pressure from above or below each type of valve opens the valves.

Atrioventricular valves

Semilunar valves

450 E X E R C I S E 2 7 H E A R T S T R U C T U R E A N D F U N C T I O N

9. Which ventricular wall is thicker? What is the significance of this?

10. The heart has many anastomoses. What benefit are these to the heart?

11. What is the significance of the difference in the vessel wall thickness between the aorta and the pulmonary trunk?

12. Using your knowledge, explain why mitral valve prolapse occurs more often than tricuspid prolapse.

13. How would heart function be affected if the AV valves did not completely close during ventricular contraction?

B. Coronary Circulation

Trace a drop of blood from the ascending aorta to the right coronary artery, and trace the blood back into the heart again.

• ascending aorta

• coronary sinus

• middle cardiac vein

• posterior interventricular branch

• right atrium

• right coronary artery

• right ventricular capillaries

14. ___________________________________________

15. ___________________________________________

16. ___________________________________________

17. ___________________________________________

18. ___________________________________________

19. ___________________________________________

20. ___________________________________________

O B J E C T I V E S M A T E R I A L S

• model or chart of the heart • Electrocardiography: ECG recording equipment

(if available), electrodes, cream or jelly

• Heart Sounds: stethoscope, alcohol swabs, skeleton, stickers

• Length of Cardiac Cycle: stethoscope, alcohol swabs, stopwatch or clock with second hand, calculators

• PowerPhys Experiment: Effect of Exercise on Cardiac Output

• • Biopac Laboratory Guide Experiments: • Effect of Body Position and Exercise on ECG • Heart Sounds and Events of the Cardiac Cycle

Cardiac Cycle 28 E X E R C I S E

1 Identify the parts of the cardiac conduction system

2 Describe the pathway of action potentials through the cardiac conduction system and explain its association with contractions of the atria and ventricles

3 Identify the components of a normal electrocardiogram (ECG)

4 Describe the association of ECG tracings with electrical events occurring in the heart

5 Identify normal sinus rhythm, tachycardia, and bradycardia on an ECG

6 Describe the relationship of auscultated heart sounds, pulse rate, and heart rate

7 Calculate changes in length of cardiac cycle with exercise and discuss their significance

8 Describe the effect of exercise on cardiac output

451

E ach cardiac cycle, or one complete heart beat, consists of atrial and ventricular systole (contrac-tion) and diastole (relaxation). The generation of an action potential by special cardiac muscle cells initiates atrial systole followed by ventricular systole. During sys- tole, blood pressure within the heart chamber increases and

blood is ejected. Blood flows from areas of higher pressure to areas of lower pressure. During diastole, blood pres- sure within the heart chambers is low and blood fills the chambers. Flow of blood through the heart is controlled by opening and closing of the AV and semilunar valves.

452 E X E R C I S E 2 8 C A R D I A C C Y C L E

A. Stimulation of Cardiac Muscle Contraction

Your heart beats without any stimulation from nerves, and if removed from your body, the heart would still beat. The internal stimulation that makes the heart beat by it- self is called intrinsic (intrinsic � inside) stimulation and is caused by specialized, noncontractile cells called autorhythmic cells (causing a rhythm by themselves).

1. Electrical Conduction System of the Heart

Autorhythmic cells belong to the intrinsic conduction sys- tem (nodal system) that (1) initiates the action potential that results in contraction of cardiac muscle fi bers and (2) provides a pathway for conducting the action potential to all cardiac muscle fi bers. The autonomic nervous system and hormones, known as extrinsic (extrinsic � on the out- side) stimulation, only increase or decrease the intrinsic pace. The parts of the conduction system are:

1. Sinoatrial (SA) node—called the pacemaker because it initiates action potentials first; located in the wall of the right atrium just inferior to the opening of the superior vena cava; stimulates the atria to contract.

2. Atrioventricular (AV) node—receives action poten- tials from the atrial muscle fibers; located in the lower interatrial septum anterior to the opening of the coro- nary sinus; sends the action potentials to the AV bundle (bundle of His).

3. AV bundle (bundle of His)—located in a membranous septum between the atria and ventricles superior to the interventricular septum; this is the electrical connection between the atria and ventricles; sends action poten- tials to the bundle branches.

4. Right and left bundle branches—located in the inter- ventricular septum; sends action potentials to the Pur- kinje (conduction) fibers.

5. Purkinje (conduction) fibers—located in the apex of the myocardium, as well as in the lateral walls of the right and left ventricles; sends action potentials to the ventricular cardiac muscle fibers and papillary muscles and stimulates them to contract.

LAB ACTIVITY 1 Cardiac Conduction System

1 On a model, chart, or Real Anatomy (Cardiovascular), identify the location of conduction system structures. ■

Before Going to Lab

1 Label the structures of the conduction system in Figure 28.1.

• atrioventricular (AV) node

• AV bundle (bundle of His)

• left bundle branch • Purkinje (conduction)

fibers in left ventricle • Purkinje (conduction)

fibers in right ventricle • right bundle branch • sinoatrial (SA) node

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

7 ________________________

FIGURE 28.1 Cardiac conduction system.

E X E R C I S E 2 8 C A R D I A C C Y C L E 453

In addition to these three waves, an ECG also contains in- tervals or segments between the waves:

• P-Q interval—the interval between the beginning of the P wave until the beginning of the Q (in the QRS wave); some texts call this the P-R interval; it rep- resents the time it takes for the electrical conduction (excitation) to travel through the atria and AV node to the Purkinje (conduction) fibers.

• S-T segment—the segment from the end of the S (in QRS wave) to the beginning of the T wave; it represents the time the ventricular fibers are fully depolarized.

• Q-T interval—the interval that begins at the Q (in the QRS wave) to the end of the T wave; it represents the time from the beginning of ventricular depolar- ization until the end of ventricular repolarization.

2. Electrocardiography

The conduction of action potentials throughout the heart can be detected as electrical currents. An instrument called an electrocardiograph is used to record the electrical changes in the heart. The chart recording of the electrical events that occur before each heartbeat is called an elec- trocardiogram (ECG; originally called an EKG). The electrical events that are recorded are from the entire heart muscle (i.e., the atria and the ventricles) and not just the conduction system activity. The ECG records only voltage changes over time and not the force of contraction. Car- diac muscle will contract after the action potential has occurred. ECGs are usually recorded by indirect leads, with elec- trodes placed on the skin of the subject’s arms and legs rather than on the heart itself. The electrical impulses gen- erated by the depolarization and repolarization of the atria and ventricles are detected on the body surface due to the conductivity of the ions in extracellular fl uid. Clinically, 12 leads are used to record an ECG for diagnosing abnormali- ties of the conduction system, myocardial infarctions, and other clinical situations. However, in anatomy and physiol- ogy classes, usually a standard three-lead ECG is utilized (Figure 28.2). The main parts of a standard three-lead ECG are:

• P wave—first wave; small, curved upward deflec- tion; represents atrial depolarization that spreads from the sinoatrial (SA) node just before the atria contract.

• QRS complex—short downward deflection (Q), tall upward deflection (R), medium downward deflec- tion (S); represents ventricular depolarization that spreads from the AV node to the AV bundle, to right and left bundle branches, and to the Purkinje (con- duction) fibers just before the ventricles contract.

NOTE: Atrial Repolarization takes place during the QRS complex but gets overshadowed by the more prominent ven- tricular depolarization.

• T wave—medium, curved upward deflection; rep- resents ventricular repolarization and occurs just before the ventricles relax.

FIGURE 28.2 Standard three-lead positions.

Lead II

Lead I Lead III

Ground

– – –

454 E X E R C I S E 2 8 C A R D I A C C Y C L E

Before Going to Lab

1 Label the terms for an ECG in Figure 28.3, a normal ECG.

LAB ACTIVITY 2 Electrocardiography

1 Record an ECG at rest and after exercise if equipment is available. • Do this activity with a lab partner. Choose who will

be the subject and who will do the recording. • Swab the skin where the electrodes will be placed

with alcohol, and then apply electrode paste, jelly, or cream to the same area (see Figure 28.2).

• Attach the electrodes to the anterior surface of each wrist and to the inside area of each ankle.

• Connect the patient cables to the electrodes and also to the recording instrument.

• Follow your instructor’s directions for recording the ECG with your equipment.

• Label the P wave, QRS complex, T wave, P-Q inter- val, S-T segment, and Q-T interval on the recorded ECG.

2 Complete Biopac Laboratory Guide Experiment: Effect of Body Position and Exercise on ECGs. ■

LAB ACTIVITY 3 Heart Rate Calculations

1 Calculate the heart rate for the ECGs in Figure 28.4(a), (b), and (c). • Heart rate can be easily calculated from an ECG.

Standard ECGs are printed on paper moving at a paper speed of 25 mm/sec. Therefore, the distance of 5 mm (1 large square on standard ECG paper) is equivalent to 0.20 sec and the distance covered by 30 large squares is equivalent to 6 sec.

• Count the number of P waves or R waves in 30 large squares. Multiply this number by 10 to obtain the number of contractions (heartbeats) per minute. This gives you an approximate heart rate.

• P wave • P-Q interval • QRS complex • Q-T interval • S-T segment • T wave

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

0.60.2 0.40

–0.5

1.0

0.5

0.8 Seconds

M ill

iv ol

ts (

m V

)

4 5

6 2

FIGURE 28.3 Section of a normal ECG, lead II.

3. Determining Heart Rate Using an ECG

In an adult, a heart rate of 60 to 100 beats/min is a normal sinus rhythm (NSR). A heart rate above 100 beats/min is called tachycardia, but in young children, this rate would be considered normal. Heart rates below 60 beats/min are normal for highly conditioned individuals, but in other adults, heart rates below 60 beats/min are called brady- cardia. Neither condition is considered to be pathological. Prolonged tachycardia can develop into ventricular fi bril- lation, rapid uncoordinated heart contractions that do not pump blood.

NOTE: The heart rate calculated using the number of R waves is the ventricular rate, while the heart rate calculated using the number of P waves is the atrial rate. In normal sinus rhythm (NSR), the atrial rate equals the ventricular rate.

Figure 28.4(a) � ______ beats/min Figure 28.4(b) � ______ beats/min Figure 28.4(c) � ______ beats/min

E X E R C I S E 2 8 C A R D I A C C Y C L E 455

2 Determine which ECG in Figure 28.4 illustrates the fol- lowing heart rates and write the term next to the figure letter. • normal sinus rhythm Figure 28.4(a) ________ • tachycardia Figure 28.4(b) ________ • bradycardia Figure 28.4(c) ________

3 Calculate the heart rate before and after exercise on the ECGs your lab group recorded in Lab Activity 2. • Heart rate before exercise � ___________ beats/min • Heart rate after exercise � ___________ beats/min

■

FIGURE 28.4 Tracings of ECGs, lead II.

(a)

(b)

(c)

456 E X E R C I S E 2 8 C A R D I A C C Y C L E

B. Opening and Closing of Heart Valves

Opening of the atrioventricular (AV) valves occurs when the blood pressure in the atria exceeds the blood pressure in the ventricles. This occurs during atrial and ventricu- lar diastole. The semilunar valves open during ventricular systole at the point when the blood pressure in the ven- tricles exceeds the blood pressure in the pulmonary trunk and aorta. Closing of the AV valves is due to the fl ow of blood back toward the atria that occurs at the beginning of ven- tricular systole. Closure of the semilunar valves is due to the fl ow of blood back toward the ventricles at the begin- ning of ventricular diastole. Closure of the AV and semilunar valves causes the heart sounds heard by auscultation. Auscultation (auscult- � lis- tening) means listening to body sounds, typically using a stethoscope. Two particular heart sounds can be detected during one heartbeat. These sounds occur after the heart valves quietly close and blood strikes against the closed valve, causing turbulence that we can hear with a stetho- scope. Although there are four sounds generated during one heartbeat, only the fi rst and second sound can easily be heard without additional amplifi cation. The fi rst sound, lubb, is a little longer and louder than dupp (or dubb), the second sound that occurs shortly after the fi rst. The fi rst sound (S1) occurs with blood turbulence from the closure of the two atrioventricular (AV) valves at ventricular systole.

CLINICAL NOTE: Heart Murmurs are abnormal heart sounds caused by the restriction of blood flow or backflow of blood that typically indicate an abnormality in valve struc- ture or function. It usually takes special training and a very quiet room to be able to detect heart murmurs.

Before Going to Lab

1 Find a website that provides heart sounds and listen to them.

2 On yourself, find the location to auscultate the bicus- pid (mitral) valve (5th intercostal space just left of the nipple) in the mid-clavicular line and the aortic valve (2nd intercostal space just right of the sternum). Refer to Figure 28.5.

LAB ACTIVITY 4 Heart Sounds

1 On an articulated skeleton, place a sticker on the loca- tion where you will auscultate the mitral valve and a sticker on the location where you will ausculate the aor- tic valve. Red circles on Figure 28.5 are the auscultation locations.

2 Preparation for auscultation of heart sounds. • Obtain a stethoscope and alcohol swabs. • Clean the earpieces with an alcohol swab. • Point earpieces forward to facilitate hearing heart

sounds. • Put the earpieces in place and gently tap the bell to

check that you can hear sounds.

3 Auscultate the mitral valve (Figure 28.5). • Auscultate heart sounds on your chest or your lab

partner’s while seated. • To clearly hear the first heart sound (lubb), you will

auscultate the mitral valve. Place the large bell of the stethoscope at the apex of the heart. This is located in the 5th intercostal space just left of the nipple.

• If the heart sound is difficult to hear, have the subject bend forward to tip the heart against the anterior tho- racic wall and try the auscultation again.

FIGURE 28.5 Locations for auscultation of the heart.

Aortic valve

Pulmonary valve Bicuspid valve

Tricuspid valve

The second sound (S2) is at ventricular diastole when the two semilunar valves close. The sounds that you will hear are lubb-dupp, pause. . . lubb-dupp, pause. Remember that these two heart sounds, lubb-dupp, equal one heartbeat.

E X E R C I S E 2 8 C A R D I A C C Y C L E 457

4 Auscultate the aortic valve (Figure 28.5). • Palpate the suprasternal (jugular) notch and then the

sternal angle (marks the insertion of the 2nd rib). • Now drop down another 1 inch on the sternum from

the sternal angle and then move right 1 inch. • You should be in the 2nd intercostal space just to

the right of the sternum where you can clearly hear dupp, or the second heart sound.

5 Answer Discussion Question with your lab group. 6 Complete Biopac Laboratory Guide Experiment:

Heart Sounds and Events of the Cardiac Cycle.

DISCUSSION QUESTION Heart Sounds

1 At rest, which heart sound is louder, lubb or dupp? Explain.

C. Cardiac Cycle Length and Cardiac Output

Heart rate is the number of heartbeats per minute. Each heartbeat represents one cardiac cycle, which includes atrial and ventricular systole (contraction) and atrial and ventricular diastole (relaxation). The heart rate can be measured by counting the number of heartbeats per minute or by the number of pulses per minute. A pulse is the blood pressure wave that travels through the arteries when the ventricles contract. Pulses are commonly felt in the radial and carotid arteries. The number of heartbeats per minute (heart rate) will be very close to, but not necessarily equal to, the number of pulses per minute. The length of one cardiac cycle in seconds can be calcu- lated by dividing 60 seconds by the heart rate (heartbeats/ min). Therefore the length of the cardiac cycle varies with heart rate. Cardiac output is equal to heart rate � stroke volume. An increase in stroke volume results in more blood being ejected from the ventricles and causes an increase in the blood pressure wave traveling through arteries. Therefore an increase in stroke volume is refl ected by an increase in the force of the pulse.

LAB ACTIVITY 5 Experiment: Effect of Exercise on Cardiac Cycle Length and Cardiac Output

1 Prediction: Exercise causes the length of the cardiac cycle (seconds) to increase or decrease. (Circle the cor- rect choice in italics.)

2 Materials: Obtain materials for Length of Cardiac Cycle (see Materials list).

3 Locate the radial and carotid pulses. • Radial pulse: Locate the groove in your lab part-

ner’s wrist between the radius and the tendon just medial to the radius. Palpate the radial artery by pressing down with your index and middle fingers. Because the thumb has a noticeable pulse of its own, it is not used.

• Carotid pulse: Locate your lab partner’s Adam’s apple (thyroid cartilage of larynx). Using your index and middle fingers again, palpate the carotid artery on either side of the larynx.

4 Data Collection: Measure heart rate and pulse rate at rest and after exercise and record your results in Table 28.1. Compare force of pulse before and after exercise. • Decide who will be the subject, who will count

heartbeats and pulses, and who will be the recorder and the timer. The subject should not have heart problems and should be in good health.

• Locate the radial and carotid pulses on the sub- ject and decide which pulse will be used for this experiment.

Heart beats and pulses at rest • Listen for the subject’s heartbeat and count the num-

ber of heartbeats in 15 seconds. Record your data in Table 28.1.

• Count the number of pulses in 15 seconds and record your data in Table 28.1.

• Feel the force of each pulse at rest.

Heart beats and pulses after exercise • Have the subject run in place for 2 minutes. • Immediately count the number of heartbeats and pulses

in 15 seconds and record your data in Table 28.1.

TABLE 28 .1 Heart Rate and Pulse Rate Before and After Exercise

ACT IV ITY BEATS /15 SEC BEATS /MIN

Heart rate at rest

Pulse rate at rest

Heart rate after exercise

Pulse rate after exercise

■

458 E X E R C I S E 2 8 C A R D I A C C Y C L E

EXPERIMENTAL REPORT Cardiac Cycle Length and Cardiac Output

Results: • State whether heart rate and pulse rate increase or

decrease immediately after exercise. • State whether heart rate and pulse rate at rest are the

same and whether exercising heart rate and pulse rates are the same.

• State the time for recovery after exercise. • State whether the length of the cardiac cycle increases

or decreases immediately after exercise. • State whether the force of pulse increased or decreased

with exercise. • Based on the force of pulse, did stroke volume increase

or decrease with exercise? • Based on your heart rate and force of pulse, did cardiac

output increase or decrease with exercise?

Discussion: • Discuss what causes the change in heart rate and pulse

rate with exercise. • Discuss why heart rate equals pulse rate at rest and after

exercise. • Discuss how the change in cardiac cycle length with

exercise affects heart muscle perfusion and time for ventricular fi lling.

• Discuss factors that affect pulse rate and recovery time. • Discuss how changes in fi lling time and venous return

with exercise affect end diastolic volume (EDV). • Discuss how changes in EDV and force of contraction

with exercise affect stroke volume.

Conclusion: • Write a statement that describes the correlation among

heart rate, length of the cardiac cycle, and length of diastole.

• Write a statement that correlates changes in pulse rate, force of pulse, and cardiac output.

• Repeat the pulse count every minute until the pulse rate returns to the initial resting rate. Record the time for recovery: ______________ minutes.

• Did exercise cause the force of pulse to increase or decrease?

5 Data Analysis: • Calculate the resting and exercising heart rates

(beats/min) and record them in Table 28.1. Multiply the number of heartbeats measured in 15 seconds by 4 to convert to beats/min.

• Calculate the resting and exercising pulse rates (pulses/min) and record them in Table 28.1. Multiply the number of pulses measured in 15 seconds by 4 to convert to pulses/min.

• Calculate resting and exercising cardiac cycle lengths and record them in Table 28.2.

60 sec

# of heartbeats/min � length of 1 cardiac cycle in sec

• Calculate the length of diastole and systole at rest and record in Table 28.2.

At rest, systole �1/3 of cardiac cycle. At rest, diastole � 2/3 of cardiac cycle. The change in length of systole and diastole with

exercise cannot be calculated with a simple formula. The length of systole and diastole both decrease with exercise.

6 Clean up as directed by your instructor. 7 Complete Experimental Report with your lab group.

Use your textbook for reference.

8 Complete PowerPhys Experiment: Effect of Exercise on Cardiac Output.

TABLE 28 .2 Cardiac Cycle Length

AT REST LENGTH /SECONDS

Cardiac cycle

Systole

Diastole

AFTER EXERC ISE

Cardiac cycle

■

459

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

28 E X E R C I S E

A. Heart Sounds

Fill in the blank with the correct term.

1. The first heart sound heard is _______________ that is due to blood hitting against the _______________ valves.

2. The second heart sound heard is _______________ that is due to blood hitting against the _______________ valves.

3. What is a heart murmur?

4. Which heart sound is the loudest sound when auscultated, the lubb or dupp? Why?

5. Valerie’s radial pulse rate is 70/min. Assuming her heart and arteries are in good health, what is her approximate heart rate (beats/min)?

6. Jaxton’s heart rate is 68/min. What is the length of his cardiac cycle in seconds?

B. Electrical Conduction System of the Heart

Circle True or False for the following questions.

1. The heart beats without extrinsic stimulation from the autonomic nervous system. True or False

2. Autorhythmic cells are located only in the interventricular septum. True or False

3. Each heart chamber contracts separately, first the right atrium, then the right ventricle, left atrium, and left ventricle. True or False

4. The ECG records the electrical stimulation of cardiac muscle by the conduction system and not the contraction of the muscle itself. True or False

5. The normal pacemaker of the heart is the AV node. True or False

6. Number the following structures of the cardiac conduction system in the normal order of depolarization (1 to 5).

_______________ AV bundle (of His) _______________ AV node _______________ Purkinje (conduction) fibers _______________ Right and left bundle branches _______________ SA node

460 E X E R C I S E 2 8 C A R D I A C C Y C L E

C. Electrocardiography

Match the following descriptions with the correct terms. A term may be used more than once.

bradycardia fibrillation P wave QRS complex T wave tachycardia

1. depolarization of the atria

2. depolarization of the ventricles

3. fast heart rate above 100 beats/min

4. repolarization of the atria

5. repolarization of the ventricles

6. slow heart rate below 60 beats/min

7. uncontrolled, rapid heart contractions

Measurements Using the ECG

Using the ECG tracing in Figure 28.4(b), calculate the:

8. QRS complex length: __________________ sec

9. P-Q interval: __________________ sec

10. Q-T interval: __________________ sec

11. Heart rate: __________________ beats/min

461

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

28 A. Auscultations of Heart Sounds

1. Sam counted his lab partner’s heartbeats as 12 beats in 15 seconds. What is the lab partner’s heart rate? What other information would you like to have about Sam’s lab partner to decide if this heart rate is abnormal?

B. Electrical Conduction System

2. Larry had damage to his SA node. What will happen now that the “pacemaker” is not functional?

3. In a normal cardiac cycle, what two chambers of the heart contract first?

4. What two structures directly receive an electrical impulse from the SA node?

5. Valerie’s heart rate is 80 beats/min. What is the length of one cardiac cycle?

462 E X E R C I S E 2 8 C A R D I A C C Y C L E

C. Electrocardiography

6. Fibrillation is an asynchronous contraction of cardiac muscle fibers. Is atrial fibrillation or ventricular fibrillation more serious? Explain.

7. If a myocardial infarction damaged the left bundle branch, how would this affect the spread of the action potential?

8. How would damage to the left bundle branch affect blood flow in the systemic circulation?

Use the abnormal ECG tracing in Figure 28.6 to answer questions 9 and 10. 9. Does the atrial rate equal the ventricular rate in this ECG tracing? Explain.

10. Would you be able to feel a pulse during atrial systole only? Explain.

FIGURE 28.6 Tracing of abnormal ECG, lead II.

P P P P

O B J E C T I V E S M A T E R I A L S

• compound microscope, lens paper, prepared microscope slide of transverse section through artery and vein

• Blood Pressure Measurements: sphygmomanom- eter, stethoscope, alcohol wipes, meterstick, exercise mat

• Effect of Exercise on Blood Pressure: sphygmoma- nometer, stethoscope, alcohol wipes, stopwatch or watch with second hand, graph paper

• PowerPhys Experiment: Effect of Exercise on Blood Pressure and Vascular Resistance

• • Biopac Laboratory Guide Experiment: • Effect of Body Position on Resting Blood Pressure

• Effect of Exercise on Blood Pressure

Blood Vessel Structure and Function

29 E X E R C I S E

1 Compare and contrast the structure of arteries, capillaries, and veins

2 Identify layers or tunics of an artery and vein

3 Measure systolic and diastolic blood pressure at rest and after exercise

4 Discuss how exercise and body position affect blood pressure

463

A rteries carry blood away from the heart and divide into smaller vessels called arterioles that branch into the tiniest vessels called cap- illaries. At the capillary level, an exchange of nutrients, wastes, and gases occurs between blood and interstitial fluid (fluid surrounding tissue cells). Capillaries join to form small venules that will merge to form larger veins that carry blood back to the heart. The structure of these vessels reflects their functions. There are two main circulatory routes within the body: the systemic circulation and the pulmonary circulation. In the systemic circulation, arteries carry oxygen-rich blood to the body tissues, and veins return oxygen-poor blood to the heart where it will then enter the pulmonary circulation. In the pulmonary circulation, arteries carry oxygen-poor blood from the right ventricle to the lungs where gas exchange occurs, and veins return oxygen-rich blood back to the left atrium.

A. Blood Vessel Structure

1. Arteries

Arterial walls have three layers or tunics: the tunica ex- terna, tunica media, and tunica interna. The outer tunica externa is composed mainly of elastic and collagen fi bers (proteins) that provide support and protection. The tunica media is the middle and thickest layer that contains elas- tic fi bers and smooth muscle fi bers (cells) encircling the diameter of the vessel. The sympathetic nervous system regulates the diameter of the blood vessel by innervating smooth muscle fi bers. Contraction of smooth muscle fi bers causes a decrease in lumen diameter or vasoconstriction, whereas relaxation causes vasodilation, an increase in lumen diameter. Elastic fi bers in the tunica media allow the vessel to be stretched and return to its original shape. The tunica interna (intima) contains simple squamous

464 E X E R C I S E 2 9 B L O O D V E S S E L S T R U C T U R E A N D F U N C T I O N

lation. Muscular arteries branch into smaller and smaller arteries that eventually form arterioles, small blood vessels from which capillaries branch. Arterioles have a tunica media containing mainly smooth muscle and few elastic fi bers. These vessels control blood fl ow into capillaries and play a large role in controlling blood pressure.

2. Veins

Blood fl ows from capillaries into venules (venule � little vein) that drain into veins. Venule walls contain a tunica interna of endothelium only and a tunica media with a few smooth muscle fi bers. The walls of veins contain a tunica interna, a tunica media, and a tunica externa. Compared with arterial vessels, the tunica interna and tunica media are thinner, and the tunica media contains fewer smooth muscle fi bers and elastic fi bers. Veins lack an internal and external elastic lamina. The tunica externa is the thickest of the three layers and like arterial vessels is composed of elastic and collagen fi bers. The lumen of veins is larger than arteries and often appears collapsed in tissue sections.

epithelium (endothelium), a basement membrane, and elastic tissue (internal elastic lamina) that is adjacent to the tunica media. The endothelium lines the lumen of all blood vessels and forms a smooth, slick barrier that promotes blood fl ow. Damage to the endothelium causes platelets to stick to the blood vessel wall, forming plaques that narrow the lumen and impede blood fl ow. The thickness and exact composition of each tunic varies according to vessel type. Elastic arteries, such as the aorta, are large-diameter arteries that have more elas- tic fi bers in their tunica media than other arteries. Elastic fi bers stretch under greater pressure when blood is pumped into them during systole. During diastole, the recoiling of elastic fi bers in elastic arteries continues blood fl ow. Muscular arteries, smaller in diameter than elastic ar- teries, have more smooth muscle and fewer elastic fi bers in their tunica media than elastic arteries. However, they have a layer of elastic tissue, the external elastic lamina, between the tunica externa and the tunica media. Muscu- lar arteries distribute blood to different areas of the body (e.g., brachial artery distributes blood to arm) and control blood fl ow to these areas by vasoconstriction or vasodi-

FIGURE 29.1 Transverse sections through a frog arteriole.

25 �

NE added

0.5 mm

Tunica media

Lumen

Tunica externa

Tunica interna

(a) (b)

E X E R C I S E 2 9 B L O O D V E S S E L S T R U C T U R E A N D F U N C T I O N 465

The blood pressure gradient in the veins is very small and often is not enough to overcome gravity. Muscular activity squeezes the veins and pushes blood toward the heart while venous valves, found in many veins, prevent the backfl ow of blood, especially in the limbs. Valves are tunica interna folds whose fl ap-like cusps point toward the heart. Faulty or incompetent valves allow backfl ow of blood and result in pooling of blood in veins, a condition called varicose veins.

Before Going to Lab

1 In Figure 29.1 compare the lumen diameter, thickness of tunics, and shape of tunica interna in two sections of a frog arteriole. Norepinephrine (NE) was applied to one area of the arteriole to induce vasoconstriction. Identify which cross-section is vasoconstricted, (a) or (b).

2 Label the components of a muscular artery wall in Figure 29.2.

3 Label the components of the wall of a vein in Figure 29.3.

2 4

• basement membrane • endothelium • external elastic lamina • internal elastic lamina • smooth muscle • tunica externa • tunica interna • tunica media

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

7 ________________________

8 ________________________

FIGURE 29.2 Structure of a muscular artery.

2 3

• basement membrane • endothelium • tunica externa • tunica interna • tunica media (smooth

muscle) • valve

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

FIGURE 29.3 Structure of a vein.

466 E X E R C I S E 2 9 B L O O D V E S S E L S T R U C T U R E A N D F U N C T I O N

3. Capillaries

Capillaries have the smallest diameter and thinnest walls of any blood vessels. Their lumen is so small that red blood cells can pass through only one at a time. Capillary walls are composed of a single layer of endothelial cells (simple squamous endothelium) supported by a basement mem- brane. The endothelial cells of capillaries can exhibit:

• tight junctions—fusion of plasma membranes of adjacent cells

• intercellular clefts—spaces between cells • fenestrations (fenestra � window)—holes in plasma

membrane covered by a diaphragm (thin membrane) • vesicles

Only substances that are lipid soluble or have mem- brane carriers can cross capillary walls with tight junctions between cells. However, many other substances can cross capillary walls containing fenestrations, intercellular clefts, and vesicles. The size of the fenestrations and intercellular clefts between endothelial cells determines which mol- ecules can cross. Molecules can also be transported across capillary walls by vesicles, a process called transcytosis (trans- � across; cyto � cell). Hydrostatic pressure (blood pressure) at the arterial end of the capillaries causes plasma to be fi ltered across the capillary wall into the interstitial fl uid. The fi ltered plasma containing nutrients, hormones, and other substances is called interstitial fl uid once it leaves the capillaries and en- ters the space around tissue cells. Blood osmotic pressure draws interstitial fl uid into the venous end of the capillary (reabsorption) bringing fl uid, metabolic wastes, hormones, or other substances into the blood. The combination of these opposing pressures causes some fi ltered plasma to remain in the interstitial fl uid to bathe the tissue cells.

LAB ACTIVITY 1 Arteries and Veins

1 Examine a prepared microscope slide containing a transverse section of a small artery and vein. • Using the low-power objective lens, focus and center

one blood vessel in the field of view and switch to high power.

• Using the high-power objective lens, focus with fine adjustment knob only and examine the three tunics in the vessel. Note the thickness of the tunica media.

• Repeat procedure with other blood vessel. • Decide which vessel is the artery and which is the

vein. ■

Before Going to Lab

1 Identify and label the tunics of the blood vessels in Figure 29.4.

• lumen of artery • lumen of vein • tunica externa of artery • tunica externa of vein • tunica interna of artery • tunica interna of vein • tunica media of artery • tunica media of vein

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

7 ________________________

8 ________________________

1 2 3 65 7 84

FIGURE 29.4 Transverse section through small artery and vein.

E X E R C I S E 2 9 B L O O D V E S S E L S T R U C T U R E A N D F U N C T I O N 467

Before Going to Lab

1 Label the blood vessels in Figure 29.5. Identify the arteriole and a capillary.

2 Observe the capillaries in Figure 29.6(a), (b), and (c) and label the capillary structures.

(b) 3

4 (c)

19,000�

• fenestration • intercellular cleft • tight junctions • vesicles involved in trans-

cytosis.

1 _______________________

2 ________________________

3 ________________________

4 ________________________

(a)

FIGURE 29.6 Transmission electron micrographs showing capillary walls.

1 2

• arteriole • capillary

1 ________________________

2 ________________________

FIGURE 29.5 Photomicrograph showing capillary network.

468 E X E R C I S E 2 9 B L O O D V E S S E L S T R U C T U R E A N D F U N C T I O N

be heard until blood fl ow returns to normal. These sounds are called the Korotkoff (koh-ROT-koff) sounds. Although there is a range of values considered normal, the average normal systolic pressure (the fi rst sound heard) is 120 mm Hg, and normal diastolic pressure (the last, faint sounds heard) is 80 mm Hg, usually written as 120/80. Venous blood pressure can also be measured directly with a pressure transducer inserted into a venous vessel or indirectly. Indirect measurement of venous pressure, described in Lab Activity 2, is an estimate at best because blood pressure in veins is very low. The average venous blood pressure is 16 mm Hg.

B. Blood Pressure

Blood pressure, the pressure exerted by blood against blood vessel walls, is highest in the aorta and large elastic arteries, and decreases as the arteries branch and blood travels farther from the heart. Blood pressure drops sig- nifi cantly in the arterioles and steadily decreases through capillaries, venules, and veins, and drops to zero in the right atrium. The difference in blood pressure between two areas of the circulatory system is the blood pressure gradient. The blood pressure gradient between the aorta and right atrium causes blood to fl ow through the systemic circulation, and the blood pressure gradient between the pulmonary trunk and the left atrium causes blood to fl ow through the pulmonary circulation. With each ventricular contraction, blood pressure fl uc- tuates in the large arteries (i.e., the aorta, pulmonary trunk, and other elastic and large muscular arteries). Blood pres- sure during ventricular systole, systolic blood pressure, is higher than blood pressure during ventricular diastole, or diastolic blood pressure. During diastole, the ventricles are in relaxation, and blood is not being ejected. These fl uctuations diminish within the arterioles, and little or no fl uctuations in blood pressure between systole and diastole are observed in the capillaries and venous vessels. The blood pressure gradient between veins and the right atrium is low, making it diffi cult for venous blood fl ow to overcome the force of gravity. Therefore, when standing with arms hanging down, blood may pool in the large veins of the limbs.

1. Blood Pressure Measurements

Arterial blood pressure is reported in millimeters of mer- cury (mm Hg) and can be measured directly by inserting a pressure transducer into a large artery or indirectly with a sphygmomanometer. A sphygmomanometer (SFIG-moe- mah-NOH-meh-ter), or blood pressure cuff, can be used to measure systolic and diastolic blood pressure in any large artery. Clinically, the brachial artery is used most often. The sphygmomanometer contains a pressure gauge attached to an infl atable rubber cuff that is connected by a rubber tube to a hand pump (rubber bulb) or automatic pump. Clinically, it is important to use the right size cuff—pediatric, standard, or large arm—to obtain an accurate reading. The pump is used to infl ate the rubber cuff to a pressure greater than the systolic pressure. This puts pressure on the artery, fl attens it, and stops blood fl ow in the artery. A stethoscope is placed over the brachial artery in the antecubital area, and the pres- sure in the cuff is slowly released by opening a valve. When blood pressure is greater than the pressure in the cuff, the artery opens and blood fl ow returns. The examiner listens for the sound caused by the turbulent fl ow of blood that can

LAB ACTIVITY 2 Blood Pressure Measurements

1 Measure resting systemic arterial blood pressure. • Work in teams of two, alternating who will be the

subject and who will measure blood pressure. • The subject should sit and rest for 5 minutes before

blood pressure is measured. • Wipe the earpieces of the stethoscope with alcohol

and completely deflate the blood pressure cuff. • Place the cuff of the sphygmomanometer around

the arm as shown in Figure 29.7. If the cuff does not fit the arm, the blood pressure measurements will probably be inaccurate. The inflatable portion of the cuff should be over the anterior surface of the arm. If there is an arrow on the cuff, place it over the brachial artery. The brachial artery is located in the anterior arm, immediately superior to the antecubital fossa and lateral to biceps brachii. The bottom of the cuff should be approximately 1 inch above the elbow.

• Close the valve on the rubber bulb. • Insert earpieces; place the large bell of the stetho-

scope over the brachial artery inferior to the cuff, and listen for the brachial pulse.

• Inflate the cuff to 160 to 180 mm Hg. • Immediately use the valve on the hand pump to

slowly release air to deflate the cuff, and listen for the first sound.

• The first sound, the systolic pressure, is the return of blood flow through the partially occluded brachial artery. Watch the pressure gauge and continue to listen; the sound will increase, then muffle, and stop. The diastolic pressure is the pressure when the last, faint sound is heard.

• Record blood pressure measurements in Table 29.1. • Deflate cuff and have subject rest for 2 minutes

before repeating the blood pressure measurement. Record second value in Table 29.1.

E X E R C I S E 2 9 B L O O D V E S S E L S T R U C T U R E A N D F U N C T I O N 469

2 Calculate pulse pressure and mean arterial pressure. • The pulse pressure is the difference between the

systolic and diastolic blood pressure. The larger the pulse pressure, the greater the volume of blood ejected from the ventricle. Mean arterial pressure (MAP or MABP) is the average blood pressure (BP) over the course of the cardiac cycle.

• Calculate the pulse pressure and record in Table 29.1. Pulse pressure � systolic pressure � diastolic pressure.

FIGURE 29.7 Measuring arterial blood pressure with a sphygmomanometer.

Subject has normal blood pressure 120 systolic 80 diastolic

Brachial artery

Inflate cuff to 160–180 mm Hg; brachial artery closes; no audible sounds

180

Pressure in cuff 120; first Korotkoff sound audible

120

Pressure in cuff 80; last faint Korotkoff sound audible

(a) (b) (c) (d)

TABLE 29 .1 Resting Blood Pressures

SYSTOL IC D IASTOL IC PULSE VENOUS SUBJECT PRESSURE PRESSURE PRESSURE MAP PRESSURE

Subject 1 1. 1. 1. 1. 1.

2. 2. 2. 2. 2.

Avg. Avg. Avg. Avg. Avg.

Subject 2 1. 1. 1. 1. 1.

2. 2. 2. 2. 2.

Avg. Avg. Avg. Avg. Avg.

• Calculate the mean arterial pressure (MAP) and record in Table 29.1.

MAP � diastolic BP � (pulse pressure)

3 Estimate systemic venous pressure. • Decide who will be the subject, the observer, and the

recorder.

470 E X E R C I S E 2 9 B L O O D V E S S E L S T R U C T U R E A N D F U N C T I O N

DISCUSSION QUESTIONS Blood Pressure Measurements

1 Did the subject’s BP change after altering body position?

2 Did the subject’s HR change after altering body position?

3 Explain what happens in regard to BP when a person changes from a supine to a standing position. Why does this occur?

■

2. Regulation of Blood Pressure

The body maintains blood pressure (BP) to ensure ade- quate blood fl ow to body tissues (tissue perfusion). If blood pressure is too low, tissue perfusion may not be suffi cient to provide oxygen and nutrients to cells, especially brain neurons, or to remove metabolic wastes. If blood pres- sure is too high, it may cause damage to capillaries and the endothelial lining of blood vessels. Eye exams can often detect early hypertension. Damaged retinal vessels can be observed with an ophthalmoscope. During exercise, cardiac output increases to provide ad- equate tissue perfusion. The increased stroke volume puts more pressure on the blood vessel walls, causing arterial systolic blood pressure to increase. During aerobic exercise, diastolic blood pressure stays the same or decreases slightly due to vasodilation. Even though there is a greater volume of blood in the arteries due to increased stroke volume, the amount of vasodilation causes diastolic pressure to remain the same as resting or to decrease slightly. During resistance exercise (weight training), diastolic pressure may increase. The skeletal muscle contractions required to lift weight squeezes the arteries in muscles, effectively causing vaso- constriction. This causes peripheral resistance to increase, resulting in an increase in both systolic and diastolic blood pressure during exercise. The changes in blood pressure that occur during exercise are temporary; however, exer- cising regularly will reduce resting systolic and diastolic pressures.

• Have the subject stand with arms hanging at the side. Observe the blood pooling in the veins on the dorsal surface of the hands.

• Have the subject abduct one arm and observe the veins become smaller in size and flatten (collapse) as the arm is raised above the level of the right atrium. When the force of gravity exceeds venous pressure, the blood in the veins drains away quickly and does not exert enough pressure on the walls of the veins to keep them open.

• Lower the arm to pool blood in the veins of the hand again.

• Have the subject stand in front of a white (or black) board. With the subject’s hands at the sides, locate the level of the right atrium (approximately 2 inches above the nipple). Mark on the board where the subject’s hand touches the board.

• Have the subject abduct the arm and hand until the veins on the surface of the hand flatten (collapse). Mark where the hand touches the board. Using a meterstick, measure the vertical distance above the right atrium that the hand has traveled in millimeters (1 cm � 10 mm): ___________ mm. Each 12.88 mm elevation of the hand above heart level repre- sents an approximately 1 mm rise in Hg.

• Venous pressure (mm Hg) �

mm measured

12.88 mm elevation/mm Hg

• Repeat measurement and record in Table 29.1.

4 Observe the effect of body position on blood pressure. • Decide who will be the subject, who will do the

measuring, and who will record. • Have subject lie on a mat (supine position) for

2 minutes. Measure BP and heart rate (HR). Record in Table 29.2.

• Have subject stand and immediately measure BP and HR. Record in Table 29.2.

• Take the BP and HR again after the subject stands for 2 minutes. Record in Table 29.2.

5 Answer Discussion Questions with your lab group. 6 Complete Biopac Laboratory Guide Experiment:

Effect of Body Position on Resting Blood Pressure.

TABLE 29 .2 Effect of Body Position on Blood Pressure

SUBJECT SYSTOL IC /D IASTOL IC BP (mm Hg) HR

Supine

Immediately after standing

After standing for 2 minutes

E X E R C I S E 2 9 B L O O D V E S S E L S T R U C T U R E A N D F U N C T I O N 471

• Immediately count the number of heartbeats (or pulses) in 15 seconds and multiply by 4 to obtain HR. Record the results in Table 29.3.

4 Data Analysis: • Calculate resting and post-exercise pulse pressures

and MAP. Record in Table 29.3. • Pool heart rate and MAP class data, calculate

averages, and record in Table 29.3. • If graph paper is available, graph your data.

5 Clean up your lab area as directed by your instructor. 6 Complete the Experimental Report with your lab

group.

7 Complete the PowerPhys Experiment: Effect of Exercise on Blood Pressure and Vascular Resistance.

8 Complete Biopac Laboratory Guide Experiment: Effect of Exercise on Blood Pressure.

EXPERIMENTAL REPORT Effect of Exercise on Blood Pressure

Results: • State whether systolic and diastolic BP increased or

decreased after exercise. • State whether pulse pressure and MAP increased or

decreased after exercise. • State whether HR increased or decreased after exercise.

Discussion: • Why was the resting blood pressure taken standing

rather than sitting? • Discuss how the body changes BP during exercise. • Discuss why the body changes BP during exercise.

Conclusion: • Write a statement that postulates how increasing levels

of exercise affect BP, pulse pressure, and MAP.

■

LAB ACTIVITY 3 Experiment: Effect of Exercise on Blood Pressure

1 Prediction: Circle the correct choice (in italics) in each statement. • Exercise will cause systolic and diastolic BP to

increase or decrease. • Exercise will cause pulse pressure to increase or

decrease. • Exercise will cause MAP to increase or decrease.

2 Materials: Obtain materials for the Regulation of Blood Pressure experiment from Materials list.

3 Data Collection: • Decide who will be the subject, who will measure

BP and HR, and who will be the recorder and timer. The subject should not have heart problems and should be in good health.

• Measure the effect of exercise on BP and record the results in Table 29.3.

BP and HR at rest • Have the subject stand still at rest for 2 to 3 minutes. • Measure systolic and diastolic BP, and record the

results in Table 29.3. • Measure the number of heartbeats (or pulses) in 15

seconds and multiply by 4 to obtain HR. Record the results in Table 29.3.

BP and HR immediately after exercise • Have the subject run in place for 5 minutes. • Immediately measure systolic and diastolic BP, and

record the results in Table 29.3.

Mean arterial blood pressure increases when car- diac output increases and when resistance to blood fl ow increases. Blood viscosity, total blood vessel length, and blood vessel diameter affect resistance to blood fl ow. How- ever, blood vessel diameter is the only variable that can be changed to make immediate changes in blood pressure. Increasing blood vessel diameter (vasodilation) decreases resistance and lowers BP, while decreasing blood vessel di- ameter (vasoconstriction) increases resistance and raises BP.

TABLE 29 .3 Effect of Exercise on Blood Pressure

SYSTOL IC BP D IASTOL IC BP PULSE PRESSURE MAP (mm Hg) (mm Hg) HR (mm Hg) (mm Hg)

Subject At rest

Post-exercise

Class Average At rest

Post-exercise

473

Name ___________________________________ Date _________________ Section ______________________________

29 E X E R C I S EReviewing Your Knowledge

A. Structure of Arteries and Veins

Name the components of each blood vessel tunic. More than one term may apply to each description, and terms may be used more than once.

smooth muscle endothelium elastic fibers collagen fibers

1. Tunica media of arteries

2. Tunica media of veins

3. Tunica interna of arteries

4. Tunica interna of veins

5. Tunica externa of arteries

6. Tunica externa of veins

Circle True or False for the following questions. If false, underline and change word(s) that are incorrect to make the statement true.

7. The tunica media of veins is thicker than the tunica media of arteries. True or False

8. The tunica media of elastic arteries contains more elastic fibers than muscular arteries. True or False

9. Venous valves are folds of the tunica externa. True or False

10. Venous valves prevent backflow of blood. True or False

11. Walls of veins are thicker than the walls of arteries of the same size. True or False

12. The lumen of a vein is larger than the lumen of an artery of the same size. True or False

474 E X E R C I S E 2 9 B L O O D V E S S E L S T R U C T U R E A N D F U N C T I O N

B. Structure of Capillaries

Match the term to the correct description. More than one term may apply to each description. Terms may be used more than once.

fenestrations intercellular clefts tight junctions transcytosis

1. Holes in plasma membrane through which molecules pass across capillary walls

2. Fusion of plasma membranes of adjacent endothelial cells; forms very selective barrier

3. Vesicles transport substances across capillary wall

4. Spaces between cells through which substances pass

Circle True or False for the following questions. If false, underline and change word(s) that are incorrect to make the statement true.

5. Capillary walls are composed of an endothelium and a basement membrane only. True or False

6. Hydrostatic pressure forces plasma across capillary walls at venous end of capillary, and interstitial fluid enters arterial end of capillary by osmotic pressure. True or False

C. Blood Pressure

Fill in the blank with the correct term.

1. Term used for arterial pressure during ventricular systole

2. Term used for arterial pressure during ventricular diastole

3. Device used to measure arterial blood pressure in the brachial artery

4. Average normal adult arterial blood pressure

5. Average venous blood pressure

6. Sounds of turbulent blood flow that occur when blood flow resumes in an artery that has been occluded

Circle True or False for the following questions. If false, underline and change word(s) to make the statement true.

7. The blood pressure gradient from the aorta to the capillaries is greater than the blood pressure gradient from the venules to the right atrium. True or False

8. The blood pressure gradient from the aorta to the capillaries is less than the blood pressure gradient from the arterial end of the capillary to the venous end of the capillary. True or False

9. Kate’s systolic blood pressure is 115 and diastolic is 72. Her pulse pressure is 47. True or False

10. Scott’s blood pressure is 126/84; therefore, his MAP is 96. True or False

E X E R C I S E 2 9 B L O O D V E S S E L S T R U C T U R E A N D F U N C T I O N 475

D. Regulation of Blood Pressure and Blood Flow

Circle True or False for the following questions. If false, underline and change word(s) that are incorrect to make the statement true.

1. Increasing heart rate increases blood pressure. True or False

2. Systemic vasoconstriction decreases blood pressure. True or False

3. Increasing arterial blood pressure increases blood flow. True or False

4. Recoil of muscular arteries maintains blood flow during ventricular diastole. True or False

5. Muscular arteries control the blood flow to different body areas. True or False

6. Vasoconstriction of the renal arteries (arteries supplying blood to kidneys) would decrease blood flow to the kidneys. True or False

7. Blood pressure is higher in the supine position than in the standing position. True or False

8. The greater the pulse pressure, the lower the pressure gradient driving blood from the aorta through the systemic circulation. True or False

9. Exercise increases MAP. True or False

477

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

29 A. Blood Vessel Structure and Function

1. In coronary bypass surgery, a section of vein is used to replace (bypass) occluded coronary arteries. Over time, the vein wall becomes more like an arterial wall. Describe the changes that would occur in the vein wall.

2. The smooth muscle fibers within the wall of an artery do not receive their nutrients from the blood within the lumen of the artery. Why not?

3. Blood flow within the capillaries is slower than within arterial or venous vessels. Explain why this is important.

4. Blood flow to the skeletal muscles increases with exercise. Explain how the autonomic nervous system mediates the increase in blood flow to skeletal muscles.

5. Explain how blood flow to the kidneys is decreased with exercise.

6. Explain why the differences in the amount of elastic fibers and smooth muscle fibers in the tunica media of elastic arteries and muscular arteries is important to their function.

7. Why does the tunica interna of the vasoconstricted section of the arteriole in Figure 29.1 exhibit folds?

8. Capillaries within the brain have tight junctions, whereas capillaries within the anterior pituitary and other endocrine glands contain fenestrations, intercellular clefts, and vesicles for transcytosis. Explain how these structural differences are important to the function of the brain and the anterior pituitary.

478 E X E R C I S E 2 9 B L O O D V E S S E L S T R U C T U R E A N D F U N C T I O N

9. Compare the strength of arterial and capillary walls.

10. Marfan’s syndrome is an inherited genetic disorder that results in malformed elastic fibers that are weak. What effect would this have on the aorta?

B. Blood Pressure Homeostasis

Use the terms in bulleted list to complete the schematic diagram of blood pressure homeostasis in Figure 29.8.

• ADH • aldosterone • blood pressure

• blood volume • cardiac output • sympathetic nerves

FIGURE 29.8 Blood pressure homeostasis.

HOMEOSTASIS Normal BP and volume

Decreased BP and volume

Short Term Regulation Nervous System

Long Term Regulation Hormones

Stimulation of baroreceptors and chemoreceptors

Stimulation of cardiovascular center

stimulation

Blood pressure

Homeostasis restored

Renin (kidney)

Angiotensin ll activation

EPO4

(Adrenal gland)

Peripheral vasoconstriction

Stimulation

(Posterior pituitary) erythropoietin (kidney)

RBC production

Blood Vessel Identification 30

E X E R C I S E

479

A rteries carry blood from the heart to cap-illaries where gas and nutrient exchange occurs, while veins carry blood back to the heart. There are two circulatory routes within the body: the pulmonary circulation and the systemic circulation. In the pulmonary circulation, arteries carry oxygen-poor blood from the right ventricle to the lungs where gas exchange occurs, and veins carry oxygen-rich blood back to the left atrium. In

the systemic circulation, arteries carry oxygen-rich blood to body tissues, and veins return oxygen-poor blood to the heart where it enters the pulmonary circulation. Anastomoses provide alternative routes or detours for blood fl ow in case the main route is blocked or damaged. Arterial anastomoses are blood vessels that connect arteries, while venous anastomoses connect veins.

O B J E C T I V E S M A T E R I A L S

• models or charts showing human arteries, veins, and circulatory pathways or Real Anatomy (Cardiovascular)

• Dissection: preserved cats or fetal pigs, dissecting equipment, disposable gloves, safety glasses, and dissection manual

• Real Anatomy: Virtual Cadaver Dissection

1 Identify the major arteries and veins of the systemic circulation

2 Identify the major vessels of the cerebral arterial circle (circle of Willis), pulmonary circulation, hepatic portal system, and fetal circulation

3 Palpate main arterial pulses

4 Trace blood flow through the cardiovascular system

5 Dissect a cat, fetal pig, or cadaver and identify selected blood vessels

480 E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N

A. Systemic Arteries

All major arteries of the systemic circulation branch off the aorta. These arteries transport blood to different regions of the body where blood is distributed to smaller arteries and fi nally to arterioles that connect to capillaries.

1. Major Arteries of the Ascending Aorta and Aortic Arch

Blood is ejected from the left ventricle and into the ascend- ing aorta. The right and left coronary arteries branch off the ascending aorta near its origin and travel to the heart. The ascending aorta curves superiorly toward the left and becomes the aortic arch. The superior portion of the aortic arch is posterior to the sternal angle. Three major arteries branch off the aortic arch in the following order from right to left: the brachiocephalic trunk, the left common carotid artery, and the left subclavian artery. The brachiocephalic trunk divides to form the right common carotid and right

LAB ACTIVITY 1 Major Arteries of the Ascending Aorta and Aortic Arch

1 Identify the arteries on a model or chart, or use the search text box in Real Anatomy (Cardiovascular) to find these structures.

2 Palpate your sternal angle. The superior portion of the aortic arch is posterior to it. ■

Before Going to Lab

1 Review the arteries in Figure 30.1(a). 2 Observe the locations of these arteries in Table 30.1. 3 Label the arteries in Figure 30.1(b) using the locations

described in Table 30.1.

FIGURE 30.1 Major arteries of the ascending aorta and aortic arch.

Left common carotid

Left subclavian

Left coronary

Right common carotid

Right subclavian

Brachiocephalic trunk

Ascending aorta

Right coronary

Intercostal

Diaphragm

Celiac trunk

Common hepatic

Right suprarenal

Right renal

Internal iliac

External iliac

Femoral

(a)

Right gonadal

Thoracic aorta

Left gastric

Left suprarenal

Splenic

Superior mesenteric

Left renal

Left gonadal

Abdominal aorta Inferior mesenteric

Left common iliac

Aortic arch

subclavian arteries. The left and right vertebral arteries branch off their respective subclavian arteries.

E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N 481

FIGURE 30.1 Major arteries of the ascending aorta and aortic arch, continued.

• aortic arch • ascending aorta • brachiocephalic trunk • left common carotid • left subclavian • right common carotid • thoracic aorta

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

5 _____________________________________________________

6 _____________________________________________________

7 _____________________________________________________

Diaphragm

Left primary bronchus

5 Left vertebral

Larynx

Inferior vena cava

Esophagus

Trachea

(b)

TABLE 30 .1 Major Arteries of the Ascending Aorta and Aortic Arch

ARTERY LOCAT ION

Ascending aorta Begins at left (aortic) semilunar valve and becomes the aortic arch at the level of the sternal angle Right and left coronary arteries Branch off ascending aorta just superior to the left aortic valve and end when they divide into their respective arterial branches Aortic arch Begins at the level of the sternal angle and becomes the thoracic aorta at the level of the intervertebral disc between the fourth and fifth vertebrae Brachiocephalic trunk First branch off aortic arch, divides into right subclavian artery and right common carotid artery at level of sternoclavicular joint Right common carotid artery Formed from division of brachiocephalic trunk and divides into the right external and right internal carotid arteries at the superior border of the larynx Right subclavian artery Formed from division of brachiocephalic trunk and is renamed axillary artery within axillary region Left common carotid artery Second branch off aortic arch, divides into the left external and left internal carotid arteries at the superior border of the larynx Left subclavian artery Third branch off aortic arch, renamed axillary artery within the axillary region

482 E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N

2. Major Arteries Supplying the Head (Including Circle of Willis)

The common carotid arteries branch to form the internal and external carotid arteries. The internal carotid arteries travel through the neck and enter the skull through the carotid canal within each temporal bone and supply struc- tures within the skull. Each internal carotid artery branches to form an anterior cerebral artery and a middle cere- bral artery that supply blood to these areas of the brain. The external carotid arteries ascend along the lateral surface of the neck and terminate as two arteries near the temporomandibular joint that supply structures external to the skull. There are two vertebral arteries, one branching off each subclavian artery. The vertebral arteries travel supe- riorly through the transverse foramen of the cervical ver- tebrae and then through the foramen magnum to reach the base of the brain, where they merge to form the basilar artery. The posterior cerebral artery is a branch of the basilar artery supplying the posterior part of the brain. Blood supply to the brain is vital, and the confi guration of the blood vessels supplying the brain ensures continuous blood fl ow even when blockage occurs in a blood vessel. The cerebral arterial circle (circle of Willis) is a ring of

blood vessels formed by three anastomoses—the anterior communicating artery and the right and left posterior com- municating arteries. The anterior communicating artery connects the two anterior cerebral arteries, and the posterior communicating arteries connect the internal carotid arteries to the posterior cerebral arteries.

Before Going to Lab

1 Label the arteries in Figure 30.2(a) using the locations described in Table 30.1 and Table 30.2.

2 Label the arteries forming the cerebral arterial circle (circle of Willis) in Figure 30.2(b) using the locations described in Table 30.2.

LAB ACTIVITY 2 Major Arteries Supplying the Head

1 Identify the arteries on a model or chart, or use the search text box in Real Anatomy (Cardiovascular) to find these structures.

2 Palpate the right common carotid artery pulse by placing your fingers just lateral to the larynx. ■

TABLE 30 .2 Major Arteries Supplying the Head

ARTERY LOCAT ION

External carotid arteries Begin as terminal branches off the common carotid arteries near the superior border of the larynx, anterior to the sternocleidomastoid muscle, and end within the parotid gland

Internal carotid arteries Begin as terminal branches off the common carotid arteries and divide into the anterior and middle cerebral arteries below the inferior surface of the brain

Anterior cerebral arteries Branch off internal carotid arteries that pass anterior to the optic chiasma and run along the midline of the base of the brain

Middle cerebral arteries Branch off internal carotid arteries that run toward the lateral surface of the base of the brain

Vertebral arteries First major branch off subclavian artery that ends near inferior surface of brain, where it forms the basilar artery

Basilar artery Formed when right and left vertebral arteries merge along the inferior surface of the medulla oblongata and divides to form the right and left posterior cerebral arteries near the superior border of pons along the base of the brain

Posterior cerebral arteries Formed when basilar artery divides and travels along the base of the brain toward the posterior surface of the cerebrum

Anterior communicating artery Connects right and left anterior cerebral arteries anterior to the optic chiasma Right and left posterior Connect posterior cerebral arteries and internal carotid arteries communicating arteries

E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N 483

FIGURE 30.2 Arteries of the head and neck.

(a) Right lateral view of major arteries of the head and neck

Right internal carotid

• brachiocephalic trunk • common carotid • external carotid • internal carotid • vertebral

1 _______________________________________

2 _______________________________________

3 _______________________________________

4 _______________________________________

5 _______________________________________

(b) Inferior view of brain showing cerebral arterial circle

• anterior cerebral • anterior communicating • basilar • internal carotid • middle cerebral • posterior cerebral • posterior communicating • vertebral

6 _______________________________________

7 _______________________________________

8 _______________________________________

9 _______________________________________

10 _______________________________________

11 _______________________________________

12 _______________________________________

13 _______________________________________

484 E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N

3. Major Arteries of the Upper Extremities

The subclavian artery is renamed the axillary artery within the axilla and continues as the brachial artery as it enters the arm. As the brachial artery enters the forearm, it divides to form the radial artery and the ulnar artery. The superfi cial palmar arch and the deep palmar arch, both of which supply blood to the fi ngers and palms, con- nect the radial and ulnar arteries at their distal ends and are examples of arterial anastomoses.

Before Going to Lab

1 Review the arteries in Figure 30.3(a). 2 Observe the locations of these arteries in Table 30.3. 3 Label the arteries in Figure 30.3(b) using the locations

described in Table 30.3.

LAB ACTIVITY 3 Arteries of the Upper Extremities

1 Identify the arteries on a model or chart, or use the search text box in Real Anatomy (Cardiovascular) to find these structures.

2 Flex your arm and palpate the brachial artery by plac- ing the second and third fingers in the brachial groove (between the biceps and triceps).

3 Palpate the radial artery by placing the second and third fingers medial to the distal end of the radius. ■

FIGURE 30.3 Arteries supplying the upper extremities.

Subclavian artery

Axillary artery

Brachial artery

Radial artery

Ulnar artery

Femoral artery

(a)

E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N 485

TABLE 30 .3 Arteries Supplying the Upper Extremities

ARTERY LOCAT ION

Axillary arteries Continuation of subclavian artery that begins at the outer border of first rib and is renamed the brachial artery as it enters the arm

Brachial arteries Continuation of axillary artery that begins near the tendon of the teres major muscle and ends just distal to the elbow where it divides into the radial and ulnar arteries

Radial arteries Terminal branch of brachial artery that runs along lateral surface of forearm into the wrist and hand

Ulnar arteries Terminal branch of brachial artery that runs along medial surface of forearm into the wrist and hand

Deep palmar arch Anastomoses that connect radial and ulnar arteries; located deep to the tendons of flexor muscles and proximal to superficial palmar arch

Superficial palmar arch Anastomoses that connect radial and ulnar arteries; located superficial to flexor tendons and distal to deep palmar arch

• axillary • brachial • radial • subclavian • ulnar

1 _______________________________________

2 _______________________________________

3 _______________________________________

4 _______________________________________

5 _______________________________________

Deep palmar arch

Superficial palmar arch

(b)

FIGURE 30.3 Arteries supplying the upper extremities, continued.

486 E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N

into the common iliac arteries that are the terminal branches of the abdominal aorta.

4. Major Arterial Branches of the Descending Aorta

The diaphragm divides the descending aorta into thoracic and abdominal sections. The thoracic aorta lies to the left of the midline, just anterior to the vertebral column, and has branches that supply thoracic structures. Nine pairs of posterior intercostal arteries branch off the thoracic aorta to follow the ribs. The abdominal aorta is also anterior to the vertebral column but closer to the midline. It supplies the abdomen, pelvis, and lower extremities. The major branches of the abdominal aorta are the celiac trunk (which divides into the left gastric artery, splenic artery, and common hepatic artery), the superior mesenteric artery, the paired suprarenal arteries, the paired renal arteries, the paired gonadal arteries (ovarian arteries in females and testicular arteries in males), the inferior mesenteric artery, and four pairs of lumbar arteries. Within the pelvis, the abdominal aorta bifurcates

LAB ACTIVITY 4 Major Arterial Branches of the Descending Aorta

1 Identify the arteries on a model or chart, or use the search text box in Real Anatomy (Cardiovascular) to find these structures.

2 Palpate the anterior superior iliac spines. The abdominal aorta bifurcates into the common iliac arteries at this level. ■

• abdominal aorta • celiac trunk • common hepatic • inferior mesenteric • right common iliac • right external iliac • right internal iliac • left renal • splenic • superior mesenteric

1 ____________________

2 ____________________

3 ____________________

4 ____________________

5 ____________________

6 ____________________

7 ____________________

8 ____________________

9 ____________________

10 ____________________

Diaphragm

Inferior vena cava

Right adrenal (suprarenal) gland

Right kidney

Hepatic veins

Ureter

FIGURE 30.4 Descending aorta and major arterial branches.

Before Going to Lab

1 Label the arteries in Figures 30.4 and 30.5 using the locations described in Table 30.4.

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TABLE 30 .4 Major Arterial Branches of the Descending Aorta

ARTERY LOCAT ION

Thoracic aorta Continuation of aortic arch that starts at the level of the intervertebral disc between the fourth and fifth thoracic vertebrae and becomes the abdominal aorta at the diaphragm

Abdominal aorta Continuation of the thoracic aorta that begins at the diaphragm and ends at the level of the fourth lumbar vertebra where it divides into the right and left common iliac arteries

Celiac trunk Short branch off abdominal aorta just inferior to the diaphragm that immediately divides into three arteries: the left gastric, splenic, and common hepatic arteries

Left gastric artery Smallest of the three celiac trunk branches, it comes off the left anterior side and courses to the left toward the esophagus and stomach

Splenic artery Largest of the three celiac trunk branches, it comes off the left anterior side and courses to the left toward the spleen and branches into three arteries: the pancreatic artery, the left gastroepiploic artery, and the short gastric artery

Common hepatic artery Intermediate of three celiac trunk branches, it comes off the right anterior side and courses toward the right and branches into three arteries

Superior mesenteric artery Arises off the anterior surface of the abdominal aorta just inferior to the celiac trunk at the level of the first lumbar vertebra; it has many anastomoses and branches into five arteries

Right and left suprarenal Branch off the lateral surface of the abdominal aorta at the level of the first lumbar arteries vertebra and course toward the adrenal glands Right and left renal Branch off the lateral surface of the abdominal aorta at the level of the second arteries lumbar vertebra and course toward the kidneys Right and left gonadal Branch off the anterior surface of the abdominal aorta inferior to the renal arteries; arteries ovarian arteries course toward the ovaries and testicular arteries pass through the inguinal canal toward the testes Inferior mesenteric artery Branches off the abdominal aorta at the level of the third lumbar vertebra; it has many anastomoses and branches into three arteries Right and left common iliac Begin at division of abdominal aorta at level of fourth lumbar vertebra and terminate arteries terminate into internal and external iliac arteries

2 3

• celiac trunk • common hepatic • left gastric • splenic

1 _______________________________________

2 _______________________________________

3 _______________________________________

4 _______________________________________

FIGURE 30.5 Anterior view of celiac trunk and its arterial branches.

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5. Major Arteries of the Pelvis and Lower Extremities

The common iliac arteries divide into the internal iliac and external iliac arteries. The internal iliac arteries are medial terminal branches off the common iliac arteries just anterior to the lumbosacral joint. They course posteriorly to the pelvis. The external iliac artery, the larger of the two arteries, becomes the femoral artery as it enters the thigh. The femoral artery descends along the middle of the anterior two-thirds of the thigh and travels to the pos- terior thigh, becoming the popliteal artery as it enters the posterior knee area. The popliteal artery divides into the anterior and posterior tibial arteries. The anterior tibial artery travels to the anterior surface of the leg and descends to the ankles where it becomes the dorsalis pedis artery. The posterior tibial artery descends along the posterior aspect of the leg and terminates at the ankle where it di- vides into the medial and lateral plantar arteries. The fi bular (peroneal) artery branches off the posterior tibial artery and travels down the lateral side of the leg to the foot.

TABLE 30 .5 Major Arteries of the Pelvis and the Lower Extremities

ARTERY LOCAT ION

Internal iliac arteries Terminal branches of common iliac arteries that begin at the level of the intervertebral disc between vertebrae L5 and S1 and travel posteriorly until they divide in the pelvis

External iliac arteries Terminal branches of common iliac arteries that run along the psoas major muscles and become femoral arteries posterior to the inguinal ligaments

Femoral arteries Begin posterior to inguinal ligaments; descend along the midline of the anterior two-thirds of the thighs; travel to the posterior thigh and become the popliteal arteries in the popliteal region of the lower extremity

Popliteal arteries Continuation of femoral arteries that begin in the popliteal region and end in the upper leg where they divide into the anterior and posterior tibial arteries

Anterior tibial arteries Terminal branches of popliteal arteries that begin in the upper posterior leg and travel to the anterior leg; end in the ankles where they become the dorsal arteries of the foot (dorsalis pedis arteries)

Dorsal arteries of the foot Continuation of anterior tibial arteries that begin in the ankles and form branches (dorsalis pedis arteries) within the foot Posterior tibial arteries Terminal branches of popliteal arteries that begin in the upper leg and terminate

at the medial malleolus of the tibia where they divide into the medial and lateral plantar arteries

Fibular (peroneal) arteries Branch off the posterior tibial artery slightly distal to the point where the popliteal artery divides into the anterior and posterior tibial arteries; descends down the lateral surface of the leg, and terminates within the foot

Before Going to Lab

1 Label the arteries in Figure 30.6(a) and (b) using the locations described in Table 30.5.

LAB ACTIVITY 5 Major Arteries of the Pelvis and Lower Extremities

1 Identify the arteries on a model or chart, or use the search text box in Real Anatomy (Cardiovascular) to find these structures.

2 Palpate the femoral artery pulse by placing two finger- tips over the inguinal area, specifically in the crease between the thigh and the trunk.

3 Palpate the popliteal artery pulse by placing two fingertips on the posterior surface of the knee. It is best to palpate in the supine position with the knee slightly flexed.

4 Palpate the pulse of the dorsal artery of the foot (dorsalis pedis artery) by placing two fingertips over the dorsal surface of the medial side of the foot near the ankle. ■

E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N 489

• anterior tibial • common iliac • dorsal artery of the foot (dorsalis pedis) • external iliac • femoral • fibular (peroneal) • internal iliac • popliteal • posterior tibial

1 _______________________________________

2 _______________________________________

3 _______________________________________

4 _______________________________________

5 _______________________________________

6 _______________________________________

7 _______________________________________

8 _______________________________________

9 _______________________________________

(a) Anterior view (b) Posterior view

9 Medial plantar

Lateral plantar

FIGURE 30.6 Major arteries of the pelvis and lower extremities.

490 E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N

1. Veins Carrying Blood to the Right Atrium of the Heart

Three large veins carry oxygen-poor blood into the right atrium—the superior vena cava, the inferior vena cava, and the coronary sinus.

B. Systemic Veins

Veins carry blood from the capillaries back toward the heart. Veins can be found under the skin (superfi cial veins) or deep within the body, typically near an artery. Veins that accompany arteries usually have the same name as the ar- tery. Veins carrying blood from the lungs to the left side of the heart carry oxygen-rich blood and are part of the pulmonary circulation, whereas veins carrying blood from all other body tissues carry oxygen-poor blood and are part of the systemic circulation.

CLINICAL NOTE: A thrombus in a deep vein can cause a pulmonary embolus if not treated with anticoagulant, whereas a thrombus in a superficial vein does not tend to form an embolus.

Before Going to Lab

1 Label the veins in Figure 30.7 using the locations de- scribed in Table 30.6.

TABLE 30 .6 Veins Carrying Blood to the Heart

VEIN LOCAT ION

Superior vena cava Formed from the merger of the right and left brachiocephalic veins at the level of the first costal cartilage and ends where it enters the right atrium at the level of the third costal cartilage

Coronary sinus Formed from the merger of the great, middle, and small cardiac veins, located in the coronary sulcus, and empties into the right atrium

Inferior vena cava Formed from the merger of the common iliac veins at the level of the fifth lumbar vertebra and ascends behind the peritoneum just right of the midline and empties into the right atrium

(posterior)

• coronary sinus • inferior vena cava • superior vena cava

1 _______________________________________

2 _______________________________________

3 _______________________________________

FIGURE 30.7 Systemic veins carrying blood to the heart.

LAB ACTIVITY 6 Veins Carrying Blood to the Heart

1 Identify the arteries on a model or chart, or use the search text box in Real Anatomy (Cardiovascular) to find these structures. ■

E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N 491

2. Major Veins Draining the Head and Neck

Three large paired veins—the internal jugular veins, the external jugular veins, and the vertebral veins—drain blood from the head and neck. The internal jugular veins run lateral to the internal carotid and common carotid arteries, the external jugular veins are superfi cial veins descend- ing along the lateral surface of the neck, and the vertebral veins descend through the transverse foramina of the vertebral column with the vertebral arteries. The external jugular veins drain the scalp and face and empty into the subclavian veins. The internal jugular and subclavian veins join to form the brachiocephalic veins. The right and left brachiocephalic veins merge to form the superior vena cava.

Before Going to Lab

1 Label the veins in Figure 30.8 using the locations de- scribed in Table 30.7.

TABLE 30 .7 Major Veins of the Head and Neck

VEIN LOCAT ION

Internal jugular veins Begin at the jugular foramina; run lateral to the internal carotid and common carotid arteries; merge with the subclavian veins to form the brachiocephalic veins

External jugular veins Begin in the occipital region and the parotid gland; descend through the neck along the sternocleidomastoid muscle and end near the middle of the clavicle where they drain into the subclavian veins

Vertebral veins Originate inferior to the occipital condyles; travel through the transverse foramina of the first through sixth cervical vertebrae and drain into the area where the subclavian and internal jugular veins merge to form the brachiocephalic veins in the root of the neck

• brachiocephalic • external jugular • internal jugular • subclavian • vertebral

1 _______________________________________

2 _______________________________________

3 _______________________________________

4 _______________________________________

5 _______________________________________

FIGURE 30.8 Major veins of the head and neck.

LAB ACTIVITY 7 Major Veins Draining the Head and Neck

1 Identify the arteries on a model or chart, or use the search text box in Real Anatomy (Cardiovascular) to find these structures.

2 Observe the external jugular vein. This vein is located lateral to the sternocleidomastoid muscle. To observe this vein, look in the mirror while clenching your teeth and place your fingers above the clavicle, pressing firmly to prevent blood from draining the external jugular vein. This should cause the vein to enlarge. ■

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3. Major Veins Draining the Upper Extremities

Superfi cial veins are visible running beneath the skin of the arm. As we age, these veins become more visible. The major superfi cial veins of the upper extremities are the basilic and the cephalic veins. Each arm has a cephalic vein that travels along the anteriolateral surface of the entire limb and merges with the axillary vein inferior to the clavicle. Each basilic vein travels along the medial sur- face of the forearm and the anterior surface of the arm. Each median cubital vein, a common site for obtaining blood samples, is an anastomosis anterior to the elbow that connects the basilic and cephalic veins. The major deep veins of the arm and forearm run along with arteries and are named for the arteries they accom- pany. The radial and ulnar veins, found in each forearm, merge to form the brachial veins. The brachial veins ascend the arm and join with the basilic vein to form the axillary vein. The axillary vein becomes the subclavian vein as it leaves the axillary region.

Before Going to Lab

1 Label the veins in Figure 30.9(a) and (b) using the de- scriptions supplied for superficial veins in Table 30.8 and deep veins in Table 30.9.

LAB ACTIVITY 8 Major Veins Draining the Upper Extremities

1 Identify the arteries on a model or chart, or use the search text box in Real Anatomy (Cardiovascular) to find these structures.

2 Identify the median cubital vein on yourself. 3 Observe the cephalic and basilic veins on yourself by

clenching your fist and extending your arm by your side. ■

FIGURE 30.9 Major veins of the right upper extremity.

Right external jugular

Superior vena cava

Right subclavian

(a) Anterior view of superficial veins

Sternum

Right internal jugular

(b) Anterior view of deep veins

• basilic • cephalic • median cubital

1 ______________________________

2 ______________________________

3 ______________________________

(a) • axillary • brachial veins • radial veins • subclavian • ulnar veins

4 ______________________________

5 ______________________________

6 ______________________________

7 ______________________________

8 ______________________________

(b)

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splenic vein, which carries blood from the stomach, pan- creas, and spleen. The superior mesenteric vein drains blood from the small intestine and merges with the splenic vein to form the hepatic portal vein, which carries nutrient-rich blood to the liver for processing. The liver is drained by the hepatic veins that empty into the inferior vena cava.

4. Major Veins Draining the Thorax, Abdomen, and Pelvis (Including Hepatic Portal Circulation)

The azygos system of veins includes the azygos vein, the hemiazygos vein, and the accessory hemiazygos vein. These veins drain most thoracic structures and the abdom- inal wall. They also form anastomoses with the large veins draining the lower limbs and abdomen. Therefore, the azygos system can serve as a bypass if the inferior vena cava becomes obstructed. The internal and external iliac veins in the pelvis merge to form the common iliac veins that unite to form the inferior vena cava. The lumbar veins, gonadal veins, renal veins, suprarenal veins, and hepatic veins drain directly into the inferior vena cava. The veins draining the stomach, intestines, spleen, pan- creas, and gallbladder do not drain directly into the infe- rior vena cava but enter the hepatic portal circulation fi rst. The major veins of the hepatic circulation are the inferior mesenteric vein, the splenic vein, the superior mesenteric vein, and the hepatic portal vein. The inferior mesenteric vein, which drains blood from the large intestine, joins the

TABLE 30 .8 Superficial Veins Draining the Upper Extremities

VEIN LOCAT ION

Cephalic veins Begin at lateral edge of the dorsal venous arches (superficial veins of the hand); travel laterally along the anterior surface of the entire limb and end inferior to the clavicle where they drain into the axillary vein

Basilic veins Begin at the medial edge of the dorsal venous arches and travel medially along the posterior surface of the forearm and the anterior surface of the arm; in the middle of the arm, this vein travels deep and eventually merges with the brachial vein in the axillary region to form the axillary vein

Median cubital veins Travel laterally across the anterior surface of the elbow to connect the basilic and cephalic veins

TABLE 30 .9 Deep Veins Draining the Upper Extremities

VEIN LOCAT ION

Radial veins From venous palmar arches, travel along lateral forearm with the radial arteries and end at brachial veins

Ulnar veins From superficial palmar venous arches, travel along medial forearm with ulnar arteries and end at brachial veins

Brachial veins From merger of radial and ulnar veins, run superiorly until merge with basilic veins to form axillary veins

Axillary veins From merger of basilic and brachial veins, run with axillary arteries until they become subclavian veins at the border of first ribs

Subclavian veins Continuation of axillary veins that begin at the border of first ribs; end at the sternal end of the clavicle where they join with the internal jugular veins to form the brachiocephalic veins

Before Going to Lab

1 Label the veins in Figure 30.10 using the descriptions supplied in Tables 30.10 and 30.11.

2 Label the veins in Figure 30.11 using the locations described in Table 30.11.

LAB ACTIVITY 9 Major Veins Draining the Thorax, Abdomen, and Pelvis

1 Identify the arteries on a model or chart, or use the search text box in Real Anatomy (Cardiovascular) to find these structures. ■

494 E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N

FIGURE 30.10 Major veins draining the thorax, abdomen, and pelvis.

• accessory hemiazygos • azygos • hemiazygos • hepatic veins • inferior vena cava • left brachiocephalic • left common iliac • left external iliac • left gonadal • left internal iliac • left renal • left suprarenal • right brachiocephalic • right common iliac • right external iliac • right gonadal • right internal iliac • right renal • right suprarenal • superior vena cava

1 __________________________________

2 __________________________________

3 __________________________________

4 __________________________________

5 __________________________________

6 __________________________________

7 __________________________________

8 __________________________________

9 __________________________________

10 __________________________________

11 __________________________________

12 __________________________________

13 __________________________________

14 __________________________________

15 __________________________________

16 __________________________________

17 __________________________________

18 __________________________________

19 __________________________________

20 __________________________________

TABLE 30 .10 Veins Draining the Thorax

VEIN LOCAT ION

Right and left brachio- Formed by the merger of the subclavian and internal jugular veins and unite to form cephalic veins the superior vena cava (brachi- � arm; cephalic � head) Azygos vein Forms near the diaphragm; runs anterior and to the right of the vertebral column

and ends in the superior vena cava Hemiazygos vein Begins below the diaphragm; runs anterior and to the left of the vertebral column

and ends at the level of the ninth thoracic vertebra, where it joins the azygos vein Accessory hemiazygos Superior to the hemiazygos vein; runs anterior and to the left of the vertebral column vein from the level of the second thoracic vertebra to the eighth, joining the azygos vein

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TABLE 30 .11 Veins Draining the Abdomen and Pelvis

VEIN LOCAT ION

Common iliac veins Formed by the merger of the internal and external iliac veins near the sacroiliac joint and end when both common iliac veins form the inferior vena cava

Internal iliac veins Begin near the greater sciatic notch and drain into the common iliac veins External iliac veins Continuations of femoral veins that are renamed within the inguinal region; drain

into the common iliac veins Gonadal veins Run adjacent to the gonadal arteries in the posterior abdomen; left gonadal veins

drain into the left renal vein; right gonadal veins drain into the inferior vena cava Renal veins Run anterior to renal arteries and drain into the inferior vena cava Suprarenal veins Run adjacent to the suprarenal arteries and drain into the inferior vena cava

HEPAT IC PORTAL C IRCULAT ION

Inferior mesenteric vein Formed from the fan-like network of veins from the inferior mesentery; drains into splenic vein and joins the splenic vein near the pyloric region of the stomach to form the hepatic portal vein

Splenic vein Drains the spleen and joins the superior mesenteric vein near the inferior region of the stomach to form the hepatic portal vein

Superior mesenteric vein Formed from the fan-like network of veins of the superior mesentery; joins the splenic vein near the inferior region of the stomach to form the hepatic portal vein

Hepatic portal vein Begins at merger of splenic vein and superior mesenteric vein and ends in the liver Hepatic veins Multiple hepatic veins form in the liver and drain into the inferior vena cava slightly

inferior to the diaphragm

2 4

Vein network of superior mesenteric vein

Vein network of inferior mesenteric vein

Gastric veins • hepatic • hepatic portal • inferior mesenteric • splenic • superior mesenteric

1 _______________________________________

2 _______________________________________

3 _______________________________________

4 _______________________________________

5 _______________________________________

FIGURE 30.11 Hepatic portal circulation.

496 E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N

popliteal vein ascends along the posterior surface of the knee and becomes the femoral vein, which travels up the posterior thigh and becomes the external iliac vein in the pelvis.

5. Major Veins Draining the Lower Extremities

The great saphenous vein and the small (short) saphenous vein are the major superfi cial veins of the leg. The great saphenous vein is the longest vein in the body, running along the medial surface of the leg and thigh, and contains between 10 and 20 valves to prevent backfl ow of blood. The small saphenous vein ascends along the lateral poste- rior surface of the leg. Varicose veins are common in both of these veins. Deep veins of the leg ascend in the leg adjacent to the arteries of the same name. The anterior and paired poste- rior tibial veins ascend in the anterior and posterior leg, and unite inferior to the popliteal fossa to form the popliteal vein. The paired fi bular (peroneal) veins travel superiorly along the lateral leg and join the posterior tibial veins. The

Before Going to Lab

1 Label the veins in Figure 30.12 using the descriptions of veins in Table 30.12.

LAB ACTIVITY 10 Major Veins Draining the Lower Extremities

1 Identify the arteries on a model or chart, or use the search text box in Real Anatomy (Cardiovascular) to find these structures. ■

7 5

(b) Posterior view(a) Anterior view

FIGURE 30.12 Veins of the right lower limb.

• anterior tibial • external iliac • femoral • great saphenous • small saphenous

1 __________________________________

2 __________________________________

3 __________________________________

4 __________________________________

5 __________________________________

(a)

• femoral • fibular (peroneal) • great saphenous • popliteal • posterior tibial • small saphenous

6 __________________________________

7 __________________________________

8 __________________________________

9 __________________________________

10 __________________________________

11 __________________________________

(b)

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C. Pulmonary Circulation

The pulmonary circulation carries oxygen-poor blood from the right ventricle to the capillaries of the lung, where oxygen is added and carbon dioxide is removed. The pul- monary trunk carries oxygen-poor blood from the right ventricle and divides to form the right and left pulmonary arteries, which carry blood to the lungs. Oxygen-rich blood leaves the lungs via the pulmonary veins, which drain into the left atrium.

Before Going to Lab

1 Label the blood vessels in Figure 30.13.

LAB ACTIVITY 11 Major Blood Vessels of the Pulmonary Circulation

1 Identify the arteries on a model or chart, or use the search text box in Real Anatomy (Cardiovascular) to find these structures. Note that all oxygen-rich blood vessels are red and oxygen-poor blood vessels are blue. ■

TABLE 30 .12 Veins of the Lower Extremities

VEIN LOCAT ION

Great saphenous veins Superficial veins that form at the medial end of the dorsal venous arches (venous networks on dorsal surface of foot); run anterior to the medial malleolus, ascend along the medial leg and thigh, and drain into the femoral veins in the groin area

Small saphenous veins Superficial veins that form at the lateral end of the dorsal venous arches; run posterior to the lateral malleolus, ascend along the lateral posterior leg, and empty into the popliteal veins

Posterior tibial veins Paired deep veins formed from plantar veins draining the foot posterior to the medial malleolus; ascend deep within the posterior leg accompanying the posterior tibial arteries and merge with the anterior tibial veins just inferior to the popliteal fossa to form the popliteal veins

Fibular (peroneal) veins Paired deep veins that run lateral to the posterior tibial veins; drain into the posterior tibial veins two-thirds of the way up the leg

Anterior tibial veins Form from the dorsal venous arch (venous network on dorsal surface of foot); travel up the anterior surface of the leg accompanying the anterior tibial arteries; merge with the posterior tibial veins to form the popliteal veins just inferior to the popliteal fossa

Popliteal veins Form from the merger of the anterior and posterior tibial veins just inferior to the popliteal fossa; become the femoral veins just superior to the knee

Femoral veins Continuation of popliteal veins that begin just superior to the knee; accompany the femoral arteries up the posterior surface of the thigh; become the external iliac veins as they enter the pelvis

2 3 4 5

• left pulmonary artery • left pulmonary vein • pulmonary trunk • right pulmonary artery • right pulmonary vein

1 _______________________________________

2 _______________________________________

3 _______________________________________

4 _______________________________________

5 _______________________________________

FIGURE 30.13 Blood vessels of the pulmonary circulation.

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D. Fetal Circulation

Because the fetus cannot breathe or ingest food, the mother’s circulatory system provides the fetus with oxygen and nutrients, and eliminates carbon dioxide and other wastes from fetal blood. This exchange occurs across the placenta, which forms within the uterus during early preg- nancy. Uterine blood vessels enter the placenta, and sub- stances are exchanged by diffusion between maternal and placental capillaries without direct mixing of maternal and fetal blood. Two umbilical arteries carry oxygen-poor fetal blood to the placenta, and one umbilical vein carries the oxygen-rich blood back to the fetus. The ductus veno- sus allows blood to enter the inferior vena cava. Several circulatory modifi cations in the fetus allow blood to bypass the nonfunctioning fetal lungs and gastrointestinal tract

Before Going to Lab

1 Label the structures in Figure 30.14(a) and (b) using the description in Table 30.13.

LAB ACTIVITY 12 Fetal Circulation

1 Identify the arteries on a model or chart, or use the search text box in Real Anatomy (Cardiovascular) to find these structures. ■

SAFETY NOTE: Wear safety glasses and gloves when using fresh or preserved tissue. Wash hands thoroughly with soap and water when you are done.

E. Dissection of Blood Vessels

If you are dissecting a cat or fetal pig to observe blood ves- sels, refer to the appropriate dissection manual.

The blood vessels of a cat or fetal pig are similar to those of the human. The dissection will illustrate how blood vessels are enfolded in connective tissue and dive deep to disappear between skeletal muscles. Sometimes you will discover that an artery, vein, and nerve will be traveling together and will separate to journey to separate destinations. Real Anatomy, a virtual cadaver dissection, can be used to complement or substitute for animal dissection of blood vessels.

TABLE 30 .13 Fetal Circulation

STRUCTURE LOCAT ION AND FUNCT ION STRUCTURAL MODIF ICAT ION AFTER B IRTH

Umbilical arteries Branch off internal iliac arteries; carry Close and fill with connective tissue and become fetal blood to the placenta the medial umbilical ligaments Umbilical vein Formed at the placenta and travels to Vessel collapses and renamed ligamentum teres the liver, where it forms two branches, (round ligament) the ductus venosus and another vein that drains into the hepatic portal vein Ductus venosus Major branch of umbilical vein that Vessel collapses and renamed ligamentum venosum carries most of fetal blood from the placenta to the inferior vena cava Foramen ovale Opening in atrial septum that allows Closes and becomes the fossa ovalis blood to pass from right atrium to left atrium Ductus arteriosus Arterial vessel that connects Closes and becomes the ligamentum arteriosum pulmonary trunk with the aorta

(Table 30.13). The foramen ovale and the ductus arterio- sus allow blood to bypass the fetal lungs, and after birth, vascular changes occur to allow blood to enter the lungs.

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FIGURE 30.14 Fetal circulation and modifications after birth.

7 _____________________________

8 _____________________________

9 _____________________________

10 _____________________________

11 _____________________________

• fossa ovalis • ligamentum arteriosum • ligamentum teres • ligamentum venosum • medial umbilical

ligaments

(b) • ductus arteriosus • ductus venosus • foramen ovale • placenta • umbilical arteries • umbilical vein

1 _____________________________

2 _____________________________

3 _____________________________

4 _____________________________

5 _____________________________

6 _____________________________

(a)

6 7

(b) Modifications after birth

(a) Fetal circulation

Name ___________________________________ Date _________________ Section ______________________________

30 E X E R C I S EReviewing Your Knowledge

501

A. Arteries and Veins

1. Which arteries carry oxygen-poor blood, and which veins carry oxygen-rich blood?

2. What are the external iliac arteries called when they pass the inguinal ligaments?

3. Varicose veins in the legs are common, but are there also varicose arteries in the legs? Why or why not?

4. What are the names of the paired veins that drain the head and neck?

5. In the arm and forearm, is it the deep veins or superficial veins that accompany arteries with the same names as the veins?

6. Which vein of the upper limb is typically used to draw a blood sample?

7. Where is the azygos vein located, and what area does it drain?

8. Usually arteries carry nutrient-rich blood, but there are veins that do also. What are their names?

502 E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N

B. Review of Arteries

Identify each artery in Figure 30.15 and write its name next to the number.

FIGURE 30.15 Major arteries.

25 26

33 (posterior)

35 (posterior)

4 5

E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N 503

C. Review of Veins

Identify each vein in Figure 30.16 and write its name next to the number.

FIGURE 30.16 Principal veins.

6 5

7 8

504 E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N

D. Arterial Blood Distribution

Complete the schematic diagrams of arterial blood distribution in Figure 30.17.

FIGURE 30.17 Schematic diagram illustrating arterial blood distribution.

Abdominal aorta

Left common iliac (gives rise to same branches as right common iliac, except that arteries are labeled left instead of right)

Right internal iliac

(b) Pelvis and lower limb

(a) Arch of aorta; brain and upper limb

Right dorsalis pedis

Right middle

cerebral

Right posterior cerebral

Right vertebral

Left external carotid

Left axillary

(gives rise to same branches as right axillary, except that arteries are labeled left instead of right)

Right subclavian

Left subclavian

Right superficial

palmar arch

Right deep

palmar arch

Arch of aorta

1 2

10 11 12

13 14

21 22

5 6 7 8

Name ___________________________________ Date _________________ Section ______________________________

Using Your Knowledge

30 E X E R C I S E

505

A. Blood Vessel Identification

1. Balloon catheters are inserted into the femoral artery to unblock coronary vessels. Name all the arterial structures, in order, that the balloon catheter passes through from the right femoral artery to the right coronary artery.

2. Trace a drop of blood from the aorta to the small intestine and back to the right atrium. Include, in order, the major arteries and veins.

3. Trace a drop of blood from the aorta to the skin of the face and back to the right atrium. Include, in order, the major arteries and veins.

4. A blockage in the right internal carotid does not necessarily cause a loss of blood supply to the brain. (a) Identify the area of the brain supplied by the right internal carotid, and name the vessels that would supply blood

to this area if there is a blockage in the right internal carotid artery.

(b) Is a thrombus in the external carotid life-threatening? Why or why not?

Identify the blood vessel that supplies blood to each of the structures in questions 5–7:

5. Radius (bone) and radial nerve

6. Skin covering anterior thigh

7. Rectus femoris muscle

506 E X E R C I S E 3 0 B L O O D V E S S E L I D E N T I F I C AT I O N

Use the angiogram in Figure 30.18 to answer questions 8–10.

8. Identify the blood vessel marked in the angiogram. (Note: Only one branch of the aorta can be seen. The other two cannot be observed because of the angle of the angiogram.)

9. Identify the blood vessel marked in the angiogram.

10. Identify the blood vessel marked in the angiogram.

FIGURE 30.18 Angiogram.

O B J E C T I V E S M A T E R I A L S

• human torso or chart with lymphatic organs or use Real Anatomy

• compound microscope, lens paper, prepared slides of the lymph nodes, thymus, and spleen or use Real Anatomy (Histology)

• Dissection: preserved cats or fetal pigs, dissection equipment, disposable gloves, safety glasses, and cat or fetal pig dissection manual

Lymphatic System Structure and Immune System Function

31 E X E R C I S E

1 List the functions of the lymphatic system

2 Describe lymph formation

3 Describe the lymphatic vessels and the flow of lymph through the body

4 Name the organs and tissues of the lymphatic system and list their functions

5 Describe the gross anatomy and histology of the lymph nodes, thymus, and spleen

6 Describe the immune cells involved in body defense

7 Dissect the cat or fetal pig and identify the main lymphatic structures

507

T he components of the lymphatic system are lymphatic organs and tissues, lymphatic vessels, and lymph. The lymphatic system is the struc- tural location where much of the immune response takes place. The lymphatic system also collects excess interstitial fluid and returns this fluid to the bloodstream. In addition, it delivers dietary lipids and lipid-soluble vitamins (A, D, E, and K) absorbed from the small intestine to the bloodstream.

A. Lymph and Lymphatic Vessels

Lymph, the fl uid found within lymphatic vessels, is formed from blood plasma. As blood fl ows through blood capil- laries, hydrostatic and osmotic pressures fi lter more plasma out of the blood capillary and into the interstitial spaces

than is drawn back inside. The excess fl uid in the intersti- tial spaces (between blood capillaries and tissues) is now called interstitial fl uid. When the interstitial fl uid enters the lymphatic capillaries, which lie near blood capillaries and are closed at one end, it is called lymph. Interstitial fl uid and lymph are identical in composition but different in location. Blood plasma, however, differs from both of these fl uids in that plasma contains many plasma proteins (including albumin) that are too large to cross the blood capillary endothelium into the interstitial fl uid. Lymph fl ows from lymphatic capillaries into many lymphatic vessels that take lymph toward the neck region. Lymphatic vessels follow the pathway of veins in the body and also have a similar structure, but they have thinner walls and more valves than veins. Just as a body massage is help- ful for moving blood through the veins and toward the heart, a light massage is also helpful for moving lymph through the lymphatic vessels and nodes to cleanse the lymph.

508 E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N

Lymphatic vessels fl ow into a series or chain of lymph nodes where lymph is fi ltered. Within a body region, the lymph vessels exiting the last lymph nodes in each chain of nodes merge to form lymph trunks. Lymph trunks merge to form two main ducts, the thoracic duct (left lymphatic duct) and the right lymphatic duct. In the abdominal area, lymph trunks merge to form a sac-like reservoir called the cysterna chyli. The long thoracic duct begins at the cysterna chyli and continues superiorly to drain the lymph from the legs, abdomen, left arm, and left side of the tho- rax, neck, and head into the left subclavian vein. The right lymphatic duct is the lesser and very short duct that drains lymph from the right arm via the right jugular trunk and right side of the thorax, neck, and head via the right sub- clavian trunk. Each duct enters the subclavian vein at its juncture with an internal jugular vein to drain lymph into venous blood.

Before Going to Lab

1 Label the lymphatic structures in Figures 31.1(a) and (b) and 31.2(a–c).

2 Examine the lymphatic vessel with valve in Figure 31.1(c).

Blood

Venule

(a) Lymphatic and blood capillaries

Arteriole

Endothelium of lymphatic capillary

Anchoring filament

Opening into lymphatic capillary

(b) Lymphatic capillary

Closed valve

FIGURE 31.1 Lymphatic capillaries.

• blood capillary • interstitial (inter-STIH-shul)

fluid • lymphatic capillary • tissue cell

1 ________________________

2 ________________________

3 ________________________

4 ________________________

• interstitial fluid • lymph in lymphatic

capillary • tissue cell

5 ________________________

6 ________________________

7 ________________________

E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N 509

(a) • cisterna chyli • lymphatic vessel in arm • lymphatic vessel in leg • right lymphatic duct • thoracic duct draining into

subclavian vein • thoracic duct in thorax

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

(b) • area drained by right

lymphatic duct • area drained by thoracic duct

7 ________________________

8 ________________________

Left subclavian

vein

Left jugular

trunk

Right subclavian trunk

Right jugular trunk

Right internal jugular vein

Intestinal and

lumber trunks

(a) Overview of lymphatic vessels

(b) Lymph drainage

FIGURE 31.2 Lymphatic vessels.

510 E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N

Thoracic duct

Azygos vein

Diaphragm

Vena cava

Spleen

Left internal jugular vein

Left brachiocephalic vein

Left broncho- mediastinal trunk

Accessory hemiazygos vein

Hemiazygos vein

Left lumbar trunk

Intestinal trunk

Right internal jugular vein

Right brachiocephalic vein

Right broncho- mediastinal trunk

Right subclavian vein

Rib

Intercostal muscle

Azygos vein

Right lumbar trunk

Inferior vena cava

Superior vena cava

FIGURE 31.2 Lymphatic vessels, continued.

• cisterna chyli

• right jugular trunk

• right lymphatic duct

• right subclavian trunk

• thoracic duct

• thoracic (left lymphatic) duct in thorax

9 _______________________________________

10 _______________________________________

11 _______________________________________

12 _______________________________________

13 _______________________________________

14 _______________________________________

E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N 511

respiratory, urinary, and reproductive tracts are called mucosa-associated lymphoid tissue (MALT). Aggrega- tions of large nodules (follicles) include Peyer’s patches in the small intestine, lymphoid follicles in the appendix (appendix � appendage), fi ve tonsils (one pharyngeal tonsil and paired palatine and lingual tonsils), and bron- chial nodules located in the walls of the respiratory tract. The pharyngeal tonsil is located in the posterior nasophar- ynx, while the palatine tonsils are in the posterior portion of the oral cavity. The lingual tonsils are located under the tongue. All of these nodules protect the body from foreign substances that are ingested, inhaled, or otherwise enter body openings.

B. Lymphatic Organs and Tissues

Lymphatic organs and tissues are located throughout the body. Lymphatic organs are surrounded by a capsule and include the thymus, lymph nodes, and spleen. Lymphatic tissues are not surrounded by a capsule and are called lym- phatic nodules. Because their functions differ, lymphatic organs and tissues are divided into two categories based on function: primary lymphatic organs, and secondary lymphatic organs and tissues. Primary lymphatic locations contain stem cells that produce lymphocytes and are the site where these lympho- cytes become immunocompetent (recognize and mount immune system response). The two primary lymphatic or- gans are red bone marrow and the thymus. The thymus, which is located in the mediastinum just superior to the heart, is much larger in children and decreases consider- ably in size as they get older. Secondary lymphatic organs and tissues are sites for defense against invading agents and cancer cells and in- clude the lymph nodes, spleen, and lymphatic nodules (follicles). Lymph nodes are named for their location in the body. Single lymphatic nodules located in the connec- tive tissue of mucous membranes of the gastrointestinal,

LAB ACTIVITY 1 Lymphatic Organs and Tissues

1 Identify the lymphatic structures in Figure 31.3(a) and (b) on a human torso or chart.

2 Use the Real Anatomy search text box to find lym- phatic structures in Figure 31.3(b). ■

Before Going to Lab

1 Label the lymphatic structures in Figure 31.3(a) and (b).

(a) Sagittal view

Sagittal plane

FIGURE 31.3 Lymphatic organs and tissues.

• lingual (LING-wal) tonsil

• palatine (PAL-ih-tine) tonsil

• pharyngeal (fuh-RIN-gee-al) tonsil

1 ________________________________________

2 ________________________________________

3 ________________________________________

512 E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N

• appendix (vermiform)

• axillary lymph node

• cervical lymph node

• iliac lymph node

• inguinal lymph node

• intestinal lymph node

• mammary lymph node

• Peyer’s patches (aggregated lymphatic follicles)

• red bone marrow

• spleen

• submandibular lymph node

• thoracic lymph node

• thymus (THY-mus)

4 __________________________

5 __________________________

6 __________________________

7 __________________________

8 __________________________

9 __________________________

10 __________________________

11 __________________________

12 __________________________

13 __________________________

14 __________________________

15 __________________________

16 __________________________

FIGURE 31.3 Lymphatic organs and tissues, continued.

Left internal jugular vein

Left subclavian vein

Small intestine

4 5

Right subclavian vein

Large intestine

(b) Anterior view

E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N 513

LAB ACTIVITY 2 Flow of Lymph

1 With your lab group, trace the flow of lymph from the thigh to the heart in Figure 31.4. Note that lymph moves superiorly to return to the circulatory system. • brachiocephalic vein • cisterna chyli • iliac lymph nodes • inguinal lymph nodes

FIGURE 31.4 Flow of lymph.

14. heart

13.

12.

11.

10.

2. interstitial fluid

1. blood capillaries

• junction of jugular and subclavian veins • lumbar trunk • lymphatic capillaries • lymphatic vessels (use term twice) • superior vena cava • thoracic duct ■

514 E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N

the lymph to move slowly through the lymph nodes, al- lowing time for immune system cells (lymphocytes and macrophages) to attack pathogens, cancer cells, and foreign molecules. Enlarged lymph nodes could be caused by, but the causes are not limited to, infection, cancer, or scarring from a chronic lesion.

C. Structure of the Lymph Node

Lymph nodes are bean-shaped structures that fi lter lymph and are usually found in groups. Clusters of these nodes are generally found in different body regions (i.e., the cer- vical, axillary, and inguinal areas) and are named for their location. Each node has a capsule with extensions called trabeculae (trabecula � little beam) that compartmentalize the node. The nodes are composed of reticular (reticulum � process) tissue, with reticular fi bers forming the net-like support for reticulocytes (specialized fi broblasts). Two main regions of lymph nodes are the cortex (superfi cial re- gion) and medulla (deep region). There are many lighter- colored oval lymphatic nodules in the outer cortex that contain many immune system cells. Lymph enters each node via many afferent vessels; travels through the following spaces, subcapsular sinus, trabecular sinuses, and medullary sinuses; and exits the node via fewer efferent vessels. The hilum (hila � depression or pit) is the indented area of the node where the efferent vessels leave the node. This design causes

LAB ACTIVITY 3 Lymph Node Structure

1 Examine a prepared slide of a lymph node, or use Real Anatomy (Histology). • Using low power, identify the structures listed in

Figure 31.5(b). • Using high power, identify the reticulocytes and re-

ticular fibers of the lymph node [Figure 31.5(c)]. ■

Before Going to Lab

1 Label the lymph node structures in Figure 31.5(a), (b), and (c).

2 Observe lymph nodes and lymphatic vessel in Figure 31.6.

7 6

Trabecula

5 Lymphatic nodule

(a) Partially sectioned lymph node

FIGURE 31.5 Lymph node.

• afferent vessels • capsule • cortex • efferent vessels • hilum

• medulla • medullary sinus • subcapsular sinus • trabecular sinus • valve

1 _______________________________________

2 _______________________________________

3 _______________________________________

4 _______________________________________

5 _______________________________________

6 _______________________________________

7 _______________________________________

8 _______________________________________

9 _______________________________________

10 _______________________________________

E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N 515

FIGURE 31.5 Lymph node, continued.

11 12

Blood vessel

Medullary sinus

(b) Photomicrograph of a portion of a lymph node

17�LM

400�LM

(b)

• capsule

• cortex

• lymphatic nodule

• medulla

• trabecula

11 _______________________

12 _______________________

13 _______________________

14 _______________________

15 _______________________

(c)

• reticular fiber

• reticulocyte

16 _______________________

17 _______________________

Lymph nodes

Lymphatic vessels

Inguinal ligament

Vastus lateralis

Femoral artery

Sartorius

Rectus femoris

Great saphenous vein

FIGURE 31.6 Lymph nodes and lymphatic vessels of left thigh.

516 E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N

through a maturation process that begins when they enter the lobule that “educates” them to recognize and enable an immune response against microbes and foreign molecules that do not belong to your body.

D. Structure of the Thymus

The thymus is bi-lobed organ that is one of the primary lym- phatic organs (see Figure 31.7a). Each lobe of the thymus is covered by a connective tissue capsule. Trabeculae, ex- tensions of the capsule, divide each lobe into lobules. Each lobule has an outer cortex and inner medulla. It is located in the mediastinum between the sternum and the superior vena cava. The thymus is larger in infants and children and begins to atrophy during puberty and continues in adult- hood. Not much active thymic tissue remains in an elderly person, and most of the thymus is infi ltrated with fat. The main purpose of the thymus gland is to support and stimulate immature T lymphocytes (T cells) that migrate to this gland from their origin in red bone marrow. With the help of thymic hormones, thymosin and others, T cells go

• capsule • cortex of lobule • medulla of lobule • trabecula of lobule

1 ________________________________________

2 ________________________________________

3 ________________________________________

4 ________________________________________

LAB ACTIVITY 4 Thymus Structure

1 Examine a prepared slide of the thymus, or use Real Anatomy (Histology).

2 Using low power, identify the structures listed in Fig- ure 31.7(b). ■

Before Going to Lab

1 Label the structures of the thymus in Figure 31.7(b).

FIGURE 31.7 Thymus.

Trachea Thymus (left lobe)

Thyroid gland

Parietal pericardium

(a) Thymus of adolescent

Diaphragm

Right lung

Left lung

Superior vena cava

Thymus (right lobe)

Right common carotid artery

Brachiocephalic veins

(b) Thymic lobules

30�LM

Blood vessels

E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N 517

platelets and contains reticular fi bers that cannot be seen at this magnifi cation. It stains a lighter color because its many red blood cells are anucleate. Many macrophages can also be found here to phagocytize foreign substances in the blood.

E. Structure of the Spleen

The largest lymphatic organ, the spleen, fi lters blood of for- eign organisms and particles, eliminates aged erythrocytes, and is a blood reservoir for platelets. The spleen is the main organ that fi lters blood, similar to the lymph nodes being the main organs that fi lter the lymph. This highly vascular organ lies posterior and lateral to the stomach in the left up- per quadrant (LUQ). The splenic artery enters the spleen and the splenic vein and efferent lymphatic vessels exit the spleen at the hilum. The spleen is an encapsulated organ with extensions of the capsule forming trabeculae. Histologically, the spleen has regions of white pulp and red pulp that are named for their appearance in fresh speci- mens. On prepared slides you will see stained specimens with different colors. White pulp resembles nodules with many lymphocytes and macrophages and appears dark purple when stained. Both B and T lymphocytes carry out immune functions here, and macrophages engulf any aged blood cells, foreign material, or debris. Red pulp stores

LAB ACTIVITY 5 Structure of the Spleen

1 Examine a prepared slide of the spleen, or use Real Anatomy (Histology). • Using low power, identify the capsule, trabecula, red

pulp, and white pulp. • Using high power, identify reticular fibers, reticulo-

cytes, and lymphocytes in white pulp and the reticu- lar fibers, reticulocytes, and red blood cells (RBCs) in the red pulp. ■

Before Going to Lab

1 Label the splenic structures in Figure 31.8(a) and (b).

FIGURE 31.8 The spleen.

(b) • capsule • trabecula • white pulp

4 ________________________

5 ________________________

6 ________________________

(a) Gross structure

SUPERIOR

Colic impression

Renal impression

Gastric impression

Red pulp

Central artery

(b) Portion of the spleen

25�LM

(a) • hilum • splenic artery • splenic vein

1 ________________________

2 ________________________

3 ________________________

518 E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N

destroy them. After B and T cells either destroy or render foreign cells and molecules inactive, macrophages phago- cytize debris. Memory T cells are also produced to become activated later on.

F. Immune Cells Involved in Body Defense

The cells involved in body defense are the T cells (lympho- cytes), B cells (lymphocytes), and macrophages (macro- � big; phago- � to eat). T and B cells (immune cells) and macrophages are originally produced in red bone marrow from pluripotent stem cells, which are immature stem cells that can develop into various mature blood cells. B cells complete their maturation and become immuno- competent in the red bone marrow. Immature T cells mi- grate to the thymus through the bloodstream to complete maturization and become immunocompetent there. After being programmed for their work, mature T and B cells are now immunocompetent and are released into the bloodstream. They travel to secondary lymphatic organs and tissue to be activated and cloned in the immune re- sponse. Secondary lymphatic organs include the lymph nodes and the spleen. Lymphatic tissue (nodules) includes MALT, Peyer’s patches, appendix, tonsils, and bronchial nodules. When stimulated and activated by specifi c antigens, B cells transform into a specialized group of cloned plasma cells that make antibodies against foreign intruders. This type of immune response is called antibody-mediated immunity. B cells also make B memory cells that will become active if the same antigen is introduced into your body. T cells are involved in cell-mediated immunity by bringing into play three types of T cells. When stimulated by specifi c antigens, helper T cells clone and activate both cytotoxic T cells and B cells. Cytotoxic T cells clone and directly attack foreign cells with toxic chemicals that

LAB ACTIVITY 6 Cells Involved in Body Defenses

1 With your lab group, identify where T and B cells are produced and programmed, and where active T and B cells are located in Figure 31.9(b). Note that one letter is used more than once. ■

Before Going to Lab

1 Observe a macrophage (pink) phagocytizing a bacte- rium (green) in Figure 31.9(a).

G. Dissection of Lymphatic Organs

You may have already looked at the lymphatic organs in your previous dissections. As you dissected the blood ves- sels, you may have noticed small, 1/8- to 1/4-inch lymph nodes in the axillary or inguinal areas. Because the nodes are small, they are easy to miss if you do not know their structure or location. Consult the appropriate cat or fetal pig dissection man- ual for your dissection instructions.

(a) Phagocytosis by a macrophage, human lung

Macrophages

Bacterium

FIGURE 31.9 Cells of the lymphatic and immune systems.

E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N 519

Axillary node 8

Spleen 9

Peyer’s patches 10

Iliac node 11

Inguinal node 12

1 Palatine tonsil

2 Submandibular node

3 Cervical node

4 Thymus gland

5 Intestinal node

6 Appendix

7 Red bone marrow

(b) Location of immune system cells

FIGURE 31.9 Cells of the lymphatic and immune systems, continued.

(a) origin of T cells (b) origin of B cells (c) T cells become immunocompetent (d) B cells become immunocompetent (e) active T cells, B cells, and

macrophages

521

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

31 E X E R C I S E

A. Structure of Lymphatic Organs and Tissues

Write the name of the organ or tissue that matches the description. Terms may be used more than once.

1. Regresses considerably with age

2. Largest lymphatic organ; red and white pulp

3. Bean-shaped; has efferent and afferent vessels

4. Primary lymphatic organs

6. Secondary lymphatic organs

8. Secondary lymphatic nodules associated with the nasal and oral cavities

9. Secondary lymphatic nodules located in connective tissue of mucous membranes

10. Secondary lymphatic nodules located in the small intestine

¯ ˘

˙ ¯

˘ ˙

522 E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N

B. Physiology of Lymphatic Tissues and Organs

Write the name of the organ or tissue that matches the description. Terms may be used more than once.

Peyer’s patches appendix (vermiform) lymph nodes mucosa-associated lymphoid tissue (MALT) red bone marrow spleen thymus tonsils

1. Filters lymph

4. Sites for the immune response 5.

8. Filters blood and contains red and white pulp

9. Programs T cells for immunocompetence

10. Programs B cells for immunocompetence

C. Formation of Lymph

Write the name of the term that matches the phrase.

blood interstitial fluid plasma

1. Fluid that becomes interstitial fluid

2. Fluid that becomes lymph

3. Interstitial fluid plus blood cells and large proteins

¯ ˚

˚ ˚

˘ ˚

˚ ˚

˚ ˙

E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N 523

D. Lymphatic Vessels

Write the name of the vessel that matches the description. Terms may be used more than once.

cisterna chyli lymphatic vessels right lymphatic duct thoracic duct lymphatic trunks

1. Sac-like vessel

2. Left lymphatic duct

3. Merge to form lymphatic trunks

4. Merge to form lymphatic ducts

5. The thoracic duct begins here

6. Drains the legs, abdominal area, and left side of the body

7. Drains the right side of thorax, arm, head, and neck

8. The longer lymphatic duct

E. Immune Cells Involved in Body Defense

Write the name of the immune cells that matches the description. Terms may be used more than once.

1. Maturation and immunocompetency in red bone marrow

2. Maturation and immunocompetency in the thymus gland

3. Located in secondary organs and tissues

4. ¯ ˘

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F. Immune Response

Complete the flow chart in Figure 31.10 with the correct terms from the bulleted list below.

• antibodies • antibody-mediated immunity • cell-mediated immunity • cytotoxic T cells • mature T cells

• memory B cells • memory T cells • plasma cells • T helper cells • thymus

FIGURE 31.10 Cells of the immune response.

Mature B cellsPre-T cells

(clone)

(type of immunity)

(clone)

Red bone marrow

4 5

525

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

31 A. Lymphatic and Immune Systems

1. How would the lymph that is leaving the cisterna chyli differ from lymph draining into the right lymphatic duct?

2. If you look into a child’s mouth, there are “golf balls” puffing from each side of the oral cavity. What are these structures?

3. How do lymphatic capillaries differ from blood capillaries?

4. If you dissected a fetal pig or a young cat, what difference would you expect in the thymus compared to the adult?

5. Why are the walls of lymphatic vessels thin, like veins?

6. Bacteria and viruses in infected tissues easily enter lymph vessels. Explain why.

7. If a woman had a radical mastectomy (removal of a cancerous breast, surrounding tissues with axillary lymph nodes, and anterior thoracic muscles), would you expect the arm on that side to be edematous (have edema)? Explain.

526 E X E R C I S E 3 1 LY M P H AT I C S Y S T E M S T R U C T U R E A N D I M M U N E S Y S T E M F U N C T I O N

8. Would you describe the flow of lymph through lymph nodes as being fast or slow compared with blood capillaries? Explain.

9. What would be missing in lymph exiting a lymph node compared with lymph entering the node?

10. A patient has enlarged right inguinal lymph nodes that are very tender to the touch. Examination of the feet reveals a small cut between the right 3rd and 4th toes, which are warm and red. What would your initial impression be, and why are the lymph nodes enlarged?

11. Figure 36.11 depicts a person with elephantitis. How does a person contract this disease?

12. How does this disease affect the lymphatic system?

FIGURE 31.11 Person with elephantitis.

O B J E C T I V E S M A T E R I A L S

• models or charts with respiratory organs or use Real Anatomy (Respiratory)

• sagittal section model or chart of the human head, neck, and thorax; larynx model or use Real Anatomy (Respiratory)

• compound microscope, lens paper, prepared slides of trachea and lung or use Real Anatomy (Histology)

• Dissection: preserved cats or fetal pigs, dissection equipment, disposable gloves, safety glasses, and cat or fetal pig dissection manual

• Real Anatomy: Virtual Cadaver Dissection

Respiratory System Structure and Function

32 E X E R C I S E

1 Locate and identify the organs of the respiratory system

2 Describe the structure and function of the respiratory system organs

3 Trace the path of air from the nose to the alveoli

4 Dissect a cat, fetal pig, or cadaver, and identify the main respiratory organs

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T he respiratory system provides an airway for movement of air into and out of the body. It is also the site where atmospheric oxygen diffuses into the bloodstream to be delivered to all body cells and carbon dioxide produced by these cells diffuses out of the bloodstream to be exhaled into the atmosphere. This gas exchange takes a coordinated effort of the respiratory and cardiovascular systems.

A. Gross Anatomy of the Respiratory Organs

The main organs of the respiratory system are the nose, pharynx, larynx, trachea, bronchi, and lungs. Clinically, the nose and pharynx are organs of the upper airways, and the larynx, trachea, bronchi, and lungs constitute the lower airways. Functionally the respiratory system is divided into the conducting zone (nose to the terminal bronchioles) and the respiratory zone (respiratory bronchioles to the alveoli).

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1. Nose

The framework of the nose is composed of bone and car- tilage. Bones make up the base of the nose, and hyaline cartilage the anterior portion. Two external nares (naris, sing.) are the openings for air to enter a space called the nasal cavity, which is lined with a mucous membrane. The nasal septum separates this cavity into right and left portions. The nasal septum is highly vascularized and is the site of nosebleeds. A deviated septum may result from trauma, such as a blow to the nose, and can cause dif- fi culty in breathing. On either side of the nose, three curved bony structures extend into the nasal cavity: the

LAB ACTIVITY 1 Structures of the Respiratory System

1 Identify the respiratory structures on a model or chart, or use the search text box in Real Anatomy (Respiratory) to find these structures. ■

Before Going to Lab

1 Label the structures of the respiratory system in Fig- ure 32.1(b).

(a)

Larynx

Trachea

Right primary (main) bronchus

Right phrenic nerve

Lungs

7 8 9

(b) Anterior view

FIGURE 32.1 Organs of the respiratory system.

• larynx (LAIR-inks) • lungs • nasal cavity • nose • pharynx (FAIR-inks) • right primary or main bronchus (BRON-kus) • trachea (TRAY-key-a)

1 ________________________________________

2 ________________________________________

3 ________________________________________

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7 ________________________________________

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superior, middle, and inferior nasal conchae (concha � shell-shaped), or turbinates (turbinum � scroll-shaped). Beneath each nasal concha is a concavity called a meatus (meatus � passage) that increases surface area in the nose. When incoming air passes over the vascularized mucous membranes of the meatuses, the air is warmed and humidi- fi ed. This is the reason that the pharynx gets dry if a per- son’s nose is stopped up and breathing is done through the mouth. The bony hard palate forms the fl oor of the nasal cavity. At the junction of the hard and soft palates are the internal nares, two openings that lead into the tubular na- sal pharynx posteriorly. When the skull was discussed in the axial skeleton exercise, it was mentioned that the nasal cavity is surrounded by four paranasal sinuses.

LAB ACTIVITY 2 Nasal Structures

1 Identify the nasal structures on a sagittal section model or chart, or use the search text box in Real Anatomy (Respiratory) to find these structures. ■

Before Going to Lab

1 Label the structures of the nose in Figure 32.2(a) and (b).

Sphenoidal sinus

Sphenoid bone

(a) Sagittal section

Frontal bone

Frontal sinus

3 4

(b) Frontal section

Frontal sinus

Ethmoidal sinus

13 10

Maxillary sinus

FIGURE 32.2 Nasal structures within nasal cavity.

(b)

• inferior nasal concha • inferior nasal meatus • middle nasal concha • middle nasal meatus • nasal septum

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(a)

• external naris (NEH-ris) • hard palate • inferior nasal concha or

turbinate (CON-cha; TUR-bin-it)

• inferior nasal meatus (mee-AY-tus)

• internal naris • middle nasal concha or

turbinate • middle nasal meatus • superior nasal concha or

turbinate • superior nasal meatus

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2 ________________________

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9 ________________________

The frontal, maxillary, ethmoidal, and sphenoidal bones have mucous membrane-lined sinuses or cavities that also warm and moisten the air. These paranasal cavities have ducts that drain into the nasal cavity.

530 E X E R C I S E 3 2 R E S P I R AT O R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

(palate) and lingual (tongue) tonsils. Note that the mucous membranes of the nose, paranasal sinuses, pharynx, and middle ear are connected by ducts, which explains why in- fections can spread to any adjacent areas.

2. Pharynx

The pharynx or throat is divided into three regions: the nasopharynx (naso- � nose), oropharynx (oro- � mouth), and laryngopharynx (laryngo- � larynx), corresponding to the anatomical structures nearby. The nasopharynx begins at the internal nares and ends at the soft palate. The oro- pharynx begins at the soft palate and extends to the level of the hyoid bone, and the laryngopharynx extends from the hyoid bone to the beginning of the esophagus. The soft palate is found in the pharynx as a posterior extension of the hard palate. The oval-shaped uvula dangles inferiorly as an extension of the soft palate. During swallowing, the soft palate pushes superiorly to close off the nasopharynx and to direct food toward the laryngopharynx. Two auditory tubes (Eustachian tubes) have openings from the middle ear into the nasopharynx, and the single pharyngeal tonsil (adenoid) is located in its posterior wall. The oropharynx has two pairs of tonsils, the palatine

LAB ACTIVITY 3 The Pharynx

1 Identify the pharyngeal structures on a sagittal model or chart, or use the search text box in Real Anatomy (Respiratory) to find these structures. ■

Before Going to Lab

1 Label the three divisions of the pharynx in Figure 32.3(b). 2 Label the pharyngeal structures in Figure 32.3(c).

(a)

Internal naris

Soft palate

Oropharynx

Lingual tonsil

Pharyngeal tonsil

Laryngopharynx

Nasopharynx

Auditory tube opening

FIGURE 32.3 The pharynx and associated structures.

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(b) Divisions of the pharynx

FIGURE 32.3 The pharynx and associated structures, continued.

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• laryngopharynx (la-rin-go-FAIR-inks)

• nasopharynx • oropharynx

(oro-FAIR-inks)

1 _______________________

2 _______________________

3 _______________________

(c)

• internal naris • laryngopharynx • lingual (LING-gwal) tonsil • nasopharynx • opening of auditory tube

(Eustachian)

• oropharynx • palatine tonsil • pharyngeal (fair-IN-gee-al)

tonsil • soft palate • uvula (YOU-view-la)

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back into the laryngopharynx. Lateral to the glottis are two pairs of folds. The superior folds are the ventricular (little belly) folds (vestibular folds), or false vocal cords, while the vocal folds or true vocal cords are inferior and medial. The vocal folds attach via small muscles to the arytenoid (arytenoid � ladle-like) cartilage. The vocal folds, which contain elastic tissue, vibrate with phonation or speaking. If these folds become infl amed or have tumors, they cannot vibrate and hoarseness (laryngitis) results.

3. Larynx

The larynx or voice box connects the laryngopharynx with the trachea. This organ consists of nine hyaline cartilages and houses the vocal cords. The larynx contains three paired cartilages—the arytenoid, cuneiform, and cornicu- late cartilages—which are small cartilages located in the posterior wall of the larynx, and three single cartilages— the thyroid cartilage, cricoid cartilage, and epiglottis— which constitute the main body of the larynx. The largest cartilage, the thyroid cartilage (thyroid � shield-shaped), is seen anteriorly and has a prominence called the Adam’s apple, which is made of hyaline cartilage. The cricoid car- tilage (cricoid � ring-like), which is inferior to the thy- roid cartilage, is larger on the posterior side than on the anterior side and consists of hyaline cartilage. As the term cricoid suggests, this is the only cartilage that is a complete ring in the larynx or trachea. The glottis is the opening that allows air into the larynx. The oval-shaped epiglottis (epi- � over; -glottis � tongue) is composed of elastic car- tilage and closes over the glottis during swallowing. If you have food or drink in your mouth and start laughing, the glottis opens and you could aspirate these substances into the larynx with the air. Coughing forces the food or liquid

LAB ACTIVITY 4 The Larynx

1 Identify the laryngeal structures on a model or chart, or use the search text box in Real Anatomy (Respiratory) to find these structures.

2 Palpate your thyroid cartilage. Swallow and feel the thyroid cartilage move upward. ■

Before Going to Lab

1 Label the laryngeal structures listed in Figure 32.4(c), (d), (e), and (f).

FIGURE 32.4 The larynx and associated structures.

Epiglottis

Thyroid cartilage

Cricoid cartilage

Tracheal cartilage

(a) Anterior view

Epiglottis

Thyroid cartilage

Cricoid cartilage

(b) Posterior view

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4 Hyoid bone

Corniculate cartilage2 5

Arytenoid cartilage

3 6

Thyroid gland

Tracheal cartilage

Hyoid bone

Cuneiform cartilage

Corniculate cartilage

(e) Midsagittal

Posterior Anterior

(f) Superior

FIGURE 32.4 The larynx and associated structures, continued.

(c)

• cricoid (CRY-koid) cartilage

• epiglottis • thyroid cartilage

1 _______________________

2 _______________________

3 _______________________

(d)

• cricoid cartilage • epiglottis • thyroid cartilage

4 _______________________

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6 _______________________

(e)

• arytenoid (ar-ih-TEE-noid) cartilage

• cricoid cartilage • epiglottis • thyroid cartilage • ventricular fold • vocal fold

7 _______________________

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9 _______________________

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12 _______________________

(f)

• glottis • ventricular fold • vocal fold

13 _______________________

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15 _______________________

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4. Bronchial Tree

Just as a tree has a trunk, branches, twigs, and fruit, the lower airways have a trachea, bronchi, bronchioles, and alveoli. If the trachea and bronchi were inverted, they would resemble the branches of a tree, hence the name bronchial tree. The trachea (trachea � sturdy) or windpipe is a tube-like conduit that conducts air from the larynx to the bronchi. It is located anterior to the esophagus and can be palpated on the anterior surface of the neck. When palpat- ing the trachea, horizontal tracheal cartilages that keep the airway open can be felt as bumps one on top of the other. Tracheal cartilages are C-shaped, and a smooth muscle, the trachealis muscle, connects the open sides of the C-shaped cartilage. The trachealis muscle is on the posterior surface of the trachea and allows expansion of the esopha- gus into the trachea during swallowing. The trachea ends at the carina (carina � keel of a boat) inferiorly and branches into a shorter right and longer left primary bron- chus, each serving the corresponding lung. Each primary (main) bronchus branches into secondary (lobar) bronchi to supply a lobe of each lung. The right primary bronchus branches into three secondary bronchi, and the left primary bronchus branches into two secondary bronchi. The sec- ondary bronchi further subdivide into tertiary (segmental) bronchi that enter bronchopulmonary segments within a lobe. Tertiary bronchi divide into bronchioles, each serv- ing small compartments called lobules. Bronchioles fur- ther subdivide into terminal bronchioles, which branch into respiratory bronchioles that begin the respiratory zone of the lung. Respiratory bronchioles further divide into alveolar ducts that lead into clusters of alveoli called alveolar sacs. Alveoli bud off alveolar sacs like individual grapes in a grape cluster. Simple squamous alveolar cells and simple squamous blood capillary cells form the respi- ratory membrane, where gas exchange occurs. Several changes occur as the bronchi turn into bronchioles. The diameter of the airway diminishes, the epithelium changes, cartilage disappears early in the tertiary bronchi, and the bronchioles have only smooth muscle spiraled around them. Because smooth muscle in the bronchioles causes constriction, asthmatic inhalers with bronchial dilators cause the smooth muscle to relax during asthmatic attacks.

LAB ACTIVITY 5 Bronchial Tree

1 Locate the bronchial tree structures on a lung model, or use the search text box in Real Anatomy (Respiratory) to find these structures.

2 Palpate the sternal angle to locate where the trachea divides into the primary (main) bronchi.

3 Observe the sheep pluck demonstration with the bronchial tree dissected. ■

Before Going to Lab

1 Label the bronchial tree structures in Figure 32.5(a) and (b) and Figure 32.6.

(a) Anterior view

FIGURE 32.5 Bronchial tree.

(a)

• bronchiole (BRON-key-ol) • carina (ka-RYE-na) • diaphragm • larynx • left primary (main)

bronchus • left tertiary (segmental)

bronchus • right primary (main)

bronchus • right secondary (lobar)

bronchus • trachea • tracheal cartilage

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2 ______________________

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Bronchiole

14 15

Cartilage plates

Smaller bronchii

Trachea

Cartilage rings

(b) Bronchial tree branching

FIGURE 32.5 Bronchial tree, continued.

CLINICAL NOTE: The airways can be clinically divided into three areas according to size:

Large airways—trachea and bronchi Medium airways—bronchioles and terminal bronchioles Small airways—respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli

Respiratory medicine uses these terms to identify the location of diseases. Bronchitis is a large airway disease, asthma is a middle airway disease, and emphysema is a small airway disease.

(b)

• alveolar (al-VEE-oh-lur) sac • primary (main) bronchus • respiratory bronchiole • secondary (lobar) bronchus • terminal bronchiole • tertiary (segmental) bronchus

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Terminal bronchiole

3 Visceral pleura

• alveolar ducts • alveolar sac • alveoli • respiratory bronchiole

1 _______________________

2 _______________________

3 _______________________

4 _______________________

FIGURE 32.6 Diagram of portion of lung lobule.

536 E X E R C I S E 3 2 R E S P I R AT O R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

The pleural cavity is the space between the two pleural layers that contains pleural fl uid.

5. Lungs

The two lungs are divided into three lobes on the right side and two lobes on the left. The three right lobes are the superior, middle, and inferior lobes, and the left lobes are called the superior and inferior lobes. The rounded supe- rior part of the lung is the apex, and the broader inferior part is the base, which rests on the diaphragm. The left lobe has a concave surface called the cardiac notch, which has the apex of the heart projecting into it. Each lung has a hilum, an area surrounded with pleura, where the bron- chi, blood and lymphatic vessels, and nerves enter or exit the medial side of the lung. The lungs are in the thoracic cavity and are separated from each other by the heart and the mediastinum. Parietal pleura lines the thoracic cavity wall, and visceral pleura covers the surface of each lung.

Before Going to Lab

1 Label the structures of the lung in Figure 32.7(a), (b), (c), and (d).

2 Label the parts of the pleura in Figure 32.8(a) and (b).

LAB ACTIVITY 6 Lungs and Pleura

1 Identify the lung structures on a model or chart, or use the search text box in Real Anatomy (Respiratory) to find these structures. ■

(a) Anterior right lung

(b) Anterior left lung

FIGURE 32.7 Lung structures.

(a) • apex • base • inferior lobe • middle lobe • superior lobe

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(b) • apex • base • cardiac notch • inferior lobe • superior lobe

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FIGURE 32.7 Lung structures, continued.

(d) • cardiac notch • hilum • inferior lobe • superior lobe

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(a) • diaphragm • parietal pleura • pleural cavity • visceral pleura

1 ______________________

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3 ______________________

4 ______________________

(space) 3

(a) Anterior view (b) Transverse section through thorax (inferior view)

Transverse plane

Inferior view

(space) 8

FIGURE 32.8 Pleura.

(b) • left lung • parietal pleura • pleural cavity • right lung • visceral pleura

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B. Microscopic Anatomy of the Respiratory System

There are four basic types of epithelium in the respiratory system, with areolar connective tissue as the underlying tissue just beneath the epithelia. As can be seen in Table 32.1, the mucous membranes of the upper airways are lined with pseudostratifi ed ciliated columnar epithelium. This epithelium has goblet cells which secrete viscous mucus that traps dust and other particles. There are also cilia, which beat to move mucus toward the pharynx to be swallowed. The oropharynx and laryngopharynx are common areas for both the digestive and respiratory systems. Since abrasive food particles will travel through these two structures, they are lined with nonkeratinized stratifi ed squamous epithe- lium. The multilayers of this type of epithelium protect the underlying tissue. This epithelium continues into the upper part of the larynx. In the lower larynx, pseudostratifi ed cili- ated columnar epithelium resumes and extends through the trachea and primary (main) bronchi. Deeper into the bronchial tree, the epithelium gradually changes from high pseudostratifi ed columnar epithe- lium to simple columnar and fi nally to simple cuboidal, with an accompanying gradual loss of cilia. The respiratory zone structures (respiratory bronchioles to the alveoli) all have simple squamous epithelium that allows the highly vascularized alveoli to facilitate diffusion of respiratory gases, oxygen, and carbon dioxide.

Before Going to Lab

1 Label the structures of the trachea and esophagus in Fig- ure 32.9(a) and the lung in Figure 32.9(b).

LAB ACTIVITY 7 Microscopic Examination of Respiratory Tract Tissues

1 Examine a prepared slide of the trachea and esophagus, or use Real Anatomy (Histology) to find these structures. • Using the low-power objective lens, identify the

structures listed in Figure 32.9(a). • Using the high-power objective lens, identify the

pseudostratified ciliated columnar epithelium lining the tracheal lumen and the hyaline cartilage within the tracheal wall. Identify a goblet cell within the epithelium.

2 Examine a prepared slide of lung tissue, or use Real Anatomy (Histology) to find these structures. • Using the low-power objective lens, identify

alveoli and, if present, the other structures listed in Figure 32.9(b).

• Using the high-power objective lens, identify the simple squamous epithelium forming the alveolar walls.

3 Answer the Discussion Questions with your lab group.

TABLE 32 .1 Respiratory Epithelia

RESP IRATORY STRUCTURE EP ITHEL IA

Nasal cavity Pseudostratified ciliated columnar Paranasal sinuses Pseudostratified ciliated columnar Nasopharynx Pseudostratified ciliated columnar Oropharynx Stratified squamous Laryngopharynx Stratified squamous Larynx (vocal folds and above) Stratified squamous Larynx (below vocal folds) Pseudostratified ciliated columnar Trachea Pseudostratified ciliated columnar Primary (main) bronchi Pseudostratified ciliated columnar Secondary (lobar) bronchi Simple columnar with fewer cilia Tertiary (segmental) bronchi Simple columnar; no cilia End of tertiary (segmental) bronchi Simple cuboidal; no cilia Bronchioles, including terminal bronchioles Simple cuboidal; no cilia Respiratory bronchioles Begins as simple cuboidal; ends as simple squamous Alveolar ducts, alveolar sacs, alveoli Simple squamous

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Esophagus

Lumen

Trachea

Transverse plane

Epithelial lining

Trachealis muscle

1 2 53 4

(3�) (a) Transverse section of trachea and esophagus

Terminal bronchiole

Blood vessel

8 (tissue)

Visceral pleura

(about 30�)

(b) Sectional view of lung

FIGURE 32.9 Sectional views of the trachea and lung.

(a) • epithelial lining of trachea • lumen of esophagus • lumen of trachea • tracheal cartilage • trachealis muscle

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(b) • alveolar ducts • alveolar sacs • alveoli • respiratory bronchiole • simple squamous

epithelium

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C. Dissection of Respiratory Structures

If you are dissecting a cat or fetal pig to observe respira- tory system structures, refer to the appropriate dissection manual. The respiratory system organs of a cat or fetal pig are similar to those of the human. This dissection will illustrate the structure of the larynx and trachea, the relationship of respiratory organs to other organs in the mediastinum, and the connective tissues surrounding these organs. Real Anatomy, a virtual cadaver dissection, can be used to complement or substitute for animal dissection of respiratory structures.

DISCUSSION QUESTIONS Microscopic Anatomy of Respiratory System

1 Which connective tissue type allows the lungs to expand and regain their original size and shape (recoil) during inhalation and exhalation?

2 Which connective tissue type in the bronchial tree pro- vides the support to maintain an open airway?

3 Discuss the significance of the changing epithelia along the respiratory tree.

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Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

32 E X E R C I S E

A. Air Flow

Trace the air flow through the respiratory system starting with the external nares. Number the structures 1 through 17.

____________ alveolar duct

____________ alveolar sac

____________ alveolus

____________ bronchiole

____________ external nares

____________ internal nares

____________ laryngopharynx

____________ larynx

____________ nasal cavity

____________ nasopharynx

____________ oropharynx

____________ primary (main) bronchus

____________ respiratory bronchiole

____________ secondary (lobar) bronchus

____________ terminal bronchiole

____________ tertiary (segmental) bronchus

____________ trachea

B. Structural Changes in the Respiratory Tree

Name three structural changes that occur in the bronchi as they branch into bronchioles.

1. ___________________________________________

2. ___________________________________________

3. ___________________________________________

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C. Structure and Function of the Respiratory System

Write the name of the structure described.

1. Tubular airways that begin the respiratory zone

2. Connects the laryngopharynx with the trachea

3. Tube-like structure that conducts air from the larynx to the bronchi

4. Closes over the glottis during swallowing

5. Keep the trachea from collapsing

6. Division of the bronchi that enter bronchopulmonary segments

7. Last division of the conducting zone

8. Conducts air from the nasopharynx to the laryngopharynx

9. Small, round sacs where gas exchange occurs

10. Small conduction airway that serves a lobule

D. Location and Function of Epithelial Tissue

Match the type of epithelium with its location in the respiratory system and its function.

Epithelial Tissue a. pseudostratified ciliated columnar d. simple squamous b. simple columnar e. stratified squamous c. simple cuboidal

Location 1. Nasal cavity through nasopharynx

2. Oropharynx through larynx above vocal cords

3. Larynx below vocal cords through primary (main) bronchi

4. Secondary (lobar) bronchi through tertiary (segmental) bronchi

5. Bronchioles through beginning of respiratory bronchiole

6. End of respiratory bronchiole through alveoli

Function 7. Secretes mucus to trap and remove dust and debris

8. Diffusion of respiratory gases

9. Protects underlying tissues

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Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

32 A. Anatomy of the Respiratory System

Answer the following questions.

1. Explain how it is possible for a person to drink liquid and then have the liquid come out through the nose when the person laughs.

2. Explain how an infection in the nasopharynx can also result in an infection in the paranasal sinuses and/or the middle ear.

3. Asthma attacks are caused by smooth muscle spasms in the bronchial tree. These spasms can close the airway. What airway structures are closed? Why are these areas closed but not the rest of the bronchial tree?

4. Emphysema is characterized by destructive changes of alveolar walls resulting in large air-filled spaces due to overinflation. There is a loss of lung elasticity, decreased gas exchange, and large air-filled spaces.

Pneumonia is an acute inflammation of the lungs with the alveoli and bronchioles becoming plugged with an exudate (fluid), and the alveolar cell membranes thickening.

In Figure 32.10, identify which alveolar section came from a person with no lung disease (normal alveoli), with emphysema, or with pneumonia.

FIGURE 32.10 Normal and diseased alveolar sections.

(a) ________________________________ (b) ________________________________ (c) ________________________________

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Explain how the changes in alveolar structure cause a decrease in blood oxygen levels in:

5. Emphysema

6. Pneumonia

Identify the structures in Figures 32.11 and 32.12.

FIGURE 32.12 Bronchoscopic view of the larynx.

9 ____________________________________________________

10 ____________________________________________________

Epiglottis

9 10

FIGURE 32.11 Thoracic cavity, cross-section.

7 _____________________________________________ (include right or left)

8 _____________________________________________ (membrane)

Pulmonary Ventilation 33

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The respiratory system supplies oxygen needed by body cells to produce adenosine tri-phosphate (ATP) for metabolism and removes car- bon dioxide produced by metabolic reactions. Respiration involves three steps and requires the cardiovascular system to transport oxygen and carbon dioxide throughout the body. 1. Pulmonary ventilation, or breathing, is the movement

of air between the atmosphere and the lungs that occurs when we inhale (inhalation) and exhale (exhalation).

2. External respiration is the movement of oxygen from the alveoli into pulmonary capillaries and carbon dioxide from pulmonary capillaries to the alveoli.

3. Internal respiration is the movement of oxygen from capillaries into body cells and carbon dioxide from body cells into capillaries.

A. Pulmonary Ventilation

During pulmonary ventilation, air moves from an area of higher pressure to an area of lower air pressure. Changes in air pressure in the lung (alveolar pressure) occur when lung volume changes. The relationship between pressure and volume is described by Boyle’s Law, which states that the pressure of a gas in a closed container is inversely propor- tional to the volume of the container. Therefore, when lung volume increases, the pressure of the air inside decreases and air fl ows into the lungs. When lung volume decreases, the pressure of the air inside increases and air fl ows out of the lungs.

O B J E C T I V E S M A T E R I A L S

• models, charts, or use Real Anatomy (Muscular) • bell jar model of lungs • Effect of Exercise on Lung Volumes and Capacities:

handheld dry spirometer, disposable mouth- pieces, nose clip, 70% alcohol and cotton or alcohol wipes

• Formation of Bicarbonate and Hydrogen Ions: paper bag (lunch size), straws, 50-mL beakers, 100-mL beakers, 25-mL graduated cylinders, pH meter, squeeze bottle of deionized water, stop- watch or watch with second hand

• PowerPhys Experiments: • Respiratory Volumes • Regulation of Pulmonary Ventilation • • Biopac Laboratory Guide Experiments:

• Effect of Exercise on Lung Volumes and Capacities

• Comparison of Predicted and Measured FVC and FEV1

1 Describe how respiratory muscle contraction causes thoracic volume changes

2 Explain how changes in thoracic and lung volumes and lung pressures result in pulmonary ventilation

3 Define and measure or calculate lung volumes and capacities

4 Discuss the relationship between blood carbon dioxide levels and pulmonary ventilation

546 E X E R C I S E 3 3 P U L M O N A R Y V E N T I L AT I O N

1. Changing Thoracic and Lung Volumes

When the diaphragm and other respiratory muscles contract or relax, they change the size of the thorax, which in turn changes lung volume. Normal inhalation is caused mainly by contraction of the diaphragm. The diaphragm is dome- shaped when relaxed and fl attens when contracted. When the diaphragm fl attens, the length of the thoracic cavity and its volume increase. During quiet inhalation, contrac- tion of the external intercostal muscles further increases the width of the thoracic cage by raising the ribs. Contrac- tion of the sternocleidomastoid, scalenes, and pectoralis minor muscles cause a greater increase in thoracic volume during forced inhalation by elevating the rib cage and ster- num, resulting in a greater volume of air inhaled. Normal exhalation is a passive process involving re- laxation of the diaphragm and elastic recoil of the chest wall and lungs. The diaphragm becomes dome-shaped and decreases the length of the thoracic cavity and thoracic volume. In forced exhalation, contraction of the internal intercostal muscles depresses the rib cage. Contraction of the abdominal muscles (external oblique, internal oblique, transverse abdominis, and rectus abdominis)

pushes the diaphragm superiorly, further decreasing thoracic volume and resulting in a greater volume of exhaled air.

Before Going to Lab

1 Label the respiratory muscles in Figure 33.1. Refer to Exercise 14: Skeletal Muscles and Their Actions or your textbook.

LAB ACTIVITY 1 Respiratory Muscles and Volume Changes

1 Identify the respiratory muscles on a model or chart, or use the search text box in Real Anatomy (Respiratory) to find these structures.

2 Pronounce the muscle names as you point to them. 3 Complete Table 33.1 by circling the correct choice in

the column “Effect on Thoracic Dimensions.”

4 Examine the radiographs in Figure 33.2. Decide whether a radiograph was taken after inhalation or exhalation, and put your answer in the appropriate blank. ■

TABLE 33 .1 Respiratory Muscle Functions

EFFECT ON THORACIC D IMENSIONS MUSCLE FUNCT ION ( c i rc le cor rec t cho i ce )

External intercostals Elevate ribs 1. Increase or decrease diameter

Internal intercostals Depress ribs 2. Increase or decrease diameter

Sternocleidomastoids Elevate the sternum 3. Increase or decrease diameter

Scalenes Elevate 1st and 2nd ribs 4. Increase or decrease diameter

Pectoralis minors Elevate 3rd, 4th, and 5th ribs 5. Increase or decrease diameter

Diaphragm Flattens when contracted 6. Increase or decrease length

Abdominal muscles Compress abdominal contents, increase abdominal 7. Increase or decrease length pressure, and force diaphragm superiorly

E X E R C I S E 3 3 PULMONARY VENTILATION 547

Linea alba

(a) Anterior superficial view (b) Anterior deep view

• diaphragm • external intercostals • external oblique • internal intercostals • internal oblique • pectoralis (pek-tor-A-lis)

minor

• rectus abdominis • scalenes (SKAY-leens) • sternocleidomastoid

(ster-no-kli-doh-MAS-toid) • transverse abdominis

1 __________________________

2 __________________________

3 __________________________

4 __________________________

5 __________________________

6 __________________________

7 __________________________

8 __________________________

9 __________________________

10 __________________________

FIGURE 33.1 Respiratory muscles.

548 E X E R C I S E 3 3 P U L M O N A R Y V E N T I L AT I O N

DISCUSSION QUESTIONS Bell Jar (Model Lung) Demonstration

1 (a) In the model lung demonstration, the bell jar is filled with air. What is in the pleural cavity in the thorax? (b) Compare the relative size of the pleural space in the model lung to that in the human lung.

2. Pressure Changes During Pulmonary Ventilation

As the thorax expands, the parietal pleura attached to the internal thoracic wall is pulled outward. The pleural cavity slightly increases in volume, causing a decrease in intra- pleural pressure, the pressure between the pleural layers. The decrease in intrapleural pressure and the surface ten- sion of pleural fl uid cause the visceral pleura, and therefore the lungs, to be pulled outward. As the lungs increase in volume, the alveolar (intrapulmonic) pressure decreases to below atmospheric pressure, and air enters the lungs. When the thorax decreases in size the lungs recoil, causing intrapleural pressure and alveolar pressure to increase, and air leaves the lungs.

(a) ____________________________________________________

(b) ____________________________________________________

FIGURE 33.2 Radiographs of the thorax taken either after inhalation or exhalation.

(a) (b)

Indicate whether the view shows inhalation or exhalation.

LAB ACTIVITY 2 Pressure Changes During Pulmonary Ventilation

1 Using the model lung (bell jar model), observe what happens when the rubber diaphragm at the base of the model is domed or flattened.

2 Complete Table 33.2 by circling the correct choice in the column “Movement of Diaphragm.”

3 Answer Discussion Questions with your lab group.

Before Going to Lab

1 Label the bell jar model lung in Figure 33.3.

E X E R C I S E 3 3 PULMONARY VENTILATION 549

2 (a) In the model lung, is the air in the bell jar at atmo- spheric pressure or subatmospheric pressure? (b) Is the pressure in the pleural cavity atmospheric or subatmo- spheric?

3 (a) If the chest wall (including parietal pleura) is punc- tured, would the pressure in the pleural cavity increase or decrease? (b) Would lung size increase or decrease? (c) What is this condition called?

4 (a) In humans, is there one pleural cavity surrounding both lungs or two separate pleural cavities, one sur- rounding each lung? (b) Does this differ from the model lung?

5 In the model lung demonstration, air flows into the bal- loons through a rigid tube that divides once. Compare the rigidity and the number of branches of the conduct- ing structures in the model to the rigidity and number of branches of the conducting structures in the human respiratory system.

6 In the model lung demonstration, the bell jar does not change in size. Describe the changes in the correspond- ing human respiratory system structures during inhala- tion and exhalation.

■

• bronchus • diaphragm • lungs covered with visceral

pleura • parietal pleura and

thoracic wall • pleural cavity • trachea

1 _______________________

2 _______________________

3 _______________________

4 _______________________

5 _______________________

6 _______________________

FIGURE 33.3 Model lung (bell jar model).

TABLE 33 .2 Bell Jar (Model Lung) Demonstration

MOVEMENT OF D IAPHRAGM

As D iaphragm Domes As D iaphragm F la t tens OBSER VAT IONS ( c i rc le cor rec t cho i ce ) ( c i rc le cor rec t cho i ce )

Volume of air in bell jar 1. Increased or decreased 5. Increased or decreased

Pressure of air in bell jar 2. Increased or decreased 6. Increased or decreased

Balloon size 3. Inflated or deflated 7. Inflated or deflated

Direction of air flow 4. Into or out of balloons 8. Into or out of balloons

550 E X E R C I S E 3 3 P U L M O N A R Y V E N T I L AT I O N

this activity, RV will be calculated with equations that were developed using RV values from many individuals.

B. Lung Volumes and Capacities

Lung volumes and capacities are defi ned in Table 33.3. Notice that lung capacities are equal to 2 or more volumes. Both lung volume and lung capacity values vary according to gender, age, and height. Lung volume and some, but not all, capacity values vary with exercise.

1. Measuring and Calculating Lung Volumes and Capacities

A spirometer is an instrument used to measure lung vol- umes. There are different types of spirometers, depending on how they measure air volumes and capacities. Some spirometers measure only expiratory volumes and ca- pacities, while others measure both inspiratory and expi- ratory volumes and capacities. In the following activity, directions are given for using a dry, handheld spirometer. Exhale only into this type of spirometer. It does not mea- sure inspiratory volumes. Spirometers that measure inspi- ratory air volumes must be cleaned or supplied with new fi lters when used by a different person to prevent spread of infection. Your instructor will supply you with instructions if you are using a different type of spirometer instead of the dry, handheld spirometer. Dry, handheld spirometers cannot be used to measure inspiratory volumes and capacities. However, IRV and IC can be calculated using values for TV, ERV, and VC. Clinically, FRC is measured indirectly with special equip- ment, and RV is calculated using values for FRC and ERV. In

LAB ACTIVITY 3 Experiment: Effect of Exercise on Lung Volumes and Capacities

1 Prediction: With your lab group, predict how exercise will affect TV, IRV, ERV, VC, and TLC. Circle your answer (in italics) below. • During exercise TV will increase, decrease, or stay

the same. • During exercise IRV will increase, decrease, or stay

the same. • During exercise ERV will increase, decrease, or stay

the same. • During exercise VC will increase, decrease, or stay

the same. • During exercise TLC will increase, decrease, or stay

the same.

2 Materials: Obtain the materials for Effect of Exercise on Lung Volumes and Capacities given in the Materials list.

3 Data Collection: Measure TV, ERV, and VC before and after exercise and record the values in Table 33.4. • Decide who will be the subject, who will prepare the

spirometer, who will prepare and coach the subject, and who will be the timer and recorder. The subject should not have heart problems and should be in good health.

TABLE 33 .3 Lung Volumes and Capacities

AVERAGE VOLUME OR REST ING CAPACITY ABBREVIAT ION DEF IN IT ION VALUES

Tidal volume TV The amount of air inhaled and exhaled during 500 mL one normal breath Inspiratory reserve volume IRV Maximum amount of air that can be inhaled 3,100 mL after a normal inhalation Expiratory reserve volume ERV Maximum amount of air that can be exhaled 1,200 mL after a normal exhalation Residual volume RV Amount of air that remains in the lungs after 1,200 mL a maximal exhalation Inspiratory capacity IC IC � TV � IRV 3,600 mL Functional residual capacity FRC FRC � RV � ERV 2,400 mL Vital capacity VC Maximum volume of air expelled after a 4,800 mL maximal inhalation VC � IRV � TV � ERV Total lung capacity TLC TLC � IRV � TV � ERV � RV 6,000 ML

E X E R C I S E 3 3 PULMONARY VENTILATION 551

• Measure expiratory reserve volume (ERV)—Reset the dial to 0. The subject should take two or three normal breaths, and then inhale normally and exhale normally. Without taking another breath, place the spirometer to the subject’s mouth and have the subject exhale as much air as he or she can. Record the value for ERV in Table 33.4. Repeat this process two more times, resetting the dial to 0 before each measurement.

• Measure vital capacity (VC)—Reset the dial to 0. Have the subject take two or three normal breaths, then inhale as much air as possible. Place the spirometer to the subject’s mouth and instruct the subject to exhale as much air as he or she can. Record the value for VC in Table 33.4. Repeat this process two more times, resetting the dial to 0 before each measurement.

Measuring TV, ERV, and VC after exercise • The subject should not have heart problems and

should be in good health. • Have the subject run in place for 5 minutes. • Measure tidal volume (TV)—Reset the dial on the

spirometer to 0. Have the subject take two or three breaths, and then inhale normally. Place the spirom- eter to the subject’s mouth and instruct the subject to exhale normally into the spirometer. Record the value for TV in Table 33.4. Repeat this process two more times, but this time reset the dial before each measurement.

• Measure expiratory reserve volume (ERV) as before. • Measure vital capacity (VC) as before.

4 Clean up as directed by your instructor.

Preparing the spirometer • Wipe the nozzle of the spirometer with 70% alcohol. • Place a clean, disposable mouthpiece on the nozzle. • With use, water will condense inside the dial.

Follow instructions included with your spirometer for removing condensation.

Preparing and coaching the subject • Have the subject use a noseclip or fingers to close

the nostrils to prevent air leaking out of the nose. • When blowing into the spirometer, it should be held

in a horizontal position with the face of the dial upward.

• Have subject practice breathing to measure TV, ERV, and VC. When measuring TV, the subject should breathe normally. When measuring ERV, the subject should take two or three breaths, then inhale normally and exhale as much air as possible. Verbally encourage the subject to exhale as much air as possible. When measuring VC, the subject should take two or three normal breaths, then completely fill the lungs with air, and exhale as much air as possible.

• Remind subject to exhale only into a handheld spirometer.

Measuring TV, ERV, and VC at rest • Measure tidal volume (TV)—Reset the dial on the

spirometer to 0. The subject should take two or three normal breaths and then inhale normally. The spirometer is then placed in the subject’s mouth and the subject is instructed to exhale normally into the spirometer. Repeat this process two more times, and do not reset the dial before each measurement. Divide the volume by 3 to obtain the average TV. Record the average TV in Table 33.4.

TABLE 33 .4 Measured Lung Volumes and Capacities

AT REST VALUE 1 VALUE 2 VALUE 3 AVERAGE VALUE

TV N/A N/A N/A

ERV

AFTER EXERC ISE VALUE 1 VALUE 2 VALUE 3 AVERAGE VALUE

ERV

552 E X E R C I S E 3 3 P U L M O N A R Y V E N T I L AT I O N

EXPERIMENTAL REPORT Effect of Exercise on Lung Volumes and Capacities

Results: State how the various lung volumes and capaci- ties changed with exercise.

Discussion:

1 Refer to Table 33.7 to answer this question. If TLC and RV remain constant, indicate whether an increase in TV would cause the following volumes and capacities to increase, decrease, or remain the same.

• IRV—increase, decrease, remain the same • ERV—increase, decrease, remain the same • IC—increase, decrease, remain the same • VC—increase, decrease, remain the same 2 Discuss why TV changed during exercise. 3 Discuss why the change of TV during exercise either

did or did not cause a change in the following lung volumes and capacities. • IRV • FRC • ERV • VC • IC • TLC

Conclusion: In one or two sentences, state how exercise affects lung volumes and capacities. ■

5 Data Analysis: Calculate average ERV and VC and re- cord in Table 33.4. Calculate IRC, IC, FRC, and TLC and record values in Table 33.5.

Calculate average ERV and VC • Add the individual ERVs and divide by 3. Record the

average ERV in Table 33.4. • Add the individual VCs and divide by 3. Record the

average VC in Table 33.4.

Calculate IRV and IC using average TV, ERV, and VC values • Use the equations for VC and IC in Table 33.3 to

calculate IRV and IC. Rearrange the VC equation to formulate an equation to calculate IRV.

• Calculate the values and record them in Table 33.5.

Calculate RV, FRC, and TLC • Use the appropriate equation in Table 33.6 to calcu-

late your RV based on gender and age, and record the RV in Table 33.5.

• Calculate your FRC and TLC using the equations in Table 33.3 and record the value in Table 33.5.

6 Graphs: If graph paper is available, construct a bar graph that compares resting and exercising lung vol- umes and capacities.

7 Complete the Experimental Report with your lab group. 8 Complete PowerPhys Experiment: Respiratory Volumes. 9 Complete Biopac Laboratory Guide Experiment:

Effect of Exercise on Lung Volumes and Capacities.

1. Polgar G, Promadhat V: Pulmonary Function Testing in Children. Techniques and Standards. Philadelphia: WB Saunders Co., 1971. 2. Goldman HI, Becklake MR: Respiratory function tests—normal values at median altitudes and the prediction of normal results. Am Rev Tuberc

79:457–467, 1959.

TABLE 33 .5 Calculated Lung Volumes and Capacities

VOLUME OR CAPACITY EQUAT ION VALUE

IRV

FRC

TLC

TABLE 33 .6 Equations for Calculating Residual Volume

GENDER AGE EQUAT ION TO PREDICT R V ( l i te r s )

Male or female1 <19 RV � (0.029 � height in inches) � 0.9192 Female2 19–99 RV � (0.0813 � height in inches) � (0.009 � age in years) � 3.9 Male2 19–99 RV � (0.0686 � height in inches) � (0.017 � age in years) � 3.45

E X E R C I S E 3 3 PULMONARY VENTILATION 553

TABLE 33 .7 Lung Volumes and Capacities M

ill ili

te rs

( m

L) 6000

5000

4000

3000

2000

1000

TLC (6000 mL)

VC (4800 mL)

RV (1200 mL)

IRV (3100 mL)

ERV (1200 mL)

RV (1200 mL)

TV (500 mL)

IC (3600 mL)

FRC (2400 mL)

2. Timed Forced Expiratory Volumes

A timed forced expiratory volume is used to indicate whether someone has a condition in which air fl ow is obstructed or restricted. The subject is asked to inhale as much air as pos- sible and then forcibly blow as much air as fast as possible into the spirometer. The total volume of forcibly and rapidly expelled air is the forced vital capacity (FVC), and the vol- ume of air forcibly expelled in the fi rst second is the forced expiratory volume in 1 second (FEV1). These volumes and the ratio of FEV1/FVC are used to determine if a person has an obstructive lung disease such as emphysema, chronic ob- structive pulmonary disease (COPD), or asthma or a restric- tive lung disease such as pneumonia or lung cancer.

LAB ACTIVITY 4 Measuring FEV1 and FVC

1 The graph in Figure 33.4 illustrates the change in vol- ume over time. The x-axis indicates time, and the y-axis indicates volume.

2 Use the values on the y-axis to determine the maximum volume indicated by the curved line. Record this FVC value in the space under the graph in Figure 33.4.

3 On the x-axis, find 1 second after the beginning of the forced exhale. Using a ruler, draw a vertical line that in- tersects the curve at this point. Find the corresponding volume on the y-axis, the FEV1, and record this value in Figure 33.4.

4 Calculate the FEV1/FVC ratio by dividing the FEV1 by the FVC, and record this value in Figure 33.4.

5 Complete the Biopac Laboratory Guide Experiment: Comparison of Predicted and Measured FVC and FEV1. ■

FIGURE 33.4 Timed forced expiratory volume.

Time (sec) 10 2 3 5 64

V ol

um e

(L )

FVC � _______ L FEV1 � _______ L FEV1/FVC � _______

554 E X E R C I S E 3 3 P U L M O N A R Y V E N T I L AT I O N

The pH of blood is determined by the concentration of hydrogen ions in blood. Blood carbon dioxide levels in- crease during exercise (carbon dioxide is a by-product of aerobic respiration). The chemical equation shifts to the right and more hydrogen and bicarbonate ions are formed. This results in a decrease in blood pH due to the increased levels of hydrogen ions. The increased levels of hydrogen ions stimulate chemoreceptors in the brain, aortic arch, and carotid bodies, resulting in an increased rate of pulmonary ventilation and an increased depth of breathing. This in- crease in depth and rate of pulmonary ventilation allows the lungs to exhale more carbon dioxide. As blood carbon dioxide levels decrease, the chemical equation shifts to the left and more hydrogen ions and bicarbonate ions form carbonic acid. The blood hydrogen ion levels decrease, blood pH returns to normal, and pulmonary ventilation returns to resting levels.

C. Control of Pulmonary Ventilation: The Role of Carbon Dioxide

Carbon dioxide is formed during aerobic cellular res- piration when glucose, fatty acids, and amino acids are chemically broken down to make ATP. Carbon dioxide then diffuses out of cells into the interstitial fl uid and then into the bloodstream. Blood travels to the lungs where carbon dioxide diffuses across pulmonary capillaries and into the alveoli, leaving the lungs when we exhale. Exhaled air has a greater percentage of carbon dioxide than atmospheric air. Carbon dioxide is transported in the bloodstream as dis- solved carbon dioxide, bound to hemoglobin, or as bicar- bonate ions. The majority of carbon dioxide is transported as bicarbonate ions. Bicarbonate ions (HCO3�) are formed from carbon dioxide as follows: 1. Carbon dioxide combines with water to form carbonic

acid. CO2 � H2O —¡ H2CO3

2. Carbonic acid dissociates in water to form hydrogen ions and bicarbonate ions.

H2CO3 —¡ H � � HCO3�

The chemical equation for the formation of bicarbonate and hydrogen ions from carbon dioxide and water is:

CO2 � H2O —¡ H2CO3 —¡ H �� HCO3�

The ratio of carbon dioxide to carbonic acid to bicar- bonate ions is constant. If blood carbon dioxide levels in- crease (as occurs after exercise), then more carbonic acid and bicarbonate and hydrogen ions are formed. If carbon dioxide levels are reduced (as occurs in lungs after expira- tion), then more bicarbonate ions and hydrogen ions will form carbonic acid, which will dissociate back into carbon dioxide and water.

LAB ACTIVITY 5 Formation of Bicarbonate and Hydrogen Ions

1 Prediction: With your lab group, predict how exhaling into water after exercise will change the pH of the water. Circle your answer (in italics) below. • Exhaling into water after exercise will increase, de-

crease, or not change the pH.

2 Materials: Obtain the materials for Formation of Bicarbonate and Hydrogen Ions given in the Materials list.

3 Data Collection: Measure change in pH after exhaling into water while at rest and after exercise. Record your results in Table 33.8. • Decide who will be the subject, who will set up the

experiment, who will be the timer, and who will measure and record. The subject should be in good health.

TABLE 33 .8 Exhaled CO2 Levels and Breathing Rate Before and After Exercise

PROCEDURE : CLASS BLOWING BREATHING RATE CONTROL EXPER IMENTAL % pH AVERAGE OF AIR INTO BEAKER (b reaths /min ) pH pH CHANGE % pH CHANGE

At rest

After exercise

E X E R C I S E 3 3 PULMONARY VENTILATION 555

EXPERIMENTAL REPORT Bicarbonate and Hydrogen Ion Formation

Results: State the pH values at rest and after exercise, and state the change in pH values after exercise.

Discussion: • Explain how blowing air into the water caused the

change in pH.

• Describe how hydrogen ion concentration and bicarbon- ate ion concentration change as pH changes.

• Describe why exercise caused the observed change in pH.

• Describe why exercise caused the observed change in breathing rate.

Conclusion: In one or two sentences, state how exercise causes pH changes, which, in turn, lead to respiratory changes.

■

• Measure 20 mL of deionized water using a graduated cylinder and pour into a 50-mL beaker.

• Measure pH of the deionized water and record the value in Table 33.8 as control pH.

• Count the number of breaths the subject takes over a 30-second period, multiply by 2, and record the number of breaths/min in Table 33.8.

• Have the subject take a deep breath and, using a straw, blow air into the water for four 10-second exhalations. Inhale between exhalations.

• Measure the pH of the water and record the value in Table 33.8 as experimental pH.

• Discard water and rinse the beaker with deionized water.

Change in pH after exercise • Measure 20 mL of deionized water using the gradu-

ated cylinder and pour into the 50-mL beaker. • Measure pH of the deionized water and record the

value in Table 33.8 as control pH. • Have the subject run in place or climb steps for at

least 3 minutes. During the last 30 seconds, count the number of breaths over this 30-second period, mul- tiply by 2, and record the number of breaths/min in Table 33.8.

• As soon as the subject stops exercising, have the sub- ject take a deep breath and, using a straw, blow air into the water for four 10-second exhalations. Inhale between exhalations.

• Immediately measure the pH of the water and record the value in Table 33.8 as experimental pH.

• Discard the water.

4 Clean up as directed by your instructor. 5 Data Analysis: Calculate the percentage change

in pH for both procedures and record your values in Table 33.8. • % change in pH � (control pH � experimental pH)/

control pH � 100 • Pool the class data and calculate average values for

percent change in pH and breathing rate for both pro- cedures, and record in Table 33.8.

6 Graphs: If graph paper is available, construct a bar graph that compares resting and exercising pH values.

7 Complete the Experimental Report with your lab group. 8 Complete PowerPhys Experiment: Regulation of Pul-

monary Ventilation.

557

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

33 E X E R C I S E

A. Respiratory Muscles

Match the respiratory muscles to the appropriate muscle function. Muscles may be used more than once.

1. elevates 3rd, 4th, and 5th ribs

2. elevates the sternum

3. depresses ribs

4. compresses abdominal contents and increases abdominal pressure

5. elevates 1st and 2nd ribs

6. elevates ribs

7. main inspiratory muscle

8. muscles used in forced exhalation

B. Volume and Pressure Changes During Pulmonary Ventilation

Indicate whether the volume or pressure increases or decreases during inhalation and exhalation in Table 33.9.

a. abdominal muscles b. diaphragm c. external intercostals d. internal intercostals e. pectoralis minors f. scalenes g. sternocleidomastoids

TABLE 33 .9 Volume and Pressure Changes During Pulmonary Ventilation

VOLUME OR PRESSURE INHALAT ION EXHALAT ION

Thoracic volume 1. 2.

Intrapleural cavity volume 3. 4.

Intrapleural pressure 5. 6.

Lung volume 7. 8.

Alveolar (intrapulmonic) pressure 9. 10.

¯ ˘

558 E X E R C I S E 3 3 P U L M O N A R Y V E N T I L AT I O N

C. Lung Volumes and Capacities

Match lung volumes and capacities with the appropriate defi nition or equation.

1. equal to TV � IRV � ERV � RV

2. equal to IC � TV

3. equal to FRC � ERV

4. equal to TV � IRV

5. volume of air remaining in lungs after normal exhalation

6. maximum amount of air that can be exhaled after a normal exhalation

7. maximum amount of air that can be exhaled after a maximal inhalation

8. equal to IC � IRV

D. Control of Pulmonary Ventilation: The Role of Carbon Dioxide

Circle True or False for the following questions. If false, underline and change the word(s) that are incorrect to make the statement true.

1. If blood carbon dioxide levels increase, then blood hydrogen ion levels will decrease. True or False

2. If blood carbon dioxide levels increase, then blood pH will decrease. True or False

3. Increasing blood carbon dioxide levels decreases breathing rate. True or False

a. expiratory reserve volume b. functional residual capacity c. inspiratory capacity d. inspiratory reserve volume e. residual volume f. tidal volume g. total lung capacity h. vital capacity

559

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

33 E X E R C I S E

A. Physiology of the Respiratory System

Write a short answer for the following questions.

1. A 32-year-old man presented to the emergency room with a pneumothorax. The right lung was collapsed, but the left lung was still inflated. Explain.

2. How does a pneumothorax affect lung volume and alveolar pressure when inspiratory muscles contract? How does this affect air flow?

3. The Valsalva maneuver is forced exhalation against a closed glottis. How would you demonstrate the Valsalva maneuver using the model lung?

A 42-year-old woman is breathing rapidly and deeply after exercise. Indicate whether each of the following volumes increases, decreases, or stays the same when compared to resting volumes.

Example: TLC: stays the same

4. RV: ______________________________________

5. TV: ______________________________________

6. IRV: ______________________________________

7. ERV: ______________________________________

560 E X E R C I S E 3 3 P U L M O N A R Y V E N T I L AT I O N

8. A 5-year-old child announces to her parents (former A&P students) that she is going to hold her breath until she is allowed to watch more television. The parents are not worried. (a) Explain why the parents are not worried. (b) Explain how the child’s blood carbon dioxide levels and blood hydrogen ion and bicarbonate ion levels change while she is holding her breath.

9. Women in the late nineteenth and early twentieth centuries wore whalebone corsets that severely restricted the respiratory and digestive systems. These corsets were worn to have a wasp-like waist. It was quite common for these women to faint—in fact, they had “fainting couches.” Explain the physiological reason for their fainting problems.

10. When individuals are hyperventilating, they are told to breathe into a paper bag or into their cupped hands. (a) Explain why this increases blood carbon dioxide levels. (b) What will this do to the breathing rate?

Digestive System Structure and Function

34 E X E R C I S E

561

The digestive system contains organs of the gastrointestinal (GI) tract and accessory digestive organs. The GI tract, or alimentary (alimentary � nourishment) canal, is a tube that extends from the mouth to the anus. The lumen of the GI tract opens to the external environment at either end, and anything inside the lumen is therefore considered to be external to the body. Functions of the digestive system include ingestion of food; secretion of digestive juices; mixing and propulsion of food; diges- tion of food into small, absorbable molecules; absorption of digestive products across the GI tract wall and into the body; and defecation. Digestion includes both mechanical digestion, mechanically breaking food into smaller pieces,

and chemical digestion, enzymatically breaking large mol- ecules into smaller ones.

A. Organs of the Digestive System

The GI tract organs include the mouth, most of the phar- ynx, esophagus, stomach, small intestine (duodenum, je- junum, ileum), large intestine (colon or bowel), rectum, and anus. The accessory digestive organs (teeth, tongue, salivary glands, liver, gallbladder, and pancreas) assist in digestion.

O B J E C T I V E S M A T E R I A L S

• human torso model, sagittal section of head model, or use Real Anatomy (Digestive)

• skull with teeth • Length of GI Tract and Transit Time: 2�-wide roll

of adding machine paper (19 ft per group), tape measure, yardstick, or ruler for each group

• compound microscope, lens paper, prepared slides: esophagus, stomach, small intestine, large intestine, pancreas, and liver, or use Real Anatomy (Histology)

• Dissections: preserved cat or fetal pig, dissection equipment, disposable gloves, safety glasses, and cat or fetal pig dissection manual

• Real Anatomy: Virtual Cadaver Dissection • PowerPhys Experiment: • Effect of Dietary Fiber on Transit Time and Bile

1 Identify the major gastrointestinal (GI) tract organs and accessory digestive organs

2 Describe the layers of the GI tract walls and the peritoneum

3 Describe the functions of each GI tract organ and accessory digestive organ

4 Identify the major microscopic structures of digestive organs

5 Dissect and identify the main digestive organs of a cat, fetal pig, or cadaver

562 E X E R C I S E 3 4 D I G E S T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

Before Going to Lab

1 Label the digestive structures in Figure 34.1.

LAB ACTIVITY 1 Organs of the Digestive System

1 Identify the digestive organs on a model or chart, or use the search text box in Real Anatomy (Digestive) to find these structures. ■

1 _______________________

2 _______________________

3 _______________________

4 _______________________

5 _______________________

6 _______________________

7 ______________________

8 ______________________

9 ______________________

10 ______________________

11 ______________________

9 (Posterior)

Diaphragm

Stomach

Descending colon (large intestine)

Jejunum (small intestine)

Liver

Transverse colon (large intestine)

Ileum (small intestine)

FIGURE 34.1 Organs of the digestive system.

• anus • esophagus • gallbladder • large intestine • liver • mouth (oral cavity)

• pancreas • pharynx • salivary glands • small intestine • stomach

E X E R C I S E 3 4 DIGESTIVE SYSTEM STRUCTURE AND FUNCTION 563

3 4

Lumen

FIGURE 34.2 Layers of the gastrointestinal tract.

large folds not found in other serous membranes that secure organs together and to the abdominal walls. Some of these peritoneal folds are the mesentery, mesocolon, falciform liga- ment, greater omentum, and lesser omentum. The mesentery holds the small intestine to the posterior abdominal wall, whereas the large intestine is similarly secured to the poste- rior abdominal wall by the mesocolon. The liver is bound to the anterior abdominal wall by the falciform ( falc- � sickle- shaped) ligament. The greater omentum (omentum � fat skin) is a large, fatty-looking apron that folds back on itself and attaches to the transverse colon. It forms a pouch that hangs between the body wall and the anterior surface of the small intestine. Attached to the lateral curve of the stomach and duodenum, the greater omentum loosely covers the transverse colon and small intestine. The lesser omentum connects the medial curve of the stomach with the liver.

B. Layers of the Gastrointestinal Tract and the Peritoneum

The esophagus, stomach, small intestine, and large intestine have a similar four-layered arrangement to their walls. From the interior (deep layer) to the exterior (superfi cial layer), the four layers are: the mucosa, submucosa, muscularis, and either serosa or adventita. The mucosa is a moist layer that includes the surface epithelium, connective tissue (lamina propria), and smooth muscle (muscularis mucosae). Inspect the inside of your cheek with your tongue. The wet, slick feeling is the mucosa that lines all the organs of the GI tract. The submucosa is areolar connective tissue, and the muscu- laris in all GI tract organs except the stomach is composed of two layers: an inner layer of circular smooth muscle and an outer layer of longitudinal smooth muscle. The stomach muscularis has three layers: an inner oblique, middle circu- lar, and an outer longitudinal smooth muscle layer. Adven- titia is the outermost layer of the esophagus, whereas the outermost layer of GI tract organs in the abdominopelvic cavity is serosa. Adventitia is comprised of areolar connec- tive tissue and fi brous connective tissue, and anchors or- gans to other body structures. Serosa, the outermost layer of organs within body cavities, is the visceral layer of the serous membrane and reduces friction during organ movement. The largest serous membrane in the body, the peri toneum, is a combination of simple squamous mesothelium (epithe- lium) with underlying connective tissue. As with all serous membranes, the parietal peritoneum lines the inner surface of the abdominopelvic wall and the visceral peritoneum (serosa) covers organs within the abdominopelvic cavity. Peritoneal (serous) fl uid is found between the two peritoneal layers in the peritoneal cavity. Organs that lie outside the peritoneal cavity are called retroperitoneal (retro- � behind) organs (i.e., pancreas and kidneys). The peritoneum has

Before Going to Lab

1 Label the structures in Figure 34.2 and Figure 34.3(a)–(d).

LAB ACTIVITY 2 Layers of the GI Tract and the Peritoneum

1 Identify the digestive structures on a model or chart, or use the search text box in Real Anatomy (Digestive) to find these structures. ■

• mucosa (myu-KOH-sa) • muscularis • serosa (sir-OH-sa) • submucosa

1 ______________________________

2 ______________________________

3 ______________________________

4 ______________________________

564 E X E R C I S E 3 4 D I G E S T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

Stomach

6 7

8 (space)

Diaphragm

Liver

Transverse colon

Jejunum

Rectum

Uterus

Sigmoid colon

Ileum

Urinary bladder

Pubic symphysis

(a) Sagittal section

ANTERIORPOSTERIOR

Heart

Lesser omentum

Mesentery

Greater omentum

Stomach

Transverse colon

Small intestines

Urinary bladder

Rectum

Mesocolon

FIGURE 34.3 Peritoneal folds. • greater omentum (oh-MEN-tum) • lesser omentum • mesentery (MEH-sen-tary) • mesocolon • parietal peritoneum (per-ih-toe-NEE-um) • peritoneal cavity • retroperitoneal organs • visceral peritoneum (serosa)

1 _________________________________________________

2 _________________________________________________

3 _________________________________________________

4 _________________________________________________

5 _________________________________________________

6 _________________________________________________

7 _________________________________________________

8 _________________________________________________

E X E R C I S E 3 4 DIGESTIVE SYSTEM STRUCTURE AND FUNCTION 565

muscle) is posterior to this. The soft palate forms the two arches that border the fauces, and also hangs down to form the oval process called the uvula. During swallowing, the soft palate keeps food from entering the nasal cavity. When you look into a mirror with your mouth wide open, you see two arches, the palatoglossal arch (anterior) and palato- pharyngeal arch (posterior), with the uvula hanging down in between. The palatine tonsils are located between the two arches. Digestive system functions that occur in the mouth in- clude ingestion, secretion, mechanical and chemical di- gestion, mixing, and propulsion. The teeth break food into smaller pieces by a mechanical process called masti- cation. The tongue mixes food with saliva that is secreted into the mouth by the salivary glands, initiating chemical digestion. Movements of the tongue and soft palate propel food into the oropharynx during swallowing.

C. Gastrointestinal Tract Organs

1. Mouth

Food fi rst enters the digestive system through the mouth. The hard and soft palates form the roof of the mouth, the tongue forms the fl oor, and the cheeks form the lateral walls. The anterior border is the lips, and the posterior bor- der is the fauces ( fauces � passages), which is the open- ing to the oropharynx. The mouth is also called the oral or buccal (bucca- � cheeks) cavity. The vestibule (vesti- bule � courtyard or entrance) is the space between the lips and teeth. The lips are attached to the gingiva (gingiva � gums) by the labial frenulum ( frenulum � small bridle). The palatine bone and the palatine processes of the max- illae form the hard palate, and the soft palate (smooth

Stomach

Duodenum

Descending colon

Gallbladder

Liver

Transverse colon

Ascending colon

Sigmoid colon

Heart

Lungs

Stomach

Left lobe of liver

Right lobe of liver

Diaphragm

(b) Anterior view

FIGURE 34.3 Peritoneal folds, continued.

Descending colon

Transverse colon

Jejunum

Ileum

Sigmoid colon

Anterior view with greater omentum lifted and small intestine reflected to right side

(d)

• falciform ligament • greater omentum • greater omentum (reflected) • lesser omentum • mesentery • mesocolon

9 ________________________________

10 ________________________________

11 ________________________________

12 ________________________________

13 ________________________________

14 ________________________________

566 E X E R C I S E 3 4 D I G E S T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

of the laryngopharynx, ensuring food and drink enter the digestive pathway and not the respiratory pathway. The only digestive system function that occurs in the pharynx is propulsion. Contractions of the muscularis layer of the pharynx propel food to the esophagus.

2. Pharynx

The pharynx is divided into three specifi c areas, named after structures that are in close proximity. The nasophar- ynx, the superior area, is posterior and inferior to the nose and has respiratory functions. This part of the pharynx be- gins at the internal naris and ends at the inferior end of the uvula. The middle area, the oropharynx, is posterior to the fauces of the oral cavity. This area has both respiratory and digestive functions because air, food, and liquid pass through it. The oropharynx begins at the uvula and extends to the hyoid bone. The inferior area is the laryngopharynx, located posterior to the larynx. This area is also a common passageway for air, food, and liquid. The laryngopharynx begins at the hyoid bone and divides into digestive and respiratory pathways just inferior to the epiglottis. During swallowing, the epiglottis closes off the inferior portion

Before Going to Lab

1 Label the structures of the mouth and pharynx in Fig- ures 34.4 and 34.5.

LAB ACTIVITY 3 Mouth and Pharynx

1 Identify mouth and pharyngeal structures on a model or chart, or use the search text box in Real Anatomy (Digestive) to find these structures. ■

• cheek • fauces • gingivae (gums) • hard palate • inferior labial frenulum

(FREN-u-lum) • inferior lip

1 _______________________

2 _______________________

3 _______________________

4 _______________________

5 _______________________

6 _______________________

• palatine tonsil • soft palate • superior lip • tongue • uvula • vestibule

7 ______________________

8 ______________________

9 ______________________

10 ______________________

11 ______________________

12 ______________________

Palatoglossal arch 7

Palatopharyngeal arch

Anterior view

(space)

FIGURE 34.4 The mouth.

E X E R C I S E 3 4 DIGESTIVE SYSTEM STRUCTURE AND FUNCTION 567

4. Stomach

The esophagus leads into the superior part of the stomach, which lies against the diaphragm superiorly. The J-shaped stomach has four areas: the cardia, fundus, body, and pylorus. The cardia is the fi rst part of the stomach, infe- rior to the lower esophageal sphincter. The fundus is the elevated area to the left of the cardia that serves as a tempo- rary holding area for food. The body is the largest, curved part of the stomach, whereas the pylorus continues to the right of the body after the curve. The pylorus is divided into two areas, the pyloric antrum (antrum � cave), which is next to the body, and the pyloric canal, which is nearer the pyloric sphincter. The pyloric sphincter is a smooth muscle that allows food to enter the fi rst part of the small intestine, the duodenum. The stomach has large, conspicuous ridges in the mucosa called rugae that allow the stomach to be stretched when food and drink are present. Rugae disappear

3. Esophagus

Food and drink move from the mouth into the oropharynx, laryngopharynx, and then the esophagus. The esophagus is a fl attened muscular tube about 10 inches long that ap- pears oval in cross-section but distends when food moves through it. The esophagus is posterior to the trachea and is bound with it by connective tissue. The upper esopha- geal sphincter controls the passage of food from the la- ryngopharynx into the esophagus. Food then continues through the esophagus and the lower esophageal sphinc- ter (cardiac sphincter) into the stomach. The esophageal hiatus is the opening in the diaphragm through which the esophagus passes and is the site of a hiatal hernia. The only digestive system function that occurs in the esophagus is propulsion, which moves food into the stomach. This is accomplished by peristalsis, a series of contractions and relaxations of the muscularis layer.

• esophagus • fauces • hard palate • laryngopharynx (la-RIN-go-FAIR-inks) • nasopharynx (NA-zo-fair-inks) • oral or buccal cavity • oropharynx (OR-o-fair-inks) • soft palate • tongue • uvula (YOU-vu-la)

1 __________________________________

2 __________________________________

3 __________________________________

4 __________________________________

5 __________________________________

6 __________________________________

7 __________________________________

8 __________________________________

9 __________________________________

10 __________________________________

8 9

Sagittal section

Sagittal plane

FIGURE 34.5 Mouth and pharynx.

568 E X E R C I S E 3 4 D I G E S T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

as the stomach becomes fully distended. The lateral curve of the stomach is the greater curvature, and the smaller, medial curve is called the lesser curvature. The digestive system functions that occur in the stomach include secretion of gastric juices, mixing and propulsion, and mechanical and chemical digestion. Contractions of the muscularis layer of the stomach mechanically mix and churn food, breaking it into smaller pieces, and propel food through the stomach and into the small intestine. Gastric juices begin the chemical digestion of protein and lipids and stop the chemical digestion of carbohydrates.

LAB ACTIVITY 4 Esophagus and Stomach

1 Identify the esophagus and stomach structures on a model or chart, or use the search text box in Real Anatomy (Digestive) to find these structures. ■

Before Going to Lab

1 Label the structures of the esophagus and stomach in Figure 34.6. Refer to cadaver figure.

4 2 3

7 (muscle

layer)

8 (muscle

layer)

9 (muscle

layer)

11 (folds) 12

Duodenum

Rugae of mucosa

Lesser curvature

Pyloric sphincter

Duodenum

Pylorus

Pyloric canal

Esophagus

FundusCardia

Lower esophageal sphincter

Body

Greater curvature

Pyloric antrum

FIGURE 34.6 Esophagus and stomach.

1 _______________________

2 _______________________

3 _______________________

4 _______________________

5 _______________________

6 _______________________

7 _______________________

8 _______________________

9 _______________________

10 _______________________

11 _______________________

12 _______________________

13 _______________________

14 _______________________

15 _______________________

• body • cardia • circular muscle layer • esophagus • fundus • greater curvature • lesser curvature • longitudinal muscle layer

• lower esophageal sphincter (cardiac sphincter)

• oblique muscle layer • pyloric antrum • pyloric canal • pyloric sphincter • pylorus • rugae

E X E R C I S E 3 4 DIGESTIVE SYSTEM STRUCTURE AND FUNCTION 569

Digestive system functions of the small intestine include secretion, mixing and propulsion, mechanical and chemical digestion, and absorption. Most absorption occurs in the small intestines. Secretions of the pancreas, liver, and intestinal glands are deposited into the lumen of the small intestine. Local contractions of the muscu- laris layer of the small intestine mix and churn food by segmentation and propel it through the small intestine into the large intestine by peristalsis. Pancreatic and intestinal enzymes digest larger food molecules of carbohydrates, proteins, and lipids into smaller, absorbable molecules. The small intestine has three special anatomical modifi - cations for increasing the surface area available for absorp- tion. The circular folds or plicae circularis are folds or ridges of the mucosa that can be observed with the unaided eye. The other two structural specializations, the villi and microvilli, can be observed only with the microscope and will be studied in the histology of the digestive system.

5. Small Intestine

The small intestine is a long tube (about 10 feet long in a living person) divided into three sections: the duode- num, jejunum, and ileum (see Figure 34.7). The shortest section, the duodenum, resembles the shape of a “C” and receives food through the pyloric sphincter. The duodenum (duodenum � 12 fi ngers) is about 10 inches long, or ap- proximately the width of 12 fi ngers. Secretions from the pancreas, liver, and gallbladder enter the duodenum at the hepatopancreatic ampulla, located about 4 inches inferior to the pyloric sphincter. The next section, the jejunum (jejunum � empty), is about 3 feet long and has a thicker layer of smooth muscle. It is named jejunum because on death it is found to be empty. The ileum (ileum � intestine), the last section of the small intestine, is about 6 feet long and ends at the ileocecal sphincter (valve), where it joins the large intestine. From the exterior, it is diffi cult to distin- guish these three sections of the small intestine.

FIGURE 34.7 Entire small intestine, longitudinal section.

570 E X E R C I S E 3 4 D I G E S T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

LAB ACTIVITY 5 Small and Large Intestines

1 Identify the structures of the small and large intestines on a model or chart, or use the search text box in Real Anatomy (Digestive) to find these structures. ■

Before Going to Lab

1 Label the structures of the small and large intestines in Figure 34.8(a)–(c).

6. Large Intestine

The large intestine, also known as the colon (colon � food passage) or large bowel, is approximately 5 feet long and is composed of the cecum, colon, rectum, and anal canal. A blind pouch called the cecum, which is about 2 to 3 inches long, extends inferiorly from the large intestine at the ileocecal sphincter in the lower right quadrant. The slender appendix, which is lymphatic tissue, branches off the cecum and is also about 2 to 3 inches long. From the ileocecal junction, the ascending colon extends superiorly to the liver on the right side of the abdomen and makes a 90� turn to the left at the right colic (hepatic) fl exure. The colon continues as the transverse colon until it reaches the spleen, where it makes another 90� turn at the left colic (splenic) fl exure. The descending colon then continues inferiorly on the left side to an S-shaped curve called the sigmoid colon at the level of the iliac crest. Teniae coli are three longitudinal bands of smooth muscle that run along the length of the large intestine. Contractions of the teniae coli form pouches called haustra. Epiploic appendages are fat-fi lled pouches of visceral peritoneum that hang from the teniae coli. Following the sigmoid colon, at about the third sacral vertebra level, is the rectum. The last segment of the colon is the anal canal, which has longitudinal anal columns or folds rich with blood vessels. The anal canal opens to the exterior at an opening called the anus. There are two sets of muscle sphincters in the anus: the internal sphincter of smooth muscle, which is involuntary, and the external sphincter, which is voluntary skeletal muscle. The digestive system functions of the large intestine in- clude secretion, mixing and propulsion, chemical digestion (by bacterial enzymes), absorption, and defecation. The large intestine absorbs a large amount of water, concen- trating the undigested feces into a solid form. It is the site where bacteria complete digestion and produce vitamins. The large intestine also secretes mucus and eliminates fecal material from the body through the anus.

CLINICAL NOTE: A sigmoidoscopy views the lining of the sigmoid colon, whereas a colonoscopy views the lining of the entire colon.

2 6

(a) Anterior view

(a) • ascending colon • descending colon • duodenum • ileum • jejunum • rectum • stomach • transverse colon

1 ______________________________________________

2 ______________________________________________

3 ______________________________________________

4 ______________________________________________

5 ______________________________________________

6 ______________________________________________

7 ______________________________________________

8 ______________________________________________

FIGURE 34.8 Small intestine and large intestine.

E X E R C I S E 3 4 DIGESTIVE SYSTEM STRUCTURE AND FUNCTION 571

(b) Large intestine, anterior view

30 29

FIGURE 34.8 Small intestine and large intestine, continued.

(b) • anal canal • anus • appendix • ascending colon • cecum (SEE-cum) • descending colon • epiploic (ep-ih-PLOH-ic)

appendages • haustra (HAW-struh) • ileocecal (ileo-SEE-cal)

sphincter • ileum • left colic (splenic) flexure • rectum • right colic (hepatic)

flexure • sigmoid colon • teniae coli (TEE-nee-ee

CO-lye) • transverse colon

9 _______________________

10 _______________________

11 _______________________

12 _______________________

13 _______________________

14 _______________________

15 _______________________

16 _______________________

17 _______________________

18 _______________________

19 _______________________

20 _______________________

21 _______________________

22 _______________________

23 _______________________

24 _______________________

25 _______________________

26 _______________________

27 _______________________

28 _______________________

29 _______________________

30 _______________________

572 E X E R C I S E 3 4 D I G E S T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

• Write the name of each organ in the appropriate seg- ment of the paper.

• In addition, mark the location of the following structures:

• pyloric sphincter • hepatopancreatic ampulla • ileocecal sphincter • cecum (2.4 inches or 6 cm) • appendix (3 inches or 8 cm)

2 Calculate the velocity of peristalsis through each portion of the GI tract for organ transit times stated. • The time it takes for food to travel through each portion

of the GI tract is indicated in Table 34.1. • Normally, organ transit times are stated as a range

of values. In order to simplify this activity, a specific time within the range was chosen.

• Velocity � length in inches/sec (or cm/sec) in GI tract organ.

• Using the length of the organ and the organ transit time columns, calculate the velocity of peristalsis through each segment and write it in Table 34.1. Note that velocity will vary depending on composi- tion and volume of food, physical activity, emotional state, illness, and medications.

3 Calculate your total transit time. • Because there isn’t a way for you to calculate your

own individual organ transit times, you will be watching the total time it takes for food to travel through your entire GI tract. This total transit time can be calculated at home using kernel corn or beets.

• Decide whether you are going to eat kernel corn or beets, and avoid eating this food for a week.

D. Length of GI Tract and Transit Time

The gastrointestinal (GI) tract is a tube that spans the distance between the mouth and the anus, with its sections varying in length and diameter. Most people don’t realize how long this tube actually is until they see it stretched out its entire length. The lengths of the segments given here are those found in an average living adult and will obviously vary in length de- pending on the person’s size. The GI tract length is noticeably longer in a cadaver, 30 ft (9 m), due to smooth muscle relax- ation and the lack of muscle tone compared to the total length in a live adult of approximately 19 ft (5.8 meters). The time it takes for food to pass through GI tract is called transit time. Transit time is typically 24–72 hours and is affected by a variety of factors including composi- tion and volume of food, physical activity, emotional state, illness, and medication. Peristalsis moves food through the GI tract, and the velocity of peristalsis differs for each segment of the GI tract.

LAB ACTIVITY 6 GI Tract Length and Transit Time

1 Measurement of GI tract length • Obtain the materials for GI Tract Length and Transit

Time from the Materials list. • Find a place to stretch out the paper. • Starting with the mouth, measure out and mark on

the paper the lengths of each organ with the lengths given in Table 34.1.

TABLE 34 .1 GI Tract Length and Transit Time

ORGAN LENGTH ORGAN TRANSIT T IME PER ISTALT IC VELOCITY

Mouth 2.5” (6.5 cm) NA NA

Pharynx 5” (13 cm) 1 sec

Esophagus 10” (25 cm) 5 sec

Stomach 10” (25 cm) 4 hours

Small Intestine Total length is approx 10’ (3 m) 6 hours • duodenum–10” (25 cm) • jejunum–3’ (1 m) • ileum–6’ (2 m)

Large Intestine Total length is approx 5’ (1.5 m) 16 hours • ascending, transverse

descending and sigmoid colon

Rectum 8” (20 cm)

Total GI Tract Length Approximately 19 ft (5.8 m)

E X E R C I S E 3 4 DIGESTIVE SYSTEM STRUCTURE AND FUNCTION 573

tongue have numerous papillae (papilla � nipple-shape), many of which have taste buds.

3. Teeth

Teeth mechanically break up the food into small pieces, aided by the tongue, which manipulates the food in the oral cavity. Teeth are composed of three basic regions: the crown, neck, and root. The crown is the part that can be seen above the gums, whereas the neck is the constricted region at the gum line where the crown and root meet. The root is embedded in an alveolar bony socket of the maxilla or mandible and is held in place by the periodontal (peri- � around; odont- � tooth) ligament lining the socket. Most of the tooth is formed of dentin, a hardened, calcifi ed con- nective tissue. Enamel covers and protects the dentin of the crown. Dentin of the root is covered with cementum, which attaches the tooth to the periodontal ligament. Sur- rounding each tooth is gingiva or gum tissue. In the crown of the tooth deep to the dentin is a pulp cavity fi lled with connective tissue called pulp that con- tains nerves, blood vessels, and lymphatic vessels. Root canals are slender continuations of the pulp cavity that run the entire length of the root. The small opening at the base of each root, the apical foramen, is the location for nerves, blood vessels, and lymphatic vessels to enter and exit the tooth. Adults have 32 permanent teeth, with each jaw contain- ing four incisors, two cuspids (canines), four premolars (bicuspids), and six molars. Incisors cut food, cuspids tear food, and premolars and molars crush and grind food. Premolars have two cusps (pointed surfaces), and molars have four cusps. Incisors, cuspids, and the second pre- molars have one root, the fi rst bicuspids and mandibular (lower) molars have two roots, and the maxillary (upper) molars have three roots. Children’s teeth, deciduous (decidu- � falling out) teeth or primary teeth, are temporary and are lost by the child between the ages of 6 and 12. They are replaced by permanent or secondary teeth. The deciduous set has 20 teeth, and the permanent set has 32 teeth. From the midline moving laterally, the dental formula for deciduous teeth is:

Upper teeth: 2 incisors, 1 cuspid, 0 premolars, 2 molars

Lower teeth: 2 incisors, 1 cuspid, 0 premolars, 2 molars

� 2 � 20 teeth

From the midline moving laterally, the dental formula for permanent teeth is:

Upper teeth: 2 incisors, 1 cuspid, 2 premolars, 3 molars

Lower teeth: 2 incisors, 1 cuspid, 2 premolars, 3 molars

� 2 � 32 teeth

• Record the date and time that you eat the chosen food and monitor your stools for the appearance of the food. Beets will cause your stool to turn red.

Date started: __________ Time started: __________ • Record the date and time that the food (corn kernel or

red stool) first starts appearing in your stool, and the date and time that the food stops appearing your stool.

Date food first appeared: __________

Date food stopped appearing: __________

Total transit time: __________ hours

4 Discuss with the class what surprised you or helped you to clarify concepts about the GI tract after doing this exercise.

5 Complete PowerPhys Experiment: Effect of Dietary Fiber on Transit Time and Bile. ■

E. Accessory Digestive Organs

1. Salivary Glands

The mucous membranes of the mouth and tongue have many small salivary glands that secrete saliva. However, most of the saliva secreted into the oral cavity is secreted by the parotid, submandibular, and sublingual salivary glands. Saliva moistens food and contains enzymes that initiate chemical digestion of carbohydrates. It also con- tains enzymes for lipid digestion that become activated when they reach the acidic stomach environment. The large parotid (par- � near; ot- � ear) glands are located anterior and inferior to the ears between the skin and the masseter muscle. Their salivary secretions reach the oral cavity via the parotid ducts that open near the second molar in the upper jaw. The submandibular glands are located in the posterior part of the mouth fl oor just medial to the mandible, deep to the mylohyoid muscle. The submandibular ducts open into the oral cavity lateral to the lingual frenulum. The sublingual glands are located under the tongue as the name suggests and are more medial and superior than the submandibular glands. There are several lesser sublingual ducts that open into the fl oor of the mouth; they are very small compared with the other main salivary gland ducts.

2. Tongue

Extrinsic muscles attach the tongue to bone and hold it in position, but they also allow movement to maneuver food in the mouth. The tongue is composed of skeletal muscle called intrinsic muscles that are used for speech and swal- lowing. The lingual frenulum attaches the tongue to the fl oor of the mouth. The dorsal and lateral surfaces of the

574 E X E R C I S E 3 4 D I G E S T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

LAB ACTIVITY 7 The Teeth, Tongue, and Salivary Glands

1 Identify the accessory digestive structures on a model or chart, or use the search text box in Real Anatomy (Digestive) to find these structures.

2 Identify incisors, cuspids, premolars, and molars on a skull with teeth. ■

Before Going to Lab

1 Label the accessory digestive structures in Figure 34.9(a)–(c).

(a) Location of salivary glands

Lingual frenulum

Tongue

Second maxillary molar tooth

(a) • openings of sublingual ducts • opening of parotid duct (near secondary molar) • parotid duct • parotid gland • sublingual gland • submandibular duct • submandibular gland

1 _____________________________________________________

2 _____________________________________________________

3 _____________________________________________________

4 _____________________________________________________

5 _____________________________________________________

6 _____________________________________________________

7 _____________________________________________________

FIGURE 34.9 The salivary glands, tongue, and teeth.

E X E R C I S E 3 4 DIGESTIVE SYSTEM STRUCTURE AND FUNCTION 575

FIGURE 34.9 The salivary glands, tongue, and teeth, continued.

13 14 15

(b) Tooth, frontal section

26 21

(b) • apical foramen • blood supply • cementum • crown • dentin • enamel • gingiva • neck • nerve • periodontal ligament • pulp cavity with pulp • root • root canal

8 _______________________

9 _______________________

10 _______________________

11 _______________________

12 _______________________

13 _______________________

14 _______________________

15 _______________________

16 _______________________

17 _______________________

18 _______________________

19 _______________________

20 _______________________

21 _______________________

22 _______________________

23 _______________________

24 _______________________

25 _______________________

26 _______________________

576 E X E R C I S E 3 4 D I G E S T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

join to form the common hepatic duct, which takes bile to the cystic duct of the gallbladder. The main digestive function of the liver is to make bile. Bile emulsifi es lipids (breaks large spheres of lipids into small ones), which pre- pares them for digestion in the small intestine. The gallbladder is a sac made of smooth muscle that is located on the inferior surface of the liver between the right lobe and the quadrate lobe. The main function of the gallbladder is to concentrate and store bile. Bile leaves the gallbladder via the cystic duct, which joins with the com- mon hepatic duct to form the common bile duct. The common bile duct joins the pancreatic duct in the pancreas to form the hepatopancreatic ampulla, which opens into the duodenum.

4. Pancreas

The pancreas, composed of a head, body, and tail, is located posterior to the stomach. The head is the expanded part of the pancreas that lies in the C-shape of the duode- num. The pancreatic body is in the middle, and the tail tapers to the left toward the spleen. The main pancreatic duct runs from the tail to the head of the pancreas and joins the common bile duct to form the hepatopancreatic ampulla. This ampulla opens into the duodenum at the major duodenal papilla, about 4 inches inferior to the py- loric sphincter. In the head of the pancreas, a smaller acces- sory pancreatic duct branches off the pancreatic duct and opens into the duodenum just superior to the hepatopancre- atic ampulla. The pancreas secretes digestive enzymes and bicarbonate into the duodenum.

5. Liver and Gallbladder

The liver is a large organ that lies inferior to the diaphragm and touches the diaphragm all along the liver’s superior border. The liver has two main lobes, the right lobe and left lobe, which are separated by the falciform (falc- � sickle- shaped) ligament. Two smaller lobes, the superior caudate lobe and the inferior quadrate lobe, lie on the same side of the falciform ligament as the right lobe and can be seen from the posterior view. The right and left hepatic ducts

Right lobe of liver

Left lobe of liver

Cystic duct

Gallbladder

Common bile duct

Duodenum

Hepatopancreatic ampulla

Head of pancreas

(a)

Falciform ligament

Common hepatic duct

Body of pancreas

Pancreatic duct

Tail of pancreas

FIGURE 34.10 Pancreas, liver, and gallbladder.

Before Going to Lab

1 Label the accessory digestive structures in Figure 34.10(a)–(c).

LAB ACTIVITY 8 The Pancreas, Liver, and Gallbladder

1 Identify the structures of the pancreas, liver, and gall- bladder on a model or chart, or use the search text box in Real Anatomy (Digestive) to find these structures. ■

E X E R C I S E 3 4 DIGESTIVE SYSTEM STRUCTURE AND FUNCTION 577

FIGURE 34.10 Pancreas, liver, and gallbladder, continued.

Right lobe of liver

Diaphragm

(b) Anterior view

• accessory pancreatic duct • body of pancreas • common bile duct • common hepatic duct • cystic duct • duodenum • falciform ligament • gallbladder • head of pancreas • hepatopancreatic (heh-PA-toe-pan-

cree-A-tic) ampulla • jejunum • left hepatic duct • left lobe of liver • pancreatic duct • right hepatic duct • tail of pancreas

1 ________________________________

2 ________________________________

3 ________________________________

4 ________________________________

5 ________________________________

6 ________________________________

7 ________________________________

8 ________________________________

9 ________________________________

10 ________________________________

11 ________________________________

12 ________________________________

13 ________________________________

14 ________________________________

15 ________________________________

16 ________________________________

578 E X E R C I S E 3 4 D I G E S T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

FIGURE 34.10 Pancreas, liver, and gallbladder, continued.

Mucosa of duodenum

19 20

(b) • common bile duct • duodenal papilla • hepatopancreatic ampulla • pancreatic duct

17 ________________________________

18 ________________________________

19 ________________________________

20 ________________________________

Hepatic artery

Hepatic portal vein

23 Inferior vena cava

Left hepatic vein

(d) Liver, posterior view

21 ________________________________

22 ________________________________

23 ________________________________

24 ________________________________

25 ________________________________

E X E R C I S E 3 4 DIGESTIVE SYSTEM STRUCTURE AND FUNCTION 579

fi ssures in the intestinal mucosa are lined with intestinal glands, also called the crypts of Lieberkühn. In the sub- mucosa of the duodenum, there are duodenal (Brunner’s) glands, which secrete mucus to help neutralize the acidic stomach chyme.

2. Pancreas and the Liver

The pancreas has two distinct areas: the exocrine portion of glandular epithelial cells in clusters called acini, and the endocrine portion formed of pancreatic islets (islets of Langerhans). The acinar exocrine cells secrete the diges- tive enzymes pancreatic amylase, trypsin, and pancreatic lipase. Pancreatic amylase digests carbohydrates, trypsin digests proteins, and pancreatic lipase digests triglycerides (lipids). The liver is composed of structural and functional units called lobules, which have hepatocytes (hepato- � liver) that produce bile. Hepatocytes are arranged in branching, fl at plates around a central vein. The liver lobules have modifi ed capillaries with large spaces called sinusoids where gases, nutrients, and wastes are exchanged with the hepatocytes. Special fi xed macrophages in the sinu- soids phagocytize dead or foreign matter from the blood. These fi xed macrophages are called reticuloendothelial (Kupffer’s) cells. The lobules are typically six-sided with portal triads present at each of the corners. A portal triad is composed of three structures: a branch of the hepatic portal vein, a branch of the hepatic artery, and a bile canaliculus (canaliculus � little canal).

F. Histology of the Digestive System

1. Gastrointestinal Tract Organs

The walls of the GI tract organs are composed of four layers: the mucosa (epithelium, lamina propria, and muscu- laris mucosae), submucosa, muscularis, and either serosa (GI tract organs within abdominopelvic cavity) or adventi- tia (GI tract organs outside of abdominopelvic cavity). The epithelium of the mucosa changes along the digestive tract. Stratifi ed squamous epithelium lines the mouth, orophar- ynx, laryngopharynx, and esophagus to protect underlying tissues. At the junction of the esophagus and stomach, the epithelium changes to simple columnar epithelium that lines the stomach, small intestine, and large intestine and refl ects the absorptive and secretive functions of these or- gans. The epithelium changes again to stratifi ed squamous epithelium in the anal canal, providing protection from the external environment. The simple columnar epithelium of the stomach con- tains goblet cells that secrete mucus for stomach-lining protection. The gastric epithelium dips down into the un- derlying lamina propria to form narrow channels called gastric pits. The gastric pits lead into areas called gastric glands that are lined by three types of specialized secre- tory cells: mucous neck cells, chief cells, and parietal cells. Mucous neck cells secrete mucus that protects the stom- ach lining from being digested. Chief cells produce and secrete gastric lipase, which digests triglycerides, and pep- sinogen, which is an inactive form of pepsin. Parietal cells produce hydrochloric acid and intrinsic factor. Hydrochlo- ric acid converts pepsinogen into pepsin, which begins the digestion of protein. Intrinsic factor facilitates vitamin B12 absorption in the small intestine. The small intestinal wall has an unusual feature in that the mucosa forms fi nger-like projections called villi (villi � tufts of hair) that greatly increase the surface area. In the center of each villus is the lamina propria with an arteriole, venule, blood capillary, and a lymphatic capillary called a lacteal. Absorptive cells of the simple columnar epithe- lium have microvilli on the surface facing the lumen, add- ing more surface area. When viewed with the compound microscope, the microvilli give the cell surface a brush- like appearance called the brush border. Goblet cells that secrete mucus are also found in the epithelium. Deep

Before Going to Lab

1 Label the microscopic structures of the esophagus, stomach, small intestine, pancreas, and liver in Figure 34.11(a)–(e).

LAB ACTIVITY 9 Histology of the Digestive System

1 Examine prepared slides of stomach, duodenum, pan- creas, and liver using the scanning or low-power objec- tive lens or use Real Anatomy (Histology). Identify the structures in Figure 34.11(a)–(e). ■

580 E X E R C I S E 3 4 D I G E S T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

(a) Wall of the esophagus

Lumen

17�LM

Parietal cell

Chief (zymogenic) cell

about 250LM

(b) Fundic mucosa of the stomach

FIGURE 34.11 Histology of digestive organs.

(a) • adventitia • circular layers of smooth

muscle fibers • lamina propria • longitudinal layer of

smooth muscle fibers • mucosa • muscularis mucosae • stratified squamous

epithelium • submucosa

(b) • gastric glands • gastric pit • lamina propria • simple columnar

epithelium

1 _______________________

2 _______________________

3 _______________________

4 _______________________

5 _______________________

6 _______________________

7 _______________________

8 _______________________

9 _______________________

10 _______________________

11 _______________________

12 _______________________

E X E R C I S E 3 4 DIGESTIVE SYSTEM STRUCTURE AND FUNCTION 581

(e) • central vein • hepatocytes • sinusoids

21 _________________________________

22 _________________________________

23 _________________________________

14 (cell)

FIGURE 34.11 Histology of digestive organs, continued.

(c) • duodenal (Brunner’s) gland in submucosa • goblet cell • intestinal gland (crypts of Lieberkühn) • lamina propria • simple columnar epithelium • villus

13 _________________________________

14 _________________________________

15 _________________________________

16 _________________________________

17 _________________________________

18 _________________________________

(d) • acini (exocrine) • pancreatic islet (islet of Langerhans)

19 _________________________________

20 _________________________________

19 20

450�LM

(d) Histology of the pancreas

180�LM

(e) Histology of the liver lobule

582 E X E R C I S E 3 4 D I G E S T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

Blood fl ows through each liver lobule from branches of the hepatic artery and the portal vein to the sinusoids. The hepatic artery carries oxygen-rich blood, and the hepatic portal vein carries oxygen-poor blood plus nutrients from the digestive system. The sinusoids empty blood into the central vein, and blood then fl ows from the central vein to the hepatic vein and fi nally into the inferior vena cava. Hepatocytes produce and secrete bile fi rst into narrow bile canaliculi and then into the bile ducts, part of the lobule triad. During this time, bile travels in an opposite direction from the blood in the triad and sinusoids. Bile eventually empties into the hepatic ducts and on to the cystic duct to be stored and concentrated in the gallbladder.

Before Going to Lab

1 Label the liver lobule structures in Figure 34.12.

• bile canaliculus • bile duct • branch of hepatic portal vein • branches of hepatic artery • central vein • hepatic vein • hepatocytes • portal triad • sinusoids

1 _________________________________

2 _________________________________

3 _________________________________

4 _________________________________

5 _________________________________

6 _________________________________

7 _________________________________

8 _________________________________

9 _________________________________

3 2

To inferior vena cava

Hepatic portal vein

Hepatic artery

To hepatic duct

6 7

FIGURE 34.12 Flow of blood and bile through a liver lobule.

G. Dissection of Digestive System

If you are dissecting a cat or fetal pig to observe digestive system structures, refer to the dissection manual. In your dissection of the digestive system, you will fi nd many organs and structures similar to the human. Pay at- tention to all the connective tissue, the greater omentum, and the mesentery. Real Anatomy, a virtual cadaver dissection, can be used to complement or substitute for animal dissection of the digestive system.

SAFETY NOTE: Wear safety glasses and gloves when using preserved or fresh tissue. Wash hands thoroughly with soap and water when you are finished.

583

Name ___________________________________ Date _________________ Section ______________________________

A. Layers of the Gastrointestinal Tract

Name the layers of the GI tract that are described.

______________________ 1. The layer that contracts to churn food or move food along

______________________ 2. Layer consisting of a membrane that lines a body cavity that opens to the exterior; overlays smooth muscle

______________________ 3. Areolar connective tissue layer located deep to the mucosa

______________________ 4. A serous membrane that is the external layer of a GI tract organ

B. Gastrointestinal Tract Organs

Write the name of the term that is described.

______________________ 1. Its only function is propulsion

______________________ 2. A continuous digestive tube from the mouth to the anus

______________________ 3. Conducts both air and food

______________________ 4. Primary site of nutrient absorption; is composed of 3 sections

______________________ 5. Section of small intestine that receives bile, pancreatic secretions, and food from the stomach

______________________ 6. Churns food and begins protein digestion

______________________ 7. Has two sphincters that control elimination of feces from the body

______________________ 8. Has regions called the cardia, fundus, body, and pylorus

______________________ 9. Has regions called the cecum, colon, rectum, and anal canal

______________________ 10. Receives secretions from salivary glands; mastication occurs here

Reviewing Your Knowledge

34 E X E R C I S E

584 E X E R C I S E 3 4 D I G E S T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

C. Digestive Organ Structures

Write the name of the organ that is described.

______________________ 1. Finger-like extensions increasing surface area in the small intestine

______________________ 2. Folds in the gastric mucosa

______________________ 3. Permanent deep ridges in the small intestine mucosa

______________________ 4. Sphincter valve between the stomach and duodenum

______________________ 5. Serous membrane that lines the abdominal wall

______________________ 6. Serous membrane that covers the abdominal organs

______________________ 7. Sphincter that connects the small and large intestine

______________________ 8. Fluid that begins digestion of carbohydrates

______________________ 9. Bony plate between the mouth and nose

______________________ 10. Forms a brush border; extension of epithelial cells

______________________ 11. Keeps food and fluids from going up into the nasopharynx

______________________ 12. Area between the lips and teeth

______________________ 13. Region of the stomach where the lower esophageal sphincter meets the stomach

______________________ 14. Has regions called ascending, transverse, descending, and sigmoid

______________________ 15. Narrowed region of the stomach before the small intestine

______________________ 16. A series of gathered pouches in the large intestine

D. Accessory Digestive Organs and the Peritoneum

Write the name of the organ that is described.

______________________ 1. Mechanically breaks up food during mastication

______________________ 2. Secretes enzymes that digest carbohydrates, proteins, lipids, and nucleic acids

______________________ 3. Salivary glands located under the tongue with ducts that open in the floor of mouth

______________________ 4. Produces and secretes bile into ducts

______________________ 5. Peritoneal membrane that holds the small intestine to the posterior abdominal wall

______________________ 6. The secretions of this gland join with bile to enter the duodenum

______________________ 7. Peritoneal fold that holds the liver to the anterior abdominal wall

E X E R C I S E 3 4 DIGESTIVE SYSTEM STRUCTURE AND FUNCTION 585

______________________ 8. Manipulates food in mastication

______________________ 9. Fatty, large fold of peritoneum covering the transverse colon and small intestine

______________________ 10. Largest salivary glands whose ducts open by the upper second molars

______________________ 11. Stores and secretes bile into the duodenum

______________________ 12. Peritoneal membrane that attaches the stomach and duodenum to the liver

______________________ 13. Salivary glands whose ducts open lateral to the lingual frenulum

14. Trace bile from its secretion to the gallbladder for storage and concentration, and then to the duodenum, listing the structures in order, using Figure 34.10.

(a) hepatocytes

(b) ________________________________________

(d) ________________________________________

(e) ________________________________________

(f) ________________________________________

(g) gallbladder

(h) ________________________________________

(i) ________________________________________

(j) ________________________________________

(k) duodenum

15. Trace blood from the hepatic portal vein through the liver to the inferior vena cava, listing the structures in order, using Figure 34.12.

(a) hepatic portal vein

(b) ________________________________________

(d) ________________________________________

(e) ________________________________________

(f) inferior vena cava

587

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Name ___________________________________ Date _________________ Section ______________________________

A. Digestive System Structure

1. A hiatal hernia or failure of the lower esophageal (cardiac) sphincter to close causes the stomach contents to back up into the esophagus. This causes the esophageal wall to have a burning sensation (heartburn) and, in serious cases, bleeding. What causes the burning sensation and bleeding to occur?

2. How does removal of the gallbladder affect digestion?

B. Identification of Digestive System Structures

Identify the structures numbered 3–6 on the X-ray of the human stomach shown in Figure 34.13.

3. _____________________________

4. _____________________________

5. _____________________________

6. _____________________________

Using Your Knowledge

34 E X E R C I S E

FIGURE 34.13 X-ray of the human stomach.

3 (folds)

588 E X E R C I S E 3 4 D I G E S T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

Identify the structures numbered 7–10 on the X-ray of the lower GI tract, shown in Figure 34.14.

7. _____________________________

8. _____________________________ (sacs)

9. _____________________________

10. _____________________________

FIGURE 34.14 X-ray of lower GI tract.

Mechanical and Chemical Digestion 35

E X E R C I S E

589

D igestion includes both mechanical digestion, mechanically breaking food into smaller pieces, and chemical digestion, the enzymatic breakdown of large molecules into smaller ones that can be absorbed into the bloodstream.

A. Mechanical Digestion

Mechanical digestion begins in the mouth and continues in the stomach and small intestine. Chewing or mastica- tion breaks down large pieces of food into smaller ones that are swallowed. In the stomach, peristaltic waves mechani- cally churn and mix the food with gastric juices to enhance digestion. Churning continues in the small intestine by smooth muscle contractions called segmentations, or back

and forth movements of portions of the small intestine, that mix the chyme with digestive enzymes prior to peristaltic contractions moving the contents along. Mechanical diges- tion enhances the speed of chemical digestion by creating a greater surface area for digestive enzymes to do their work.

B. Chemical Digestion

Chemical digestion involves digestive enzymes breaking the bonds of the food macromolecules. The food we eat contains macromolecules of carbohydrates, lipids, and proteins. Because these large molecules cannot be absorbed by the gastrointestinal tract, enzymes secreted by various parts of the digestive system catabolize or break down large molecules into small ones that can be absorbed. Starch, a carbohydrate,

O B J E C T I V E S M A T E R I A L S

• Starch Digestion (per group): 6 test tubes, test tube rack, test tube holder, wax marker, Parafilm, 37�C water bath, 1 saltine cracker (starch), and 1 dropper bottle each of salivary amylase, 0.5% HCl (hydrochloric acid), pH 7.4 buffer, distilled water

• Starch Test (per group): Lugol’s iodine (IKI) in dropper bottle, 1 clean spot plate with 6 depressions, wax marker

• Sugar Test (per group): Benedict’s reagent in dropper bottle, 250-mL beaker, hot plate

• Starch Digestion in Mouth (per person): 21∕2-inch- square portions of unsalted soda crackers (saltine-type)

• Bile Emulsification (per group): bile salts, vegetable oil, medicine dropper, distilled water in dropper bottle, 2 test tubes, test tube rack, test tube holder, wax marker

• PowerPhys Experiment: Enzyme Activity

1 Name the substrate for each of the following enzymes and the products produced from the enzyme-catalyzed reaction: amylase, protease, peptidase, and lipase

2 Describe the importance of mechanical digestion and chemical digestion

3 Explain the importance of pH on digestive enzyme function

4 Describe the action of bile salts on lipids

590 E X E R C I S E 3 5 M E C H A N I C A L A N D C H E M I C A L D I G E S T I O N

is digested into disaccharides (di- � two; saccharide � sugar) and monosaccharides (mono- � one) by the action of specifi c enzymes called amylases. Disaccharidases break down disaccharides into monosaccharides. Lipids are macromolecules that are catabolyzed or digested to glycerol and fatty acids by the enzyme lipase. Proteases digest proteins into peptides and amino acids. Peptidases digest peptides into amino acids. Monosaccharides, glyc- erol and fatty acids, and amino acids are small enough to be absorbed across the wall of the gastrointestinal tract and are used by cells for building new macromolecules or to provide energy (ATP). Table 35.1 contains digestive en- zymes, substrates, and products. Enzymes are typically large protein molecules produced by cells of the body that are special biological catalysts acting on specific substrates to produce products. Enzymes speed up the rate of chemical reactions between substrates without becoming chemically changed in the reaction. Enzymes work best on food substrates that are chewed and broken down mechanically into smaller particles with a greater surface area. Each enzyme has environmental conditions, typically temperature and pH, that allow it to be the most active. Enzymes in our body function well at body temperature

(37ºC) but will denature and become inactive if temperature becomes too high. The pH of the digestive system changes from the mouth to the small intestine; therefore, the enzymes in these different areas have different optimal pHs. In this exercise, we are using one specifi c enzyme, sali- vary amylase, to demonstrate digestion of carbohydrates into glucose. Whole pieces of cracker (starch) are compared with crumbled crackers to observe the importance of me- chanical digestion. The activity of amylase will be observed at a pH similar to that of the oral cavity and a pH similar to the stomach to demonstrate the importance of pH on en- zyme activity. Carbohydrate digestion begins in the mouth with a pH of about 7.4, but salivary amylase is denatured by the low pH in the stomach due to the presence of hydro- chloric acid (HCl). Pancreatic buffers bring the pH back to 7.4, a favorable pH for pancreatic amylase, allowing carbo- hydrate digestion to continue in the small intestine.

TABLE 35 .1 Chemical Digestion: Enzymes, Substrates, and Products

ORGAN ENZYMES PRESENT SUBSTRATES PRODUCTS

Mouth Salivary amylase Starches (polysaccharides) Shorter polysaccharides and maltose (disaccharide)

Lingual lipase (not active in mouth) N/A N/A

Esophagus None N/A N/A

Stomach Gastric lipase (limited role in adults) Triglycerides (fats and oils) Fatty acids and monoglycerides

Pepsin (secreted as pepsinogen and Proteins Peptides converted to pepsin by HCL)

Lingual lipase (activated by HCl; Triglycerides (fats and oils) Fatty acids and diglycerides limited action)

Small Intestine Major Pancreatic Juice Enzymes

• Amylase Starches (polysaccharides) Disaccharides and shorter polysaccharides

• Trypsin and other proteases Proteins Peptides

• Lipase Triglycerides (fats and oils) Fatty acids and monoglycerides

Small Intestine Brush Border Enzymes

Disaccharidases Disaccharides Monosaccharides

Peptidases Peptides and dipeptides Amino acids

SAFETY NOTE: • Wear safety glasses when heating test tubes and working

with acids. • Use a test tube clamp for handling heated test tubes.

E X E R C I S E 3 5 MECHANICAL AND CHEMICAL DIGESTION 591

• Appoint one member of your group to be the timer for timing the tubes, and have this person gently shake the test tube rack periodically for best results.

• Proceed to the bile salts preparation setup in Lab Activity 3 while these tubes incubate.

• Start water boiling in the 250-mL beaker for the sugar test.

Determine the amount of starch in each tube • Mark the depressions on the spot plates 1–6, matching

the test tube identification. • Obtain test tubes from the water bath and swirl to mix. • Place 2 drops of each test tube solution in the

appropriately marked depression on the spot plate. • Place 1 drop of Lugol’s iodine (IKI) solution

(brown) on top of the sample drops. • Observe the color and record this in Table 35.2. IKI

turns blue or black depending on the amount of starch present and indicates a positive starch test. If there is no color change, this indicates a negative starch test.

brown (�) dark blue (��) light blue (�) black (��) medium blue (� �)

Determine the amount of sugar formed when starch is digested by amylase • Place 3 drops of Benedict’s solution (light blue) in

the remaining solutions in all 6 tubes and swirl. • Put all 6 tubes into the beaker when the water is

boiling and time it for 3 minutes. • Observe the color of the solution and record this in

Table 35.2. A positive sugar test is green, yellow, orange, or red, depending on the amount of sugar present. If the color remains blue, you have a negative sugar test.

blue (�) orange (��) green (�) red (��) yellow (��)

LAB ACTIVITY 1 Experiment: Digestion of Starch

1 Prediction: Circle the correct tube choice for each statement. • The greatest amount of starch digestion will occur

using: whole cracker, crumbled cracker • The optimum pH for amylase to digest starch is: 7.0

(water), 7.4 buffer, acidic pH (HCl)

2 Materials • Materials: Obtain materials for Starch Digestion,

Starch Test, and Sugar Test (see Materials list).

3 Data Collection: • Read the procedures and decide who will do each step.

Digestion of starch by amylase • Mark the tubes 1–6 with the wax pencil and put

your initials on the upper part of the test tube for identification in the water bath. Place tubes in the test tube rack. Test tubes 1 and 2 are your controls to be used as comparisons with your results in tubes 3–6.

• In tubes 1, 3, and 5, place 1/8 of a piece of saltine cracker, uncrumbled. Add 12 drops of buffer to each tube and swirl it around.

• In tubes 2, 4, and 6, crumble 1/8 of a saltine cracker into very small pieces; crush with a mortar and pestle, if available. Add 12 drops of buffer to each tube and swirl it around.

• Swirl to mix the amylase solution before using. To tubes 3–6, add 3 drops of amylase.

• To tubes 5 and 6, add 3 drops of 0.5% hydrochloric acid (HCl).

• Add 6 drops of water to tubes 1 and 2, and 3 drops of water to tubes 3 and 4 to equal the liquid in tubes 5 and 6.

• Cover the test tubes with Parafilm and shake the tubes well to mix the contents.

• Remove the Parafilm and place the test tube holder with all 6 filled tubes in a 37�C water bath. Incubate for at least 30 minutes.

TABLE 35 .2 Digestion of Starch by Salivary Amylase

TUBE NO. 1 2 3 4 5 6

Contents Whole Crumbled Whole Crumbled Whole Crumbled added cracker cracker cracker cracker cracker cracker to test tubes Buffer Buffer Buffer Buffer Buffer Buffer Water Water Amylase Amylase Amylase Amylase Water Water 0.5% HCI 0.5% HCI

IKI test results for starch

Benedict’s test results for

sugar

592 E X E R C I S E 3 5 M E C H A N I C A L A N D C H E M I C A L D I G E S T I O N

4 Clean up as directed by your instructor. 5 Complete the Experimental Report with your lab group. 6 Complete PowerPhys Experiment: Enzyme Activity.

EXPERIMENTAL REPORT Digestion of Starch

Results: • List the test tubes that tested positive for sugar from

highest amount of sugar to lowest. • Identify any test tubes that tested negative for sugar. • List the test tubes that tested positive for starch from

lowest amount of starch to highest. • Identify any test tubes that tested negative for starch. • State the pH that was most effective for starch digestion.

Discussion: • Compare the amounts of sugar and starch in all of the

test tubes. Explain the differences. • Discuss how the results would be different if the

incubation time were longer. • Identify which test tube mimicked the conditions in

the mouth, esophagus, and the stomach.

Conclusion: • State how the presence of an enzyme infl uences the

digestion of starch to sugar. • State how substrate size and pH infl uence enzyme

activity. ■

8 Pool your results with the rest of your class and calcu- late the following averages: • Average time to taste sweetness for whole cracker.

______ sec. • Average time to taste sweetness for chewed cracker.

______ sec. • Average % of time to taste sweetness of chewed

cracker compared with whole cracker. ______ sec.

9 Explain the difference in average time to taste sweet- ness between the whole cracker and chewed cracker.

10 Compare your results with the class averages and ex- plain any differences. Think how conditions in your mouth may differ from other students in the class. List all possible differences. ■

C. Bile Emulsification

Bile is not a digestive enzyme. Bile is composed of a mix- ture of substances, including bile salts, that aid in digestion by physically breaking up large aggregates of lipid mol- ecules into smaller aggregates of lipid molecules with a greater surface area, a process called emulsifi cation.

LAB ACTIVITY 2 Starch Digestion in the Mouth

1 Obtain a cracker and break off two squares, each ap- proximately a 1/2 inch square.

2 Place one square on your tongue (do not chew it and do not swallow it).

3 Time how long it takes for you to taste sweetness. ______ sec.

4 Swallow the cracker and rinse your mouth with water. 5 Place the other square in your mouth and chew it (do

not swallow).

6 Time how long it takes for you to taste sweetness. _______ sec.

7 Calculate time to taste sweetness for the chewed cracker as a percentage of the time to taste sweetness for the whole cracker. ______ %

LAB ACTIVITY 3 Bile Emulsification

1 Read the procedure and decide who will do each step. 2 Obtain materials for Bile Emulsification (see Materials list). 3 Observe the ability of bile salts to emulsify lipids.

• Mark the tubes 1 and 2 with wax marker. • To each test tube, add 12 drops of water and 2 drops

of vegetable oil (a lipid). • To test tube 2, add a pinch of bile salts. • Cover the tubes with Parafilm and shake them to mix well. • Let the tube contents stand for 15 minutes. • Describe the contents of the 2 tubes:

Tube 1 ___________________________________

Tube 2 ___________________________________

4 Clean up as directed by your instructor. 5 Answer Discussion Questions with your lab group.

DISCUSSION QUESTIONS Bile Emulsification

1 In which tube had the oil emulsified? ______________

2 Is bile a digestive enzyme? _________ Explain.

3 Explain how emulsification increases chemical diges- tion of lipids by lipases.

■

593

Name ___________________________________ Date _________________ Section ______________________________

Reviewing Your Knowledge

A. General Terminology

Write the term that matches the description.

absorption macromolecule amylase product enzyme protease lipase substrate

______________________ 1. Large molecules resulting from anabolism

______________________ 2. A biological catalyst

______________________ 3. The molecule acted on by an enzyme

______________________ 4. Process that happens to nutrients after digestion

______________________ 5. Enzyme that hydrolyzes lipid

______________________ 6. Enzyme that hydrolyzes protein

______________________ 7. Enzyme that hydrolyzes starch

______________________ 8. The molecule produced as a result of an enzymatic process

B. Substrates and Products

Fill in the blank with the appropriate term.

1. Proteins are hydrolyzed into and absorbed as ______________________.

2. Lipids are hydrolyzed into and absorbed as ______________________ and ______________________.

3. Carbohydrates are hydrolyzed into and absorbed as ______________________.

4. Carbohydrate digestion begins in the ______________________.

5. Bile salts prepare lipids for digestion by a process called ______________________.

6. Lipid digestion begins in the ______________________.

7. Protein digestion begins in the ______________________.

35 E X E R C I S E

594 E X E R C I S E 3 5 M E C H A N I C A L A N D C H E M I C A L D I G E S T I O N

C. Carbohydrate Digestion Exercise

Fill in the blank with the appropriate term. 1. The reagent used to test for the presence of starch was ______________________.

2. The reagent used to test for the presence of sugar was ______________________.

3. The three major food macromolecules digested in our GI tract are ______________________, ______________________, and ______________________.

4. Why were there 2 tubes in Lab Activity 1 that had no enzyme added to them?

5. The enzymes that digest carbohydrates work best at a(n) ______________________ pH.

6. The reason why we chew food (and crumbled the cracker in Lab Activity 1) is to

7. A positive test for the presence of sugar is indicated by which colors?

8. A positive test for the presence of starch is indicated by which colors?

595

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Name ___________________________________ Date _________________ Section ______________________________

A. Digestion

1–3. Enzymes that digest carbohydrates are produced by what organs?

1. ___________________________________________

2. ___________________________________________

3. ___________________________________________

4–6. Enzymes that digest lipids are produced by what organs?

4. ___________________________________________

5. ___________________________________________

6. ___________________________________________

7–9. Enzymes that digest proteins are produced by what organs?

7. ___________________________________________

8. ___________________________________________

9. ___________________________________________

10. People who practice purging themselves after eating (bulimics) ruin the dentin of their teeth. What causes the dentin loss?

35 E X E R C I S EUsing Your Knowledge

O B J E C T I V E S M A T E R I A L S

• male and female urogenital models, charts, or use Real Anatomy (Urinary)

• human kidney and nephron models; articulated skeleton

• Compound microscope, lens paper, prepared slides of the kidney and a transverse section through a ureter or urinary bladder

• Dissection: Fresh or preserved kidney, dissection equipment, disposable gloves, safety glasses

• Dissection: Preserved cat or fetal pig, dissection equipment, disposable gloves, safety glasses, dissection manual

• Real Anatomy: Virtual Cadaver Dissection

Urinary System Structure and Function

36 E X E R C I S E

1 Identify the organs of the urinary system

2 Describe the structure of urinary system organs

3 Describe the structure of the nephron and trace the path of filtrate through the nephron

4 Trace the path of urine from the collecting ducts to the exterior of the body

5 Describe the blood supply to the kidneys and trace the pathway of blood from the renal artery to the renal vein

6 Dissect a cat, fetal pig, or cadaver and identify the main urinary tract organs

597

U rinary system organs include the kidneys, ureters, urinary bladder, and urethra. Urine is formed in the kidneys and flows through the ureters to the urinary bladder, which stores urine until it is eliminated from the body through the urethra.

A. Location and Gross Anatomy of Urinary System Organs

1. Kidneys

Kidneys are bean-shaped structures that are retroperitoneal (retro � behind), located between the abdominal wall and

the peritoneum. They are found at waist level between the 12th thoracic vertebra and the 3rd lumbar vertebra. The concave surface of each kidney faces the vertebral column and contains a vertical fi ssure, the renal hilum. The ure- ter, renal arteries and veins, nerves, and lymphatics pass through the renal hilum. The kidney is attached to the abdominal wall by the renal fascia, an outer layer of dense irregular connective tissue. The renal capsule, a thin fi brous membrane, covers the outer surface of the kidney. Between the renal fascia and the renal capsule is adipose tissue which forms the adipose capsule for protection and padding. Within the kidney are three main regions: the cortex, medulla, and sinus. The renal cortex, a smooth area, is the most superfi cial region, whereas the renal medulla is deeper. The medulla contains cone-shaped renal pyramids

598 E X E R C I S E 3 6 U R I N A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

and extensions of the cortex, renal columns, that are be- tween each pyramid. The base of each pyramid faces the cortex, and the renal papilla is the apex that is pointed toward the renal sinus. The cortex and medulla contain nephrons, the structural and functional units of the kidney that form urine. Urine drains into papillary ducts that exit through the openings in the renal papilla. The renal sinus is a space or cavity that is adjacent to the medulla and extends to the renal hilum. Within the renal sinus are minor and ma- jor calyces and the renal pelvis, which collect urine from the papillary ducts and deliver it to the ureters. The minor calyces are cup-like structures adjacent to the renal papillae, which receive urine from the papillary ducts. Several minor ca- lyces drain into a major calyx. Each kidney has 8 to 18 minor calyces and 2 to 3 major calyces. The major calyces drain into the renal pelvis, which is continuous with the ureter. Blood vessels, lymphatics, and nerves also travel through the renal sinus. Adipose tissue fi lls the remaining space within the renal sinus.

LAB ACTIVITY 1 Location and Structure of Kidneys

1 Identify the urinary system structures on a human torso model or chart, or use the search text box to find the structures in Real Anatomy (Urinary).

2 Use an articulated skeleton to identify which ribs help protect the kidneys.

3 Identify the structures from Figure 36.3 on a dissectible kidney model.

4 Answer the Discussion Questions with your lab group.

DISCUSSION QUESTIONS

1 Which kidney is lower? Identify the organ that forces this kidney into a lower position.

2 Which ribs protect the kidneys?

■

Before Going to Lab

1 Label the urinary system structures in Figures 36.1, 36.2, and 36.3.

FIGURE 36.1 Organs of the female urinary system.

Right renal vein

Rectum

Interior vena cava

Abdominal aorta

Diaphragm

Esophagus

Left adrenal (suprarenal) gland

Uterus

Right renal artery

• right kidney • right ureter • urethra • urinary bladder

1 ______________________

2 ______________________

3 ______________________

4 ______________________

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7 5

Transverse section through the abdomen (lying down and

viewed from the feet)

FIGURE 36.2 Location and coverings of the kidneys.

• adipose capsule • left kidney • peritoneum • renal capsule • renal fascia • renal hilum • right kidney

1 ________________________

2 ________________________

3 ________________________

4 ________________________

5 ________________________

6 ________________________

7 ________________________

FIGURE 36.3 Internal structure of the kidney.

1 ______________________________________

2 ______________________________________

3 ______________________________________

4 ______________________________________

5 ______________________________________

6 ______________________________________

7 ______________________________________

8 ______________________________________

9 ______________________________________

10 ______________________________________

11 ______________________________________

12 ______________________________________

Adipose tissue

1 (region)

2 (region) • major calyx (KAY-liks) • minor calyx • renal artery • renal capsule • renal column • renal cortex • renal hilum

• renal medulla • renal papilla • renal pelvis in renal

sinus • renal pyramid • renal vein

600 E X E R C I S E 3 6 U R I N A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

to the rectum and posterior to the pubic symphysis. In fe- males, the urinary bladder is anterior to the vagina, inferior to the uterus, and posterior to the pubic symphysis. The tube-like urethra carries urine from the internal urethral orifi ce to the external urethral orifi ce, the open- ing through which urine exits the body. The internal ure- thral sphincter is a layer of circular, involuntary smooth muscle that controls passage of urine into the urethra from the urinary bladder. Voluntary skeletal muscle within the urogenital diaphragm (deep muscles of perineum) forms the external urethral sphincter that permits the passage of urine to the external urethral orifi ce. During micturi- tion, the detrusor muscle contracts and forces urine out of the urinary bladder, and the internal and external urethral sphincters relax to allow the passage of urine. In females, the urethra is short (4 cm), whereas the urethra in males is longer (15–20 cm). The male urethra has three regions: the prostatic urethra that passes through the prostate gland, the membranous urethra that passes through the urogeni- tal diaphragm, and the spongy (penile) urethra that passes through the penis.

2. Ureters, Urinary Bladder, and Urethra

The ureters are narrow, 25- to 30-cm long muscular tubes located behind the peritoneum (retroperitoneal). The di- ameter of the ureters varies from 1 to 10 mm. The ureters descend toward the urinary bladder, curving medially as they approach the inferior portion of the bladder, and enter the posterior wall of the bladder at an oblique angle. Urine is propelled through the ureters by peristalsis, hydrostatic pressure, and gravity. The urinary bladder is a hollow, muscular organ that distends to store urine. Its superior surface is covered by visceral peritoneum and is secured to the pelvic wall by pa- rietal peritoneal folds. The smooth muscle within the wall of the urinary bladder is called the detrusor muscle, and the epithelial lining of the bladder forms folds or rugae. The inferior surface of the urinary bladder contains three openings that form a triangle called the trigone. The two posterior openings are the ureteral openings, whereas the anterior opening is the opening into the urethra, the internal urethral orifi ce. In males, the urinary bladder is anterior

CLINICAL NOTE: BPH, or benign prostatic hypertrophy, is a noncancerous enlargement of the prostate gland that restricts the prostatic urethra and inhibits urine flow, causing urinary retention.

LAB ACTIVITY 2 Location and Gross Anatomy of the Ureters, Urinary Bladder, and Urethra

1 Identify the urinary system structures from Figures 36.4 and 36.5 on urogenital models or charts, or use the search text box to find the structures in Real Anatomy (Urinary). ■

Before Going To Lab

1 Label the urinary system structures in Figures 36.4 and 36.5(a) and (b).

4 5

9 (opening)

FIGURE 36.4 Ureters, urinary bladder, and urethra in a female.

• detrusor muscle of urinary bladder

• external urethral orifice • external urethral

sphincter • internal urethral orifice

• internal urethral sphincter • trigone (TRY-goan) • ureteral openings • ureters • urethra

1 _______________________

2 _______________________

3 _______________________

4 _______________________

5 _______________________

6 _______________________

7 _______________________

8 _______________________

9 _______________________

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(a)

• anus • external urethral orifice • internal urethral orifice • membranous urethra • prostatic urethra • rectum • spongy urethra • ureter • ureteral opening • urinary bladder • urogenital diaphragm

1 ______________________

2 ______________________

3 ______________________

4 ______________________

5 ______________________

6 ______________________

7 ______________________

8 ______________________

9 ______________________

10 ______________________

11 ______________________

(b)

• anus • external urethral orifice • internal urethral orifice • rectum • urethra • urinary bladder • urogenital diaphragm • uterus • vagina

12 ______________________

13 ______________________

14 ______________________

15 ______________________

16 ______________________

17 ______________________

18 ______________________

19 ______________________

20 ______________________

(a) Sagittal section through male pelvis

Prostate gland

FIGURE 36.5 Comparison of the urinary bladder and urethra in males and females.

(b) Sagittal section through female pelvis

602 E X E R C I S E 3 6 U R I N A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

B. Structure of the Nephron

The 1 million nephrons in each kidney fi lter the blood and form urine. Each nephron is composed of a renal cor- puscle that fi lters blood and a renal tubule that modifi es the fi ltrate to form urine. The renal corpuscle, which is located in the renal cortex, consists of a glomerulus (capil- lary network) and a glomerular (Bowman’s) capsule, a cup-shaped epithelial membrane surrounding the glomeru- lus. Blood is fi ltered across a fi ltration membrane formed by the walls of the glomerulus and the glomerular capsule into the capsular space (glomerular cavity). The liquid, now called fi ltrate, drains into the renal tubule. Each renal tubule is subdivided into three structural and functional sections. Starting at the glomerular capsule, these sections are proximal convoluted tubule, loop of Henle, and distal convoluted tubule. The proximal convo- luted tubule is located in the renal cortex and connects to the loop of Henle (nephron loop), which dips down into the renal medulla. The third portion is the distal convo- luted tubule, which is located in the cortex. Distal convoluted tubules from several nephrons drain the liquid (now called urine) into collecting ducts that de- scend through the renal pyramids and merge to form larger papillary ducts. These ducts open into the renal papillae, and immediately drain urine into minor calyces, then into major calyces, the renal pelvis, ureters, and fi nally into the urinary bladder for storage.

The vasculature of the nephron is important to the for- mation of urine. The glomerulus is located between two arterioles—a larger-diameter afferent arteriole that de- livers systemic blood to the glomerulus and a smaller- diameter efferent arteriole that receives blood from the glomerulus. The efferent arteriole then delivers blood to a second capillary bed, the peritubular capillary network that entwines the renal tubule. There are two types of nephrons: cortical nephrons and juxtamedullary nephrons. Cortical nephrons have short loops of Henle that descend slightly into the medulla, whereas juxtamedullary nephrons have long loops of Henle that extend deep into the medulla. In addition to peri- tubular capillaries, the loops of Henle of juxtamedullary nephrons are supplied by vasa recta, long capillary loops that extend from the efferent arteriole.

LAB ACTIVITY 3 Structure of the Nephron

1 Identify the structures of the nephron in Figure 36.6(a) and (b) on a nephron model or chart. ■

Before Going to Lab

1 Label the renal tubule in Figure 36.6(a), and the blood vessels and renal tubule in Figure 36.6(b).

E X E R C I S E 3 6 U R I N A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N 603

(b) Renal corpuscle and vasculature of the renal tubule

8 9

(a) Renal tubule of cortical nephron

FIGURE 36.6 Structure and vascular supply of a cortical nephron.

(b)

• afferent arteriole • efferent arteriole • glomerular capsule • glomerulus • peritubular capillary • renal corpuscle

8 _______________________________________

9 _______________________________________

10 _______________________________________

11 _______________________________________

12 _______________________________________

13 _______________________________________

(a)

• ascending limb of loop of Henle • collecting duct • descending limb of loop of Henle • distal convoluted tubule • glomerular (glow-MER-u-lar) capsule • papillary duct • proximal convoluted tubule

1 _______________________________________

2 _______________________________________

3 _______________________________________

4 _______________________________________

5 _______________________________________

6 _______________________________________

7 _______________________________________

604 E X E R C I S E 3 6 U R I N A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

C. Blood Flow Through the Kidneys

During rest, the renal arteries carry 20 to 25% of the car- diac output to the kidneys, and the renal veins return blood to the inferior vena cava. The pathway of blood through the kidneys is outlined below. LAB ACTIVITY 4 Blood Flow

Through the Kidneys

1 Identify the blood vessels on a model or chart. 2 Answer the Discussion Questions with your lab group.

Before Going to Lab

1 Label the blood vessels in Figure 36.7. Find the renal artery and label it first to follow the blood flow.

Renal artery ↓

Segmental arteries ↓

Interlobar arteries ↓

Arcuate arteries ↓

Interlobular arteries ↓

Afferent arteriole ↓

Glomerular capillaries ↓

Efferent arterioles

Renal vein ↑

Interlobar veins ↑

Arcuate veins ↑

Interlobular veins Peritubular → capillaries → and/or vasa recta

Blood supply of the nephron

4 1

Glomerulus

FIGURE 36.7 Blood supply of the kidney.

• afferent arteriole • arcuate artery • arcuate vein • efferent arteriole • interlobar artery • interlobar vein • interlobular artery

• interlobular vein • peritubular capillary • renal artery • renal vein • segmental artery • vasa recta

1 ______________________

2 ______________________

3 ______________________

4 ______________________

5 ______________________

6 ______________________

7 ______________________

8 ______________________

9 ______________________

10 ______________________

11 ______________________

12 ______________________

13 ______________________

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D. Dissection of a Pig (or Sheep) Kidney

Pig and sheep kidneys are very similar to human kidneys. This dissection will illustrate the location of the calyces and renal pelvis within the renal sinus.

DISCUSSION QUESTIONS Blood Flow Through the Kidney

Use Figure 36.7 to answer the following questions.

1 Identify the arteries and veins that travel through the renal sinus.

2 Identify the artery and vein that travel through the renal columns.

3 Identify the artery and vein that arch over the base of the renal pyramid between the cortex and medulla.

4 Identify the blood vessels located in the renal cortex.

■

LAB ACTIVITY 5 Kidney Dissection

1 Identify the boldface structures listed below on a pig or sheep kidney, using Figure 36.8 as a reference.

2 If you have a fresh kidney, carefully remove any fat on its exterior. If you are lucky, the adrenal glands may still be located on the superior surface. Adrenal glands are usually not present on preserved kidneys.

3 If you have a preserved kidney, rinse it to remove excess preservative.

4 Locate the renal hilum on the concave surface. Iden- tify the ureter, renal artery, and renal vein that travel through the hilum. The renal artery will have a thicker wall than the renal vein.

5 Using a scalpel or knife, carefully cut along the frontal plane to separate the kidney into anterior and posterior sections.

6 Observe the cut surface. Using a needle probe, pull the thin renal capsule away from the surface of the kidney. The outer region of the kidney, the cortex, will be a slightly lighter color than the deeper medulla.

SAFETY NOTE: Wear gloves and safety glasses when using preserved or fresh tissue. Wash hands thoroughly with soap and water when you are done.

FIGURE 36.8 Frontal section of preserved triple-injected pig kidney.

Cortex Renal column

Renal pelvis

Pyramid

Renal papillae

Minor calyx

Major calyx

Hilum

Renal capsule

606 E X E R C I S E 3 6 U R I N A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

The descending limb of the loop of Henle (nephron loop) is lined by simple squamous epithelium. The initial part of the ascending limb or thin section of the ascending limb is also lined by simple squamous epithelium, whereas the thick section of the ascending limb of the loop of Henle (nephron loop) is lined by simple cuboidal to low columnar cells. The distal convoluted tubule is lined with simple cuboidal epithelium. These cells do not have a brush bor- der and appear shorter than the simple cuboidal cells lining the proximal convoluted tubule. The fi nal part of the distal convoluted tubule and the collecting ducts are lined with simple cuboidal epithelium.

7 Glomeruli may be observed in preserved kidneys that are injected with red and blue latex. The glomeruli will appear as red and blue dots within the cortex.

8 Within the medulla, extensions of light-colored cortical tissue, renal columns, are found between the darker, cone-shaped renal pyramids. Identify the renal papillae located at the apices of the renal pyramids.

9 Between the medulla and the renal hilus is a space called the renal sinus. Within the renal sinus are the minor and major calyces, and the renal pelvis. Adi- pose tissue, blood vessels, lymphatics, and nerves fill the remaining space within the renal sinus.

10 Clean up as directed by your instructor. ■

E. Dissection of the Urinary System

The urinary system organs of the cat and fetal pig are simi- lar to those of the human. This dissection will illustrate the retroperitoneal location of the urinary system organs, the relationship of urinary system organs to other organs, and how well these organs are secured by connective tissues. Refer to the appropriate accompanying cat or fetal pig dis- section manual for dissection instructions and fi gures. Real Anatomy, a virtual cadaver dissection, can be used to complement or substitute for animal dissection of the urinary system.

F. Histology of the Urinary System

1. Kidneys

The glomerular (Bowman’s) capsule is composed of a visceral and parietal epithelial layer. The visceral layer, which forms part of the fi ltration membrane, is adjacent to the glomerulus, and the parietal layer forms a funnel-like structure that collects the fi ltrate within the capsular space (glomerular cavity). Both layers are simple squamous epi- thelium; however, the simple squamous epithelial cells of the visceral layer have foot-like projections that wrap around glomerular capillary walls and these cells are named podocytes ( podo � foot). The epithelium lining the proximal convoluted tubule is simple cuboidal epithelium. The microvilli forming the brush border on the apical surface of these epithelial cells give a brush-like appearance.

LAB ACTIVITY 6 Histology of the Kidney

1 Observe a prepared slide of the kidney. • Using a low-power objective lens, identify renal

corpuscles and proximal and distal renal tubules in the cortex and the loops of Henle and collecting ducts that extend into the renal medulla.

• Place a renal corpuscle in the center of the field of view, and using a high-power objective lens, iden- tify the following structures: simple squamous epithelium of the parietal layer of the glomerular capsule, capsular space, and glomerulus.

• Return to a low-power objective lens, and place a section of the cortex with proximal and distal con- voluted tubules in the center of the field of view. Switch to a high-power objective lens and identify the simple cuboidal epithelium lining a proximal convoluted tubule and a distal convoluted tubule.

• Return to a low-power objective lens and place a section of the renal medulla with collecting tubules in the center of the field of view. Switch to a high- power objective lens and identify the epithelial lin- ing of the collecting tubules.

2 Answer Discussion Questions with your lab group.

Before Going to Lab

1 Label the microscopic kidney structures in Figure 36.9(a) and (b). Notice that, with this stain, the distal convo- luted tubules stain a lighter pink than the proximal convoluted tubules.

E X E R C I S E 3 6 U R I N A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N 607

DISCUSSION QUESTIONS Histology of the Kidney

1 State the function of the simple squamous epithelium of the visceral layer of the glomerular capsule.

2 The epithelium lining of the proximal convoluted tubule has a brush border. Name the cell structure that forms the brush border and state its function.

■

FIGURE 36.9 Sectional view of the kidney.

Capsule

16�

(a) Survey photomicrograph of kidney cortex

Lumen of

proximal convoluted

tubule

Lumen of

distal convoluted

tubule

4 5 6

1225�

(b) Renal corpuscle and proximal and distal convoluted tubules

(a)

• loop of Henle and collecting ducts • proximal and distal convoluted tubules (outer cortex) • glomerulus

1 ________________________________________

2 ________________________________________

3 ________________________________________

(b)

• parietal layer of glomerular capsule (simple squamous epithelium)

• capsular space • glomerulus

4 ________________________________________

5 ________________________________________

6 ________________________________________

608 E X E R C I S E 3 6 U R I N A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

DISCUSSION QUESTION Histology of Ureters, Urinary Bladder, and Urethra

1 Explain why the epithelial layer changes to strati- fied squamous epithelium near the external urethral orifice.

■

2. Ureters, Urinary Bladder, and Urethra

The ureters are composed of three layers: a mucosa that lines the lumen, a muscular layer called the muscularis, and an outer adventitial layer. The mucosa contains transitional epithelium, which can distend to accommodate urine, and an underlying lamina propria of areolar connective tissue. The muscularis layer contains smooth muscle. Peristalsis, the function of the muscularis layer, moves urine from the renal pelvis to the urinary bladder. The adventitia secures the ureters in place. The urinary bladder contains the same layers as the ure- ter. The epithelium of the mucosa is transitional epithelium, and the muscularis contains smooth muscle. Contraction of the muscularis layer forces urine out of the urinary blad- der, and the adventitia secures the bladder in place. The urethra consists of a mucosa surrounded by a mus- cularis layer of circular smooth muscle. In both males and females, the epithelium of the mucosa changes along the course of the urethra. The epithelium is transitional near the urinary bladder, becomes stratifi ed columnar or pseu- dostratifi ed columnar distally, and changes to stratifi ed squamous epithelium near the external urethral orifi ce.

LAB ACTIVITY 7 Histology of the Ureters, Urinary Bladder, and Urethra

1 Obtain a prepared microscopic slide of a transverse sec- tion through the ureter or urinary bladder or use Real Anatomy (Histology). • Using a low-power objective lens, identify the

mucosa, the muscularis, and the adventitia. • Using the high-power objective lens, identify the

transitional epithelium lining the lumen.

2 Answer the Discussion Question with your lab group.

Before Going to Lab

1 Label the urinary tract tissues in Figure 36.10.

FIGURE 36.10 Sectional view of the ureter.

• adventitia • lamina propria • lumen • mucosa • muscularis • transitional epithelium

1 ________________________________________

2 ________________________________________

3 ________________________________________

4 ________________________________________

5 ________________________________________

6 ________________________________________

40�LM

609

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

36 E X E R C I S E

A. Renal Structures

Write the renal structure that the phrase describes.

1. Urine-forming structure of the kidney

2. Region of the kidney deep to cortex; contains collecting ducts

3. Extensions of renal cortex found in between renal pyramids

4. Urine flowing through this structure drains into a minor calyx

5. Located between renal fascia and renal capsule

6. Apex of renal pyramid

7. Urine flowing through this structure drains into the renal pelvis

8. Vertical fissure in concave surface of kidney through which blood vessels and ureters pass

9. Covers outer surface of kidney

10. Dense irregular connective tissue that covers the adipose capsule and attaches the kidney to the abdominal wall

11. Receives urine from the major calyces

12. Space within kidney that is adjacent to renal medulla, contains calyces and renal pelvis

13. Cup-like structure that is located in renal sinus that receives urine from openings of papillary ducts

14. Cone-shaped structures located within the renal medulla

15. Outermost region of the kidney, contains renal corpuscles

610 E X E R C I S E 3 6 U R I N A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

B. Ureters, Urinary Bladder, and Urethra

Write the name of the structure that the phrase describes.

1. Detrusor muscle is the main muscle for this structure

2. Region of male urethra that passes through the prostate gland

3. Two openings in posterior urinary bladder wall

4. Region of male urethra that passes through penis

5. Area bounded by ureteral openings and internal urethral orifice

6. Voluntary skeletal muscle in urogenital diaphragm that allows passage of urine to exterior of body

7. Carries urine from renal pelvis to urinary bladder

8. Urine is excreted through this opening

9. Circular smooth muscle that involuntarily controls passage of urine from the urinary bladder to the urethra

10. Anterior opening in urinary bladder that leads into urethra

11. Region of male urethra that passes through urogenital diaphragm

C. The Nephron

Write the name of the structure the phrase describes.

1. Blood vessel that delivers blood to glomerulus

2. Blood from the efferent arteriole flows into this capillary bed

3. Structure that surrounds glomerulus and collects filtrate

4. Section of renal tubule that descends into medulla

5. Capillary network within the renal corpuscle

6. Structure composed of glomerulus and glomerular capsule

7. Blood vessel that drains blood from glomerulus

8. Capillary loops that extend from the efferent arteriole and run along loop of Henle (nephron loop) of juxtamedullary nephrons

E X E R C I S E 3 6 U R I N A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N 611

D. Urine Formation and Flow

Trace the flow of filtrate and urine through the urinary system. Write the structures in order, starting with the glomerulus.

1. glomerulus

2. ________________________________

3. ________________________________

4. ________________________________

5. ________________________________

6. ________________________________

7. ________________________________

8. ________________________________

9. ________________________________

10. ________________________________

11. ________________________________

12. ________________________________

13. ________________________________

14. external urethral orifice

E. Blood Flow Through the Kidneys

Trace blood flow through the kidneys. Start at the renal artery and number the blood vessels in sequence.

________ afferent arteriole

________ arcuate artery

________ arcuate vein

________ efferent arteriole

________ glomerulus

________ interlobar artery

________ interlobar vein

________ interlobular artery

________ interlobular vein

________ peritubular capillary

___1____ renal artery

________ renal vein

________ segmental artery

613

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

36 Observe the X-ray in Figure 36.11 and identify the structures.

FIGURE 36.11 Urinary system structures in the cat.

1. ________________________________

2. ________________________________

3. ________________________________

4. ________________________________

5. ________________________________

6. Is the urinary bladder full or partially voided? [Refer to Figure 2.5(d) for another view of the urinary bladder.]

7. Explain why pregnancy increases the frequency of urination.

2 3 (organ)

614 E X E R C I S E 3 6 U R I N A R Y S Y S T E M S T R U C T U R E A N D F U N C T I O N

8. Epithelial cells that reabsorb solutes are cuboidal, but epithelial cells involved in filtration are thin, squamous cells. The cuboidal cells contain more cytoplasm and organelles, especially mitochondria and rough endoplasmic reticulum (RER), than the squamous cells. Why do the cuboidal cells of the kidney tubules need more mitochondria and RER?

9. Define ptosis of the kidney.

10. Define incontinence and describe how this situation would be different in a child under 2 years old versus in an adult.

Urine Formation and Urinalysis 37

E X E R C I S E

615

T he formation of urine by the 1 million neph-rons in each kidney enables the body to remove metabolic wastes from blood and to maintain homeostasis by regulating water volume, concentration of ions in blood, and blood pH. A urinalysis is a simple test that can determine if urine formation is normal or abnor- mal. This test analyzes the volume of urine, and the physi- cal, chemical, and microscopic composition of urine. In addition, the level of some metabolic wastes in the blood is assessed. The two main components of the nephron are the renal corpuscle and the renal tubule. The subdivisions of the renal tubule are the proximal convoluted tubules, the loop of Henle, and the distal convoluted tubule. Many distal convoluted tubules empty fi ltrate into a collecting duct, which is not part of the nephron.

A. Function of the Nephrons

Urine is produced by the nephron and collecting ducts through three different processes—glomerular fi ltration, which occurs in the renal corpuscle, and tubular reabsorp- tion and secretion, which occur in the renal tubules.

• Filtration—The first step in urine production. Water and most solutes in blood pass through the filtration membranes (glomerular capillary walls and visceral wall of glomerular capsule) into the capsular (Bowman’s) space (glomerular cavity).

• Tubular reabsorption—Water and solutes cross the wall of the renal tubule, diffuse through the intersti- tial fluid, and return to blood by entering the peritu- bular capillaries or vasa recta.

• Tubular secretion—Solutes leave the peritubular capillaries or vasa recta, diffuse through the intersti- tial fluid, cross the wall of the renal tubule, and are eliminated in urine.

O B J E C T I V E S M A T E R I A L S

• Filtration: filter paper, funnel, ring stand with ring, 250-mL beaker, 5% powdered charcoal solution, and 1% copper sulfate solution

• Urinalysis: 100-mL beakers (4 per group), 50-mL beakers (4 per group), wax pencils, urine test strips, 1 normal and 3 abnormal artificial urines (obtained from a supply house or made with instructions on the Instructor Companion Site); slides and Sedi stain (if desired)

• PowerPhys Experiment: Influence of Fluid Intake on Urine Formation

1 Describe the function of the nephron

2 Describe the main components of the nephron

3 Explain the process of urine formation

4 Describe the major features of a urinalysis

5 Describe the composition and properties of normal urine

6 Compare and contrast the characteristics of normal and abnormal urine

616 E X E R C I S E 3 7 U R I N E F O R M AT I O N A N D U R I N A LY S I S

• Fold the circular filter paper in half twice, and open it to form a cone. Place the cone in the funnel and place the funnel in a ring on the ring stand. Put the beaker under the funnel (Figure 37.1).

• Stir or mix the solution composed of water, copper sulfate (blue), and powdered charcoal, and pour it into the funnel to just below the top of the filter paper. Watch so the edges of the filter paper do not capsize or that the solution doesn’t go over the top.

• As soon as the liquid slows down enough to count individual drops, count the number of drops in 15, 30, 45, 60, and 90 seconds. Record your information in Table 37.1.

5 Clean up as directed by your instructor. 6 Complete the Experimental Report with your lab group.

1. Function of the Renal Corpuscle

Each nephron has a renal corpuscle that is composed of a glomerulus and a glomerular capsule. In the nephron, blood plasma is fi ltered across the fi ltration membrane (glomerular capillary walls and the visceral wall of the glomerular capsule) into the capsular space (glomerular cavity). Filtrate, the liquid and solutes fi ltered into the cap- sular space, contains all the components of plasma except those that are too large to pass through the pores in the fi ltration membrane—the blood cells, platelets, and most plasma proteins. The rate of fi ltration across the glomeru- lus is determined by blood pressure (hydrostatic pressure). The greater the blood pressure, the greater the fi ltration rate. Also, fi ltrate moves by hydrostatic pressure into the fi rst section of the renal tubule, the proximal convoluted tubule.

LAB ACTIVITY 1 Experiment: Filtration

In this activity, you will observe the selectivity of the fil- tration membrane and the effect of hydrostatic pressure on filtration rate.

1 Prediction: With your lab partners, predict which sub- stances will pass through the filter: water, copper sulfate (blue), or charcoal.

__________________ will pass through the filter.

__________________ will not pass through the filter. 2 Read the procedure and decide who will do each step. 3 Materials: Obtain materials for Filtration (see

Materials list).

4 Data Collection: Observe and record the substances that pass through a filter paper in the kidney filtration simulation. Record your data in Table 37.1.

FIGURE 37.1 Filtration setup.

Filtrate

Filter paper

Funnel

TABLE 37 .1 Filtration Results

T IME ( sec ) #DROPS

E X E R C I S E 3 7 URINE FORMATION AND URINALYSIS 617

Conclusion: Write a statement that postulates what substances can pass through the glomerulus of the kidney and how blood pres- sure affects the fi ltration rate.

■

2. Function of the Proximal Convoluted Tubule

The proximal convoluted tubule is the major site of tubular reabsorption of water and solutes from the fi ltrate. Proximal convoluted tubules reabsorb 100% of most organic solutes and nutrients (glucose, amino acids, lactic acid, water soluble vitamins); 65% of water, sodium ions, and potassium ions; 50% of chloride ions; and 80 to 90% of the bicarbonate ions. Water follows the solutes via osmosis. The proximal convoluted tubule also secretes hydro- gen ions and urea (nitrogenous waste) into the tubular fl uid. The hydrogen ions secreted into the tubular fl uid assist in the reabsorption of bicarbonate ions. Because the amount of water reabsorbed is approxi- mately equal to the amount of solutes reabsorbed (minus the solutes secreted into the tubule), the osmolarity (solute concentration) of the fi ltrate at the end of the convoluted tubule is the same as at the beginning of the convoluted tubule.

3. Function of the Loop of Henle (Nephron Loop)

The remaining fi ltrate travels on through the renal tubule to the descending limb of the loop of Henle (nephron loop), which is permeable to water but not to solutes. As the fi ltrate travels through the descending limb of the loop of Henle (nephron loop) toward the medulla of the kidney, the high solute content (higher osmolarity) of the intersti- tial fl uid in the renal medulla causes 15% of the original fi ltered water to be reabsorbed by osmosis. This causes the osmolarity of the fi ltrate to increase. The ascending limb of the loop of Henle (nephron loop) is impermeable to water but permeable to solutes. Therefore, the opposite occurs. As the fi ltrate travels toward the cortex, the decrease in solute content (lower osmolarity) of the interstitial fl uid causes reabsorption of Na� and Cl�. The osmolarity of the fi ltrate decreases and becomes more dilute than the proximal convoluted tubule fi ltrate as it heads toward the distal convoluted tubule.

EXPERIMENTAL REPORT Filtration

Results: • State how fi ltration rate changed over time.

• Name the substance(s) that passed through the fi lter paper.

• Name the substance(s) that did not pass through the fi lter paper.

Discussion: • Discuss why you saw a difference in the fi ltration rate

during the activity.

• Identify the force that drives the fi ltration rate.

• Identify the cell structure that the fi lter paper represents.

• Compare the substances that were not fi ltered in this experiment to the substances that are not fi ltered in the kidney.

• Compare your results of this experiment with your predictions.

618 E X E R C I S E 3 7 U R I N E F O R M AT I O N A N D U R I N A LY S I S

4. Function of the Distal Convoluted Tubule

As the fi ltrate enters the distal convoluted tubule, which is located in the cortex of the kidney, a total of 80% of water has been reabsorbed into the blood. In this segment of the tubule, further Na� and Cl� are reabsorbed into the blood and a small amount of water follows the solute by osmosis. The fi ltrate in the DCT is more dilute than in the PCT.

5. Function of the Late Distal Tubules and Collecting Ducts

When the fi ltrate reaches the collecting ducts, 90 to 95% of the water and solutes present in the original fi ltrate have been removed. The fi ltrate is now more dilute than in the proximal convoluted tubule. In the late distal tubules and collecting ducts, there is additional reabsorption of Na� and Cl� and the secretion of K�. Hormones affect reabsorption and secretion in the late distal tubules and collecting ducts. ADH determines whether a concentrated (higher osmolarity) or dilute (lower osmolarity) urine is produced. High levels of ADH increase water reabsorption, producing concentrated urine. When ADH levels are low, dilute urine is produced. Aldosterone acts on the collecting ducts, increasing the reabsorption of Na� and Cl� and the secretion of K�.

LAB ACTIVITY 2 Function of the Nephron

1 With your lab group, write the number of the structure shown in Figure 37.2 next to the phrase that describes its function. A number may be used more than once.

2 With your lab group, complete Table 37.2 by com- paring the osmolarity of the filtrate in each portion of the renal tubule or collecting duct with the osmolar- ity of the filtrate in the glomerular capsule. Write in one of the following choices: no change, increased, decreased, change dependent on presence of ADH and/ or aldosterone.

3 Complete PowerPhys Experiment: Influence of Fluid Intake on Urine Formation. ■

1 5

________ additional reabsorption of solutes and water

________ ADH increases reabsorption of water, additional reabsorption and secretion of solutes

________ aldosterone increases reabsorption of Na� and Cl� and secretion of K�

________ filtration

________ major site of tubular reabsorption of water and solutes; secretion of solutes

________ Na� and Cl� reabsorbed but not water

________ water reabsorbed but not solutes

FIGURE 37.2 Structure and function of a cortical nephron.

E X E R C I S E 3 7 URINE FORMATION AND URINALYSIS 619

the presence of solutes in urine. The more solutes present in urine, the higher the specifi c gravity. Normal urine contains 95% water and 5% solutes. The solutes found in normal urine include electrolytes (sodium, potassium, chloride, and other ions), urea (formed from breakdown of amino acids), creatinine (formed from breakdown of creatine phosphate), uric acid (formed from breakdown of nucleic acids), and metabolic end products of hormones and other substances. Although drugs are not a normal solute in urine, they will be excreted in urine if present in the bloodstream. Selected abnormal components of urine are listed in Table 37.4. Your textbook may include a more extensive list. The presence of these substances in urine indicates an abnormality in metabolism or kidney function.

B. Urinalysis

A urinalysis is an analysis of the physical, chemical, and microscopic characteristics of urine and a measure of urine volume. The normal characteristics of urine are listed in Table 37.3. Urine volume varies depending on the water content of the body and decreases when body fl uid volume is low. ADH secreted by the posterior pituitary gland acts on the collecting ducts to stimulate reabsorption of water from the fi ltrate. If body fl uid volume is high, ADH secre- tion is inhibited, the collecting ducts do not reabsorb water from the fi ltrate, and dilute urine is excreted. The specifi c gravity of urine is the weight of a volume of urine divided by the weight of the same volume of distilled water. Urine weight per volume is higher than distilled water because of

TABLE 37 .2 Comparison of Filtrate Osmolarity in Renal Tubule and Glomerular Capsule

OSMOLARITY OF F I LTRATE PART OF RENAL TUBULE IN RENAL TUBULE

End of proximal convoluted tubule

End of descending limb of the loop of Henle

End of ascending limb of the loop of Henle

Distal convoluted tubule

Collecting duct

TABLE 37 .3 Normal Characteristics of Urine

CHARACTER IST IC DESCR IPT ION

Volume One to two liters per 24 hours; considerable variation in normal volume

Color Yellow or amber color; urine color is darker in concentrated urine

Turbidity Transparent in freshly voided urine; will turn cloudy after standing; microbes, pus, epithelial cells, or crystals may cause cloudiness in fresh urine

Odor Aromatic when fresh; ammonia-like after standing because of breakdown of urea to ammonia by bacteria

pH Normal range is 4.6–8.0, with an average of 6.0; high-protein diets produce an acidic urine; vegetarian diets produce an alkaline urine

Specific gravity Normal range is 1.001–1.035; low specific gravity represents dilute urine; higher values represent a concentrated urine

620 E X E R C I S E 3 7 U R I N E F O R M AT I O N A N D U R I N A LY S I S

beaker. You will have 1 normal (control) and 3 abnormal urine samples.

• Look at the urine samples to determine the color and turbidity. Record the color and turbidity in Table 37.5.

• Using a urinometer, measure the specific gravity for each urine sample using instructions provided by your instructor. Do not discard urine; use it for the next test.

• Urine test strips contain small squares of different reagent paper that change color when they con- tact specific reagents (chemicals). Use a urine test strip to measure the pH and presence or absence of glucose, albumin (protein), hemoglobin (blood), leukocytes, and ketone bodies. Follow the instruc- tions on the test strip container and record the results in Table 37.5.

• If desired by your instructor, view one or more microscope slides of real urine that has been centrifuged. The sediment is mounted on a slide and stained with Sedi-stain for better viewing of the sediment constituents (Figure 37.3).

4 Clean up as directed by your instructor. 5 Complete the Experimental Report with your lab group.

TABLE 37 .4 Selected Abnormal Constituents of Urine

ABNORMALITY POSS IBLE CAUSE

Glucosuria (glucose in urine) Caused by diabetes mellitus but sometimes may be caused by stress (epinephrine stimulates glycogen breakdown); diabetes mellitus and stress result in high blood glucose levels and therefore high levels of glucose in the filtrate; glucose transporters cannot work fast enough to reabsorb all glucose from filtrate.

Hematuria (erythrocytes in urine) Caused by inflammation of urinary system organs, irritation by kidney stones, kidney disease, trauma to urinary system organs, or polyps or tumors within the urinary system.

Pyuria (white blood cells in urine) Caused by an infection in the kidney, ureter, urinary bladder, or urethra.

Albuminuria (excess albumin Results from an increase in filtration membrane permeability caused by high in urine) blood pressure, kidney trauma, disease, or inflammation; trace amounts of albumin in urine is normal.

Ketonuria (ketone bodies in urine) Caused by a metabolic condition called ketosis; ketosis occurs when cells do not have enough glucose to completely break down fatty acids; ketosis can occur from starvation, low-carbohydrate diets, or untreated diabetes mellitus.

Casts (hardened clumps of material The following conditions may result in cast formation: albuminuria, abnormally formed by protein precipitation acidic urine, and highly concentrated urine. and/or cell agglutination in renal tubules)

Calculi or kidney stones (insoluble Calculi can form anywhere within the kidney tubules, ureters, urinary bladder, salt crystals) or urethra and can cause considerable pain as they pass through the lumens of urinary system organs. Some causes of calculi are dehydration and ingesting too much of the salts that form calculi.

Urinary tract infection (microbes) Presence of bacteria or other microorganisms indicate the presence of a urinary tract infection (UTI); normal urine is sterile (no microorganisms present);

however, microbes present on the skin surrounding the external urethral orifice may contaminate the urine sample if the urine sample is not carefully obtained.

LAB ACTIVITY 3 Experiment: Urinalysis

1 Prediction: Predict the normal urine values for each of the following characteristics by circling your choice (in italics). • Color: yellow or red • Turbidity: clear or cloudy • pH range: 3.0–4.0 or 4.6–8.0 or 8.5–9.5 • Presence of glucose: negative or positive • Presence of protein: negative, trace, or positive • Presence of ketone bodies: negative, trace, or

positive • Presence of hemoglobin: negative, trace, or positive • Presence of leukocytes: negative, trace, or positive

2 Materials: Obtain materials for Urinalysis (from Materials list).

3 Data Collection: Determine color, turbidity, specific gravity, pH, and presence or absence of glucose, pro- tein, ketone bodies, hemoglobin, or leukocytes and re- cord the results in Table 37.5. • Label each of four 100-mL beakers as Urine Sample

#1, 2, 3, or 4. • Put 50 mL from each of the 4 stock artificial urine

samples into each appropriately labeled 100-mL

E X E R C I S E 3 7 URINE FORMATION AND URINALYSIS 621

Discussion: For each abnormal urine sample, name the abnormality and give the possible cause. Refer to Table 37.4

Urine Sample #________ Abnormality: Cause:

Conclusion: Give an overall statement regarding the characteristics of normal urine.

■

EXPERIMENTAL REPORT Urinalysis

Results: For each urine sample, state whether the urine sample is normal or abnormal. For each abnormal sample, specify which characteristic of the urinalysis was abnormal.

Urine Sample #1:

Urine Sample #2:

Urine Sample #3:

Urine Sample #4:

TABLE 37 .5 Urinalysis Results

CHARACTER IST IC SAMPLE 1 SAMPLE 2 SAMPLE 3 SAMPLE 4

Color

Turbidity

Specific gravity

Glucose

Albumin (protein)

Blood (hemoglobin)

Ketone bodies

Casts

Microbes

622 E X E R C I S E 3 7 U R I N E F O R M AT I O N A N D U R I N A LY S I S

(a) (b)

(e) (f)

(g) (h)

FIGURE 37.3 Microscopic components of urinary sediments. (a) waxy cast and granular cast, (b) granular cast, (c) hyaline cast, (d) hemoglobin cast, (e) uric acid crystals, (f) calcium oxide crystals, (g) triple phosphate crystals, (h) tyrosine crystals

623

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

37 E X E R C I S E

A. Functions of the Nephron

Write name of the part of the nephron that has the following function.

______________________ 1. Reabsorption of an additional 15% of water by osmosis. Impermeable to solutes.

______________________ 2. Hormones determine if urine is concentrated.

______________________ 3. Filters blood and forms filtrate.

______________________ 4. Reabsorption of majority of water and solutes from filtrate by active and passive processes. Also secretion occurs here.

______________________ 5. Reabsorption of more sodium, chloride, and about 10 to 15% more water.

______________________ 6. Reabsorption of sodium and chloride decreases the osmolarity of filtrate. Nearly imper- meable to water.

B. Hormones and Urine Formation

Write the term the phrase describes.

______________________ 1. Hormone that increases sodium and chloride ion reabsorption and potassium secretion

______________________ 2. Process of moving substances from renal tubule into the peritubular capillary

______________________ 3. ADH acts mainly at this portion of the nephron

______________________ 4. Process of moving substances from the peritubular capillary into renal tubule

______________________ 5. Process occurring across wall of glomerular capillary and visceral layer of glomerular capsule

______________________ 6. The act of voiding (emptying) the urinary bladder

______________________ 7. Hormone that increases water reabsorption in the late distal convoluted tubule and collecting duct

624 E X E R C I S E 3 7 U R I N E F O R M AT I O N A N D U R I N A LY S I S

C. Urinalysis

Answer the following questions with a short answer.

1. What is the normal volume of urine output per day in an adult?

2. What is the normal color of urine?

3. What could make urine cloudy?

4. What is the normal specific gravity of urine?

5. What makes urine have a higher specific gravity than distilled water?

6. Name five normal solutes found in urine.

7. Normal urine contains _________ % water and __________ % solutes.

8. Is normal daytime urine output dilute or concentrated?

9. What is the normal pH of urine?

10. What is pyuria?

11. What is ketonuria?

12. What is hematuria?

13. What is glucosuria?

14. True or false. Normal urine has some bacteria in it even if the urine sample was taken properly.

625

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

37 E X E R C I S E

A. Urine Formation

1. Explain how a kidney stone blocking urine flow through the ureter eventually may decrease filtrate formation in the glomerular capsule. (Hint: hydrostatic pressure.)

2. Explain how inflammation of the glomerular capsule causes hematuria.

3. Compare the contents of the filtrate in the glomerular capsule and the contents of urine in the renal pelvis. (Yes, you can answer this question without research.)

B. Urinalysis

For each of the urine samples in Table 37.6, indicate whether the urine is normal or abnormal. If abnormal, name the abnormality and indicate the probable cause.

4. Urine A

5. Urine B

6. Urine C

7. Urine D

8. Which urine has the (a) lowest concentration of solutes? (b) highest concentration of solutes?

626 E X E R C I S E 3 7 U R I N E F O R M AT I O N A N D U R I N A LY S I S

9. Which urines are: (a) acidic? (b) basic?

10. Which specific gravity value is the most concentrated? Urine: ____________

TABLE 37 .6 Urinalysis Results

MEASUREMENT UR INE A UR INE B UR INE C UR INE D

Color Yellow Slightly yellow Amber Red

Turbidity Clear Clear Clear Turbid

pH 6.0 6.5 4.0 7.5

Specific gravity 1.01 1.001 1.04 1.02

Glucose Negative Positive Negative Negative

Red blood cells Negative Negative Negative Positive

White blood cells Negative Negative Negative Positive

Albumin Negative Negative Negative Negative

Ketone bodies Negative Positive Negative Negative

Casts Negative Negative Positive Negative

Calculi Negative Negative Positive Negative

Microbes Negative Negative Negative Positive

O B J E C T I V E S M A T E R I A L S

• models or charts of the male reprod uctive system, or use Real Anatomy (Reproductive)

• compound microscopes, lens paper, prepared slides of sperm and a cross section of testis, or use Real Anatomy (Histology)

• Dissection: preserved cats or fetal pigs, dissection equipment, disposable gloves, safety glasses, cat or fetal pig dissection manual

Male Reproductive System Structure and Function

38 E X E R C I S E

1 Describe the structure and function of the male reproductive organs

2 Identify the location of male reproductive organs

3 Name the accessory sex glands and describe their secretions and functions

4 Describe spermatogenesis

5 Trace a spermatozoan from its production to ejaculation

6 Name the organ and cells that produce male hormones and describe the functions of the hormones

7 Identify the microscopic structures of the testes

8 Dissect a cat, fetal pig, or cadaver and identify the main male reproductive structures

627

T he male reproductive system has testes that produce gametes called sperm (spermato-zoa), ducts that store and transport sperm, and accessory sex glands that secrete fluid that, along with sperm, form semen. Supporting reproductive structures are the scrotum that houses the testes and the penis that transfers sperm into the female vagina.

A. Male Reproductive Organs

1. Scrotum and Testes

The scrotum (scrotal sac) is a pouch of loose skin that is suspended from the root of the penis outside the abdomi- nopelvic cavity. The scrotum is internally divided into two portions by a central scrotal septum (partition) with one testis in each section. The dartos muscle (dartos � skinned) is within the scrotal septum and scrotal wall. This smooth muscle wrinkles and raises the scrotum when con- tracted. The cremaster muscles (cremaster � hanging)

628 E X E R C I S E 3 8 M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

structures before being ejaculated from the body. Sperm are produced by a process called spermatogenesis in tiny seminiferous tubules that are located within the lobules of the testes. Seminiferous tubules form straight tubules that carry the sperm into a network of tubules called the rete testis (rete � network). Efferent ducts connect the rete testis to the epididymis (epi- � on or upon; didymus � pair), the fi rst part of the male duct system.

are continuations of the internal oblique muscles and are located in the spermatic cords superior to the testes, one on each side of the groin. The contraction or relaxation of the cremaster muscles occurs when it is cold or hot, respec- tively, to adjust the distance of the testes from the body wall. Being on the exterior of the body, the scrotum is pro- vided with a cooler temperature, 2 to 3�C lower than body temperature for normal sperm development. The testes (testicles or male gonads) are oval-shaped glands that are covered with a white fi brous capsule called the tunica albuginea (tunic � coat or covering; albus � white). The tunica albuginea is dense fi brous connective tissue that extends into the testis to form septa, partitions that divide the testes into small compartments or lobules. External to this coat is an extension of the peritoneum, called the tunica vaginalis, and spermatic fascia composed of loose connective tissue. The testes produce and release male hormones called androgens, primarily testosterone; they also produce and release sperm, which will travel through a series of tubular

Before Going to Lab

1 Label the structures of the testes and scrotum in Fig- ures 38.1 and 38.2.

LAB ACTIVITY 1 Testes and Scrotum

1 Locate the structures of the testes and scrotum on a model or chart, or use the search text box to find the structures in Real Anatomy (Reproductive). ■

FIGURE 38.1 Anterior view of the testes and scrotum.

Spermatic fascia

Spermatic cord

Internal oblique muscle

Transverse section of penis

Tunica vaginalis

• cremaster (kree-MAS-ter) muscle • dartos (DAR-tohs) muscle • scrotum (SCROH-tum) • tunica albuginea (TUNE-ih-kah

ahl-byoo-GIN-ee-uh) of testis

1 ______________________________

2 ______________________________

3 ______________________________

4 ______________________________

E X E R C I S E 3 8 M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N 629

• efferent duct • lobule • rete testis (REE-tee) • seminiferous (sem-ih-NIF-er-us) tubules • septum • straight tubule • tunica albuginea

1 ________________________________________

2 ________________________________________

3 ________________________________________

4 ________________________________________

5 ________________________________________

6 ________________________________________

7 ________________________________________

Seminiferous tubules

Rete testis

Tunica albuginea

Testis

Tunica vaginalis

FIGURE 38.2 Sagittal section of the testis showing seminiferous tubules.

630 E X E R C I S E 3 8 M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

contractions in the wall of the ductus deferens and the ejaculatory ducts propel the semen (semen � seed) into the urethra. The urethra has three regions: the prostatic urethra that passes through the prostate gland, the membranous urethra within the urogenital diaphragm, and the spongy (penile) urethra within the penis. Semen leaves the urethra through the external urethral orifi ce.

2. The Male Duct System

The male duct system includes the ducts of the testes, epididymis, ductus (vas) deferens, ejaculatory duct, and urethra. Each epididymis, the site of sperm maturation and storage, curves over the posterior of the correspond- ing testis. Peristaltic contractions of smooth muscle in the wall of the epididymis move sperm into the ductus deferens (duct � to lead; deferens � carrying away) or vas deferens (vas � vessel). The initial portion of the duc- tus deferens leaves the scrotum and enters the spermatic cord that travels between the testes and the inguinal canal. Each spermatic cord contains an artery, vein, lymphatic vessels, nerves, ductus (vas) deferens, and a cremaster muscle. Spermatic cord structures enter the pelvic cavity through passageways in the anterior abdominal wall called inguinal (inguinal � groin) canals. The exterior and inte- rior openings of the inguinal canals, respectively, are called superfi cial inguinal and deep inguinal rings. Because the testes descended through the inguinal canal before the male was born, this is a weaker area in the abdominal wall where inguinal hernias can occur. Within the pelvic cavity, each ductus (vas) deferens travels posteriorly, passing over a ureter as it turns me- dially and inferiorly to the posterior side of the urinary bladder. The ductus (vas) deferens broadens into an ampulla (ampulla � fl ask-like bottle) that unites with the seminal vesicle duct to form the short ejaculatory duct. Two ejaculatory ducts, one on either side, enter the prostate gland (prostate � standing before) located in- ferior to the urinary bladder. Peristaltic smooth muscle

LAB ACTIVITY 2 Male Reproductive Organs and Duct System

1 Identify the structures on a model or chart of the male duct system, or use the search text box to find the struc- tures in Real Anatomy (Reproductive). ■

Tunica vaginalis

(a) Lateral view of testis and associated structures

Spermatic cord

Head of epididymis

Testis

Body of epididymis

Tail of epididymis

• blood vessels and nerves • ductus (vas) deferens

(DUK-tus DEAF-er-ens) • epididymis

(ep-ih-DID-ih-miss) • spermatic (sper-MAT-ic)

cord

1 _______________________

2 _______________________

3 _______________________

4 _______________________

(b) The epididymis and ductus deferens

FIGURE 38.3 The testis and epididymis.

Before Going to Lab

1 Label the structures of the male duct system in Fig- ures 38.3 and 38.4.

E X E R C I S E 3 8 M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N 631

• ampulla (AM-pyoo-la) of ductus deferens • ductus (vas) deferens in inguinal canal • ejaculatory duct • epididymis • external urethral orifice • membranous urethra • penis • prostate (PRAH-state) gland • prostatic (prah-STA-tic) urethra • scrotum • spongy (penile) urethra • testis

1 _____________________________________

2 _____________________________________

3 _____________________________________

4 _____________________________________

5 _____________________________________

6 _____________________________________

7 _____________________________________

8 _____________________________________

9 _____________________________________

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ANTERIORPOSTERIOR

Prostate Ejaculatory duct

Prostatic urethra

Membranous urethra

Seminal vesicle

Ductus (vas) deferens

Rectum

Urinary bladder (opened)

Bulb of penis Bulbospongiosus muscle

Glans penis

Testis

Spongy (penile) urethra

Corpus spongiosum penis

Corpora cavernosum penis

Pubic symphysis

3 2

FIGURE 38.4 Male reproductive organs and duct system, sagittal section.

632 E X E R C I S E 3 8 M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

The prostate gland increases in size during male develop- ment and is known to enlarge after age 45, a condition known as BPH or benign prostatic hypertrophy. BPH can constrict the prostatic urethra causing diffi culty in urina- tion and ejaculation. The smallest accessory glands are the paired bulboure- thral (Cowper’s) glands (bulbus � swollen root) that are located on either side of the membranous urethra within the urogenital diaphragm, a skeletal muscle. These small glands secrete an alkaline secretion that neutralizes the acidic male urethra and secrete mucus that lubricates the urethra and glans penis.

B. Accessory Structures

1. Accessory Sex Glands and Semen

Three types of accessory glands—the seminal vesicles, prostate gland, and bulbourethral (Cowper’s) glands— make and secrete most of the fl uid portion of the semen. To assist sperm movement, the testes secrete a small amount of fl uid before the addition of fl uid from these three glands. The seminal vesicles (seminal � pertaining to semen) are sac-like glands posterior to the bladder, fl anking either side. When sperm cells reach the end of the ampulla (expanded end) of the ductus deferens, additional fl uid is added from the seminal vesicle through the seminal vesicle duct. This alkaline fl uid constitutes about 60% of the semen volume and neutralizes the acidic male urethra and female vagina because sperm motility is adversely affected by an acidic environment. It also contains fructose, an energy source for sperm, and prostaglandins that stimulate sperm motility and muscular contractions in the female reproduc- tive tract. The prostate gland surrounds the prostatic urethra in- ferior to the urinary bladder. Its milky secretion has sev- eral proteolytic (proteo- � protein; lytic � to break apart) enzymes, including prostate-specifi c antigen (PSA). This slightly acidic secretion, constituting approximately 25% of the semen volume, increases sperm viability and motility.

LAB ACTIVITY 3 Male Reproductive Organs and Accessory Sex Glands

1 Identify the structures of the accessory sex glands on a model or chart, or use the search text box to find the structures in Real Anatomy (Reproductive). ■

Ureter

Urinary bladder

Urogenital diaphragm

Pubic bone (cut)

FIGURE 38.5 Male reproductive organs and accessory sex glands, posterior view.

• ampulla of ductus deferens • bulbourethral (buhl-boh-your-REETH-

ruhl) gland • ductus (vas) deferens • ejaculatory duct • membranous urethra • prostate gland • prostatic urethra • seminal vesicle (SEM-ih-nul

VES-sih-kul) • spongy (penile) urethra

1 _____________________________________

2 _____________________________________

3 _____________________________________

4 _____________________________________

5 _____________________________________

6 _____________________________________

7 _____________________________________

8 _____________________________________

9 _____________________________________

Before Going to Lab

1 Label the accessory sex gland structures in Figures 38.5 and 38.6.

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with prepuce (foreskin) in an uncircumcised male. Circumcision removes the prepuce, exposing the glans penis. The external urethral orifi ce is the external opening of the urethra in the glans penis.

2. Penis

The penis is a cylindrical shaft that contains the distal portion of the urethra, a passageway for urine and for the ejaculation of semen. The penis is located medial and an- terior to the scrotum and testes and contains the spongy (penile) urethra. The penis is composed of three main parts: a body, a root, and the glans penis. The body of the penis contains three separate cylinders of erectile tissue, two dorsolateral corpora cavernosa penis (corpor- � body; cavernosa � hollow) and one midventral corpus spongiosum penis, all containing blood sinuses. Fibrous connective tissue, fascia, and skin surround all three cylin- ders. The spongy (penile) urethra is located posteriorly in the corpus spongiosum penis. The glans penis (glans � acorn) is the distal, expanded portion of the corpus spongiosum that is mostly covered

• bulbourethral gland • prostate gland • seminal vesicle

1 ________________________________

2 ________________________________

3 ________________________________

FIGURE 38.6 Accessory male sex glands, sagittal section.

Before Going to Lab

1 Label the penile structures in Figure 38.7(a) and (b).

LAB ACTIVITY 4 The Penis

1 Identify the penile structures on a model or chart, or use the search text box to locate the structures in Real Anatomy (Reproductive). ■

634 E X E R C I S E 3 8 M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

(a)

• bulbourethral gland • corpora cavernosa (core-PORE-ah cav-er-NOH-suh) penis • corpus spongiosum (CORE-pus spun-gee-OH-sum) penis • external urethral orifice • glans penis • membranous urethra • prepuce (PREE-pyoos) • prostate gland • prostatic urethra • spongy (penile) urethra

1 ____________________________________________________

2 ____________________________________________________

3 ____________________________________________________

4 ____________________________________________________

5 ____________________________________________________

6 ____________________________________________________

7 ____________________________________________________

8 ____________________________________________________

9 ____________________________________________________

10 ____________________________________________________

(b)

• corpora cavernosa penis • corpus spongiosum penis • spongy (penile) urethra

11 ____________________________________________________

12 ____________________________________________________

13 ____________________________________________________

FIGURE 38.7 Penis.

(a) Frontal section

Urinary bladder

Urogenital diaphragm

Deep artery of penis

Spongy (penile) urethra

Corpus spongiosum penis

Corpora cavernosa penis

Dorsal artery

Deep dorsal vein

(b) Transverse section

Ventral

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LAB ACTIVITY 5 Function of Male Reproductive Organs

1 With your lab group, write the number of the structure shown in Figure 38.8 next to the phrase that describes its function. ■

FIGURE 38.8 Function of the male reproductive organs.

_____ carries sperm from epididymis to ejaculatory duct

_____ copulatory organ; passageway for urine and sperm

_____ organ that produces sperm

_____ secretes 60% of semen volume; alkaline pH; prostaglandins

_____ secretes 25% of semen volume; increases viability and motility of sperm

_____ secretes mucus for lubrication of glans; alkaline pH

_____ site of storage and maturation of sperm

636 E X E R C I S E 3 8 M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

C. Microscopic Anatomy of the Testes

1. Histology of the Testis and Spermatogenesis

Spermatogenesis (spermato- � sperm; genesis � origin) or the formation of haploid sperm with half the number of chromosomes, occurs in the walls of numerous seminifer- ous tubules of each testis. This process takes about 2 to 2½ months for each sperm. Between the seminiferous tubules of the testes are triangular-shaped spaces called interstitial (interstitial � stand between) spaces that contain Leydig cells or interstitial endocrinocytes (endocrine cells). Leydig cells, when stimulated by luteinizing hormone from the anterior pituitary, produce and secrete hormones called androgens, which are primarily testosterone. Spermatogenesis begins with spermatogonia, diploid (46 or 2n chromosomes) stem cells located in the outer portion of the seminiferous tubule wall just beneath the basement membrane, which surrounds the seminiferous tubules. Spermatogonia divide to form primary spermato- cytes (diploid) and more spermatogonia stem cells. Each division moves the cells closer to the lumen of the tubule. Primary spermatocytes with 46 chromosomes enlarge and their nucleus divides in meiosis I to form two haploid (n) secondary spermatocytes, each with 23 double chro- mosomes. The two secondary spermatocytes divide by a second nuclear division, meiosis II, to form four haploid (n) spermatids, each with 23 single chromosomes. Sper- matids go through a drastic change in shape and compo- sition in a process called spermiogenesis, the making of sperm. Sertoli cells surround the cells undergoing sper- matogenesis, providing the chemical environment for this process and assisting the cells to move from the basement membrane to the lumen.

2. Sperm

Sperm are also called sperm cells or spermatozoa. Mature sperm have lost most of their cytoplasm and cel- lular organelles, and do not survive in the female reproduc- tive tract more than a few days after ejaculation. Sperm are composed of a head, midpiece, and a tail. The head consists mostly of the nucleus with an acrosome (acro- � atop) covering it. The acrosome is a vesicle fi lled with hy- drolytic enzymes that allow sperm to penetrate the female oocyte for fertilization. The midpiece contains many mitochondria that are needed to produce energy (ATP) for the tail once the sperm cells are ejaculated. The tail is a fl agellum that performs a whip-like motion, propelling the sperm.

Before Going to Lab

1 Label the microscopic structures in Figures 38.9(a) and (b), 38.10, and 38.11.

LAB ACTIVITY 6 Histology of the Testis, Spermatogenesis, and Sperm

1 Observe a prepared slide of the testis, or use Real Anat- omy (Histology). • Using low power, identify the walls of the

seminiferous tubules, tails of sperm in the lumen, and interstitial spaces.

• Using high power, identify the basement mem- brane, spermatogonia, spermatocytes, sper- matids, and sperm.

2 Observe a prepared slide of sperm. • Using a lower power, locate the sperm. • Using high power, identify the head, midpiece, and

flagellum.

3 Answer the Discussion Question with your lab group.

DISCUSSION QUESTION Spermatogenesis

1 How many sperm are produced in meiosis from one primary spermatocyte? ______

■

D. Dissection of Male Reproductive System

If you are dissecting a cat or fetal pig, consult the appro- priate dissection manual. You will probably be dissecting the urinary system along with the reproductive system. Although these two systems are not identical to humans, there are several similarities, and the differences make an interesting study.

E X E R C I S E 3 8 M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N 637

(b)

• basement membrane • early spermatid • late spermatid • Leydig (interstitial) cells • primary spermatocyte • secondary spermatocyte • Sertoli cells • spermatozoa (sperm cell) • spermatogonium

6 ____________________________________________________

7 ____________________________________________________

8 ____________________________________________________

9 ____________________________________________________

10 ____________________________________________________

11 ____________________________________________________

12 ____________________________________________________

13 ____________________________________________________

14 ____________________________________________________

(a) Events of spermatogenesis

Superficial basement membrane of seminiferous tubule

Mitosis

Meiosis II

Meiosis I

2n 2n

nnnn

LumenDeep

MEIOSIS

SPERMIOGENESIS

FIGURE 38.9 Spermatogenesis.

(a)

• primary spermatocyte (spur-MAH-toe-site) • secondary spermatocyte • spermatid (SPERM-uh-tid) • spermatogonium (spur-ma-toe-GOHN-ee-um) • spermatozoa (spur-ma-toe-ZOH-uh)

1 ____________________________________________________

2 ____________________________________________________

3 ____________________________________________________

4 ____________________________________________________

5 ____________________________________________________

(b) Transverse section through a seminiferous tubule

Lumen of seminiferous tubule

Blood vessel

Sertoli cell nucleus

638 E X E R C I S E 3 8 M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

• acrosome (AK-row-sohm) • head • midpiece • mitochondria • nucleus • tail (flagellum)

1 ________________________________________

2 ________________________________________

3 ________________________________________

4 ________________________________________

5 ________________________________________

6 ________________________________________

Spermatid (n)

Secondary spermatocyte (n)

Primary spermatocyte (n)

Spermatogonium (2n)

LM 310� Transverse plane

FIGURE 38.10 Photomicrograph of transverse section of seminiferous tubules.

• basement membrane • interstitial (inter-STIH-shee-ul) space • Leydig (interstitial) cell • lumen • tails of sperm

1 ________________________________________

2 ________________________________________

3 ________________________________________

4 ________________________________________

5 ________________________________________

FIGURE 38.11 Sperm cell.

639

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

38 E X E R C I S E

A. Male Reproductive Organ Structure and Function

Write the name of the structure that the phrase describes.

1. Secretes 60% of semen volume; alkaline pH; prostaglandins

2. Organ that produces sperm

3. Part of urethra within the urogenital diaphragm

4. Site of storage and maturation of sperm

5. Secretes 25% of semen volume; increases viability and motility of sperm

6. Located in prostate; formed by union of ducts of the ductus deferens and seminal vesicle

7. Covers and protects testes

8. Contracts to pull testes close to body; located in spermatic cord

9. Last section of urethra located in penis

10. Tube located in both the spermatic cord and pelvic cavity for transporting sperm

11. Contracts to wrinkle scrotum; located in scrotal wall

12. Ejaculatory duct opens into this part of urethra

13. Copulatory organ; passageway for urine and semen

14. Secretes mucus for lubrication of glans; alkaline pH

640 E X E R C I S E 3 8 M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

B. Male Duct System

List the following ducts in order (1–11), tracing sperm from their production to ejaculation.

________ ampulla of ductus deferens

________ ductus (vas) deferens

________ epididymis

________ efferent ducts

________ ejaculatory duct

________ membranous urethra

________ prostatic urethra

________ rete testis

________ seminiferous tubules

________ spongy (penile) urethra

________ straight tubules

C. Spermatogenesis and Sperm Cells

Write the name of the structure that the phrase describes.

1. Part of sperm that contains chromosomes

2. Haploid cells formed when secondary spermatocytes undergo meiosis II

3. Cells that secrete testosterone

4. Diploid stem cells

5. Process that produces haploid sperm from diploid stem cells

6. Cells that surround spermatocytes and spermatids and provide chemical environment for spermatogenesis

7. Space within testes where Leydig cells are located

8. Diploid cells that undergo meiosis I to form two haploid secondary spermatocytes

9. Process that transforms spermatids into sperm

10. Part of sperm that produces ATP

11. Propels the sperm

641

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

38 A. Male Reproductive System

Write a short answer for the following questions.

1. Can sperm move in reverse as well as forward? Explain.

2. (a) Which men would have a higher testicular temperature, those who wear briefs or those who wear boxer shorts?

(b) Which would be more likely to cause sterility? Explain.

3. The male reproductive system has both exocrine and endocrine functions. Name one endocrine secretion.

Name four exocrine secretions.

4. _______________________________ 6. _______________________________

5. _______________________________ 7. _______________________________

8. To perform a vasectomy, does the doctor have to surgically enter the abdominal cavity? Explain.

9. A vasectomy involves cutting the ductus deferens. Does a vasectomy impede testosterone levels, having a penile erection, or having an ejaculation? Explain each situation.

10. Many body builders who take high doses of anabolic steroids have undesirable side effects. Name four side effects.

O B J E C T I V E S M A T E R I A L S

• models or charts of the female reproductive system, or use Real Anatomy (Reproductive)

• compound microscopes, lens paper, prepared slides of the ovary and uterus, or Real Anatomy (Histology)

• Dissection: preserved cats or fetal pigs, dissection equipment, disposable gloves, safety glasses, cat or fetal pig dissection manual

Female Reproductive System Structure and Function

39 E X E R C I S E

1 Describe the structure and function of the female reproductive organs

2 Identify the location of the female reproductive organs

3 Describe oogenesis

4 Trace an oocyte from its production until implantation

5 Identify the selected structures on the microscopic slides of the ovary and uterus

6 Name the organ and cells that produce the female hormones and describe the functions of the hormones

7 Dissect a cat, fetal pig, or cadaver and identify the main female reproductive structures

643

T he female reproductive system has ovaries that produce gametes (oocytes), uterine tubes to transport the oocytes, a uterus to protect and nour- ish the developing embryo and fetus, a vagina, external genitalia, and mammary glands.

A. Female Reproductive Organs

1. Ovaries and Uterine Tubes

The paired, oval-shaped gonads or ovaries (ovary � egg receptacle) are the size of unshelled almonds (about 1 inch long) and are located on either side of the uterus. Oocytes (eggs or gametes) are produced in the ovary and are released during a process called ovulation. The

644 E X E R C I S E 3 9 F E M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

lateral part of the uterus. The shorter isthmus region has a narrower lumen and thicker walls than the rest of the uterine tube. The lumen of the uterine tubes is lined with ciliated columnar epithelia. The fertilized ovum (zygote) is moved through the uterine tubes by the beating of the cilia and by peristaltic, smooth muscle contractions of the uterine tube walls. The zygote reaches the uterus about 1 week after ovulation.

hormones estrogen and progesterone are produced by the ovaries. The ovaries are anchored in place by three paired ligaments: the broad ligaments, the ovarian ligaments, and the suspensory ligaments. The sheet-like broad ligament of the uterus is a double layer of peritoneum that attaches to each ovary and also secures the uterine tube in place. The ovarian ligament on the superior medial side of each ovary attaches the ovary to the uterus. The suspensory lig- ament on the superior lateral side of each ovary attaches the ovary to the pelvic wall in the lumbar region and sur- rounds the ovarian artery and ovarian vein. Paired uterine (fallopian) tubes or oviducts curve around the ovaries to receive and transport the oocyte to the superior part of the uterus. There are three main regions of the uterine tube: the infundibulum (with fi mbriae), ampulla, and isthmus. The funnel-shaped infundibulum composes the distal portion of the uterine tube and has fi nger-like structures projecting from its expanded end called fimbriae. During ovulation, the oocyte is projected toward the infundibulum, and the beating of the fi mbriae forms a current that sweeps the oocyte into the infundibulum. The oocyte then enters the longest region of the uterine tube, the ampulla, which constitutes about two-thirds of the length of the uterine tube. Fertilization of the oocyte by a sperm cell usually occurs in the ampulla. The third region, the isthmus, is proximal to and opens into the superior

LAB ACTIVITY 1 Ovaries and Uterine Tubes

1 Identify the structures of the ovaries and uterine tubes on a urogenital model or chart, or use the search text box to locate the structures in Real Anatomy (Reproductive). ■

Before Going to Lab

1 Label the structures of the ovaries and uterine tubes in Figure 39.1(b).

Ovary

Fimbriae

Broad ligament

Fundus of uterus

Infundibulum

AmpullaUterine tube

Isthmus

Ovarian ligament

(a) Superior view

FIGURE 39.1 Ovaries, uterine tubes, and uterus.

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1 ________________________________________

2 ________________________________________

3 ________________________________________

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5 ________________________________________

6 ________________________________________

7 ________________________________________

8 ________________________________________

9 ________________________________________

FIGURE 39.1 Ovaries, uterine tubes, and uterus, continued.

• ampulla • broad ligament • fimbriae (FIHM-brih-ee) • infundibulum (in-fun-DIB-you-lum) • isthmus • ovarian ligament • ovary • suspensory ligament • uterine tube

Fundus of uterus

(b) Posterior view

646 E X E R C I S E 3 9 F E M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

of smooth muscle that have fi bers going in three different directions: oblique, circular, and longitudinal. The thin en- dometrium is the inner, vascular layer lining the uterine cavity. Although the uterus is secured in its position by four paired ligaments, only two of these ligaments are easily found on models: the broad ligaments and the round liga- ments. The large, fl at broad ligaments attach the uterus to the lateral pelvic walls. The round ligaments, located between the two layers of the broad ligaments, begin below the uterine tubes and attach the uterus to the labia majora of the external genitalia. The ligaments of the uterus keep it in an antefl exion (ante- � forward) position as it leans forward over the urinary bladder.

2. Uterus and Vagina

The pear-shaped uterus is posterior to the urinary blad- der and anterior to the rectum. The uterus normally proj- ects superiorly and anteriorly over the urinary bladder (antefl exion). It is a little smaller than the size of your fi st, but obviously larger in a recently pregnant female and smaller after menopause. Externally, three main regions of the uterus can be seen: the fundus, body, and cervix. The fundus is the dome-shaped superior portion of the uterus that is wider and meets the entrance of the uterine tubes on both sides of the uterus. The body starts inferior to the openings of the uterine tubes, is the largest region of the uterus, and decreases in size to meet the narrower cervix inferiorly. The space within the uterus is the uterine cavity. The narrowed cervix opens into the vagina inferiorly. The cavity within the cervix is the cervical canal that begins at the internal os (os � mouth), a constricted opening be- tween the uterus and the cervix, and ends at the external os, the opening between the cervix and the vagina. The uterus is a thick-walled organ with three layers: the perimetrium, the myometrium, and the endometrium. The outer, thin perimetrium (metr- � uterus) is part of the vis- ceral peritoneum, also called the serosa. The middle myo- metrium is the thickest layer, composed of three layers

LAB ACTIVITY 2 The Uterus

1 Identify the uterine structures on a urogenital model or chart, or use the search text box to locate the structures in Real Anatomy (Reproductive). ■

Before Going to Lab

1 Label the uterine structures in Figures 39.2 and 39.3.

FIGURE 39.2 Female reproductive organs, sagittal section.

• cervix • myometrium of uterus • ovary • round ligament • urinary bladder • uterine cavity • vagina

1 ___________________________________

2 ___________________________________

3 ___________________________________

4 ___________________________________

5 ___________________________________

6 ___________________________________

7 ___________________________________

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1 _______________________________________

2 _______________________________________

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6 _______________________________________

7 _______________________________________

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9 _______________________________________

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11 _______________________________________

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3 Layers of uterus

8 7

FIGURE 39.3 Posterior view of the female reproductive organs.

• body of uterus • broad ligament • cervical canal • cervix (SIR-vex) • endometrium (endo-MEE-tree-um) • external os • fundus • internal os • myometrium (my-oh-MEE-tree-um) • perimetrium (peri-MEE-tree-um) • round ligament • rugae of vagina • uterine cavity • vagina

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3. External Genitalia

The external female genitalia are referred to as the vulva (vulva � to wrap around) or pudendum (pyoo-DEN- duhm) (pudens � modest). The vulva consists of the mons pubis, labia majora, labia minora, clitoris, and vestibule. The mons (mons � mountain) pubis is an anterior pad of adipose tissue beneath the skin that covers the pubic symphysis. Posterior to this are two longitudinal folds of adipose tissue covered with skin and pubic hair called the labia majora (labium majus, sing.). Medial to these larger folds are smaller paired longitudinal folds of skin without pubic hair called the labia minora (labium minus, sing.). The clitoris, a cylindrical erectile tissue, is posterior to the mons pubis and anterior to the external urethral orifi ce. The prepuce, an anterior extension of the labia minora, covers the body of the clitoris like a hood but leaves part of the clitoris exposed. The vestibule is the area medial to the

paired labia minora and contains the external urethral orifi ce, vaginal orifi ce, hymen (if present), and openings of glands that secrete mucus for lubrication. The hymen (hymen � membrane) is a thin membrane around the perimeter of the vaginal orifi ce that partially blocks the orifi ce.

LAB ACTIVITY 3 External Genitalia

1 Identify the external genitalia structures on a urogenital model or use the search text box to locate the structures in Real Anatomy (Reproductive). ■

Before Going to Lab

1 Label the external genitalia structures in Figures 39.4(b) and 39.5.

Body of uterus

Uterine cavity Fornix of vagina

Cervix of uterus

Rectum

Vagina

Urethra

Anus

Fundus of uterus

Ovary

Urinary bladder

Uterine tube

Pubic symphysis

Labium minus

Labium majus External anal sphincter

Fimbriae

Broad ligament

Erectile tissue of clitoris

FIGURE 39.4 Female external genitalia.

(a) Cadaver, sagittal section

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• anus • clitoris • external urethral orifice • hymen (HIGH-men) • labia majora • labia minora • mons pubis • prepuce (PREE-pyoos) • vaginal orifice

1 _____________________________________

2 _____________________________________

3 _____________________________________

4 _____________________________________

5 _____________________________________

6 _____________________________________

7 _____________________________________

8 _____________________________________

9 _____________________________________

FIGURE 39.4 Female external genitalia, continued.

8 7 6

• anus • clitoris (KLIH-tor-us) • external urethral orifice • labium majus (LAY-bee-um MAY-jus) • labium minus • mons pubis (mohnz PYOO-bis) • pubic symphysis (PYOO-bik SYM-fih-sis) • vaginal orifice

1 _____________________________________

2 _____________________________________

3 _____________________________________

4 _____________________________________

5 _____________________________________

6 _____________________________________

7 _____________________________________

8 _____________________________________

FIGURE 39.5 Female external genitalia, inferior view.

1 6 7

(b) Sagittal section

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glands that are arranged in clusters called lobules. Several lobules make up a lobe. Milk is secreted from alveoli into mammary ducts that drain one lobe and then into dilated lactiferous sinuses that merge to form lactiferous ducts. Milk is ejected through lactiferous ducts in the nipple.

4. Mammary Glands

Although mammary (mamma- � breast) glands are derivatives of the skin and are categorized as modifi ed sweat glands, they belong to the reproductive system be- cause in females they secrete milk for the offspring. The mammary glands in both males and females lie anterior to the pectoralis major and serratus anterior muscles. Fe- male breasts are enlarged compared with those of the male due to a greater amount of adipose tissue that surrounds the mammary glands. The main external structures of the breasts are the darkened areola and the raised nipple with lactiferous duct openings (lact- � milk). The in- ternal structures are the alveoli, lobules, lobes, mammary ducts, lactiferous sinuses, lactiferous ducts, and adipose tissue. Alveoli (mammary glands) are milk-producing

LAB ACTIVITY 4 Mammary Glands

1 Identify the mammary gland structures on a model or chart. ■

Before Going to Lab

1 Label the mammary gland structures in Figure 39.6(a) and (b).

FIGURE 39.6 Mammary glands.

• adipose tissue • areola (ah-REE-oh-la) • lactiferous (lak-TIF-er-us) duct • lactiferous sinus • lobule with alveoli • mammary duct • nipple

1 ________________________________________

2 ________________________________________

3 ________________________________________

4 ________________________________________

5 ________________________________________

6 ________________________________________

7 ________________________________________

Rib

4 7

Intercostal muscles

Pectoralis major

(a) Sagittal section (b) Anterior view, partially sectioned

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LAB ACTIVITY 5 Function of Female Reproductive Structures

1 With your lab group, write the number of the organ shown in Figure 39.7 next to the phrase that describes its function. Numbers may be used more than once.

________ Layer of uterus that sheds during menstruation

________ Produces secondary oocytes

________ Transports secondary oocytes toward uterus

________ Usual site of fertilization

________ Beat together to bring ovulated oocyte into uterine tube

________ Implantation of zygote and development of fetus occurs here

________ Produces estrogen and progesterone

________ Narrow region of uterine tube that opens into uterus

2 Discuss the pathway of a secondary oocyte from its pro- duction until implantation in the uterus with your lab partners. ■

FIGURE 39.7 Function of the female reproductive structures.

652 E X E R C I S E 3 9 F E M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

B. Oogenesis and Microscopic Anatomy of the Ovary and Uterus

1. Oogenesis

Oogenesis (oo- � egg) is the formation of haploid ova with half the number of chromosomes that occurs in the ovary. Early in fetal development, diploid (2n) stem cells called oogonia are produced, which divide to create millions of germ cells, most of which degenerate.

Meiosis I Some of the oogonia develop into primary oocytes (2n) that begin meiosis I before birth but stop in prophase I. At puberty, several primary oocytes complete meiosis I each month, forming two haploid cells of unequal sizes, each with 23 pairs of chromosomes. The much larger cell with most of the cytoplasm and organelles is called the secondary oocyte. The smaller one is called the fi rst polar body, which may or may not survive to undergo the meiosis II division. Polar bodies are mostly DNA or genetic material and will eventually degenerate.

Meiosis II The secondary oocyte begins meiosis II but stops in metaphase II prior to ovulation. If the ovulated secondary oocyte is fertilized, it will complete meiosis II and form a larger haploid ovum and a second polar body. When the nucleus from the sperm (n) unites with the nucleus of the ovum (n), a diploid single-celled zygote (2n) is formed.

LAB ACTIVITY 6 Oogenesis

1 With your lab group, label the structures and phases in Figure 39.8.

2 Answer the Discussion Questions with your lab group.

DISCUSSION QUESTIONS Oogenesis

1 Compare the size of the secondary oocyte with the first polar body.

2 Compare the numbers of gametes produced from one stem cell by oogenesis and spermatogenesis.

■

n n

Fertilization

Ovulation

Secondary oocyte

Prenatal

• first polar body • meiosis I • meiosis II • oogonium

(oh-oh-GOHN-ee-um) • ovum • primary oocyte

(OH-oh-site) • second polar body • secondary oocyte • sperm cell • zygote

1 ______________________

2 ______________________

3 ______________________

4 ______________________

5 ______________________

6 ______________________

7 ______________________

8 ______________________

9 ______________________

10 ______________________

FIGURE 39.8 Oogenesis.

E X E R C I S E 3 9 F E M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N 653

DISCUSSION QUESTIONS Histology of the Ovary

1 Which follicle types contain fluid?

2 Describe the difference in appearance between a corpus luteum and a corpus albicans.

■

2. Histology of the Ovary

The regions of the ovary from superfi cial to deep are the germinal epithelium (simple epithelium), cortex, and me- dulla. The stringy looking medulla contains connective tissue, blood vessels, and nerves. The cortex contains follicles (oocytes surrounded by cells) in various stages of development. Primordial follicles, the smallest fol- licles, each contain a primary oocyte surrounded by a single layer of cells called follicular cells. These follicles mature into primary follicles that have granulosa cells surrounding the follicular cells; follicular cells secrete estrogen. As the primary follicle matures, the granulosa cells secrete follicular fl uid and become secondary fol- licles. Secondary follicles contain an antrum (space within granulosa cell layers) that is fi lled with follicular fl uid. Each month one secondary follicle develops into a mature or graafi an follicle. This follicle, which contains a secondary oocyte, is the largest follicle and has the great- est amount of fl uid in its antrum. When a graafi an follicle expels the secondary oocyte during ovulation, the remain- ing follicular tissue becomes a corpus luteum (corpus � body; luteum � yellow), which secretes progesterone. When this structure is no longer functional, it disintegrates and a scar-like corpus albicans (alba � white) is formed. The corpus albicans doesn’t remain in the ovary very long and also disintegrates. Because of this, neither structure may be seen in your slides of the ovary.

LAB ACTIVITY 7 Histology of the Ovary

1 Examine a prepared slide of the ovary or use Real Anatomy (Histology). • Hold the ovary slide up to the light and determine

whether or not you have a section of a complete ovary. If you do not have a complete ovary, some of the structures may not be present.

• Using low power, identify the medulla, follicles of various sizes, and the hilum.

• Search for primordial follicles, a primary follicle, secondary follicle, and a mature (graafian) follicle.

• Center the mature follicle, and observe the second- ary oocyte with its granulosa cells surrounding it, forming the corona radiata.

2 Answer the Discussion Questions with your lab group.

Before Going to Lab

1 Label the microscopic ovarian structures in Figure 39.9(a)–(d).

(a) • corpus albicans (KOR-pus

AL-bih-kanz) • corpus luteum

(LOO-tee-um) • graafian (GRAF-ee-uhn)

(mature) follicle • ovulated secondary

oocyte • primary follicles • primordial (pry-MORE-

dee-uhl) follicles • secondary follicle • secondary oocyte

1 _______________________

2 _______________________

3 _______________________

4 _______________________

5 _______________________

6 _______________________

7 _______________________

8 _______________________

1 2

Blood clot

(a) Frontal section

FIGURE 39.9 Histology of the ovary.

654 E X E R C I S E 3 9 F E M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

(b) Ovarian cortex

Germinal epithelium

Corpus luteum

LM 30�

Germinal epithelium

Theca folliculi

LM about 200�15 16

(b)

• primary follicle • primordial follicles • primary oocyte in primary

follicle • primary oocyte in second-

ary follicle

9 ______________________

10 ______________________

11 ______________________

12 ______________________

(c)

• granulosa cells • ovarian cortex • primary oocyte in primary

follicle • primordial follicles

13 ______________________

14 ______________________

15 ______________________

16 ______________________

(d) Secondary follicle

LM 70� LM

(e) Ovulation of a secondary oocyte from a graafian follicle

Ovary

Secondary oocyte

30�

(d) • follicular fluid in antrum • granulosa cells (corona

radiata) • primary oocyte

17 ______________________

18 ______________________

19 ______________________

FIGURE 39.9 Histology of the ovary, continued.

E X E R C I S E 3 9 F E M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N 655

3. Histology of the Uterus and Uterine Tube

The endometrium of the uterus has epithelium facing the uterine cavity with endometrial (uterine) glands lying deep to the epithelium. The endometrium is further di- vided into the stratum functionalis and the stratum basalis. The epithelial layer and the endometrial glands together form the stratum functionalis (functional layer). Each month estrogen and progesterone stimulate the stratum functionalis to greatly increase in size in preparation to nourish a zygote. The stratum functionalis is the layer that is sloughed off in menstruation if implantation does not occur. The stratum basalis, the layer that remains after menstruation is completed for that month, gives rise to the new stratum functionalis the following month.

LM 25�

(layer) 1

Lumen (uterine cavity) Simple columnar epithelium

3 (sublayer)

4 (sublayer)

5 (layer)

• endometrial glands • endometrium • myometrium • stratum basalis (bay-SAHL-is) • stratum functionalis

1 ______________________________________

2 ______________________________________

3 ______________________________________

4 ______________________________________

5 ______________________________________

FIGURE 39.10 Histology of the uterus.

LAB ACTIVITY 8 Histology of the Uterus

1 Observe a prepared slide of the uterus. • Using scanning power or low power, observe a

prepared slide of the uterus to identify the endome- trium and the myometrium. You will have to move the slide to see both layers. If your slide is taken from a uterus that is in the secretory phase, it will have a thick endometrium.

• Using high power, identify the simple columnar epithelium lining the lumen, endometrial glands, stratum functionalis, and stratum basalis. ■

Before Going to Lab

1 Label the microscopic uterine structures in Figure 39.10.

C. Dissection of Female Reproductive System

657

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

39 E X E R C I S E

A. The Ovaries, Uterine Tubes, and Uterus

Write the name of the structure that the phrase describes.

1. Domed portion of uterus

2. Transports secondary oocyte toward uterus

3. Usual site of fertilization

4. Found on end of infundibulum of uterine tubes

5. Opening between uterus and cervix

6. Largest portion of uterus

7. Implantation of zygote and development of fetus occurs in this organ

8. Narrower portion of uterus; connects with vagina

9. Produces secondary oocytes and hormones

10. Middle layer of uterus

11. Sheet-like ligament attaches uterus to lateral body wall

12. Layer of uterus that sheds during menstruation

13. Ligament attaches uterus to labia majora

658 E X E R C I S E 3 9 F E M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

B. Vagina, External Genitalia, and Mammary Gland

Write the name of the structure that the phrase describes.

1. Area between the labia minora with openings of urethra and vagina

2. Folds in vagina

3. Erectile tissue

4. Tissue that pads mons pubis

5. Milk-producing glands

6. Openings in the nipple

7. Organ for intercourse; canal for childbirth and menstruation

8. Another name for external genitalia

C. Histology of Ovary

Number in correct order (1–6) from the earliest to the latest stage of development.

________ corpus albicans

________ corpus luteum

________ mature (graafian) follicle

________ primary follicle

________ primordial follicle

________ secondary follicle

D. Pathway of a Secondary Oocyte

Number the structures (1–7) for the pathway of a secondary oocyte from the ovary to the uterus.

________ ampulla of uterine tube

________ body of uterus

________ fimbriae of uterine tube

________ fundus of uterus

________ infundibulum of uterine tube

________ isthmus of uterine tube

________ ovary

659

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

39 A. Female Reproductive System

Write a short answer for the following questions.

1. An ovariectomy is a surgical procedure that removes one or both ovaries, and a hysterectomy is a procedure that removes the uterus. State whether ovulation and menstruation will occur after:

(a) A bilateral (both ovaries) ovariectomy

(b) A hysterectomy

2. A hysterectomy can cause a protrusion of the urinary bladder through the wall of the vagina. Based on your knowledge of anatomy, why would a hysterectomy cause this problem?

3. Vasectomies and female tubal ligations both involve severing and tying a tube to prevent a pregnancy. Which procedure is less invasive surgically? Explain.

4. An ectopic pregnancy is a pregnancy somewhere other than in the uterus. Explain how a pregnancy could occur in the abdominal cavity.

5. Some women notice a small blood spot shortly after ovulation. Explain why ovulation can cause this.

6. Endometriosis is a condition in which the endometrial tissue grows on the outside of the uterus and in other locations in the pelvic cavity. Explain how the endometrial tissue travels to these locations.

660 E X E R C I S E 3 9 F E M A L E R E P R O D U C T I V E S Y S T E M S T R U C T U R E A N D F U N C T I O N

7. A female who has contracted gonorrhea (bacterial infection) through intercourse can develop scarring of the uterine tubes. Explain how an ectopic pregnancy may then result.

8. (a) Compare the amount of cytoplasm and number of organelles in ova to that in sperm.

(b) Explain why this difference is important to their function.

9. A homologous (homo- � same; logos � relation) structure is an organ that has the same embryonic origin. Using your textbook, look up which male structure is homologous to the clitoris.

10. Explain why it would be advisable for a patient to have an empty bladder when having a pelvic exam.

Human Development 40

E X E R C I S E

661

F ertilization is the process by which the nuclei of an egg cell and a sperm cell, each with 23 chro-mosomes, fuse to form a single cell with 46 chromo- somes. The fertilized ovum, which is a single cell called a zygote (zygote � a pair or yoked), is the beginning stage of human life. After fertilization, the zygote undergoes a phenomenal series of rapid mitotic divisions that result

in an organized ball of cells called an embryo (en- � in; -bryein � to grow). The developing human embryo contin- ues to grow, and its cells differentiate (specialize), forming organs. By 9 weeks, the developing human is called a fetus ( fetus � fruitful, unborn offspring). During this stage, all organs continue to develop and grow, taking on the appear- ance of adult organs.

O B J E C T I V E S M A T E R I A L S

• Fertilization, Cleavage, and Blastocyst Formation: compound microscope, lens paper, depression microscope slides, sea urchin egg suspension, sea urchin sperm suspension, medicine droppers, Vaseline, toothpicks

• compound microscopes, lens paper, prepared slides of sea urchin embryonic development (early and late cleavage)

• models or charts of human embryo development • models or charts of human fetal development • model or chart of pregnant human torso • fresh or preserved placenta or placenta model • Demonstration: preserved pregnant cat or other

animal

1 Describe the major events that occur during embryonic development, and give the time period during which they occur

2 Describe the process of fertilization and early cleavage to the blastocyst stage

3 Describe the process of implantation and placenta formation

4 Name the three primary germ layers and the body systems that are formed by each

5 Name the embryonic membranes and give the importance of each

6 Describe the structure and function of the placenta and umbilical cord

7 Describe the major developmental events that occur during fetal development, and give the time period during which they occur

662 E X E R C I S E 4 0 H U M A N D E V E L O P M E N T

3. Blastocyst Formation

By the 5th day, the solid morula develops a hollow cavity called the blastocyst cavity (blastocele), and the develop- ing zygote is now called a blastocyst (blasto- � to sprout, germ; cyst � bag). Blastocyst cells begin the process of differentiation by forming two different cell regions, the inner cell mass and the trophoblast. The inner cell mass is a group of cells in the interior of the blastocyst that will develop into the embryo and form the developing human body. The trophoblast (troph- � to nourish) is the super- fi cial layer of cells that form the wall of the blastocyst, which will burrow into the endometrium and subsequently form the fetal side of the placenta.

A. Embryonic Period

The embryonic period is the time from fertilization through the 8th week of development. The major events during the embryonic period are fertilization, cleavage, blastocyst formation, implantation, formation of the three primary germ layers, and formation of embryonic membranes.

1. Fertilization

After ovulation, the secondary oocyte is swept into the uterine tube by the motion of fi mbriae in the distal part of the uterine tube, the infundibulum. The secondary oocyte is surrounded by two layers, the corona radiata and the zona pellucida. The corona radiata (corona � crown) is the outer layer of cells, and the zona pellucida (pellucida � allowing light to pass through) is the translucent layer of glycoprotein just beneath the corona radiata and exte- rior to the plasma membrane. Sperm must break through both of these layers to reach the oocyte. After one sperm cell penetrates the plasma membrane, the zona pellucida is enzymatically hardened so other sperm may not enter. The secondary oocyte now completes the second meiotic division and is called an ovum. The 26-chromosome sperm cell then fertilizes the 26-chromosome ovum, and the two fuse to form a one-celled zygote with 46 chromo- somes. Fertilization usually occurs within the ampulla of the uterine tube.

2. Cleavage

The rapid series of early mitotic divisions of the zygote are referred to as cleavage (cleavage � to split into two or more). The one-celled zygote divides into two cells that are called blastomeres (blasto- � to sprout, germ; mere- � part) 24 to 30 hours after fertilization. The two blastomeres further divide into 4, 8, 16, and 32 cells. Although there is an increase in the number of cells because of rapid mitosis, each cell becomes increasingly smaller in size so that the entire ball of cells remains approximately the same size as the original zygote. By the 4th day, the 32-cell stage is a solid ball of cells called a morula (morula � raspberry) that passes through the isthmus of the uterine tube and into the uterine cavity.

LAB ACTIVITY 1 Fertilization, Cleavage, and Blastocyst Formation

1 Examine the models or charts of fertilization, cleavage, and early embryologic development.

2 Fertilization, Cleavage, and Blastocyst Formation:

Observe fertilization • Obtain materials for Fertilization and Blastocyst

Formation (see Materials list). • Using a medicine dropper, transfer one drop of sea

urchin egg-cell suspension to the well of a depres- sion slide.

• Examine the drop under a low-power objective lens and focus on one egg cell. Now go to high-power and observe the egg cell.

• Add a drop of sea urchin sperm-cell suspension to the egg-cell suspension on your slide.

• Observe the sperm cells with high-power lens to see them cluster around the egg cells. The eggs secrete chemicals that attract the sperm.

• Watch the egg cell for the rapid appearance of a fertilization membrane. This membrane appears as a clear halo and is formed when a sperm cell has penetrated the egg cell. Because of its small size, you will not actually see the nucleus of the sperm.

Before Going to Lab

1 Label the embryonic structures in Figure 40.1.

NOTE TO THE INSTRUCTOR: You may want to fertilize several eggs an hour or more before class and have the students examine those zygotes for cleavage while waiting for their slides.

E X E R C I S E 4 0 HUMAN DEVELOPMENT 663

• Use low power to view the slide approximately every 30 minutes. After the first mitotic division, examine the slide about every 15 to 20 minutes.

• Find 2-, 4-, 8-, and 16-cell stages depending on lab time available.

3 Examine the prepared slides of sea urchin embryonic development, both early and late cleavage. Find 2-, 4-, 8-, and 16-cell stages.

4 Describe the processes of fertilization and cleavage to the blastocyst stage to your lab partners. ■

Observe cleavage and blastocyst formation • Using a toothpick, place a thin line of Vaseline

around the edge of the depression and gently press a clean coverslip over the Vaseline and depression. This will prevent water evaporation.

• The first cleavage should occur in about 45 to 60 minutes. It is important to keep the slide at 72�F or 22�C. You may need to use an incubator set at that temperature.

Polar body

Cytoplasm

Zona pellucida

Corona radiata

Sperm cell

Plasma membrane of secondary oocyte Ovary

Uterine cavity

Inner cell mass

Blastocyst cavity

Trophoblast

Uterus

Zona pellucida

Cytoplasm

Nucleus

Blastomeres (cells)

Polar bodies

Endometrium

Ovulation

FIGURE 40.1 First week of development—fertilization to blastocyst.

• 2-cell stage of zygote • 4-cell stage of zygote • blastocyst, external view • fertilization of secondary oocyte • implantation of blastocyst, internal view • morula • secondary oocyte

1 ________________________________________

2 ________________________________________

3 ________________________________________

4 ________________________________________

5 ________________________________________

6 ________________________________________

7 ________________________________________

664 E X E R C I S E 4 0 H U M A N D E V E L O P M E N T

The yolk sac, formerly called the blastocyst cavity, is another embryonic membrane that lies outside the embryo and also begins to develop around the 8th day. The bilaminar disc is now located between the yolk sac and the amniotic cavity. During the 2nd and 3rd weeks, while the placenta is being established, the yolk sac, although small, gives nour- ishment to the embryo. The chorion (chorion � a skin or membrane), a mem- brane that surrounds all the other embryonic membranes, develops into the embryonic portion of the placenta. Cells of the chorion form the connecting (body) stalk, which connects the trophoblast and the bilaminar embryonic disc. The connection stalk will become the umbilical cord. The fourth embryonic membrane, the allantois (allas � sausage; -eidos � resemblance), is an extension of the yolk sac and extends into the connecting stalk of the embryo. It contains blood vessels that will become the umbilical arteries and the umbilical vein.

4. Implantation

At approximately the 7th day, the blastocyst sheds the zona pellucida and usually begins implantation, or insertion of the blastocyst into the wall of the uterus. This process starts when the blastocyst adheres to the wall of the uterus at approximately the 6th day after fertilization. Implanta- tion typically occurs in the posterior wall of the fundus or body of the uterus with the inner cell mass facing the endo- metrium. When this occurs, the endometrium of the uterus is in its secretory phase with a rich blood supply. The trophoblast secretes enzymes that allow the blastocyst to penetrate and bury itself in the endometrium. A hormone, human chorionic gonadotropin (hCG), is secreted by the trophoblast to maintain secretion of estrogen and proges- terone by the corpus luteum of the ovary. The endometrium is now called the decidua (decida � falling off), and the basal portion (next to the embryo) is the deciduas basalis, which will form the maternal side of the placenta. Although the process of implantation started in the fi rst week after fertilization, it is not completed until around the 14th day.

5. Formation of the Three Primary Germ Layers

About 8 days after fertilization, cells of the inner mass begin to differentiate into two different layers of cells that form the bilaminar embryonic disc (bi- � two; lamina � fl at layer or membrane). At approximately the 15th day, cells of the bilaminar embryonic disc further differentiate and form three layers of cells. This structure, now called the trilaminar embryonic disc, consists of three primary germ layers, the outer ectoderm, the middle mesoderm, and the inner endoderm. All tissues, organs, and body systems will arise from these three primary germ layers. The ectoderm gives rise to the epidermis, glands, ner- vous tissue, and parts of the eye and ear; the mesoderm gives rise to cartilage, bones, all three muscle types, and blood; and the endoderm gives rise to the epithelial lining of the digestive and respiratory systems, and other inter- nal organs. The tissues and organs are all growing rapidly during the embryonic period. Around the 22nd day the heart starts beating and by the end of the 8th week, the embryo takes on a human appearance and brain waves can be detected.

6. Formation of Embryonic (Extraembryonic) Membranes

The thin, protective membrane that surrounds and protects the embryo is called the amnion. This transparent sac is formed around the 8th day after fertilization. The cavity located between the amnion and the embryo is called the amniotic cavity. Amniotic fl uid fi lls the amniotic cavity, cushioning and protecting the embryo from temperature extremes and trauma. The amnion is also known as the “bag of waters.”

LAB ACTIVITY 2 Implanation, Primary Germ Layers, and Embryonic Membrane Development

1 Observe models or charts of the 4 embryonic mem- branes and locate the amnion, yolk sac, chorion, and allantois. Refer to Figure 40.4 later in this manual. State the function of each embryonic membrane.

2 Answer Discussion Questions with your lab group.

Before Going to Lab

1 Label the embryonic structures in Figure 40.2(b).

DISCUSSION QUESTIONS Implantation, Primary Germ Layers, and Embryonic Membranes

1 How does the blastocyst implant into the endometrium?

2 What body structures are produced from the three pri- mary germ layers?

3 Discuss the difference among the four embryonic mem- branes and the importance of each.

■

E X E R C I S E 4 0 HUMAN DEVELOPMENT 665

• amnion • amniotic cavity • bilaminar embryonic disc • yolk sac

1 ______________________________

2 ______________________________

3 ______________________________

4 ______________________________

(a) Implantation of blastocyst, about 8 days after fertilization

Amnion

Chorion

Amniotic cavity

Endometrial stroma

Endometrial gland

Simple columnar epithelium

Bilaminar embryonic disc

Blastocyst cavity

Endometrium of uterus:

Uterine cavity

Maternal blood vessels

Chorion

Endometrial gland (right) and sinusoid (left) emptying into lacunar network

Sinusoid

Simple columnar epithelium

(b) Development of embryonic membranes, about 12 days after fertilization

Endometrial stroma

Endometrium of uterus:

Uterine cavity

Lacunae

Lacunar network

FIGURE 40.2 Second week of development—embryonic membrane development.

666 E X E R C I S E 4 0 H U M A N D E V E L O P M E N T

7. Placenta and Umbilical Cord

At birth the placenta (placenta � fl at cake) is about 8 inches in diameter and approximately 1 inch to 1½ inches thick. The placenta is disc-shaped and dark burgundy in color. It almost has the appearance of raw meat. This is the structure in the uterus through which the developing embryo and fetus obtain nutrients and get rid of wastes. The placenta has an embryonic side (chorionic villi) and a maternal side (decidua basalis). During the 3rd week of growth, the chorion forms chorionic villi (villus � hair-like projection) with blood vessels that lengthen and protrude into the decidua basalis of the endometrium. The chori- onic villi lie in intervillus spaces surrounded by lacunae (lacuna � a pit, hollow space) that are fi lled with maternal blood. The umbilical cord is formed from the connecting stalk and is the connection between the placenta and the embryo (and later the fetus) and contains 2 arteries and 1 vein. The umbilical arteries carry oxygen-poor blood and wastes from the fetus to the placenta. The umbilical vein carries oxygen-rich blood and nutrients obtained from the intervillous spaces (containing maternal blood) in the placenta to the fetus. When the baby is born, the placenta

LAB ACTIVITY 3 Placenta and Umbilical Cord

1 Identify the structures of the placenta and umbilical cord on a model or chart of the placenta.

2 Observe the demonstration of a fresh or preserved placenta, if available. • Observe the maternal surface, which is spongy with

a cobblestone appearance. This side of the placenta is textured due to the fetal chorionic villi, which extensively branched into the endometrium.

Before Going to Lab

1 Label the structures of the placenta and umbilical cord in Figures 40.3 and 40.4.

Umbilical vein

Sinusoid— maternal blood

Maternal blood

Umbilical arteries

Intervillous space (containing maternal blood)

Chorion

FIGURE 40.3 Development of chorionic villi in a 21-day embryo.

• amniotic cavity • chorionic villus • connecting stalk • embryo • yolk sac

1 ________________________________________

2 ________________________________________

3 ________________________________________

4 ________________________________________

5 ________________________________________

separates from the uterus and is called the afterbirth. The area where the umbilical cord was attached to the baby is called the umbilicus (navel).

E X E R C I S E 4 0 HUMAN DEVELOPMENT 667

DISCUSSION QUESTIONS Placenta and Umbilical Cord

1 Create a sentence including the following three terms: fetus, placenta, umbilical cord.

2 How is the placenta formed? What are the embryonic and maternal parts of the placenta?

3 Why do the umbilical arteries carry oxygen-poor blood and the umbilical vein carries oxygen-rich blood?

■

• Now observe the smooth, shiny fetal surface of the placenta, which is somewhat translucent. The umbilical cord is attached to this side of the placenta, generally in the center.

• The umbilical cord contains 2 arteries and 1 vein, which are surrounded by mucous connective tissue called Wharton’s jelly. The shiny layer on the exterior of the umbilical cord is a layer of the amnion.

3 Observe the demonstration of a preserved pregnant cat or other animal, if available. Identify the chorion, amnion, embryo, placenta, and umbilical cord.

4 Answer Discussion Questions with your lab group.

Maternal endometrial arteriole

Maternal endometrial venule

Intervillus space

2 Amnion

Umbilical cord:

3 (Maternal portion of placenta)

12th week of development

4 (Fetal portion of placenta)

Chorionic villi Yolk sac

Amniotic fluid in amniotic cavity

Allantois Umbilical cord Chorion Amnion

FIGURE 40.4 Placenta and umbilical cord.

1 ________________________________________

2 ________________________________________

3 ________________________________________

4 ________________________________________

5 ________________________________________

6 ________________________________________

• chorion • chorionic villi • decidua basalis • fetal blood vessels • umbilical arteries • umbilical vein

668 E X E R C I S E 4 0 H U M A N D E V E L O P M E N T

B. Fetal Period

The fetal period is from week 9 to week 38. By the 9th week all organ systems are present in the fetus, and the fe- tal head is about half of the size of the body. The fetus dou- bles in size between the 12th and 20th fetal weeks, doubles again between the 16th and the 24th weeks, and more than doubles between the 20th and 38th weeks. The uterus expands as the fetus grows, and the mother’s abdominal organs are shifted from their normal locations. Although at 8 weeks, toward the end of the embryonic period, the developing embryo looks like a human, the 16-week fetus takes on even more of a human appearance.

Before Going to Lab

1 Examine the drawings in Figure 40.5 and the photo- graphs in Figure 40.6.

LAB ACTIVITY 4 Fetal Development

1 Examine the fetal development models and describe the position of the fetus in the uterus.

2 Answer Discussion Questions with your lab group.

DISCUSSION QUESTIONS Fetal Development

1 At what stage can you first identify the: • upper and lower limbs • future auditory meatus • eye • fi ngers and toes

2 Does the position of the fetus in the uterus change very much toward the end of the 38th week?

■

4 8 12 16 20 24 28 32 36 (weeks)

FIGURE 40.5 Fetal development.

E X E R C I S E 4 0 HUMAN DEVELOPMENT 669

Cut edge of amnion

Neural plate

Neural groove

Primitive streak

Somite

Yolk sac

(a) 20-day embryo

Developing brain

Heart prominence

Developing spinal cord

Somite

(b) 24-day embryo

FIGURE 40.6 Fetal development.

Upper limb bud

Pharyngeal arches

Lens placode

Heart prominence

Tail

Lower limb bud

Developing nose

Otic placode

Upper limb

Lower limb

(d) 44-day embryo

Umbilical cord

670 E X E R C I S E 4 0 H U M A N D E V E L O P M E N T

Nose

Ear

Upper limb

Lower limb

(e) 52-day embryo

Umbilical cord

Eye

(f ) Ten-week fetus inside amniotic sac in uterus

Umbilical cord

Placenta

Yolk sac

Eye

Upper limb

Rib

Nose

Ear

Lower limb

Upper limb

Mouth

Umbilical cord

(g) Thirteen-week fetus

Eye

Nose

Ear

Lower limb

Upper limb

Mouth

(h) Twenty-six-week fetus

Eye

Nose

Ear

Lower limb

FIGURE 40.6 Fetal development, continued.

671

Reviewing Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

40 E X E R C I S E

A. Embryonic Development

Give the name of the structure that the phrase describes.

1. The name of the ovulated structure prior to fertilization

2. The blastocyst structure that becomes the embryo

3. The anatomical structure where fertilization normally takes place

4. The stage of the embryo that implants in the uterine wall

5. After fertilization, implantation normally occurs on this day

6. The membrane that forms the embryonic side of the placenta

7. The structure that is formed after the morula stage

8. The structure that the blastocyst sheds before implantation

9. The structure that forms the maternal side of the placenta

10. The name of the thin, protective membrane that encompasses the embryo

11. The side of the placenta that is smooth and shiny

12. The number of umbilical arteries in the umbilical cord

13. The number of umbilical veins in the umbilical cord

14. This placental structure has villi

15. The number of primary germ layers that form all body organs

16. Sustains the embryo with nutrients and removes wastes

17. The name of the female gamete

672 E X E R C I S E 4 0 H U M A N D E V E L O P M E N T

18. The name of the male gamete

19. The inner layer of the uterus where implantation occurs

20. The name of the fertilized egg

21. Primary germ layer that becomes the outer skin and nervous system

22. Primary germ layer that gives rise to epithelial lining of digestive and respiratory organs

23. Primary germ layer that produces bone, muscle, cartilage, and blood

B. Fetal Development

Give the name of the structure that the phrase describes.

1. The “bag of waters” that breaks at birth.

2. The fetal period lasts from week _____ to week _____.

3. By week _____ all organ systems are present.

4. Toward the end of the embryonic period, week _____, the developing embryo looks like a human.

5. The fetus first doubles in size between weeks _____ and _____.

6. The fetus doubles in size again between weeks _____ and ________.

7. The fetus more than doubles between weeks _____ and _____.

673

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Using Your Knowledge

Name ___________________________________ Date _________________ Section ______________________________

40 E X E R C I S E

A. Human Development

Write a short answer for each of the following questions.

1. The acrosome of a sperm contains hydrolytic enzymes. Using your knowledge, what is the purpose of these enzymes?

2. Ectopic pregnancies occur in the uterine tubes or pelvic cavity. Explain how this can occur.

3. Amniocentesis is a test conducted on fetal cells found in amniotic fluid to determine whether the fetal cells have genetic abnormalities. Amniocentesis is usually conducted at 12 weeks. Amniotic fluid is collected by inserting a needle into the mother’s abdomen. List the structures the needle must go through to collect the amniotic fluid.

4. Are the cells obtained for culture from amniocenteses most likely derived from ectoderm, mesoderm, or endoderm? Explain your answer.

5. Chorionic villi sampling (CVS) is a test to determine whether fetal cells have genetic abnormalities and can be performed as early as 8 weeks. Chorionic villi cells are removed using a small tube that is passed through the cervix. These cells are cultured and undergo chromosomal analysis. Explain why chorionic villi cells will determine whether the fetus has genetic abnormalities.

6. Drinking alcohol during pregnancy can lead to fetal alcohol syndrome, a condition that can cause heart defects, damage to the central nervous system, deformed limbs, slow growth, and abnormal facial features. Explain how the ingested alcohol is transferred from mother to fetus.

674 E X E R C I S E 4 0 H U M A N D E V E L O P M E N T

7. Early pregnancy tests used antibodies to detect the presence of human chorionic gonadotropin (hCG) in maternal urine. Explain how hCG, produced by the chorion, gets in maternal urine.

8. Human embryonic stem cell research uses stem cells cultured from the blastula. These cells are pluripotent, meaning that these stem cells can develop many different types of human cells. Identify the part of the blastula that they are using and explain your choice.

9. During an ultrasonography, the doctor observes that all four chambers of the fetal heart are developed normally and that blood can be observed passing from the right atrium to the left atrium. Explain why it is normal for blood to pass from the right to left atrium in the fetal heart.

10. Placenta previa ( previa � before or in front of) is a condition in which either part or the entire placenta implants in the inferior part of the uterus near the cervix. Explain why this can cause spontaneous abortion or premature birth.

Heredity 41 E X E R C I S E

675

H eredity is the transfer of genetic traits, such as hair or eye color, from parents to off-spring, generation after generation. Genetics is the science that studies the principles and patterns gov- erning heredity. Geneticists can study the complete set of an organism’s genes (located on chromosomes) called a genome. The complete set of genes and alleles for all humans that is studied in genetics is called the human gene pool. Geneticists have discovered that environmen- tal influences like nutrition play a very critical part in our appearance (height, weight, etc.) and whether or not we will inherit a genetic disease.

A. Basic Genetic Language

Each chromosome contains one DNA (deoxyribonucleic acid) molecule. Genes are short segments of DNA that are the functional or heritable units of DNA. Each gene is

situated at a specifi c location on a chromosome and pro- vides a template for the cell to make one or more proteins. Each human cell contains the same 46 chromosomes, 22 pairs of homologous (homo- � same; logos � propor- tion) chromosomes called autosomes and 2 sex chromo- somes. The homologous chromosomes look identical in size and shape under the microscope and have the same genes at identical locations. There are two types of human sex chromosomes, an X chromosome and a Y chromo- some. The X and Y chromosomes not only look different in size and shape, but they also carry genes for different characteristics. Each gene has two or more alternate forms, called alleles, which occupy the same locus (location) on homol- ogous chromosomes. The different alleles code for differ- ent proteins and therefore will result in the expression of different traits. For example, there are two alleles pertain- ing to dimples. One allele of this gene codes for dimples (D) and the other allele is for no dimples (d ). If the pair of alleles of a particular gene are identical (i.e., DD or dd),

O B J E C T I V E S 1 Understand the terms and language of genetics

2 Be able to proficiently use the Punnett square

3 Complete monohybrid crosses with dominant- recessive inheritance, incomplete dominance, co-dominance, and sex-linked inheritance

4 Describe the roles genetics and the environment play in determining phenotypes

676 E X E R C I S E 4 1 H E R E D I T Y

B. Monohybrid Crosses and the Punnett Square

Gregor Mendel was the fi rst person to systematically study, record, analyze, and publish information regarding the pat- terns of inheritance. Mendel’s fi rst rule of inheritance, de- veloped while studying inheritance in garden peas, was the principle of segregation. He showed that when gametes are produced, the 2 units (genes) for a characteristic sepa- rate from each other and the sperm and ovum get only one unit each. For instance, if the genotype for one parent was Dd, as the sperm or ovum is formed, each sperm or ovum gets only a ‘D’ or a ‘d.’ An uncomplicated way to view patterns of inheritance for a single pair of alleles is by using a diagram called the Punnett square. This diagram is used to predict possible genotypes and therefore phenotypes of the offspring from two parents. In a monohybrid cross, the inheritance of only one trait is studied using a single pair of alleles. In a dihybrid or trihybrid cross, there are two and three traits, respectively, that are studied. All of the genetic activities in this exercise are monohybrid crosses. The presence or absence of dimples is used as the trait in the next activity.

the individual is homozygous (homo- � same; zygous � yoked) for that trait. If the alleles are different (Dd ), the person is heterozygous (hetero- � different). If alleles are heterozygous, one allele is usually completely expressed and is called dominant, while the other allele is not ex- pressed and is called recessive. Note that a capital letter is used to designate a dominant allele, which is written fi rst, and a lowercase letter is used for a recessive allele. The particular genetic composition of a person is the genotype (DD, Dd, or dd ), and the expressed physical traits that are observable are called the phenotype (dimples or no dimples).

LAB ACTIVITY 1 Genotypes and Phenotypes

1 For each genotype, indicate whether it is homozygous (hom) or heterozygous (het).

________ Zz ________ bb ________ MM ________ Tt ________ cc ________ AA 2 For each genotype, indicate the phenotype: The freckles allele (F) is dominant to the no freckles

allele ( f ). The attached earlobes allele (E) is dominant to the unattached earlobes allele (e).

ff _______________ Ee _______________ FF _______________ EE _______________ Ff _______________ ee _______________ 3 For each phenotype, list the genotype(s): Widow’s peak (W) is dominant to a straight hairline (w). _______________ widow’s peak (homozygous) _______________ widow’s peak (heterozygous) _______________ straight hairline ■

LAB ACTIVITY 2 Dimples or No Dimples

1 Let D � dimples and d � no dimples. The genotype of the female is homozygous dominant (DD) and the male is homozygous recessive (dd ).

2 In Figure 41.1, look at the genotype of the parents that displays the diploid state (2n). There are 2 sets of chro- mosomes, one inherited from the father and one from the mother. According to the first principle of inheri- tance, the two alleles for any trait will separate during meiosis. Therefore, each ‘D’ or each ‘d’ is now haploid (n), with half the number of chromosomes (alleles) present in the ova or sperm.

3 Put the alleles of the sperm on the side of the square, and the alleles of the ova on top. In order to have a pat- tern, always put the same parent on the same axis.

4 Combine the letters of the sperm and ova in the squares that now represent the diploid genotype(s) of their offspring.

5 In Figure 41.1, indicate the number of offspring with each genotype and the percent chance offspring has the genotype.

6 In Figure 41.1, indicate the number of offspring with each phenotype and the percent chance offspring has the phenotype. ■

E X E R C I S E 4 1 HEREDITY 677

FIGURE 41.1 Inheritance of dimples.

% chance offspring has genotype

DD Dd dd

Number of offspring with phenotype

Dimples No dimples

Number of offspring with genotype

DD Dd dd

% chance offspring has phenotype

Dimples No dimples

Homologous chromosomes of homozygous dominant father

Homologous chromosomes of homozygous

recessive mother

Possible sperm types

Possible ova types

Punnett square

Genotype(s) of zygotes (in boxes)

Meiosis

D D d d

FIGURE 41.2(b) Non- tongue roller.

FIGURE 41.2(a) Tongue roller.

LAB ACTIVITY 3 Tongue Rolling or No Tongue Rolling

1 Some people can roll the tongue into a U-shape [Fig- ure 41.2(a)], while others do not have the ability to roll the tongue [Figure 41.2(b)]. Let R � tongue roller, r � non-tongue roller. Cross a heterozygous tongue-rolling mother and father. • In Figure 41.3, choose the dominant and recessive

alleles for the sperm and the ova and write the alleles on the top and left side of the Punnett square.

• Combine the letters of the sperm and ova in the squares. These letters represent all of the possible diploid genotypes of the offspring.

2 In Figure 41.3, indicate the number of offspring with each genotype and the percent chance offspring has the genotype.

3 In Figure 41.3, indicate the number of offspring with each phenotype and the percent chance offspring has the phenotype. ■

FIGURE 41.3 Inheritance of tongue rolling.

Mother’s genotype Rr

Father’s genotype Rr

Possible sperm types

Possible ova types

Punnett square

Possible genotypes of zygotes (in boxes)

Meiosis

% chance offspring has genotype

Number of offspring with phenotype

Tongue roller Non-tongue roller

Number of offspring with genotype

RR Rr rr

% chance offspring has phenotype

678 E X E R C I S E 4 1 H E R E D I T Y

C. Incomplete Dominance

A few human traits are inherited because neither allele for a gene is dominant over the other and the offspring show an intermediate phenotype or blending of the two character- istics. This type of inheritance is called incomplete domi- nance. An example of this is curly, wavy, or straight hair. Curly hair (CC ) is incompletely dominant over straight hair (cc), therefore the heterozygous genotype (Cc) pro- duces wavy hair, a phenotype intermediate between curly and straight hair.

LAB ACTIVITY 4 Curly, Wavy, and Straight Hair

1 Cross a mother with curly hair with a father with straight hair in Figure 41.4.

2 Calculate the percentages of each genotype and pheno- type of the offspring from the Punnett square. ■

FIGURE 41.4 Inheritance of incomplete dominance.

Mother’s genotype CC

Father’s genotype cc

Possible sperm types

Possible ova types

Punnett square

Possible genotypes of zygotes (in boxes)

Meiosis

Curly hair Wavy hair Straight hair

% chance offspring has genotype

CC Cc cc

% chance offspring has phenotype

E X E R C I S E 4 1 HEREDITY 679

D. Codominance in Monohybrid Crosses

Codominance is a pattern of inheritance in which two dif- ferent alleles of a gene are equally expressed in a hetero- zygote and no blending of the characteristic occurs. There are three alleles for the ABO human blood type system: A, B, and O. The A and B alleles are codominant and both are dominant over the O allele. The A allele causes an A anti- gen to appear on the surface of red blood cells, the B allele causes a B antigen to appear on the surface of red blood cells, and the O allele results in no antigen on the surface of the red blood cell. Because each of us inherits only two of these alleles, there are six possible genotypes: AA, AB, AO, BB, BO, and OO. This means that there are only four phenotypes for blood type: A, B, AB, and O.

LAB ACTIVITY 5 ABO Blood Type

1 Cross a father with blood type AO and a mother with BO blood type in Figure 41.5.

2 Calculate the percentages of each genotype and pheno- type of the offspring from the Punnett square.

3 Cross a father with AB blood type with a mother with O blood type in Figure 41.6.

4 Calculate the percentages of each genotype and pheno- type of the offspring from the Punnett square. ■

FIGURE 41.6 Codominance with ABO blood types.

Mother’s genotype OO

Father’s genotype AB

Possible sperm types

Possible ova types

Punnett square

Possible genotypes of zygotes (in boxes)

Meiosis

% chance offspring has genotype

AO BO AB OO

A B AB O% chance offspring has phenotype

% chance offspring has genotype

AO BO AB OO

A B AB O% chance offspring has phenotype

Mother’s genotype BO

Father’s genotype AO

Possible sperm types

Possible ova types

Punnett square

Possible genotypes of zygotes (in boxes)

Meiosis

FIGURE 41.5 Codominance with ABO blood types.

680 E X E R C I S E 4 1 H E R E D I T Y

symptoms of sickle-cell disease. Heterozygous individuals are also resistant to malaria. Therefore, in regions of the world where malaria is a problem, heterozygous individu- als have an advantage and more individuals with the SA genotype survive compared to individuals with the AA genotype.

Sickle-cell anemia is another example of codomi- nance. Two alleles are present that are involved in the production of hemoglobin (Hb), a protein that carries oxygen in red blood cells. The sickle-cell allele is desig- nated S and produces an abnormal Hb. Individuals who are SS produce only the abnormal Hb. When oxygen lev- els in the red blood cells are low (i.e., at high altitudes or during exercise), the sickle-cell Hb crystallizes within red blood cells, causing the red blood cells to become sickle- or crescent-shaped (Figure 41.7). The crescent-shaped sickle cell clumps and forms clots in small blood vessels. Untreated individuals with sickle-cell anemia often die at an early age. The normal Hb allele is A, and individu- als who are AA have normal Hb and normal-shaped red blood cells. Heterozygous individuals have the sickle- cell trait (but not the disease); half of their Hb is normal and half is sickle-cell Hb. These individuals are usu- ally healthy, and only a small number experience some

FIGURE 41.7 Sickle-cell anemia.

LAB ACTIVITY 6 Sickle-Cell Anemia

1 The abbreviation for hemoglobin is Hb. Let HbS HbS � sickle-cell anemia, HbA HbA � normal Hb (unaffected), and HbS HbA � sickle-cell trait.

2 Using Figure 41.8, cross a mother with sickle-cell anemia and father with the sickle-cell trait.

3 Calculate the percentages of each genotype and pheno- type of the offspring from the Punnett square. ■

FIGURE 41.8 Codominance with sickle-cell anemia.

Mother’s genotype HbS HbS

Father’s genotype HbS HbA

HbS HbA HbS HbS

Possible sperm types

Possible ova types

Meiosis

Punnett square

Possible genotypes of zygotes (in boxes)

HbS HbS HbS HbA HbA HbA

Sickle-cell anemia

Sickle-cell trait

Normal

% chance offspring has genotype

% chance offspring has phenotype

E X E R C I S E 4 1 HEREDITY 681

DISCUSSION QUESTIONS Sex-Linked Inheritance

1 What percentage of girls, if any, would be a carrier for the color-blind allele?

2 What percentage of boys, if any, would be a carrier for the color-blind allele?

■

E. Sex-Linked Inheritance

The majority of genes are carried on autosomes, chromo- somes that code for traits not directly involved in determining the sex of the individual. There are 22 pairs of autosomes and 2 sex chromosomes (X and Y) for each person (Figure 41.9). Females have two X chromosomes (XX) while males have one X and one Y (XY). The X chromosome is as large as many of the autosomes, but the Y chromosome is about one-third of the size of the X chromosome and is missing genes present on the X chromosome. The genes car- ried only on the X chromosome are called sex-liked genes and do not produce female characteristics. Sex-linked genes have recessive alleles that cause baldness, hemophilia, and color blindness. For a woman to express these phenotypes, she must have two recessive alleles, one on each X chromo- some. However, because the male has only one X chromo- some and these sex-linked genes are not present on the Y chromosome, the presence of only one recessive allele will give a male the recessive phenotype. In sex-linked inheri- tance, the terms homozygous and heterozygous in the male do not apply. It is interesting to note that with sex-linked inheritance, the father cannot pass the condition to his son. The son can receive only a Y chromosome from his father and an X chromosome from his mother.

FIGURE 41.9 Autosomes and sex chromosomes.

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16

17 18 19 20 21 22 23 X Y

LAB ACTIVITY 7 Sex-Linked Inheritance

1 Let XC � dominant allele for normal vision and Xc � recessive allele for color blindness. Indicate the phe- notype of the following alleles for recessive sex-linked color blindness.

X CXC________ X CXc________ X cX c________ XCY________ XcY________ 2 Using Figure 41.10, cross a heterozygous female carry-

ing the allele for color blindness (a carrier) with a male with normal vision.

3 Calculate the percentages of each genotype and pheno- type of the offspring from the Punnett square.

4 Answer Discussion Questions with your lab group.

FIGURE 41.10 Sex-linked inheritance for color blindness.

Father’s genotype X CY

Normal male

Punnett square

Possible genotypes of zygotes (in boxes)

Meiosis

Mother’s genotype X CX c

Normal female who carries recessive gene

Possible ova types

Possible sperm types

X CX C X CX c

X CY X cY

X cX c

Female normal vision

Female carrier

Female color blindness

% chance offspring has genotype

% chance offspring has phenotype

Male normal vision

Male color blindness

683

Name ___________________________________ Date _________________ Section ______________________________

41 E X E R C I S EReviewing Your Knowledge

A. Basic Genetic Language

Write the name of the term that describes the phrase.

1. Two different alleles of a gene are both expressed with no blending in a heterozygous individual

2. Non-identical chromosomes that determine male or female

3. The functional units of DNA; short segments of chromosomes

4. The allele that is expressed in a heterozygous individual

5. Two or more alternate forms or variations of a gene

6. The genetic composition for a trait

7. Individual having identical alleles for a gene

8. 22 pairs of chromosomes that determine most of the body traits

9. The allele that is not expressed in heterozygous alleles

10. The physical or functional expression of a genetic trait

11. Possessing all of the normal number of chromosomes

12. Possessing half of the normal number of chromosomes

13. Explain what a “carrier” for an allele of a gene means.

14. Distinguish between a phenotype and a genotype.

15. How do we obtain two copies of each gene?

684 E X E R C I S E 4 1 H E R E D I T Y

B. Monohybrid Dominant-Recessive Inheritance

1. Unattached earlobes (E) are dominant over attached earlobes (e) [Figure 41.11(a) and (b)]. If a woman with unattached earlobes and a man with attached earlobes have children, what percentage of their children has the possibility of having unattached earlobes if the mother is homozygous for the trait?

FIGURE 41.11(b) Attached earlobes.FIGURE 41.11(a) Unattached earlobes.

2. What percentage of the offspring in question 1 above has the possibility of having unattached earlobes if the mother is heterozygous for the trait?

3. For questions 1 and 2, could the phenotype of the children born allow you to determine whether the mother is homozygous or heterozygous for the trait? Explain.

E X E R C I S E 4 1 HEREDITY 685

C. Incomplete Dominance Inheritance

1. If a woman with wavy hair and a man with curly hair have children, calculate the percentages of each genotype and phenotype of the offspring from the Punnett square.

2. If a woman with straight hair and a man with wavy hair have children, calculate the percentages of each genotype and phenotype of the offspring from the Punnett square.

D. Monohybrid Codominant Inheritance

1. If a father with type O blood and a mother with AB blood have children, calculate the percentages of each genotype and phenotype of the offspring from the Punnett square.

2. If a mother with sickle-cell anemia and a father with the sickle-cell trait have children, calculate the percentages of each genotype and phenotype of the offspring from the Punnett square.

E. Sex-Linked Inheritance

1. Cystic fibrosis is due to an inherited recessive gene. The recessive allele produces a defective version of a protein. Per- form a cross with a heterozygous (carrier) mother and a father who has a normal gene for the trait. Let C � the normal allele and c � cystic fibrosis allele. Calculate the percentages of each genotype and phenotype of the offspring from the Punnett square.

687

Answer the following questions with a short answer.

1. Why are marriages between blood relatives prohibited in the United States and other countries?

2. If a phenotypic ratio for a single trait is 3:1 (75%:25%) in the offspring, what genotypes would you propose the parents might be? Draw a Punnett square to explain.

3. The allele for baldness is on the X chromosome only. Can any sons obtain the allele for baldness from the father with the allele? Draw a Punnett square to explain.

4. Why are men more likely than women to be color blind? Explain.

5. Can a son be a carrier for an X-linked trait? Explain.

6. Could a father who has blood type A and a mother who has blood type B possibly have a child who has blood type O? Draw a Punnett square to explain.

7. Huntington’s disease is due to inheriting a lethal dominant allele that affects the nervous system and causes early dementia around age 40. Cross a heterozygous mother who has the trait with a normal father. Draw a Punnett square to explain.

(a) What are the percentages and types of genotype?

(b) What are the percentages and types of phenotype?

Name ___________________________________ Date _________________ Section ______________________________

E X E R C I S E

Name ___________________________________ Date _________________ Section ______________________________

Using Your Knowledge

41 E X E R C I S E

688 E X E R C I S E 4 1 H E R E D I T Y

8. Why does the lethal dominant allele of Huntington’s disease stay in the gene pool?

9. If there is a possibility of four different genotypes in the offspring that result from a dominant-recessive inheritance, and if the couple has four children, would they definitely have children with one expressing each genotype? Explain.

10. List the 6 possible genotypes of the four blood types. Identify the parental genotypes that could produce children with blood type AO.

Answer Key

689

Exercise 1

Figure 1.1

1. cranial 2. facial 3. cervical 4. acromial 5. axillary 6. brachial 7. antecubital 8. antebrachial 9. carpal 10. digital 11. palmar 12. femoral 13. patellar 14. crural 15. tarsal 16. digital 17. frontal 18. orbital 19. otic 20. buccal 21. nasal 22. oral 23. mental 24. sternal 25. mammary, pectoral, or thoracic 26. umbilical 27. coxal 28. inguinal 29. manual 30. pubic 31. pedal 32. occipital 33. scapular 34. vertebral 35. olecranal 36. gluteal 37. popliteal 38. sural 39. fibular (peroneal) 40. plantar 41. lumbar 42. calcaneal

large intestine small intestine liver pancreas 3. Endocrine System pancreas 4. Integumentary System none 5. Lymphatic System spleen 6. Muscular System diaphragm 7. Nervous System none 8. Reproductive System none 9. Respiratory System trachea bronchus diaphragm lung 10. Skeletal System none 11. Urinary System kidney ureter urinary bladder

Lab Activity 1 Identification of Organs on Torso

1. a, 2. b, 3. d, 4. c, 5. d, 6. b, 7. b, 8. a, 9. b, 10. b

Figure 2.2

1. cranial cavity 2. vertebral canal 3. thoracic cavity 4. diaphragm 5. abdominal cavity 6. pelvic cavity

Figure 2.3

1. parietal 2. visceral

Lab Activity 2 Directional Terms

1. a. anterior b. medial and inferior c. medial d. distal e. ipsilateral f. superficial

Figure 1.2

1. superior 2. posterior or dorsal 3. anterior or ventral 4. proximal 5. distal 6. inferior

Figure 1.3

1. frontal plane 2. oblique plane 3. transverse plane 4. parasagittal plane 5. midsagittal plane 6. longitudinal section 7. cross-section

Figure 1.4

a. midsaggital b. transverse c. frontal

Exercise 2

Figure 2.1

1. Cardiovascular System aorta heart thoracic aorta abdominal aorta inferior vena cava 2. Digestive System esophagus stomach

(Answers to Discussion Questions can be found on the Instructor Companion Site)

690 A N S W E R K E Y

Lab Activity 6 Abdominopelvic Quadrants and Regions

Quadrants 3. a. RLQ b. all four quadrants c. mainly RUQ d. LLQ and RLQ e. LUQ f. all four quadrants g. LUQ h. mainly LUQ Regions 5. a right inguinal (iliac) b. epigastric c. left inguinal (iliac) d. hypogastric (pubic) e. left hypochondriac f. epigastric

Exercise 3

Lab Activity 3 Using the Microscope

12. When you move the slide to the left, the object as seen through the ocular lens moves to the right.

When you move the slide to the right, the object as seen through the ocular lens moves to the left.

When you move the slide forward (away from you), the object as seen through the ocular lens moves backward (toward you).

When you move the slide backward (toward you), the object as seen through the ocular lens moves forward (away from you).

Exercise 4

Lab Activity 2 Cell Specialization

2. a. long, cylindrical; many nuclei b. columnar; cilia, nucleus c. irregular shape with processes that

extend from cell body; nucleus d. oval with a flagellum and is tapered

for movement; nucleus and flagellum e. biconcave; no nucleus f. round; nucleus g. columnar with microvilli; nucleus

Figure 4.4

a. interphase b. prophase c. metaphase d. anaphase e. telephase

Exercise 5

Figure 5.2

1. hypotonic solution 2. hypertonic solution

Lab Activity 4 Experiment: Osmosis in Living RBCs

1. 0.9% saline solution—isotonic; 5% saline solution—hypertonic; distilled water—hypotonic

Figure 5.3

(a) shape: normal: solution: isotonic (b) shape: swollen: solution: hypotonic (c) shape: crenated: solution: hypertonic

Exercise 6

Figure 6.3

1. cytoplasm 2. nucleus 3. plasma membrane

Figure 6.4

1. nucleus of simple squamous epithelial cell in visceral layer of pleura

2. simple squamous epithelium 3. connective tissue 4. nucleus of simple squamous epithelial

cell in alveolar wall

Figure 6.5

1. simple cuboidal epithelium 2. apical surface of simple cuboidal

epithelial cell 3. lumen of kidney tubule 4. nucleus of simple cuboidal epithelial cell

Figure 6.6

1. microvilli on apical surface of simple columnar epithelial cell

2. nucleus of simple columnar epithelial cell 3. simple columnar epithelium 4. connective tissue

Figure 6.7

1. nucleus of squamous epithelial cell 2. stratified squamous epithelium 3. nucleus of epithelial cell in basal layer

of epithelium 4. connective tissue

Figure 6.8

1. nucleus of transitional epithelial cell in apical layer

2. nucleus of transitional cell in basal layer

3. transitional epithelium 4. connective tissue

Figure 6.9

1. nucleus of ciliated columnar epithelial cell

2. cilia on apical surface of columnar epithelial cell

3. pseudostratified ciliated columnar epithelium

4. connective tissue

Figure 6.11

1. collagen fiber 2. elastic fiber 3. connective tissue cells

Figure 6.12

1. reticular fiber 2. reticulocyte

Figure 6.13

1. nucleus of adipocyte 2. lipid storage area

Figure 6.14

1. fibroblast 2. collagen fiber bundle

Figure 6.15

1. fibroblast 2. collagen fiber bundles running in

different directions 3. parallel collagen fiber bundles

Figure 6.16

1. fibroblast 2. individual elastic fiber 3. bundle of elastic fibers

Figure 6.17

1. extracellular matrix 2. lacuna 3. nucleus of chondrocyte

Figure 6.18

1. lacuna 2. nucleus of chondrocyte 3. elastic fibers

Figure 6.19

1. collagen fibers 2. lacuna 3. chondrocytes

A N S W E R K E Y 691

5. canaliculus 6. lacuna 7. osteocyte 8. periosteum 9. central canal 10. perforating canal 11. compact bone 12. trabeculae covered with endosteum 13. osteocyte in lacuna 14. interstitial lamellae

Figure 8.3(a, b, & c)

1. proximal epiphysis 2. spongy bone 3. metaphysis 4. compact bone 5. medullary cavity 6. concentric lamella 7. lacuna 8. central canal 9. canaliculi 10. osteocyte 11. trabecula

Exercise 9

Figure 9.1

1. parietal bone 2. coronal suture 3. squamous suture 4. temporal bone 5. lambdoid suture 6. occipital bone 7. frontal bone 8. sphenoid bone 9. ethmoid bone 10. lacrimal bone 11. nasal bone 12. zygomatic bone 13. maxilla 14. mandible

Figure 9.2

1. frontal bone 2. coronal suture 3. parietal bone 4. sagittal suture 5. lambdoid suture 6. occipital bone

Figure 9.3

1. maxilla 2. vomer 3. sphenoid bone 4. occipital bone 5. zygomatic bone 6. palatine bone 7. temporal bone

4. stratum spinosum 5. stratum basale 6. dermis

Figure 7.4

1. hair shaft 2. hair root 3. sebaceous gland 4. arrector pili muscle 5. hair follicle 6. hair bulb 7. eccrine sweat gland 8. papilla of hair 9. apocrine sweat gland

Figure 7.5

1. sebaceous gland 2. hair follicle 3. hair root 4. hair bulbs 5. papilla of hair

Figure 7.6(a & b)

1. free edge 2. nail body 3. lunula 4. eponychium 5. nail matrix 6. nail root 7. eponychium 8. lunula 9. nail body 10. free edge 11. hyponychium

Exercise 8

Figure 8.1

1. proximal epiphysis 2. diaphysis 3. distal epiphysis 4. articular cartilage 5. epiphyseal line 6. compact bone 7. medullary cavity 8. yellow marrow 9. periosteum 10. nutrient artery 11. endosteum 12. spongy bone

Figure 8.2(a & b)

1. spongy bone 2. trabeculae of spongy bone covered

with endosteum 3. concentric lamellae 4. blood vessels

Figure 6.20

1. lamella 2. canaliculus 3. lacuna 4. central canal

Figure 6.21

1. trabecula 2. osteocyte

Figure 6.22

1. red blood cells 2. nucleus of white blood cell 3. platelet

Figure 6.24

1. width of individual muscle fiber 2. nucleus 3. striation

Figure 6.25

1. width of cardiac muscle fiber 2. nucleus 3. branches of cardiac muscle fiber 4. intercalated discs

Figure 6.26

1. nucleus of smooth muscle fiber in cross-section

2. nucleus of smooth muscle fiber in longitudinal section

Figure 6.28

1. processes 2. cell body of multipolar neuron 3. nucleus

Exercise 7

Figure 7.1

1. epidermis 2. papillary layer of dermis 3. reticular layer of dermis 4. hypodermis 5. dermal papillae

Figure 7.2

1. dermal papillae 2. epidermis 3. papillary layer of dermis 4. reticular layer of dermis 5. hypodermis

Figure 7.3

1. stratum corneum 2. stratum lucidum 3. stratum granulosum

692 A N S W E R K E Y

Figure 9.4

1. parietal bone 2. occipital bone 3. frontal bone 4. ethmoid bone 5. sphenoid bone 6. temporal bone 7. lambdoid suture

Figure 9.5

1. parietal bone 2. sphenoid bone 3. ethmoid bone 4. lacrimal bone 5. inferior nasal concha 6. vomer 7. frontal bone 8. temporal bone 9. nasal bone 10. zygomatic bone 11. maxilla 12. mandible

Figure 9.6

1. frontal bone 2. sphenoid bone 3. zygomatic bone 4. ethmoid bone 5. lacrimal bone 6. maxilla

Figure 9.7

1. supraorbital foramen 2. orbit of eye 3. inferior orbital fissure 4. perpendicular plate of ethmoid 5. mental foramen of mandible 6. supraorbital margin 7. superior orbital fissure 8. middle nasal concha

Figure 9.8

1. external auditory meatus 2. mastoid process 3. lacrimal fossa in lacrimal bone 4. zygomatic process of temporal bone 5. condylar process 6. coronoid process 7. ramus of mandible 8. body of mandible

Figure 9.9

1. palatine process of maxilla 2. palatine bone 3. hard palate 4. pterygoid processes 5. foramen ovale 6. jugular foramen 7. occipital condyle

8. hypoglossal foramen 9. mandibular fossa 10. foramen lacerum 11. carotid foramen (canal) 12. stylomastoid foramen 13. mastoid process 14. foramen magnum 15. external occipital protuberance

Figure 9.10

1. crista galli 2. olfactory foramina 3. cribriform plate 4. sella turcica 5. foramen ovale 6. internal auditory meatus 7. foramen magnum 8. lesser wing of sphenoid 9. optic foramen 10. greater wing of sphenoid 11. foramen rotundum 12. foramen lacerum 13. jugular foramen

Figure 9.11

1. frontal sinus 2. ethmoidal sinus 3. sphenoidal sinus 4. maxillary sinus

Figure 9.12

1. perpendicular plate of ethmoid 2. septal cartilage 3. vomer

Figure 9.13(b & c)

1. anterolateral (sphenoidal) fontanel 2. posterolateral (mastoid) fontanel 3. anterior (frontal) fontanel 4. posterior (occipital) fontanel

Figure 9.15

1. cervical vertebrae 2. thoracic vertebrae 3. lumbar vertebrae 4. sacrum 5. coccyx 6. cervical curve 7. thoracic curve 8. lumbar curve 9. sacral curve

Figure 9.17(b, c, d)

1. superior articular facet 2. transverse foramen 3. transverse process 4. lamina 5. dens (odontoid process) 6. spinous process

7. body 8. transverse process 9. bifurcated spinous process 10. pedicle

Figure 9.18(a & b)

1. transverse process 2. facet for articular part of tubercle 3. superior articular facet 4. superior demifacet 5. superior articular facet 6. facet for articular part of tubercle 7. slanted spinous process 8. superior demifacet 9. inferior demifacet

Figure 9.19(a & b)

1. pedicle 2. superior articular process 3. transverse process 4. vertebral foramen 5. body 6. hatchet-shaped spinous process 7. inferior articular facet

Figure 9.20(a & b)

1. intervertebral foramen 2. nucleus pulposus 3. annulus fibrosus 4. intervertebral disc 5. herniation 6. nucleus pulposus 7. annulus fibrosus

Figure 9.21(a & b)

1. sacral ala 2. base of sacrum 3. sacral promontory 4. sacral foramen 5. coccyx 6. sacral canal 7. superior articular facet 8. auricular surface (for sacroiliac joint) 9. sacral hiatus

Figure 9.22

a. scoliosis b. kyphosis c. lordosis

Figure 9.23

1. suprasternal notch (jugular notch) 2. manubrium 3. body of sternum 4. xiphoid process 5. sternum 6. costal cartilage 7. sternal angle

A N S W E R K E Y 693

5. medial condyle 6. tibial tuberosity 7. tibia 8. medial malleolus

Figure 10.10(a & b)

1. calcaneus 2. talus 3. proximal phalanx II 4. middle phalanx II 5. distal phalanx II 6. tarsals 7. metatarsals 8. phalanges 9. calcaneus 10. tibia 11. lateral malleolus of fibula 12. talus 13. tarsals 14. metatarsals 15. phalanges

Exercise 11

Figure 11.1(a & b)

1. synovial and diarthrosis 2. synovial and diarthrosis 3. cartilaginous and amphiarthrosis 4. synovial and diarthrosis 5. fibrous and amphiarthrosis 6. fibrous and synarthrosis 7. cartilaginous and amphiarthrosis 8. cartilaginous and amphiarthrosis 9. synovial and diarthrosis 10. synovial and diarthrosis 11. fibrous and synarthrosis

Figure 11.2(b)

1. articular bone 2. fibrous membrane 3. synovial membrane 4. articular capsule 5. synovial cavity (contains synovial fluid) 6. articular cartilage

Figure 11.3(a)

1. articular cartilage of femur 2. lateral (fibular) collateral ligament 3. lateral meniscus 4. posterior cruciate ligament 5. anterior cruciate ligament 6. medial meniscus 7. medial (tibial) collateral ligament

Figure 11.4(a, b, c, d, e, & f)

1. flexion 2. extension

9. ulna 10. radius

Figure 10.5

1. carpals 2. metacarpals 3. proximal phalanx V 4. middle phalanx V 5. distal phalanx V

Figure 10.6

1. ilium 2. posterior superior iliac spine 3. posterior inferior iliac spine 4. greater sciatic notch 5. ischium 6. ischial spine 7. lesser sciatic notch 8. obturator foramen 9. ischial tuberosity 10. iliac crest 11. anterior superior iliac spine 12. anterior inferior iliac spine 13. acetabulum 14. pubis

Figure 10.7(a & b)

1. iliac crest 2. ilium 3. ischial spine 4. pelvic brim 5. pubic symphysis 6. false pelvis 7. true pelvis 8. pubis 9. ischial spine 10. false pelvis 11. sacroiliac joint 12. sacrum 13. coccyx 14. true pelvis 15. pubis

Figure 10.8(a & b)

1. head of femur 2. greater trochanter 3. neck 4. lesser trochanter 5. medial epicondyle 6. medial condyle 7. linea aspera 8. lateral epicondyle 9. lateral condyle

Figure 10.9

1. lateral condyle 2. head of fibula 3. fibula 4. lateral malleolus

8. true ribs 9. floating ribs 10. false ribs

Figure 9.24(a & b)

1. facet for articular part of tubercle 2. tubercle 3. articular part of tubercle 4. head of rib 5. tubercle 6. intervertebral foramen 7. inferior demifacet of vertebra 8. head of rib 9. superior demifacet of vertebra 10. body of rib

Exercise 10

Figure 10.2(a, b, & c)

1. acromial end 2. sternal end 3. acromion (acromial process) 4. coracoid process 5. glenoid cavity or fossa 6. lateral (axillary) border 7. subscapular fossa 8. (medial) vertebral border 9. supraspinous fossa 10. infraspinous fossa 11. acromion (acromial process) 12. spine of scapula 13. glenoid cavity or fossa

Figure 10.3(a & b)

1. greater tubercle 2. intertubercular sulcus (groove) 3. lesser tubercle 4. lateral epicondyle 5. capitulum 6. head 7. anatomical neck 8. deltoid tuberosity 9. coronoid fossa 10. medial epicondyle 11. trochlea 12. olecranon fossa 13. medial epicondyle 14. lateral epicondyle

Figure 10.4(a & b)

1. head of radius 2. radial tuberosity 3. styloid process of radius 4. olecranon (process) 5. trochlear notch (semilunar) 6. coronoid process 7. radial notch 8. styloid process of ulna

694 A N S W E R K E Y

Lab Activity 4 Isotonic and Isometric Contractions

1. Isotonic contraction occurs when flexing the knee. Isometric contraction occurs when maintaining the knee in a flexed position.

2. Concentric. Extend the leg slowly to original position.

Lab Activity 5 Record Frog Gastrocnemius Muscle Contraction

1. Force � 1.5 g; latent period � 10 msec; contraction period � 25 msec; relaxation period � 45 msec

Exercise 14

Figure 14.1(a, b, & c)

1. orbicularis oculi 2. orbicularis oris 3. platysma 4. frontalis 5. zygomaticus minor 6. zygomaticus major 7. occipitalis 8. frontalis 9. orbicularis oculi 10. zygomaticus major 11. buccinator 12. orbicularis oris 13. masseter 14. temporalis 15. lateral pterygoid 16. medial pterygoid 17. orbicularis oris 18. buccinator

Figure 14.2(a, b, & c)

1. splenius capitis 2. sternocleidomastoid 3. trapezius 4. levator scapulae 5. scalene 6. digastric, anterior belly 7. mylohyoid 8. stylohyoid 9. digastric, posterior belly 10. omohyoid 11. sternocleidomastoid 12. sternohyoid 13. mylohyoid 14. scalenes 15. levator scapulae

Figure 14.3(a & b)

1. deltoid 2. pectoralis major

9. muscle fiber 10. sarcolemma 11. myofibril 12. filament

Figure 12.2(a & b)

1. endomysium 2. skeletal muscle fiber in cross-section 3. fascicle 4. perimysium 5. width of skeletal muscle fiber 6. nucleus 7. striation

Figure 12.3(a, b, & c)

1. triad 2. sarcolemma 3. myofibril 4. T-tubule 5. terminal ciserna of sarcoplasmic

reticulum 6. sarcoplasmic reticulum 7. sarcomere 8. thin filament 9. thick filament 10. actin 11. tropomyosin 12. troponin 13. myosin heads 14. myosin tails

Figure 12.5

1. Z disc 2. M line 3. H zone 4. I band 5. A band

Figure 12.7

1. axon terminal 2. synaptic end bulb 3. synaptic vesicle with acetylcholine 4. synaptic cleft 5. motor end plate 6. receptors

Figure 12.8

1. skeletal muscle fibers 2. axon terminal with synaptic end bulbs 3. motor neuron axon

Exercise 13

Figure 13.1

1. slow oxidative fiber 2. fast glycolytic fiber 3. fast oxidative-glycolytic fiber

3. hyperextension 4. hyperextension 5. extension 6. flexion 7. flexion 8. extension 9. flexion 10. extension 11. hyperextension 12. hyperextension 13. extension 14. flexion 15. flexion 16. extension

Figure 11.5(a, b, c, d, e, & f)

1. abduction 2. adduction 3. circumduction 4. abduction 5. adduction 6. circumduction 7. adduction 8. abduction 9. abduction 10. adduction

Figure 11.6(a & b)

1. rotation 2. lateral rotation 3. medial rotation

Figure 11.7(a, b, c, d, & e)

1. elevation 2. depression 3. protraction 4. retraction 5. pronation 6. supination

Figure 11.8(a & b)

1. inversion 2. eversion 3. dorsiflexion 4. plantar flexion

Exercise 12

Figure 12.1(a & b)

1. perimysium 2. epimysium 3. fascicle 4. endomysium 5. muscle fiber 6. myofibril 7. perimysium 8. endomysium

A N S W E R K E Y 695

3. xiphisternal joint 4. xiphoid process of sternum 5. serratus anterior muscle 6. manubrium of sternum 7. sternal angle 8. pectoralis major muscle 9. ribs (deep to muscle) 10. costal margin

Figure 15.2(b)

1. rectus abdominis muscle 2. linea semilunaris 3. external oblique muscle 4. iliac crest 5. McBurney’s point 6. linea alba 7. tendinous intersection 8. umbilibus 9. anterior superior iliac spine

Figure 15.2(c)

1. tendinous insertion 2. McBurney’s point 3. serratus anterior muscle 4. rectus abdominis muscle 5. external oblique muscle 6. iliac crest 7. anterior superior iliac spine

Figure 15.2(d)

1. trapezius muscle 2. acromion 3. supraspinatus 4. infraspinatus muscle 5. teres major muscle 6. erector spinae muscle 7. spinous processes of thoracic vertebrae 8. vertebral border of scapula

Figure 15.2(e)

1. deltoid muscle, lateral fibers 2. deltoid muscle, posterior fibers 3. triangle of ascultation 4. spinous process of vertebra 5. trapezius muscle 6. teres major muscle 7. vertebral border of scapula 8. latissimus dorsi 9. spinous process of lumbar vertebra

Figure 15.2(f)

1. iliac crest 2. posterior sperior iliac spine 3. coccyx 4. greater trochanter 5. sacrum 6. gluteus medius muscle 7. gluteus maximus muscle 8. ischial tuberosity

15. gluteus medius 16. piriformis 17. biceps femoris 18. gluteus maximus 19. semitendinosus 20. semimembranosus

Figure 14.8(a, b, c, & d)

1. fibularis (peroneus) longus 2. tibialis anterior 3. extensor digitorum longus 4. fibularis (peroneus) brevis 5. gastrocnemius 6. soleus 7. fibularis (peroneus) longus 8. extensor digitorum longus 9. tibialis anterior 10. gastrocnemius 11. soleus 12. flexor hallucis longus 13. flexor digitorum longus

Exercise 15

Figure 15.1(a & b)

1. frontalis muscle 2. zygomaticus major muscle 3. mental protuberance 4. supraorbital margin 5. nasal bone 6. body of mandible 7. temporalis muscle 8. occipitalis muscle 9. external occipital protuberance 10. mastoid process 11. ramus of mandible 12. temporomandibular joint 13. masseter muscle covered by parotid

gland

Figure 15.1(c)

1. common carotid artery 2. sternocleidomastoid muscle 3. clavicle 4. hyoid bone 5. thyroid cartilage 6. cricoid cartilage 7. suprasternal (jugular) notch

Figure 15.1(d)

1. sternocleidomastoid 2. levator scapulae 3. trapezius 4. scalenes

Figure 15.2(a)

1. second rib (deep to muscle) 2. body of sternum

3. pectoralis minor 4. serratus anterior 5. external oblique 6. rectus abdominis

Figure 14.4(a & b)

1. trapezius 2. deltoid 3. latissimus dorsi 4. levator scapulae 5. rhomboid minor 6. supraspinatus 7. infraspinatus 8. teres minor 9. rhomboid major 10. teres major

Figure 14.5(a & b)

1. biceps brachii 2. subscapularis 3. teres major 4. brachialis 5. triceps brachii, long head 6. triceps brachii, lateral head 7. triceps brachii, medial head

Figure 14.6(a, b, c, & d)

1. pronator teres 2. flexor carpi radialis 3. brachioradialis 4. palmaris longus 5. flexor carpi ulnaris 6. supinator 7. flexor digitorum profundus 8. flexor pollicis longus 9. extensor carpi radialis longus 10. flexor carpi ulnaris 11. extensor carpi radialis brevis 12. extensor carpi ulnaris 13. extensor digiti minimi 14. extensor digitorum 15. supinator 16. extensor pollicis longus

Figure 14.7(a, b, & e)

1. iliacus 2. psoas major 3. tensor fasciae latae 4. rectus femoris (cut) 5. vastus intermedius 6. vastus lateralis 7. pectineus 8. adductor longus 9. gracilis 10. sartorius 11. vastus medialis 12. adductor brevis 13. gracilis 14. adductor magnus

696 A N S W E R K E Y

Figure 16.4(a & b)

1. process 2. satellite cells 3. nucleus 4. neuron cell body 5. axon 6. dendrites 7. neuron cell body

Figure 16.5(a & b)

1. unipolar 2. multipolar 3. bipolar 4. sensory neuron 5. interneuron 6. motor neuron

Figure 16.6(a & b)

(a) myelinated 1. axon 2. myelin sheath 3. Schwann cell cytoplasm 4. node of Ranvier (b) unmyelinated 5. axons 6. Schwann cell cytoplasm

Figure 16.7

1. neurolemma 2. myelin sheath 3. node of Ranvier 4. axon

Figure 16.8

1. white matter in brain and spinal cord 2. gray matter in brain and spinal cord

Before Going to Lab Synapses

1. axoaxonic 2. axodendritic 3. axosomatic 4. dendrites on postsynaptic neurons

receive neurotransmitter at synapse 5. graded potential sent toward trigger

zone 6. action potential started on postsynaptic

neuron 7. action potential travels down axon 8. action potential reaches axon terminal

Exercise 17

Figure 17.1

1. dura mater 2. pia mater

17. medial malleolus of tibia 18. lateral malleolus of fibula 19. tendon of extensor hallucis longus

muscle 20. tendons of extensor digitorum longus

muscle

Figure 15.4(b)

1. biceps femoris tendon 2. gastrocnemius muscle (medial and

lateral heads) 3. soleus muscle 4. calcaneus 5. tendon of semitendinosus 6. biceps femoris muscle 7. semitendinosus and semimembranosus

muscles

Exercise 16

Table 16.1

1. Schwann cells - PNS 2. ependymal cells - CNS 3. microglia - CNS 4. astrocytes - CNS 5. satellite cells - PNS 6. oligodendrocytes - CNS

Figure 16.1(a & b)

1. oligodendrocyte 2. microglial cell 3. astrocytes 4. ependymal cell 5. satellite cell 6. Schwann cell

Figure 16.2(a & b)

1. processes 2. cell body 3. dendrites 4. axon 5. axon hillock 6. cell body 7. nucleus

Figure 16.3

1. axon terminals 2. Schwann cell 3. node of Ranvier 4. axon collateral 5. axon or soma 6. dendrites 7. cell body 8. axon hillock 9. trigger zone (initial segment) 10. myelin sheath

Figure 15.2(g)

1. sacrum 2. greater trochanter of the femur 3. coccyx 4. gluteal cleft 5. iliac crest 6. posterior superior iliac spine 7. gluteus maximus muscle

Figure 15.3(a)

1. acromion 2. spine of scapula 3. deltoid muscle (lateral fibers) 4. acromioclavicular joint 5. clavicle 6. greater tubercle of humerus

Figure 15.3(b)

1. acromion 2. deltoid muscle (lateral fibers) 3. biceps brachii muscle 4. triceps brachii muscle 5. lateral epicondyle of humerus

Figure 15.3(c)

1. biceps brachii muscle 2. tendon of biceps brachii muscle 3. olecranon of ulna 4. medial epicondyle of humerus 5. triceps brachii muscle 6. groove for brachial artery

Figure 15.3(d)

1. median cubital vein 2. biceps brachii muscle 3. cephalic vein 4. brachioradialis muscle 5. cubital fossa 6. basilic vein

Figure 15.4(a)

1. sartorius muscle 2. adductor longus muscle 3. gracilis muscle 4. rectus femoris muscle 5. vastus lateralis muscle 6. vastus medialis muscle 7. lateral condyle of femur 8. lateral condyle of tibia 9. patellar ligament 10. medial condyle of femur 11. patella 12. medial condyle of tibia 13. tibial tuberosity 14. tibialis anterior muscle 15. anterior border of tibia (shin) 16. fibularis (peroneus) longus muscle

A N S W E R K E Y 697

Figure 19.2

1. receptor 2. sensory neuron 3. integrating center for reciprocal

innervation 4. integrating center for patellar reflex arc 5. motor neuron for patellar reflex arc 6. motor neuron for reciprocal innervation 7. effector for patellar reflex arc 8. effector for reciprocal innervation

Exercise 20

Figure 20.1

1. cerebrum 2. cerebellum 3. diencephalon 4. brain stem

Figure 20.2(a & b)

1. corpora quadrigemina 2. cerebral peduncle 3. pons 4. medulla oblongata 5. midbrain 6. midbrain 7. pons 8. medulla oblongata 9. spinal cord

Figure 20.3(a & b)

1. cerebellar hemispheres 2. vermis 3. folia 4. superior colliculus 5. inferior colliculus 6. arbor vitae (white matter) 7. cerebellar cortex (gray matter) 8. pons 9. medulla oblongata

Figure 20.4(a, b, & c)

1. thalamus 2. hypothalamus 3. pineal gland (part of epithalamus) 4. diencephalon 5. mammillary body 6. pineal gland 7. thalamus 8. intermediate mass of thalamus 9. hypothalamus 10. infundibulum 11. pituitary gland 12. lateral ventricles 13. thalamus 14. third ventricles 15. hypothalamus

3. myelin sheath 4. endoneurium

Figure 18.3(a & b)

1. spinal nerve 2. anterior (ventral) ramus 3. posterior (dorsal) ramus 4. rami communicantes 5. sympathetic ganglion 6. intervertebral foramen 7. anterior (ventral) ramus 8. posterior (dorsal) ramus 9. rami communicantes

Figure 18.4

1. sacral plexus 2. lumbar plexus 3. brachial plexus 4. cervical plexus 5. cervical nerves 6. thoracic nerves 7. lumbar nerves 8. sacral nerves 9. coccygeal nerve

Figure 18.5

1. axillary nerve 2. musculocutaneous nerve 3. median nerve 4. ulnar nerve 5. radial nerve 6. phrenic nerve

Figure 18.6

1. femoral nerve 2. pudendal nerve 3. obturator nerve 4. sciatic nerve 5. tibial nerve 6. common fibular (peroneal) nerve

Exercise 19

Table 19.1

• somatic, spinal nerve reflex • autonomic, cranial nerve reflex • autonomic, cranial nerve reflex • somatic, spinal nerve reflex

Figure 19.1

1. integrating center 2. sensory neuron axon 3. sensory neuron cell body 4. sensory receptor 5. effector 6. motor neuron axon 7. motor neuron cell body

3. epidural space 4. subarachnoid space 5. web-like projection of arachnoid mater

Figure 17.2(a)

1. cervical enlargement 2. lumbar enlargement 3. conus medullaris 4. cauda equina 5. filum terminale

Figure 17.3

1. spinal nerve 2. posterior (dorsal) root ganglion 3. posterior (dorsal) root 4. posterior median sulcus 5. central canal 6. anterior (ventral) root 7. anterior median fissure

Figure 17.4

1. anterior white column 2. anterior gray horn 3. lateral white column 4. lateral gray horn 5. posterior gray horn 6. posterior white column 7. gray commissure

Figure 17.5

1. posterior (dorsal) root 2. lateral white column 3. central canal 4. posterior median sulcus 5. posterior white column 6. posterior gray horn 7. posterior (dorsal) root ganglion 8. anterior (ventral) root 9. anterior gray horn 10. anterior white column 11. gray commissure 12. anterior median fissure

Exercise 18

Figure 18.1

1. spinal nerve 2. epineurium 3. fascicle 4. perineurium 5. myelin sheath 6. axon 7. endoneurium

Figure 18.2

1. perineurium 2. axon

698 A N S W E R K E Y

Exercise 23

Figure 23.1(a & b)

1. type I cutaneous mechanoreceptor 2. corpuscle of touch (Meissner’s) 3. type II cutaneous mechanoreceptor 4. hair root plexus 5. laminated corpuscle (Pacinian) 6. muscle spindle 7. tendon organ

Figure 23.2(a & b)

1. third-order neuron 2. second-order neuron 3. first-order neuron 4. third-order neuron 5. second-order neuron 6. first-order neuron

Exercise 24

Figure 24.1(a & b)

1. conjunctival fold 2. palpebral conjunctiva 3. bulbar conjunctiva 4. lacrimal gland 5. lacrimal canals 6. lacrimal sac 7. nasolacrimal duct

Figure 24.2(a & b)

1. superior oblique 2. superior rectus 3. lateral rectus 4. medial rectus 5. inferior oblique 6. inferior rectus

Table 24.1

Inferior oblique—moves eye superiorly and laterally Inferior rectus—moves eye inferiorly Lateral rectus—moves eye laterally Medial rectus—moves eye medially Superior oblique—moves eye inferiorly and laterally Superior rectus—moves eye superiorly

Figure 24.3

1. scleral venous sinus 2. ciliary muscle 3. ciliary process 4. ciliary body 5. choroid 6. sclera 7. retina

16. subarachnoid space 17. lateral ventricle 18. choroid plexus 19. third ventricle 20. cerebral aqueduct 21. fourth ventricle 22. central canal

Exercise 21

Figure 21.1

1. olfactory 2. optic 3. oculomotor 4. trochlear 5. trigeminal 6. abducens 7. facial 8. vestibulocochlear 9. glossopharyngeal 10. vagus 11. accessory 12. hypoglossal

Figure 21.2

1. trigeminal (mandibular branch) 2. trigeminal (maxillary branch) 3. hypoglossal 4. vestibulocochlear 5. glossopharyngeal, vagus, accessory 6. olfactory 7. optic 8. facial 9. oculomotor, trochlear, abducens,

trigeminal (ophthalmic branch)

Exercise 22

Figure 22.1

1. right sympathetic trunk ganglia 2. splanchnic nerves 3. left sympathetic trunk ganglia 4. prevertebral ganglia

Figure 22.2

1. otic ganglion 2. ciliary ganglion 3. pterygopalatine ganglion 4. submandibular ganglion

Figure 22.3

1. interneuron 2. axon of sensory neuron (afferent) 3. sensory receptor 4. axon of preganglionic motor neuron 5. autonomic ganglion 6. axon of postganglionic motor neuron 7. visceral effector

Figure 20.5(b)

1. internal capsule (projection fibers) 2. cerebral cortex (gray matter) 3. cerebral white matter 4. corpus callosum (commissural fibers) 5. fornix (association fibers) 6. basal nuclei (gray matter)

Figure 20.6

1. central sulcus 2. postcentral gyrus 3. parietal lobe 4. occipital lobe 5. transverse fissure 6. precentral gyrus 7. frontal lobe 8. insula 9. temporal lobe (cut)

Figure 20.7

1. Broca’s speech area 2. primary gustatory area 3. primary motor area 4. central sulcus 5. primary somatosensory area 6. primary visual area 7. Wernicke’s area 8. primary auditory area

Figure 20.9(a & b)

1. subarachnoid space 2. arachnoid villus 3. falx cerebri 4. white matter 5. superior sagittal sinus 6. parietal bone 7. dura mater 8. arachnoid mater 9. pia mater 10. cerebral cortex

Figure 20.10(a, b, & c)

1. lateral ventricle 2. choroid plexus 3. cerebral aqueduct 4. fourth ventricle 5. arachnoid villus 6. third ventricle 7. subarachnoid space 8. lateral ventricles 9. interventricular foramen 10. third ventricle 11. cerebral aqueduct 12. fourth ventricle 13. central canal of spinal cord 14. superior sagittal sinus 15. arachnoid villus

A N S W E R K E Y 699

6. filiform papillae 7. fungiform papillae 8. taste bud 9. taste pore 10. gustatory hairs 11. gustatory receptor cell 12. sensory axons

Exercise 25

Figure 25.1

1. pineal gland 2. parathyroid glands 3. adrenal glands 4. pancreas 5. hypothalamus 6. pituitary gland or hypophysis 7. thyroid gland 8. thymus 9. ovaries 10. testes

Figure 25.2(a, b, & c)

1. posterior pituitary or neurohypophysis 2. hypothalamus 3. infundibulum 4. anterior pituitary or adenohypophysis 5. hypothalamus 6. infundibulum 7. anterior pituitary 8. posterior pituitary 9. posterior pituitary 10. anterior pituitary

Figure 25.3(a & b)

1. right lobe of thyroid gland 2. thyroid cartilage of larynx 3. isthmus of thyroid gland 4. trachea 5. left lobe of thyroid gland 6. left lobe of thyroid gland 7. left parathyroid glands 8. right parathyroid glands 9. trachea 10. right lobe of thyroid gland 11. isthmus of thyroid gland

Figure 25.4(a & b)

1. parathyroid gland 2. thyroid gland 3. follicular cell 4. parafollicular cell or C cell 5. colloid-filled follicle

Figure 25.6(a, b, & c)

1. right adrenal gland 2. left adrenal gland 3. kidney

7. stapes attached to oval window 8. middle ear 9. internal ear 10. auditory tube 11. tympanic membrane 12. external auditory canal

Figure 24.14

1. anterior semicircular canal 2. posterior semicircular canal 3. lateral semicircular canal 4. ampulla of semicircular canal and duct 5. utricle 6. saccule 7. oval window 8. membranous semicircular duct 9. vestibule 10. round window 11. cochlea 12. cochlear duct

Figure 24.15(a & b)

1. scala vestibuli 2. scala tympani 3. vestibular membrane 4. basilar membrane 5. cochlear duct 6. spiral organ of Corti 7. vestibular membrane 8. tectorial membrane 9. basilar membrane 10. hair cells 11. cochlear duct

Figure 24.16(a & b)

1. otoliths 2. otolithic membrane 3. stereocilia in hair bundle 4. hair cell 5. vestibular branches of vestibulocochlear

nerve 6. cupula 7. hair bundle 8. hair cell

Figure 24.17(a & b)

1. olfactory bulb 2. cribriform plate 3. olfactory tract 4. olfactory nerve 5. olfactory receptor cell 6. olfactory hair

Figure 24.18(a, b, & c)

1. vallate (circumvallate) papilla 2. fungiform papilla 3. foliate papilla 4. filiform papilla 5. vallate papillae

8. cornea 9. pupil 10. iris 11. suspensory ligament (zonular fibers) 12. ora serrata

Figure 24.4

1. anterior chamber 2. posterior chamber 3. anterior cavity 4. scleral venous sinus 5. vitreous chamber 6. lens

Figure 24.6

1. macula lutea 2. central fovea 3. blood vessel 4. optic disc

Figure 24.7(a & b)

1. optic disc 2. central retinal vein 3. optic nerve 4. central retinal artery 5. central fovea 6. cornea 7. pupil 8. iris 9. ciliary body 10. lens 11. choroid 12. sclera 13. retina 14. optic disc 15. optic nerve

Figure 24.8(a & b)

1. optic nerve fibers (axons) 2. ganglion cell layer 3. bipolar cell layer 4. photoreceptor layer 5. neural portion of retina 6. pigmented epithelium of retina 7. ganglion cell layer 8. bipolar cell layer 9. photoreceptor layer 10. neural portion of retina 11. pigmented epithelium of retina

Figure 24.13

1. lobule 2. auricle 3. helix 4. external ear 5. malleus 6. incus

700 A N S W E R K E Y

18. ascending aorta 19. right pulmonary artery 20. right pulmonary veins 21. inferior vena cava

Figure 27.4(b)

1. superior vena cava opening 2. pulmonary (semilunar) valve 3. right atrium 4. coronary sinus opening 5. inferior vena cava opening 6. tricuspid valve 7. right ventricle 8. trabeculae carneae 9. left pulmonary vein openings 10. left atrium 11. aortic (semilunar) valve 12. bicuspid valve (mitral) 13. chordae tendineae 14. interventricular septum 15. papillary muscle 16. left ventricle

Before Going to Lab Systemic and Pulmonary Circulation: Blood vessels with oxygen-poor blood

a. pulmonary arteries b. pulmonary trunk c. venae cavae

Blood vessels with oxygen-rich blood

d. aorta e. pulmonary veins

Trace blood flow

1. right atrium 2. tricuspid valve 3. right ventricle 4. pulmonary (semilunar) valve 5. pulmonary trunk 6. pulmonary arteries 7. pulmonary capillaries 8. pulmonary veins 9. left atrium 10. bicuspid (mitral) valve 11. left ventricle 12. aortic (semilunar) valve 13. aorta 14. systemic arteries 15. systemic capillaries 16. systemic veins 17. venae cavae and coronary sinus 18. right atrium

Figure 27.6(c & d)

1. marginal branch 2. small cardiac vein 3. right coronary artery

Pineal Gland

melatonin

Thymus

thymosin

Exercise 26

TABLE 26.7

Summary of ABO Blood Group Interactions Antigen on RBCs: A, B, A and B; neither A nor B Antibody in plasma: anti-B, anti-A, none, anti-A and anti-B Compatible donor: A, O; B, O; A, B, AB, O; O Incompatible donor: B, AB; A, AB; none; A; B; AB

Exercise 27

Figure 27.2(a & b)

1. right auricle 2. coronary sulcus 3. right ventricle 4. left auricle 5. anterior interventricular sulcus 6. left ventricle 7. apex of heart 8. left auricle 9. coronary sulcus 10. left ventricle 11. adipose tissue 12. posterior interventricular sulcus 13. right auricle 14. right ventricle

Figure 27.3(b & c)

1. superior vena cava 2. right pulmonary artery 3. ascending aorta 4. pulmonary trunk 5. right pulmonary veins 6. inferior vena cava 7. aortic arch 8. ligamentum arteriosum 9. left pulmonary artery 10. descending aorta 11. left pulmonary veins 12. aortic arch 13. ligamentum arteriosum 14. left pulmonary artery 15. left pulmonary veins 16. coronary sinus 17. superior vena cava

4. capsule 5. adrenal cortex 6. adrenal medulla 7. capsule 8. zona glomerulosa 9. zona fasciculata 10. zona reticularis 11. adrenal medulla 12. adrenal cortex

Figure 25.8(a & c)

1. head of pancreas 2. body of pancreas 3. tail of pancreas 4. exocrine or acini cells 5. pancreatic islet

Table 25.1 Anterior pituitary

1. human growth hormone 2. thyroid-stimulating hormone 3. follicle-stimulating hormone 4. luteinizing hormone 5. prolactin 6. adrenocorticotropic hormone 7. melanocyte-stimulating hormone

Posterior pituitary

1. anti-diuretic hormone 2. oxytocin

Thyroid gland

1. thyroxine 2. triiodothyronine 3. calcitonin

Parathyroid glands

parathyroid hormone

Adrenal cortex

1. aldosterone 2. cortisol 3. androgens

Adrenal medulla

1. epinephrine 2. norepinephrine

Pancreas

1. insulin 2. glucagon

Ovaries

1. estrogen 2. progesterone

Testes

testosterone

A N S W E R K E Y 701

Figure 29.6(a, b, & c)

1. intercellular cleft 2. vesicles involved in transcytosis 3. tight junctions 4. fenestrations

Exercise 30

Figure 30.1(b)

1. right common carotid 2. brachiocephalic trunk 3. ascending aorta 4. left common carotid 5. left subclavian 6. aortic arch 7. thoracic aorta

Figure 30.2(a & b)

1. internal carotid 2. vertebral 3. external carotid 4. common carotid 5. brachiocephalic trunk 6. anterior cerebral 7. middle cerebral 8. internal carotid 9. posterior communicating 10. posterior cerebral 11. basilar 12. vertebral 13. anterior communicating

Figure 30.3(b)

1. subclavian 2. axillary 3. brachial 4. radial 5. ulnar

Figure 30.4

1. superior mesenteric 2. right common iliac 3. right internal iliac 4. right external iliac 5. common hepatic 6. splenic 7. celiac trunk 8. left renal 9. abdominal aorta 10. inferior mesenteric

Figure 30.5

1. left gastric 2. celiac trunk 3. common hepatic 4. splenic

Figure 28.3

1. P wave 2. P-Q interval 3. QRS complex 4. S-T segment 5. T wave 6. Q-T interval

Figure 28.4

2. (a) 3 (number of P waves in 30 squares) � 10 � 30 beats/min; bradycardia

(b) 6 (number of P waves in 30 squares) � 10 � 60 beats per min; NSR

Exercise 29

Before Going to Lab: Blood Vessel Structure

1. Figure 29.1(b) is vasoconstricted.

Figure 29.2

1. endothelium 2. basement membrane 3. internal elastic lamina 4. tunica interna 5. smooth muscle 6. external elastic lamina 7. tunica media 8. tunica externa

Figure 29.3

1. endothelium 2. basement membrane 3. tunica interna 4. valve 5. tunica media (smooth muscle) 6. tunica externa

Figure 29.4

1. tunica media of vein 2. tunica interna of vein 3. lumen of vein 4. tunica externa of vein 5. lumen of artery 6. tunica interna of artery 7. tunica media of artery 8. tunica externa of artery

Figure 29.5

1. capillary 2. arteriole

4. left coronary artery 5. circumflex branch 6. anterior interventricular branch (LAD) 7. great cardiac vein 8. middle cardiac vein 9. coronary sinus 10. posterior interventricular branch

Figure 27.7(a & b)

1. fibrous pericardium 2. diaphragm 3. fibrous pericardium 4. parietal layer of serous pericardium 5. pericardial cavity 6. visceral layer of serous pericardium

(epicardium) 7. endocardium 8. myocardium

Figure 27.9

1. cardiac muscle fiber 2. intercalated discs 3. branching cardiac fibers 4. nucleus

Lab Activity 8: Dissection of a Sheep Heart

10. These three cusps are half-moon shaped, and chordae tendinae are not associated with the pulmonary semilunar valve.

12. The bicuspid valve has 2 cusps. The bicuspid valve looks similar to the tricuspid valve but they differ in the number of cusps. The bicuspid and tricuspid valves have chordae tendinae and papillary muscles. The left ventricle has a smaller number of papillary muscles, but these papillary muscles are larger. The wall of the left ventricle is thicker to pump blood through the systemic circulation.

Exercise 28

Figure 28.1

1. Purkinje (conduction) fibers in right ventricle

2. right bundle branch 3. AV bundle (of His) 4. atrioventricular (AV) node 5. sinoatrial (SA) node 6. left bundle branch 7. Purkinje (conduction) fibers in left

ventricle

702 A N S W E R K E Y

9. right jugular trunk 10. right subclavian trunk 11. right lymphatic duct 12. cisterna chyli 13. thoracic duct 14. thoracic (left lymphatic) duct in thorax

Figure 31.3(a & b)

1. pharyngeal tonsil 2. palatine tonsil 3. lingual tonsil 4. submandibular lymph node 5. cervical lymph node 6. thymus 7. intestinal lymph node 8. appendix (vermiform) 9. red bone marrow 10. axillary lymph node 11. mammary lymph node 12. thoracic lymph node 13. spleen 14. Peyer’s patches (aggregated lymphatic

follicles) 15. iliac lymph node 16. inguinal lymph node

Lab Activity 2: Flow of Lymph

1. blood capillaries 2. interstitial fluid 3. lymphatic capillaries 4. lymphatic vessels 5. inguinal lymph nodes 6. lymphatic vessels 7. iliac lymph nodes 8. lumbar trunk 9. cisterna chyli 10. thoracic duct 11. junction of jugular and subclavian veins 12. brachiocephalic vein 13. superior vena cava 14. heart

Figure 31.5(a, b, & c)

1. trabecular sinus 2. afferent vessels 3. valve 4. subcapsular sinus 5. cortex 6. medulla 7. medullary sinus 8. efferent vessels 9. hilum 10. capsule 11. trabecula 12. cortex 13. medulla 14. capsule 15. lymphatic nodule 16. reticulocyte 17. reticular fiber

3. superior mesenteric 4. splenic 5. inferior mesenteric

Figure 30.12(a & b)

1. external iliac 2. femoral 3. anterior tibial 4. small saphenous 5. great saphenous 6. femoral 7. popliteal 8. great saphenous 9. posterior tibial 10. small saphenous 11. fibular (peroneal)

Figure 30.13

1. right pulmonary artery 2. right pulmonary vein 3. left pulmonary artery 4. pulmonary trunk 5. left pulmonary vein

Figure 30.14(a & b)

1. foramen ovale 2. ductus venosus 3. umbilical vein 4. umbilical arteries 5. placenta 6. ductus arteriosus 7. ligamentum arteriosum 8. fossa ovalis 9. ligamentum venosum 10. ligamentum teres 11. medial umbilical ligaments

Exercise 31

Figure 31.1(a & b)

1. tissue cell 2. interstitial fluid 3. blood capillary 4. lymphatic capillary 5. interstitial fluid 6. tissue cell 7. lymph in lymphatic capillary

Figure 31.2(a, b, & c)

1. right lymphatic duct 2. lymphatic vessel in arm 3. thoracic duct in thorax 4. cisterna chyli 5. lymphatic vessel in leg 6. thoracic duct draining into subclavian

vein 7. area drained by right lymphatic duct 8. area drained by thoracic duct

Figure 30.6(a & b)

1. common iliac 2. external iliac 3. internal iliac 4. femoral 5. popliteal 6. anterior tibial 7. posterior tibial 8. fibular (peroneal) 9. dorsal artery of the foot (dorsalis pedis)

Figure 30.7

1. superior vena cava 2. coronary sinus 3. inferior vena cava

Figure 30.8

1. vertebral 2. internal jugular 3. external jugular 4. subclavian 5. brachiocephalic

Figure 30.9(a & b)

1. basilic 2. cephalic 3. median cubital 4. subclavian 5. axillary 6. brachial veins 7. radial veins 8. ulnar veins

Figure 30.10

1. right brachiocephalic 2. left brachiocephalic 3. superior vena cava 4. azygos 5. hepatic veins 6. right suprarenal 7. right renal 8. right gonadal 9. inferior vena cava 10. right common iliac 11. right internal iliac 12. right external iliac 13. accessory hemiazygos 14. hemiazygos 15. left suprarenal 16. left renal 17. left gonadal 18. left common iliac 19. left internal iliac 20. left external iliac

Figure 30.11

1. hepatic 2. hepatic portal

A N S W E R K E Y 703

6. apex 7. superior lobe 8. cardiac notch 9. inferior lobe 10. base 11. superior lobe 12. hilum 13. middle lobe 14. inferior lobe 15. superior lobe 16. inferior lobe 17. hilum 18. cardiac notch

Figure 32.8(a & b)

1. visceral pleura 2. parietal pleura 3. pleural cavity 4. diaphragm 5. visceral pleura 6. parietal pleura 7. right lung 8. pleural cavity 9. left lung

Figure 32.9(a & b)

1. lumen of esophagus 2. trachealis muscle 3. lumen of trachea 4. epithelial lining of trachea 5. tracheal cartilage 6. respiratory bronchiole 7. alveolar ducts 8. simple squamous epithelium 9. alveoli 10. alveolar sacs

Exercise 33

Table 33.1

1. External intercostals—increase diameter 2. Internal intercostals—decrease diameter 3. Sternocleidomastoids—increase diameter 4. Scalenes—increase diameter 5. Pectoralis minors—increase diameter 6. Diaphragm—increases length 7. Abdominal muscles—decrease length

Figure 33.1(a & b)

1. sternocleidomastoid 2. scalenes 3. pectoralis minor 4. rectus abdominis 5. external oblique 6. internal oblique 7. transverse abdominis 8. internal intercostals 9. external intercostals 10. diaphragm

3. laryngopharynx 4. pharyngeal tonsil 5. nasopharynx 6. opening of auditory tube 7. uvula 8. oropharynx 9. laryngopharynx 10. internal naris 11. soft palate 12. palatine tonsil 13. lingual tonsil

Figure 32.4(c, d, e, & f)

1. epiglottis 2. thyroid cartilage 3. cricoid cartilage 4. epiglottis 5. thyroid cartilage 6. cricoid cartilage 7. arytenoid cartilage 8. cricoid cartilage 9. epiglottis 10. ventricular fold 11. vocal fold 12. thyroid cartilage 13. ventricular fold 14. vocal fold 15. glottis

Figure 32.5(a & b)

1. trachea 2. right primary (main) bronchus 3. carina 4. right secondary (lobar) bronchus 5. diaphragm 6. larynx 7. tracheal cartilage 8. left primary (lobar) bronchus 9. left tertiary (segmental) bronchus 10. bronchiole 11. primary (main) bronchus 12. secondary (lobar) bronchus 13. tertiary (segmental) bronchus 14. terminal bronchiole 15. respiratory bronchiole 16. alveolar sac

Figure 32.6

1. respiratory bronchiole 2. alveolar ducts 3. alveolar sac 4. alveoli

Figure 32.7(a, b, c, & d)

1. apex 2. superior lobe 3. middle lobe 4. inferior lobe 5. base

Figure 31.7(b)

1. capsule 2. cortex of lobule 3. medulla of lobule 4. trabecula of lobule

Figure 31.8(a & b)

1. splenic artery 2. splenic vein 3. hilum 4. capsule 5. white pulp 6. trabecula

Lab Activity 6: Cells Involved in Body Defenses

1. e 2. e 3. e 4. c 5. e 6. e 7. a, b, d 8. e 9. e 10. e 11. e 12. e

Exercise 32

Figure 32.1(b)

1. pharynx 2. right primary or main bronchus 3. lungs 4. nose 5. nasal cavity 6. larynx 7. trachea

Figure 32.2(a & b)

1. internal naris 2. superior nasal concha or turbinate 3. middle nasal concha or turbinate 4. inferior nasal concha or turbinate 5. superior nasal meatus 6. middle nasal meatus 7. inferior nasal meatus 8. external naris 9. hard palate 10. middle nasal meatus 11. nasal septum 12. inferior nasal meatus 13. middle nasal concha 14. inferior nasal concha

Figure 32.3(b & c)

1. nasopharynx 2. oropharynx

704 A N S W E R K E Y

10. ascending colon 11. ileum 12. ileocecal sphincter 13. cecum 14. appendix 15. rectum 16. transverse colon 17. left colic (splenic) flexure 18. descending colon 19. teniae coli 20. epiploic appendages 21. haustra 22. sigmoid colon 23. anal canal 24. anus 25. rectum 26. anal canal 27. internal anal sphincter 28. external anal sphincter 29. anal column 30. anus

Figure 34.9(a, b, & c)

1. parotid gland 2. parotid duct 3. opening of parotid duct

(near secondary molar) 4. openings of sublinguinal ducts 5. sublinguinal gland 6. submandibular duct 7. submandibular gland 8. crown 9. neck 10. root 11. enamel 12. dentin 13. gingiva 14. blood supply 15. pulp cavity with pulp 16. cementum 17. root canal 18. periodontal ligament 19. nerve 20. apical foramen 21. molars 22. premolars 23. cuspid 24. incisors 25. tongue 26. lingual frenulum

Figure 34.10(b, c, & d)

1. right hepatic duct 2. cystic duct 3. gallbladder 4. duodenum 5. hepatopancreatic ampulla 6. falciform ligament 7. left lobe of liver 8. left hepatic duct 9. common hepatic duct

9. falciform ligament 10. greater omentum 11. lesser omentum 12. greater omentum (reflected) 13. mesocolon 14. mesentery

Figure 34.4

1. hard palate 2. soft palate 3. uvula 4. cheek 5. vestibule 6. superior lip 7. fauces 8. palatine tonsil 9. tongue 10. gingivae (gums) 11. inferior labial frenulum 12. inferior lip

Figure 34.5

1. nasopharynx 2. soft palate 3. uvula 4. fauces 5. oropharynx 6. laryngopharynx 7. esophagus 8. hard palate 9. oral or buccal cavity 10. tongue

Figure 34.6

1. lesser curvature 2. body 3. cardia 4. lower esophageal sphincter

(cardiac sphincter) 5. esophagus 6. fundus 7. longitudinal muscle layer 8. circular muscle layer 9. oblique muscle layer 10. greater curvature 11. rugae 12. pyloric antrum 13. pyloric canal 14. pyloric sphincter 15. pylorus

Figure 34.8(a, b, & c)

1. duodenum 2. ascending colon 3. jejunum 4. ileum 5. stomach 6. transverse colon 7. descending colon 8. rectum 9. right colic (hepatic) flexure

Figure 33.2(a & b)

a. exhalation b. inhalation

Figure 33.3

1. parietal pleura and thoracic wall 2. trachea 3. bronchus 4. lungs covered with visceral pleura 5. pleural cavity 6. diaphragm

Table 33.2

1. decreased 2. increased 3. deflated 4. out of balloons 5. increased 6. decreased 7. inflated 8. into balloons

Figure 33.4

FVC � 3.1 L FEV1 � 1.9 L FEV1/FVC ratio � 0.61

Exercise 34

Figure 34.1

1. salivary glands 2. pharynx 3. esophagus 4. liver 5. gallbladder 6. large intestine 7. mouth (oral cavity) 8. stomach 9. pancreas 10. small intestine 11. anus

Figure 34.2

1. mucosa 2. submucosa 3. serosa 4. muscularis

Figure 34.3(a, b, c, & d)

1. retroperitoneal organs 2. lesser omentum 3. mesocolon 4. mesentery 5. greater omentum 6. parietal peritoneum 7. visceral peritoneum (serosa) 8. peritoneal cavity

A N S W E R K E Y 705

Figure 36.6(a & b)

1. glomerular capsule 2. proximal convoluted tubule 3. ascending limb of loop of Henle 4. descending limb of loop of Henle 5. distal convoluted tubule 6. collecting duct 7. papillary duct 8. glomerulus 9. glomerular capsule 10. renal corpuscle 11. peritubular capillary 12. efferent arteriole 13. afferent arteriole

Figure 36.7

1. afferent arteriole 2. efferent arteriole 3. vasa recta 4. peritubular capillary 5. interlobular artery 6. arcuate artery 7. interlobar artery 8. segmental artery 9. renal artery 10. renal vein 11. interlobar vein 12. arcuate vein 13. interlobular vein

Figure 36.9(a & b)

1. proximal and distal convoluted tubules (outer cortex)

2. glomerulus 3. loop of Henle and collecting ducts 4. glomerulus 5. parietal layer of glomerular capsule

(simple squamous epithelium) 6. capsular space

Figure 36.10

1. lamina propria 2. transitional epithelium 3. lumen 4. mucosa 5. muscularis 6. adventitia

Exercise 37

Figure 37.2

1. filtration 2. major site of tubular reabsorption of

water and solutes; secretion of solutes 3. water reabsorbed but not solutes 4. Na� and Cl� reabsorbed but not water 5. additional reabsorption of solutes and

water

3. urinary bladder 4. urethra

Figure 36.2

1. peritoneum 2. renal fascia 3. right kidney 4. renal capsule 5. adipose capsule 6. renal hilum 7. left kidney

Figure 36.3

1. renal medulla 2. renal cortex 3. renal column 4. renal capsule 5. renal pyramid 6. renal papilla 7. minor calyx 8. major calyx 9. renal artery 10. renal vein 11. renal hilum 12. renal pelvis in renal sinus

Figure 36.4

1. internal urethral sphincter 2. ureters 3. detrusor muscle of urinary bladder 4. ureteral openings 5. trigone 6. internal urethral orifice 7. urethra 8. external urethral sphincter 9. external urethral orifice

Figure 36.5(a & b)

1. rectum 2. anus 3. ureter 4. urinary bladder 5. ureteral opening 6. internal urethral orifice 7. prostatic urethra 8. membranous urethra 9. spongy urethra 10. external urethral orifice 11. urogenital diaphragm 12. rectum 13. anus 14. uterus 15. urinary bladder 16. internal urethral orifice 17. urethra 18. urogenital diaphragm 19. external urethral orifice 20. vagina

10. common bile duct 11. accessory pancreatic duct 12. tail of pancreas 13. body of pancreas 14. pancreatic duct 15. head of pancreas 16. jejunum 17. duodenal papilla 18. hepatopancreatic ampulla 19. common bile duct 20. pancreatic duct 21. quadrate lobe 22. left lobe 23. caudate lobe 24. right lobe 25. gallbladder

Figure 34.11(a, b, c, d, & e)

1. stratified squamous epithelium 2. lamina propria 3. muscularis mucosae 4. mucosa 5. submucosa 6. circular layer of smooth muscle fibers 7. longitudinal layer of smooth muscle

fibers 8. adventitia 9. gastric pit 10. simple columnar epithelium 11. lamina propria 12. gastric glands 13. simple columnar epithelium 14. goblet cell 15. villus 16. lamina propria 17. intestinal (crypts of Lieberkühn) gland 18. duodenal (Brunner’s) gland in

submucosa 19. acini (exocrine) 20. pancreatic islet (islet of Langerhans) 21. hepatocytes 22. sinusoids 23. central vein

Figure 34.12

1. bile canaliculus 2. hepatic vein 3. central vein 4. sinusoids 5. portal triad 6. bile duct 7. hepatocytes 8. branch of hepatic portal vein 9. branches of hepatic artery

Exercise 36

Figure 36.1

1. right kidney 2. right ureter

706 A N S W E R K E Y

3. basement membrane 4. Leydig (interstitial) cell 5. interstitial space

Figure 38.11

1. acrosome 2. nucleus 3. mitochondria 4. head 5. midpiece 6. tail (flagellum)

Exercise 39

Figure 39.1(b)

1. infundibulum 2. ampulla 3. isthmus 4. uterine tube 5. fimbriae 6. suspensory ligament 7. ovary 8. ovarian ligament 9. broad ligament

Figure 39.2

1. uterine cavity 2. myometrium of uterus 3. vagina 4. ovary 5. round ligament 6. cervix 7. urinary bladder

Figure 39.3

1. uterine cavity 2. endometrium 3. myometrium 4. perimetrium 5. round ligament 6. internal os 7. cervical canal 8. cervix 9. rugae of vagina 10. fundus 11. broad ligament 12. body of uterus 13. external os 14. vagina

Figure 39.4(b)

1. anus 2. vaginal orifice 3. pubic symphysis 4. mons pubis 5. clitoris 6. external urethral orifice

6. ampulla of ductus deferens 7. ejaculatory duct 8. bulbourethral gland 9. spongy (penile) urethra

Figure 38.6

1. seminal vesicle 2. prostate gland 3. bulbourethral gland

Figure 38.7(a & b)

1. prostate gland 2. prostatic urethra 3. membranous urethra 4. corpus spongiosum penis 5. corpora cavernosa penis 6. spongy (penile) urethra 7. glans penis 8. bulbourethral gland 9. prepuce 10. external urethral orifice 11. corpora cavernosa penis 12. corpus spongiosum penis 13. spongy (penile) urethra

Lab Activity 5: Function of Male Reproductive Organs

1. secretes 60% of semen volume; alkaline pH; prostaglandins

2. secretes 25% of semen volume; increases viability and motility of sperm

3. secretes mucus for lubrication of glans; alkaline pH

4. site of storage and maturation of sperm 5. organ that produces sperm 6. copulatory organ; passageway for urine

and sperm 7. carries sperm from epididymis to

ejaculatory duct

Figure 38.9(a & b)

1. spermatogonium 2. spermatozoa 3. spermatid 4. secondary spermatocyte 5. primary spermatocyte 6. spermatozoa (sperm cell) 7. late spermatid 8. early spermatid 9. secondary spermatocyte 10. Sertoli cells 11. primary spermatocyte 12. spermatogonium 13. basement membrane 14. Leydig (interstitial) cells

Figure 38.10

1. lumen 2. tails of sperm

6. aldosterone increases reabsorption of Na� and Cl� and secretion of K�; also ADH increases reabsorption of water, additional reabsorption and secretion of solutes

Table 37.2

1. no change 2. increased 3. decreased 4. decreased 5. Change dependent on presence of ADH

and/or aldosterone

Exercise 38

Figure 38.1

1. cremaster muscle 2. dartos muscle 3. scrotum 4. tunica albuginea of testis

Figure 38.2

1. efferent duct 2. seminiferous tubules 3. straight tubule 4. rete testis 5. tunica albuginea 6. lobule 7. septum

Figure 38.3

1. ductus (vas) deferens 2. epididymis 3. spermatic cord 4. blood vessels and nerves

Figure 38.4

1. ampulla of ductus deferens 2. ejaculatory duct 3. prostate gland 4. membranous urethra 5. epididymis 6. testis 7. scrotum 8. ductus (vas) deferens (in inguinal

canal) 9. prostatic urethra 10. spongy (penile) urethra 11. penis 12. external urethral orifice

Figure 38.5

1. seminal vesicle 2. prostate gland 3. prostatic urethra 4. membranous urethra 5. ductus (vas) deferens

A N S W E R K E Y 707

2. freckles�FF, Ff; no freckles�ff; attached earlobes�EE, Ee; unattached earlobes�ee

3. homozygous widow’s peak �WW; heterozygous widow’s peak �Ww; straight hairline�ww

Figure 41.1

DD�0; Dd�4; dd�0 DD�0%; Dd�100%; dd�0% dimples�4; no dimples�0 dimples�100%; no dimples�0%

Figure 41.3

RR � 1; Rr�2; rr�1 RR�25%; Rr�50%; rr�25% Tongue-roller�3; non-tongue roller�1 Tongue-roller�75%; non-tongue roller�25%

Figure 41.4

CC�0%; Cc�100%, cc�0% Curly hair�0%; wavy hair�100%; straight hair�0%

Figure 41.5

AO�25%; BO�25%; AB�25%; OO�25% A�25%; B�25%; AB�25%; O�25%

Figure 41.6

AO�50%; BO�50%; AB�0%; OO�0% A�50%; B�50%; AB�0%; O�0%

Figure 41.8

HbSHbS�50%; HbSHbA�50%; HbAHbA�0% Sickle-cell anemia�50%; sickle-cell trait�50%; Normal�0%

Lab Activity 7 Sex-Linked Inheritance

1. XCXC�normal; XCXc�normal; XcXc�color blind; XCY�normal; XcY�color blind

Figure 41.10

XCXC�25%; XCXc�25%; XcXc�0%; XCY�25%; XcY�25% Female normal�25%; Female carrier � 25%; female color blind�0%; male normal�25%; male color blind�25%

10. primary follicle 11. primary oocyte in primary follicle 12. primary oocyte in secondary follicle 13. primordial follicles 14. ovarian cortex 15. primary oocyte in primary follicle 16. granulosa cells 17. follicular fluid in antrum 18. primary oocyte 19. granulosa cells

Figure 39.10

1. endometrium 2. endometrial glands 3. stratum functionalis 4. stratum basalis 5. myometrium

Exercise 40

Figure 40.1

1. secondary oocyte 2. fertilization of secondary oocyte 3. 2-cell stage of zygote 4. 4-cell stage of zygote 5. morula 6. blastocyst, external view 7. implantation of blastocyst, internal

view

Figure 40.2(b)

1. yolk sac 2. amnion 3. amnionic cavity 4. bilaminar embryonic disc

Figure 40.3

1. amniotic cavity 2. embryo 3. yolk sac 4. connecting stalk 5. chorionic villus

Figure 40.4

1. chorionic villi 2. fetal blood vessels 3. decidua basalis 4. chorion 5. umbilical arteries 6. umbilical vein

Exercise 41

Lab Activity 1 Genotypes and Phenotypes

1. het�Zz, Tt; hom�bb, MM, cc, AA

7. labium minus 8. labium majus

Figure 39.5

1. labia majora 2. labia minora 3. hymen 4. anus 5. mons pubis 6. prepuce 7. clitoris 8. external urethral orifice 9. vaginal orifice

Figure 39.6(a & b)

1. lobule with alveoli 2. mammary duct 3. lactiferous sinus 4. lactiferous duct 5. adipose tissue 6. areola 7. nipple

Lab Activity 5: Function of Female Reproductive Organs

1. Beat together to bring ovulated oocyte into uterine tube

2. Usual site of fertilization 3. Narrow area of uterine tube that opens

into uterus 4. Transports secondary oocytes toward

uterus 5. Produces secondary oocytes; produces

estrogen and progesterone 6. Layer of uterus that sheds during

menstruation; implantation of zygote and development of fetus occurs here

Figure 39.8

1. secondary oocyte 2. sperm cell 3. ovum 4. zygote 5. oogonium 6. primary oocyte 7. meiosis I 8. 1st polar body 9. 2nd polar body 10. meiosis II

Figure 39.9(a, b, c, & e)

1. primordial follicles 2. primary follicles 3. secondary follicle 4. secondary oocyte 5. graafian (mature) follicle 6. ovulated secondary oocyte 7. corpus luteum 8. corpus albicans 9. primordial follicles

Appendix A: Word Roots

709

WORD ROOT DEF IN IT ION

NOUNS AND/OR ADJECT IVES FORMED FROM WORD ROOT AND A SUFF IX

WORDS FORMED BY COMBIN ING WORD ROOT WITH ANOTHER WORD ROOT, PREF IX AND/OR SUFF IX

abdomin-

acromi-

axill-

brachi-

bucc-

calcane-

carp-

cervic-

cox-

crani-

cubit-

digit-

dors-

faci-

fibul-

front-

glute-

lumb-

ment-

abdomen

high point of shoulder armpit

arm

cheek

heel

wrist bones

neck or neck-like structure hip

cranium

elbow or ulna

finger or toe

back

face

lateral leg

forehead

buttocks

lower back or loin

mind or chin

Noun: abdominis Adjective: abdominal Noun: acromion (sing.) Adjective: acromial Noun: axilla (sing.) and axillae (pl.) Adjective: axillary Noun: brachium (sing.) and brachia (pl.) Adjective: brachial Noun: bucca (sing.), buccae (pl.) Adjective: buccal Noun: calcaneus (sing.) and calcanei (pl.) Adjective: calcaneal Noun: carpus (sing.) and carpi (pl.) Adjective: carpal Noun: cervix (sing.) and cervices (pl.) Adjective: cervical Noun: coxa (sing.) and coxae (pl.) Adjective: coxal Noun: cranium (sing.), crania (pl.) Adjective: cranial Noun: cubitus (sing.), cubiti (pl.) Adjective: cubital Noun: digit and digitus (sing.) and digiti (pl.) Adjective: digital Noun: dorsum (sing.) and dorsa (pl.) Adjective: dorsal Noun: facies (sing.) Adjective: facial Noun: fibula Adjective: fibular Noun: frons (sing.) Adjective: frontal Noun: gluteus Adjective: gluteal Noun: lumbus (sing.) and lumbi (pl.) Adjective: lumbar Noun: mentum (sing.) Adjective: mental

abdominopelvic

acromioscapular

axillofemoral

brachiocephalic, antebrachium

buccinator

calcaneofibular

carpectomy

cervicothorax, cervicectomy, cervicitis

coxalgia

craniosacral, craniofacial

antecubital

digitation

dorsiflexion

facioplasty

fibulocalcaneal

frontonasal

gluteofemoral

lumbago, lumbosacral

mentalis muscle, mental foramen

710 A P P E N D I X A : W O R D R O O T S

nas-

occipit-

olecran-

or-

orbit-

ot- palm -

patell-

pector-

ped-

pelvi-

plant-

pub-

scapul-

stern-

tars-

thorac-

umbilic-

vertebr-

nose

back of head

proximal projection of ulna mouth

eye

ear flexor surface of hand kneecap

breast or chest

foot or child

pelvis, basin

sole of foot

pubis or genital area scapula (shoulder bone) chest

ankle bones or edge of eyelid chest

navel

vertebra, spinal column

Noun: nasus (sing.) Adjective: nasal Noun: occipitis, occiput (sing.) Adjective: occipital Noun: olecranon (sing.) and olecrana (pl.) Adjective: olecranal

Noun: oris (sing.) Adjective: oral Noun: orbit (sing ), orbitae (pl.) Adjective: orbital Adjective: otic Noun: palm and palma (sing.) and palmae (pl.) Adjective: palmar Noun: patella (sing.) and patellae (pl.) Adjective: patellar Noun: pectus (sing.) and pectora (pl.) Adjective: pectoral Noun: pes (sing.) and pedes (pl.) Adjective: pedal Noun: pelvis (sing.) and pelves (pl.) Adjective: pelvic Noun: planta (sing.) and plantae (pl.) Adjective: plantar Noun: pubis (sing.) Adjective: pubic Noun: scapula (sing.) and scapulae (pl.) Adjective: scapular Noun: sternum (sing.) Adjective: sternal Noun: tarsus (sing.) and tarsi (pl.) Adjective: tarsal Noun: thorax (sing.) and thoraces (pl.) Adjective: thoracic Noun: umbilicus (sing.) and umbilici (pl.) Adjective: umbilical Noun: vertebra (sing.) and vertebrae (pl.) Adjective: vertebral

nasopharynx, nasosinusitis

occipitofrontal, occipitomental

olecranarthropathy

oropharynx

orbitonasal

otitis, otolaryngology palmature

patellectomy

pectoralgia

pedicle, pedometer

pelvioperitonitis, abdominopelvic

plantarflexion, plantaris

puberty

scapulectomy

sternocleidomastoid

tarsometatarsal, tibiotarsal

thoracolumbar

umbilication

vertebroarterial

WORD ROOT DEF IN IT ION

NOUNS AND/OR ADJECT IVES FORMED FROM WORD ROOT AND A SUFF IX

WORDS FORMED BY COMBIN ING WORD ROOT WITH ANOTHER WORD ROOT , PREF IX AND/OR SUFF IX

Appendix B: Skeletal Muscle Origins and Insertions

711

Occipitofrontalis muscle Frontalis Occipitalis

Orbicularis oculi Zygomaticus minor Zygomaticus major Orbicularis oris Platysma

MUSCLES OF MASTICATION Superficial Muscles Temporalis Masseter

Deep Muscles Buccinator

Lateral pterygoid

Medial pterygoid

Anterior and Lateral Muscles Sternocleidomas toid Scalenes

Posterior Muscles Splenius capititis

Trapezius (superior portion)

Levator scapulae

MUSCLES OF FACIAL EXPRESSION

Skin superior to supraorbital margin Galea (epicranial) aponeurosis

Skin around margin of orbit Upper lip Skin at angle of mouth and orbicularis oris Skin at corner of mouth Mandible, muscles around angle of

mouth, and skin of lower face

Coronoid process and ramus of mandible Ramus and angle of mandible

Orbicularis oris

Mandibular condyle; temporomandibu- lar joint (TMJ)

Ramus and angle of mandible

Mastoid process of temporal bone Ribs 1 and 2

Occipital bone and mastoid process of temporal bone

Clavicle, acromion (process) of scapula, and spine of scapula

Superior vertebral border of scapula

Galea (epicranial) aponeurosis Occipital bone and mastoid process

of temporal bone Medial wall of orbit Zygomatic bone Zygomatic bone Muscle fibers surrounding mouth Fascia covering deltoid and

pectoralis major

Temporal bone Maxilla and zygomatic arch

Alveolar processes of maxilla and mandible

Greater wing of sphenoid and lat- eral part of pterygoid process of sphenoid bone

Medial part of pterygoid process of sphenoid bone and maxilla bone

Sternum and clavicle Transverse processes of vertebrae

C3 through C7

Ligamentum nuchae and spinous processes of vertebrae C7 through T4

Occipital bone, ligamentum nuchae, and spines of vertebrae C7 through T12

Vertebrae C1–C5

MUSCLES THAT MOVE THE HEAD AND NECK

TABLE B1 Muscles of the Head and Neck MUSCLE OR IG IN INSERT ION

MUSCLE THAT ONLY MOVES THE SCAPULA

712 A P P E N D I X B : S K E L E T A L M U S C L E O R I G I N S A N D I N S E R T I O N S

Deltoid tuberosity of humerus

Greater tubercle and intertubecular sulcus of humerus

Lesser tubercle of humerus

Vertebral border of scapula and inferior angle of scapula

Coracoid process of scapula

Cartilage of ribs 5–7 and the xiphoid process

Iliac crest and linea alba

Cartilage of ribs 9–12 and linea alba

Xiphoid process, linea alba, and pubis

Superior border of rib inferior to muscle

Inferior border of rib superior to muscle

Central tendon

Anterior fibers: acromial end of clavicle Lateral fibers: acromion of scapula Posterior fibers: spine of scapula

Clavicle (clavicular head), sternum, and costal cartilages of ribs 2–6 (sternocostal head)

Subscapular fossa of scapula

Ribs 1–9

Ribs 2–5, 3–5, or 2–4

Pubic crest and pubic symphysis

Ribs 5–12

Iliac crest, inguinal ligament, and thoracolumbar fascia

Iliac crest, inguinal ligament, lumbar fascia, and cartilage of ribs 7–12

Inferior border of rib superior to muscle

Superior border of rib inferior to muscle

Xiphoid process of sternum, costal cartilages of inferior six ribs, and lumbar vertebrae

MUSCLES THAT MOVE THE ARM AT THE SHOULDER JOINT

MUSCLE OR IG IN INSERT ION

Superficial muscles Deltoid

Pectoralis major

Deep muscle Subscapularis

Serratus anterior

Pectoralis minor

Superficial muscles Rectus abdominis

External oblique

Deep muscles Internal oblique

Transversus abdominis

MUSCLES USED IN BREATHING Deep muscles External intercostals

Internal intercostals

Diaphragm

TABLE B2 Muscles of the Anterior Trunk

MUSCLE OR IG IN INSERT ION

Suprahyoid muscles Digastric Anterior belly

Posterior belly Stylohyoid Mylohyoid

Infrahyoid Muscles Omohyoid Sternohyoid

Body of hyoid bone

Body of hyoid bone Body of hyoid bone Body of hyoid bone

Body of hyoid bone Body of hyoid bone

Inner surface of inferior border of mandible

Mastoid process of temporal bone Styloid process of temporal bone Inner surface of mandible

Superior border of scapula Manubrium and medial end of clavicle

MUSCLES THAT MOVE HYOID BONE

TABLE B1 (Continued)

MUSCLES THAT MOVE THE ABDOMINAL WALL

MUSCLES THAT MOVE THE SCAPULA

A P P E N D I X B : S K E L E T A L M U S C L E O R I G I N S A N D I N S E R T I O N S 713

Biceps brachii

Brachialis

POSTERIOR SURFACE Triceps brachii

Radial tuberosity of radius

Ulnar tuberosity and coronoid process of ulna

All three heads insert on the olecranon of ulna

Long head: tubercle superior to glenoid cavity of scapula

Short head: coracoid process of scapula

Anterior surface of distal humerus

Long head: inferior to glenoid cavity of scapula

Medial head: posterior humerus inferior to groove for radial nerve

Lateral head: posterior surface of lateral humerus superior to radial groove

TABLE B4 Muscles of the Arm MUSCLE OR IG IN INSERT ION

ANTERIOR SURFACE

Superficial muscles Deltoid Infraspinatus Teres minor Teres major Latissimus dorsi

Deep muscles Supraspinatus

Superficial muscle Trapezius

Deep muscles Levator scapulae Rhomboideus minor

Rhomboideus major

Erector spinae consists of iliocostalis, longissiumus, and spinalis groups

Deltoid tuberosity of humerus Greater tubercle of humerus Greater tubercle of humerus Intertubercular sulcus of humerus Intertubercular sulcus of humerus

Greater tubercle of humerus

Clavicle, acromion of scapula, and spine of scapula

Superior vertebral border of scapula Vertebral border of scapula superior to

spine Vertebral border of scapula inferior to

spine

Skull, ribs, and cervical, thoracic, and lumbar vertebrae

Posterior fibers: spine of scapula Infraspinous fossa of scapula Inferior lateral border of scapula Inferior angle of scapula Spines of T7–T12 vertebrae, lumbar

vertebrae, crests of sacrum and ilium, ribs 9–12

Supraspinous fossa of scapula

Occipital bone, ligamentum nuchae, and spines of vertebrae C7–T12

Vertebrae C1–C5 Spines of vertebrae C7 and T1

Spines of vertebrae T2–T5

Large group of muscles with origins on ribs, iliac crest, and cervical, thoracic, and lumbar vertebrae

MUSCLES THAT MOVE THE ARM AT THE SHOULDER JOINT

MUSCLES THAT MOVE THE VERTEBRAL COLUMN

TABLE B3 Muscles of the Posterior Trunk MUSCLE OR IG IN INSERT ION

MUSCLES THAT MOVE THE SCAPULA

714 A P P E N D I X B : S K E L E T A L M U S C L E O R I G I N S A N D I N S E R T I O N S

ANTERIOR SURFACE Superficial muscles (lateral to medial ) Brachioradialis Pronator teres

Flexor carpi radialis Palmaris longus

Flexor carpi ulnaris

Flexor digitorum superficialis

Deep muscles Supinator

Flexor pollicis longus

POSTERIOR SURFACE Superficial muscles (medial to lateral ) Extensor carpi ulnaris

Extensor digitorum Extensor carpi radialis longus and brevis

POSTERIOR SURFACE Deep muscles Supinator

Extensor pollicis longus

Superior to styloid process of radius Midlateral surface of radius

2nd and 3rd metacarpals Flexor retinaculum and palmar

aponeu rosis Pisiform, hamate, and base of 5th

metacarpal

Middle phalanx of each finger

Lateral surface of proximal one-third of radius

Base of distal phalanx of thumb

5th metacarpal

distal and middle phalanges of each finger 3rd metacarpal

2nd metacarpal

Lateral surface of proximal one-third of radius

Distal phalanx of thumb

Distal lateral border of humerus Medial epicondyle of humerus and

coronoid process of ulna Medial epicondyle of humerus Medial epicondyle of humerus

Medial epicondyle of humerus and superior posterior border of humerus

Medial epicondyle of humerus, coronoid process of ulna, and anterior surface of radius

Lateral epicondyle of humerus and ridge near radial notch of ulna (supinator crest)

Anterior surface of radius and interosseous membrane

Lateral epicondyle of humerus and posterior ulna

Lateral epicondyle of humerus Brevis: lateral epicondyle of

humerus Longus: lateral supracondylar ridge

of humerus

Lateral epicondyle of humerus and ridge near radial notch of ulna

Posterior surface of middle of ulna, and interosseous membrane

TABLE B5 Muscles of the Forearm MUSCLE OR IG IN INSERT ION

A P P E N D I X B : S K E L E T A L M U S C L E O R I G I N S A N D I N S E R T I O N S 715

ANTERIOR SURFACE (lateral to medial ) Tensor fasciae latae Quadriceps femoris

Rectus femoris Vastus lateralis

Vastus medialis Vastus intermedius

Sartorius

Iliopsoas Psoas major

Iliacus Pectineus

Adductor longus Adductor magnus

Adductor brevis Gracilis

POSTERIOR SURFACE Gluteus maximus

Gluteus medius Gluteus minimus Piriformis

Hamstrings Biceps femoris

Semitendinosus Semimembranosus

Iliotibial tract (fascia) Patella (quadriceps tendon) and tibial

tuberosity (patellar ligament)

Medial surface of body of tibia

Psoas major and iliacus insert together into lesser trochanter of femur

Pectineal line of femur between lesser trochanter and linea aspera

Linea aspera of femur Linea aspera of femur

Proximal linea aspera of femur Medial surface of body of tibia

Greater trocanter of femur and iliotibial tract

Greater trochanter of femur Greater trochanter of femur Superior border of greater trochanter

of femur

Head of fibula and lateral condyle of tibia

Medial surface of proximal part of tibia Medial condyle of tibia

Iliac crest

Anterior inferior iliac spine Greater trochanter and linea aspera

of femur Linea aspera of femur Anterior and lateral surface of body

of femur Anterior superior iliac spine

Psoas major: Transverse processes and bodies of lumbar vertebrae

Iliacus: Iliac fossa Superior ramus of pubis

Pubic crest and pubic symphysis Inferior ramus of pubis and ischium

to ischial tuberosity Inferior ramus of pubis Pubic symphysis and pubic arch

Iliac crest, sacrum, and coccyx

Ilium Ilium Anterior sacrum

Long head: ischial tuberosity Short head: linea aspera of femur Ischial tuberosity Ischial tuberosity

TABLE B6 Muscles of the Thigh MUSCLE OR IG IN INSERT ION

716 A P P E N D I X B : S K E L E T A L M U S C L E O R I G I N S A N D I N S E R T I O N S

ANTERIOR AND LATERAL SURFACE Superficial muscles Tibialis anterior

Extensor digitorum longus

Fibularis (peroneus) longus

POSTERIOR SURFACE Superficial muscles Gastrocnemius Soleus

POSTERIOR SURFACE Deep muscles Flexor digitorum longus Flexor hallucis longus

1st metatarsal and 1st (medial) cuneiform (tarsal bone)

Middle and distal phalanges 2–5

1st metatarsal and 1st (medial) cuneiform

Calcaneus via calcaneal tendon Calcaneus via calcaneal tendon

Distal phalanges 2–5 Distal phalanx of great toe

Lateral condyle and body of tibia and interosseous membrane

Lateral condyle of tibia, anterior fibula, and interosseous membrane

Lateral condyle of tibia and head and body of fibula

Lateral and medial condyles of femur Medial tibia and head of fibula

Posterior tibia Inferior fibula

TABLE B7 Muscles of the Leg and Foot MUSCLE OR IG IN INSERT ION

A P P E N D I X C : M E A S U R E M E N T S S 717

Appendix C: Measurements

717

RELAT ION TO S I (METR IC ) PARAMETER UNIT OTHER U .S . UN ITS EQUIVALENT

Length inch 1/12 foot 2.54 centimeters foot 12 inches 0.305 meter yard 36 inches 0.914 meter mile 5,280 feet 1.609 kilometers Mass grain 1/1,000 pound 64.799 milligrams dram 1/16 ounce 1.772 grams ounce 16 drams 28.350 grams pound 16 ounces 453.6 grams ton 2,000 pounds 907.18 kilograms Volume (Liquid) ounce 1/16 pint 29.574 milliliters pint 16 ounces 0.473 liter quart 2 pints 0.946 liter gallon 4 quarts 3.785 liters Volume (Dry) pint 1/2 quart 0.551 liter quart 2 pints 1.101 liters peck 8 quarts 8.810 liters bushel 4 pecks 35.239 liters

U.S. Customary System

BASE UNITS PREF IXES

UNIT QUANT ITY SYMBOL PREF IX MULT IPL IER SYMBOL

meter length m tera- 1012 � 1,000,000,000,000 T kilogram mass kg giga- 109 � 1,000,000,000 G second time s mega- 106 � 1,000,000 M liter volume L kilo- 103 � 1,000 k mole amount of matter mol hecto- 102 � 100 h deca- 101 � 10 da deci- 10�1 � 0.1 d centi- 10�2 � 0.01 c milli- 10�3 � 0.001 m micro- 10�6 � 0.000,001 � nano- 10�9 � 0.000,000,001 n pico- 10�12 � 0.000,000,000,001 p

International System (SI)

718 A P P E N D I X C : M E A S U R E M E N T S

FAHRENHE IT ( F ) TO CELS IUS (C )

CELS IUS (C ) TO FAHRENHE IT ( F )

�C � (�F � 32) � 1.8

�F � (�C � 1.8) � 32

Temperature Conversion

WHEN YOU KNOW MULT IPLY BY TO F IND

inches 2.54 centimeters feet 30.48 centimeters yards 0.91 meters miles 1.61 kilometers ounces 28.35 grams pounds 0.45 kilograms tons 0.91 metric tons fluid ounces 29.57 milliliters pints 0.47 liters quarts 0.95 liters gallons 3.79 liters

U.S. to SI (Metric) Conversion

WHEN YOU KNOW MULT IPLY BY TO F IND

millimeters 0.04 inches centimeters 0.39 inches meters 3.28 feet kilometers 0.62 miles liters 1.06 quarts cubic meters 35.32 cubic feet grams 0.035 ounces kilograms 2.21 pounds

SI (Metric) to U.S. Conversion

Photo Credits

719

Front Cover

Illustration by Bryan Christie Design

Exercise 1

Figure 1.7a: Simon Fraser/Photo Researchers*; Figure 1.7b: Alfred Pasieka/ Photo Researchers

Exercise 2

Figure 2.5a: CNRI/Phototake; Figure 2.5b: © Benedet/Phototake; Figure 2.5c: Geoff Tompkinson/Photo Researchers; Figure 2.5d: CNRI/Photo Researchers

Exercise 3

Figure 3.1: Dan Ahn/iStockphoto; Figure 3.3: Bruce Iverson/Photo Researchers

Exercise 4

Figure 4.1b: Steve Gschmeissner/Photo Researchers; Figure 4.2a, 4.2b, 4.2f: Courtesy Michael Ross, University of Florida; Figure 4.2c: Carolina Biological Supply Company/Phototake; Figure 4.2d: M. Abbey/Photo Researchers; Figure 4.2e: Robert Becker, Ph.d./Custom Medical Stock Photo, Inc.; Figure 4.4a, 4.4b, 4.4c, 4.4d, 4.4e: Courtesy Michael Ross, University of Florida; Figure 4.5: Don Fawcett/Photo Researchers

Exercise 5

Figure 5.3a, 5.3b, 5.3c: David Phillips / Photo Researchers

Exercise 6

Figure 6.4a, 6.4b, 6.5a, 6.5b, 6.6a, 6.6b, 6.7a, 6.7b, 6.8a, 6.8b, 6.9a, 6.9b, 6.11, 6.12, 6.13, 6.14, 6.15, 6.16, 6.17, 6.18,

Exercise 11

Figure 11.3a, 11.3c, 11.3d, 11.9c: Dissection Shawn Miller, Photograph Mark Nielsen

Exercise 12

Figure 12.2a, 12.2b, 12.8: Courtesy Michael Ross, University of Florida; Figure 12.2c: MedImage/Photo Researchers; Figure 12.5: Dr. Clara Franzini-Armstrong; Figure 12.6a, 12.6b, 12.6c, 12.9-11, 12.9-12, 12.9-13 Courtesy Hiroyouki Sasaki, Yale E. Goldman and Clara Franzini-Armstrong

Exercise 13

Figure 13.1: Biophoto Associates/Photo Researchers

Exercise 14

Figure 14.1a, 14.1b, 14.1c, 14.2, 14.4, 14.5a, 14.7a, 14.7b, 14.8a, 14.8b: Dissection Shawn Miller; Photograph Mark Nielsen; Figure 14.3b, 14.3c, 14.3d, 14.3e, 14.5b, 14.7e: Dissection Nathan Mortensen and Shawn Miller, Photograph Mark Nielsen

Exercise 15

Figure 15.1a, 15.1b, 15.1c, 15.2d, 15.2f, 15.3a, 15.3b, 15.3e, 15.3f: © John Wiley & Sons, Inc.; Figure 15.3a: Andy Washnik / © John Wiley & Sons, Inc.

Exercise 16

Figure 16.2a, 16.4a, 16.7: Courtesy Michael Ross, University of Florida; Figure 16.2b: Jan Leesma/Cutom Medical Stock Photo, Inc.; Figure 16.4b: Cavallini James/BSIP/Phototake; Figure 16.8a: © Glauberman/Photo Researchers; Fig. 16.8b: ISM/Phototake

6.19, 6.20, 6.21, 6.22, 6.24, 6.25, 6.26a, 6.26b, 6.30-6, 6.30-17, 6.31-1, 6.31-3: Courtesy Michael Ross, University of Florida; Figure 6.28: Jan Leesma/Custom Medical Stock Photo, Inc.; Figure 6.29-13, 6.29-14, 6.29-15, 6.30-4, 6.30-5, 6.30- 8, 6.30-10, 6.3-12, 6.31-4: Ed Reschke; Figure 6.29-12, 6.30-1, 6.30-2, 6.30-3, 6.30-9, 6.30-11, 6.30-13, 6.30-14, 6.30-15, 6.30-16, 6.30-18: Biophoto Associates/ Photo Researchers; Figure 6-30-7: Andrew Kutzman; Figure 6.31-2 ISM/ Phototake

Exercise 7

Figure 7.2, 7.3, 7.5: Courtesy Michael Ross, University of Florida; Figure 7.7a, 7.7c: Photo Researchers; Figure 7.7b: David Becker/Photo Researchers

Exercise 8

Figure 8.4: Lester V. Bergman/Corbis Images; Figure 8.5: PDSN/Phototake; Figure 8.6a: Mehau Kulyk/Photo Researchers; Figure 8.6b: Scott Camazine & Sue Trainor/Photo Researchers; Figure 8.7a: Photo Researchers; Figure 8.7b: P. Motta/Photo Researchers

Exercise 9

Figure 9.26a: Photo Researchers; Figure 9.26b: AFIP/Photo Researchers; Figure 9.27a, 9.27b: Courtesy Chaim J. Margolin

Exercise 10

Figure 10.13a: Larry Mulvehill/Photo Researchers; Figure 10.13b: © Robert Destefano/Alamy; Figure 10.13c: Photo Researchers; Figure 10.14a: Kevin Dodge/ Masterfile; Figure 10.14b: Dick Luria/ Photo Researchers

All photos in this Laboratory Manual 5e are by Mark Nielsen with the following exceptions:

* Photo Researchers is now named Science Source.

720 P H O T O C R E D I T S

Exercise 17

Figure 17.2b: Dissection Shawn Miller, Photograph Mark Nielsen; Figure 17.5: Carolina Biological Supply Company/ Phototake

Exercise 18

Figure 18.2 Courtesy of Dr. Michael Ross

Exercise 20

Figure 20.2b, 20.3b, 20.4a, 20.6, 20.9: Dissection Shawn Miller, Photograph Mark Nielsen; Figure 20.17: Stephen A. Kieffer

Exercise 21

Figure 21.1, 21.2: Dissection Shawn Miller, Photograph Mark Nielsen

Exercise 24

Figure 24.5 Courtesy of William Radke, University of Central Oklahoma; Figure 24.6: Scott Camazine/Photo Researchers; Figure 24.7b, 24.8b, 24.15a, 24.15b, 24.19: Courtesy of Michael Ross, University of Florida; Figure 24.20a, 24.20b: Schleichkorn/Custom Medical Stock Photo, Inc.

Exercise 25

Figure 25.2b, 25.2c, 25.6c, 25.8c: Courtesy Michael Ross, University of Florida; Figure 25.3a, 25.3b, 25.7: Dissection Shawn Miller, Photograph Mark Nielsen

Exercise 26

Figure 26.1a: Martin M. Rotker/Photo Researchers; Figure 26.1b: Rapho Agence de Presse/Phototake; Figure 26.2a, 26.2b, 26.2c1, 26.2c2, 26.2c3, 26.2d1, 26.2d2, 26.2d3, 26.2e1, 26.2e2: Courtesy Michael Ross, University of Florida; Figure 26.2d4: Hossler, Ph.D./Custom Medical Stock Photo, Inc.; Figure 26.4: James Hayden/ Phototake; Figure 26.6: JC REVY/ISM/ Phototake; Figure 26.7: From Lennart Nilsson, Our Body Victorious, Boehringer Ingelheim International GmbH. Reproduced with permission.

Exercise 27

Figure 27.3a, 27.6a, 27.6b: Dissection Shawn Miller, Photograph Mark Nielsen; Figure 27.9: Ed Reshke

Exercise 29

Figure 29.1: From Phelps, P.C., and J. H. Luft. Am. J. Anat. 125:399, 1969; Figure 29.4: Carolina Biological Supply Company/Phototake; Figure 29.5: Collection CNRI/Phototake; Figure 29.6a: Dennis Kunkel/Phototake; Figure 29.6b: Don W. Fawcett/Photo Researchers; Figure 29.6c: Biophoto Associates/Photo Researchers

Exercise 30

Figure 30.1, 30.4: Dissection Shawn Miller, Photograph Mark Nielsen; Figure 30.18: CNRI/Photo Researchers

Exercise 31

Figure 31.1c: Astrid & Hanns-Frieder Michler/Photo Researchers; Figure 31.5b: Leroy, Biocosmos/Photo Researchers; Figure 31.5c, 31.7: Courtesy Michael Ross, University of Florida; Figure 31.9a: Arnold Brody/Photo Researchers; Figure 31.11: John Greim/Photo Researchers

Exercise 32

Figure 32.4a, 32.4b, 32.8b: Dissection Shawn Miller, Photograph Mark Nielsen; Figure 32.4f: CNRI/Photo Researchers; Figure 32.9a: Lester V. Bergman/© Corbis; Figure 32.9b: Biophoto Associates/ Photo Researchers; Figure 32.10a: Ed Reschke; Figure 32.10b: Martin Rotker/ Phototake; Figure 32.10c: Ida Wyman/ Phototake; Figure 32.11: CNRI/Science Photo Library/Photo Researchers; Figure 32.12: CNRI/Phototake

Exercise 33

Figure 33.2: Science Photo Library/ Custom Medical Stock Photo, Inc.

Exercise 34

Figure 34.1, 34.3b, 34.6, 34.7, 34.10: Dissection Shawn Miller, Photograph Mark Nielsen; Figure 34.11a, 34.11d, 34.11e: Courtesy Michael Ross, University

of Florida; Figure 34.11b: Ed Reschke; Figure 34.11c: Biophoto Associates/Photo Researchers; Figure 34.13: Alfred Pasieka/ Photo Researchers; Figure 34.14: CNRI/ Science Photo Library/Photo Researchers

Exercise 36

Figure 36.8: Courtesy Dr. William Benyak; Figure 36.9a, 36.9b, 36.10: Courtesy Michael Ross, University of Florida; Figure 36.11: Clinical Radiology Dept./Photo Researchers

Exercise 37

Figure 37.3a, 37.3b, 37.3c, 37.3f, 37.3g, 37.3h: Custom Medical Stock Photo, Inc.; Figure 37.3d, 37.3e: Reprinted with permission of John Wiley & Sons, Inc.

Exercise 38

Figure 38.2, 38.3, 38.4, 38.7: Dissection Shawn Miller, Photograph Mark Nielsen; Figure 38.10: Ed Reschke

Exercise 39

Figure 39.1, 39.4: Dissection Shawn Miller, Photograph Mark Nielsen; Figure 39.9c: Biophoto Associates/ Photo Researchers; Figure 39.9e: Claude Edelmann/Photo Researchers; Figure 39.10: Courtesy of Andrew J. Kuntzman

Exercise 40

Figure 40.6a, 40.6g, 40.6h: Photo provided courtesy of Kohei Shiota, Congenital Anomaly Research Center, Kyoto University, Graduate School of Medicine; Figure 40.6b, 40.6c, 40.6d, 40.6e: Courtesy National Museum of Health and Medicine, Armed Forces Institute of Pathology; Figure 40.6f: From Lennart Nilsson, Our Body Victorious, Boehringer Ingelheim International GmbH. Reproduced with permission.

Exercise 41

Figure 41.2a A. Lowrey/Custom Medical Stock Photo, Inc.; Figure 41.2b Rob Lewine/Getty Images, Inc.; Figure 41.7 Omikron/Photo Researchers; Figure 41.11a, 41.11b Custom Medical Stock Photo, Inc.

721

A A bands, 178, 178f, 179f Abdomen:

MRI of, 22f radiograph of, 22f surface anatomy of, 240, 240f–241f veins of, 493, 494f, 495t

Abdominal (term), 2t Abdominal aorta, 14f, 240, 486f, 487t Abdominal cavity, 16, 16f Abdominal wall, muscles controlling, 205, 206t,

207f Abdominopelvic cavity, 16 Abdominopelvic regions and quadrants, 18, 18f Abducens nerve:

function, distribution, action of, 327, 327t, 328t

location of, 323, 324t, 325f, 326f sheep brain, 315f

Abduction, 164t, 166f Abductor digiti minimi, 215f Abductor pollicis brevis, 215f Abductor pollicis longus, 217f Abnormal vertebral curvatures, 128, 128f ABO blood typing system, 420–422, 420f, 422f

color dominance and, 679–680, 679f Accessory digestive organs, 561, 562f, 573–574,

574f–578f, 576 Accessory eye structures, 360, 360f Accessory hemiazygos vein, 493, 494f, 494t Accessory (cranial) nerve:

function, distribution, action of, 327, 327t, 328t

location of, 323, 324t, 325f, 326f Accessory pancreatic duct, 576, 577f, 578f Accessory reproductive structures, male, 632,

632f–635f A cells (alpha cells), 398, 399f Acetabulum, 144, 145f, 146f Acetylcholine, 180 Achilles refl ex (ankle jerk), 294 Achilles (calcaneal) tendon, 254, 254f ACL (anterior cruciate ligament), 162, 163f Acromial (term), 2t Acromial end (clavicle), 138, 138f Acromioclavicular joint, 246, 246f–247f Acromion of scapula, 138, 139f, 171f, 242,

242f–243f, 246, 246f–247f Acrosome, 636 ACTH, see Adrenocorticotropic hormone Actin, 176 Active processes, 41

Anal canal (anal column), 570, 571f Anaphase, of mitosis, 35, 35t, 36f Anastomoses, 479, 493 Anatomical language:

anatomical terms, 1–3, 2t, 3f body planes and sections, 5–6, 5f directional terms, 4, 4t

Anatomical neck (humerus), 140, 141f Anatomical position, 1 Anatomical snuffbox, 250, 251f Anatomical terms, 1–3, 2t, 3f Androgens, 396, 400t Anemia, 412, 417 Angiogram, 506f Angular joint movement, 164t Animals. See also specifi c animals

blood vessels of, 498 digestive system of, 582 endocrine system of, 401 respiratory system of, 540 urinary system of, 606

Ankle: Achilles refl ex, 294 bones of, 150, 150f movement of joint, 167f surface anatomy of, 252, 254

Ankle jerk, 294 Annulus fi brosus, 123 ANS, see Autonomic nervous system Antebrachial (term), 2t Antecubital (term), 2t Antecubital region, 248, 248f–249f Antefl exion position of uterus, 646 Anterior (directional term), 4f, 4t Anterior border (crest) of tibia, 252, 253f Anterior cardiac vein, 440f Anterior cerebral arteries, 482, 482t, 483f Anterior chamber (eyeball), 363, 363f Anterior communicating artery, 482, 482t, 483f Anterior cranial fossae, 310 Anterior cruciate ligament (ACL), 162, 163f Anterior gray horns, 272, 273f Anterior inferior iliac spine, 144, 145f Anterior interventricular branch (LAD), 440,

440f, 441f Anterior interventricular sulcus, 432, 433f, 434f

sheep, 444f, 445f Anterior median fi ssure (spinal cord), 272, 272f,

273f Anterior pituitary (adenohypophysis), 392, 393f,

400t Anterior ramus, 280, 281f

Adaptation, of sensory receptors, 352–353 Adduction, 164t, 166f Adductor brevis, 218, 218t, 219f Adductor longus, 218, 218t, 219f, 252, 253f Adductor magnus, 218, 218t, 219f Adductor pollicis, 215f Adenohypophysis, 392, 393f, 400t ADH, see Antidiuretic hormone Adipocytes, 60, 63f Adipose capsule, 597, 599f Adipose tissue, 60, 63f, 63t Adjuster knobs (mechanical stage), 24, 25f Adjustment knob (condenser), 24 Adrenal cortex, 396, 397f, 400t Adrenal glands, 391, 392f, 396, 396f–397f,

400t–401t Adrenal medulla, 396, 397f, 401t Adrenocorticotropic hormone (ACTH), 392,

400t Adventitia, 563, 580f, 608, 608f Aerobic cellular respiration, 188–189 Afferent arteriole, 602, 603f, 604f Afferent neurons, see Sensory neurons Afferent vessels, 514, 514f Afterbirth, 666 Agglutinated blood, 420 Agranular leukocytes, 412 Alae, 127, 127f Albuminuria, 620t Aldosterone, 396, 400t, 478f, 618, 618f Alimentary canal, see Digestive system Allantois, 664, 667f Alleles, 675–676 Alpha brain waves, 310, 310f Alpha cells (A cells), 398, 399f Alveolar ducts, 534, 535f, 538t Alveolar (intrapulmonic) pressure, 548 Alveolar sacs, 534, 535f Alveoli:

mammary glands, 650, 650f mandible, 113 maxillae, 113 respiratory system, 54f, 534, 535f tooth sockets, 160f

Amino acids, 590, 590t Amnion, 664, 665f, 667f Amniotic fl uid, 667f Ampulla:

ductus deferens, 630, 630f–632f, 632 ear, 372, 372f uterine tube, 644, 644f, 645f

Amylases, 590

Index

722 I N D E X

Anterior root, 272, 272f, 273f, 279 Anterior superior iliac spine, 144, 145f, 240,

240f–241f Anterior tibial artery, 488, 488t, 489f Anterior tibial veins, 496, 496f, 497t Anterior triangle, 198, 236, 237f Anterior white column (spinal cord), 272, 273f Anterolateral (spinothalamic) pathway, 349f Antibodies, 420, 518, 524f Antibody-mediated immunity, 518, 524f Antidiuretic hormone (ADH), 392, 400t, 478f,

618, 618f Antigens, 420 Antigenic molecules, 420 Antisera, 420 Anus, 562f, 570, 571f, 648f Aorta, 14f, 434, 434f, 435f

abdominal, 240, 486f, 487t ascending, 434, 434f, 435f, 437f, 480, 480f,

481t descending, 396f, 434, 435f, 486, 486f, 487f,

487t major arteries of, 480, 480f, 481t sheep heart, 444f, 446f thoracic, 481f, 486, 486f, 487t

Aortic arch, 238, 434, 434f, 435f, 440f major arteries of, 480, 480f, 481f, 481t sheep heart, 445f

Aortic (semilunar) valves, 436, 436f–437f, 456, 456f

Apical foramen, 573, 575f Apical surface, epithelial tissues, 52 Apocrine glands, 86, 87f Appendicular (term), 2t Appendicular skeleton, 105, 137, 138t

lower limbs, 137, 147, 148f–151f, 151–152, 151t

pectoral girdle, 137, 138, 139f pelvic girdle, 137, 144, 145f, 146f upper limbs, 137, 140, 141f–143f, 143

Appendix, 511, 512f, 519f, 570, 571f surface anatomy, 240

Aqueous humor, 363 Arachnoid mater, 269, 270f, 274f, 310, 311f Arachnoid villi, 310, 311f, 312, 312f Arachnoid villus, 313f Arbor vitae, 303, 303f Arches, fi ngerprint pattern, 90, 90f Arch of aorta, see Aortic arch Areola, 650, 650f Areolar connective tissue, 60, 60f, 62f, 63t Arm. See also Humerus; Upper limbs

body region, 1 compartments of, 211 muscles, 205, 206t, 211, 211t, 212f–213f,

214t, 215f, 216t, 217f surface anatomy, 246, 246f–249f, 248

Arm (microscope), 24, 25f Arrector pili, 86, 87f Arteries, 431, 463–464, 465f, 466f, 479

aortic arch, 434, 434f, 435f, 437f, 445f, 480, 480f, 481t

ascending aorta, 434, 434f, 435f, 480, 480f, 481f, 481t

axillary, 484, 485t basilar, 482, 482t, 483f blood distribution schematic, 504f

blood pressure in, 468 brachial, 248, 248f–249f, 484, 485t carotid, 236, 237f, 480, 480f, 481t, 482, 482t,

483f cerebral, 482, 482t, 483f communicating, 482, 482t, 483f coronary, 434, 434f, 435f, 437f descending aorta, 486, 486f, 487f, 487t dorsalis pedis, 488, 488t, 489f femoral, 488, 488t, 489f fi bular (peroneal), 488, 488t, 489f gastric, 486f, 487f, 487t hepatic, 579, 582, 582f iliac, 486, 486f, 487t, 489f lower limbs, 488, 488t, 489f pelvic, 488, 488t, 489f popliteal, 488, 488t, 489f pulmonary, 497, 497f upper limbs, 484, 484f–485f, 485t

Arterioles, 463, 464 afferent, 602, 603f, 604f efferent, 602, 603f, 604f frog, 464f

Articular capsule, 161, 161f Articular cartilage, 96, 96f, 161, 161f Articular facets, superior and inferior, 122, 122f,

123, 124f–126f Articulation (term), 159 Arytenoid cartilage, 532, 533f Ascending aorta, arteries of, 434, 434f, 435f,

437f, 440f, 480, 480f, 481f, 481t Ascending colon, 565f, 570, 570f, 571f Ascending limb (loop of Henle), 602, 603f, 606,

607f, 617 Association areas (cerebral cortex), 309, 309f Association fi bers, 306, 306f Association neurons, 260, 261f, 268f, 348,

349f Asthma, 535 Astigmatism, 369, 369f Astrocytes, 256, 257f Asynchronous contractions, 190 Atlanto-axial joint, 167f Atlanto-occipital joint, 165f Atlas (vertebra), 122, 123f, 124f, 282f ATP, and muscle contraction, 186–189, 187t,

189f Atrial depolarization and repolarization, 453 Atrioventricular (AV) node, 452, 452f Atrioventricular (AV) valves, 436, 456, 456f Atrium, 432, 434f, 437f, 441f Auditory association area, 309 Auditory canal, external, 371, 371f Auditory ossicles, 371, 371f Auditory tube (Eustachian), 371, 371f, 530,

530f, 531f Auricles, 371, 371f, 432, 433f, 434f, 437f, 440f

sheep heart, 444f–446f Auricular surfaces, 127, 127f Auscultation, 456, 456f Autonomic nervous system (ANS), 333

autonomic refl exes, 337–340, 337f, 339f effect of stress and relaxation on, 340 parasympathetic motor division, 333, 336,

336f sympathetic motor division, 333, 334, 335f

Autonomic refl exes, 289, 337f

Autonomic refl ex arc, 337, 337f Autorhythmic cells, 452 Autosomes, 675, 681, 681f AV bundle (bundle of His), 452, 452f AV (atrioventricular) node, 452, 452f AV (atrioventricular) valves, 436, 456, 456f Axial (term), 2t Axial sections, 5 Axial skeleton, 105. See also Skull; Vertebral

column hyoid bone, 120 thoracic (rib) cage, 128, 129f, 130f

Axillary (term), 2t Axillary artery, 484, 484f–485f, 485t Axillary folds (trunk), 243f Axillary nerve, 283, 283f, 283t Axillary node, 512f Axillary veins, 492, 492f, 493t Axis (vertebra), 122, 123f Axoaxonic synapses, 264 Axodendritic synapses, 264 Axon, 73, 257f, 260f, 280f

in central nervous system, 257f, 258 myelination of, 262, 262f, 263f

Axon collateral, 258, 259f Axon hillock, 258, 259f Axon terminals, 180, 180f, 258, 259f Axosomatic synapses, 264 Azygos system, 493 Azygos vein, 493, 494f, 494t, 510f

B Babinski’s sign, 294 Back, surface anatomy, 242, 242f–243f Backbone, see Vertebral column Balance test, 375t Ball-and-socket joint, 168t Barnay test, 375t Basal nuclei, 306, 307f Basal surface, epithelial tissues, 52 Base, microscope, 24, 25f Basement membrane, 52, 52f Basilar artery, 482, 482t, 483f Basilar membrane, 373, 373f Basilic veins, 248, 248f–249f, 492, 492f, 493t Basophils, 412, 413, 413t, 414f, 416t B cells (beta cells), 398, 399f B cells (lymphocytes), 518, 519f Bell jar demonstration, 549f Benign prostatic hypertrophy (BPH), 600, 632 Beta brain waves, 310, 310f Bicarbonate ions, 554 Biceps brachii, 211t, 212f, 215f, 246, 246f–249f,

248 Biceps femoris, 220f, 220t, 221f, 254, 254f Biceps refl ex (biceps jerk), 293 Bicuspid valve (mitral), 436, 436f–437f, 456f

sheep heart, 446f Bifurcated spinous process, 124f Bilaminar embryonic disc, 664, 665f Bilateral refl exes, 290 Bile, 592 Bile canaliculi, 579, 582, 582f Bile ducts, 582, 582f Bile salts, 592 Binocular lenses, 24 Bipolar cell layer, 365, 367f

I N D E X 723

C Calcaneal (term), 2t Calcaneal ligament, 224f Calcaneal (Achilles) tendon, 254, 254f Calcaneus, 149f, 254, 254f Calcitonin, 394, 400t Calcium oxide crystals, 622f Calculi, 620t Calyces, major and minor, 598, 599f Camera attachment tube, 25f Canaliculi, 61, 97, 98f, 99f Canal of Schlemm, 362, 362f, 363, 363f Cancellous bone, see Spongy bone Capillaries, 464, 466, 467f

central nervous system, 257f endothelium of, 464 lymphatic, 507, 508f, 513f peritubular, 602, 603f pulmonary, 439f

Capillary clefts, 466, 467f Capitulum of humerus, 140, 141f, 142f Capsular space, 602, 603f, 607f Capsule:

of adrenal gland, 396, 397f of thymus, 516f

Carbon dioxide, 554 Carbonic acid, 554 Cardia, 567, 568f Cardiac cycle, 451, 457–458

opening and closing of valves, 456–457, 456f

stimulation of muscle contraction, 452–454, 453f–455f

Cardiac muscle tissue, 70, 70t, 71f, 443, 443f

Cardiac notch, 536, 536f, 537f Cardiac output, 478f Cardiac veins, 440f, 441f Cardiovascular system, 14f Carina, 534, 534f Carotid artery, 236, 237f, 480, 480f, 481t, 482,

482t, 483f Carotid foramen (canal), 112, 116f Carotid pulse, 457 Carpal (term), 2t Carpals, 10f, 143f Carpal tunnel, 215f Carpus (wrist), 143, 143f

joint movement, 165f, 166f surface anatomy, 250, 251f

Cartilage, 60, 61 elastic, 61, 66f, 67t fi brocartilage, 61, 67f, 67t hyaline, 61, 66f, 67t

Cartilage plates, 535f Cartilage rings, 535f Cartilaginous joints, 160, 160f Casts, 620t Catabolization, 589 Cauda equina, 270, 271f Caudal (directional term), 4t Caudate nucleus, 307f CBC (complete blood count), 423, 423t C cells, 394, 395f Cecum, 570, 571f Celiac ganglia, 334 Celiac trunk, 486, 486f, 487f, 487t

Bone markings: appendicular skeleton, 138t axial skeleton, 113t skull, 112–113, 113t, 114f–118f, 134f, 136f

Bone marrow, 96, 96f, 511, 512f Bony labyrinth (internal ear), 372, 372f Bowman’s capsule, 54f, 602, 603f, 606, 607f Boyle’s Law, 545 BPH, see Benign prostatic hypertrophy Brachial (term), 2t Brachial artery, 484, 484f–485f, 485t

surface anatomy, 248, 248f–249f Brachialis, 211t, 212f, 215f Brachial plexus, 236, 282, 282f, 283, 283f, 283t Brachial pulse, 248 Brachial veins, 492, 492f, 493t Brachiocephalic trunk, 480, 480f, 481f, 481t,

483f Brachiocephalic veins, 491, 491f, 491t, 494f,

494t, 513f, 516f Brachioradialis muscle, 214t, 215f, 248,

248f–249f Bradycardia, 454 Brain, 299, 317f, 319f, 321f, 322f

autonomic nervous system and, 338, 339f brain stem, 299, 300f–302f, 301 cerebellum, 299, 300f, 303, 303f, 306f, 308f cerebral arterial circle in, 483f cerebrospinal fl uid, 312 cerebrum, 299, 300f, 306, 306f–309f, 308,

309 developing, 669f diencephalon, 299, 300f, 304, 304f–305f gray and white matter in, 263, 263f hypothalamus, 300f, 304, 304f–305f, 307f,

391, 392, 392f, 393f, 408f in nervous system, 268f planes and sections, 6f protection of, 310, 311f–313f, 312 regions of, 299, 300f sheep, 314, 315f, 316f ventricles of, 312, 312f–313f

Brain stem, 300f–302f, 301 medulla oblongata, 300f–303f, 301 midbrain, 300f–302f, 301 pons, 300f–303f, 301

Brain waves, 310, 310f Breathing, see Respiratory system Broad ligament of uterus, 644, 644f, 645f, 646,

647f, 648f Broca’s speech area, 309, 309f Bronchial nodule, 511 Bronchial tree, 528f, 534, 534f, 535f Bronchii, 14f, 238 Bronchioles, 534, 534f, 535f, 538t Bronchitis, 535 Bronchopulmonary segments, 534 Brunner’s (duodenal) glands, 579, 581f Brush border, 579, 581f Buccal (term), 2t Buccal (oral) cavity, 565, 566f, 567f Buccinator, 200f, 201f Bulbar conjunctiva, 360, 360f Bulbospongiosus muscle, 631f Bulbourethral (Cowper’s) glands, 632, 632f–634f Bundle of His, 452, 452f Bursa, 171f

Bipolar neurons, 260, 261f Blastocele, 662, 665f Blastocyst, 662, 663f Blastocyst cavity (blastocele), 662, 665f Blastomere, 662, 663f Blastula, 35 Blind spot, 365, 368f Blood, 60, 61, 69f, 69t. See also Platelets; Red

blood cells; White blood cells ABO and Rh typing of, 420–422, 420f, 422f blood volume, 411, 478f cell specialization, 33, 34f components of, 69f, 412, 412f, 413t, 429f glucose level, 401

Blood-brain barrier, 256 Blood pressure:

homeostasis, 478f measuring of, 468–471, 469f

Blood vessels. See also Arteries; Capillaries; Veins

of animals, 498 arterial blood distribution, 504f and blood pressure, 468–471, 469f fetal circulation, 498, 498t pulmonary circulation, 497, 497f structure, 463–466, 464f–467f systemic arteries, 480, 480f, 481f, 481t, 482,

482t, 483f–487f, 484, 485t, 486, 487t, 488, 488t

systemic veins, 490–493, 490f–492f, 490t, 491t, 493t, 494f–496f, 495t, 496, 497t

Body: of mandible, 113, 234, 234f–235f of nail, 89 of sternum, 238, 239f of stomach, 568f of uterus, 648f of vertebrae, 122, 122f, 126f

Body cavities, see Organ systems and body cavities

Body planes and sections, 5–6, 5f, 6f, 12f Body regions, 3f Body stalk, 664, 666f Bones, 60, 61, 103f, 104f. See also Appendicular

skeleton; Axial skeleton abdomen, 241 ankle, 252, 254 antecubital region, 248 arm, 246, 248 back, 242 chest, 238 classifi cation of, 95 collagen and mineral salts and, 100 compact (cortical), 61, 68f, 68t, 97, 98f–99f elbow, 246, 248 gluteal region, 244 hand, 250 head, 234 leg, 252, 254 long, 95, 96, 96f, 103f neck, 236 pelvis, 244 shoulder, 246 spongy (cancellous/trabecular), 61, 68f, 68t,

97, 98f–99f thigh, 252 wrist, 250

724 I N D E X

Cells: cell specialization, 33–34, 34f cell structures, 31–33, 32f, 33t somatic cell division, 35–36, 35f, 35t, 36f transmission electron micrograph, 40f

Cell body (soma), 73, 258, 259f Cell cycle, 35f Cell-mediated immunity, 518, 524f Cellularity, 52 Cementum, 573, 575f Central (Haversian) canal, 97, 98f, 99f Central canal (spinal cord), 272, 272f, 273f Central fovea, 365, 365f, 366f Central nervous system (CNS), 255, 257f,

261f. See also Nervous system; Nervous tissue

gray and white matter in, 263, 263f Central sulcus, 308, 308f, 309f Central vein, 579, 582 Centrioles (centrosomes), 32f, 33t Cephalic:

anatomical term, 2t directional term, 4t

Cephalic veins, 248, 248f–249f, 250, 251f, 492, 492f, 493t

Cerebellar cortex, 303, 303f gray matter in, 303f

Cerebellum, 299, 300f, 303, 303f, 306f, 308f, 312

sheep brain, 315f, 316f Cerebral aqueduct, 312, 312f, 313f Cerebral arterial circle (circle of Willis), 482,

482t, 483f Cerebral cortex, 311f

functional areas, 309, 309f gray matter in, 306, 307f in nervous system, 268f

Cerebral hemispheres, 303f, 306, 312, 313f sheep brain, 315f

Cerebral peduncles, 301, 301f–303f sheep brain, 315f

Cerebrospinal fl uid (CSF), 256, 269, 312, 313f Cerebrum, 299, 300f

cerebral cortex functional areas, 309, 309f encephalography and, 310 gray and white matter in, 306, 306f, 307f sheep brain, 316f surface features, 308, 308f

Ceruminous glands, 86 Cervical (term), 2t Cervical canal, 646, 647f Cervical enlargement, 270, 271f Cervical nerves, 282, 282f Cervical plexus, 282, 282f, 283, 283f, 283t Cervical region (vertebral column), 120, 121f,

123f, 271f, 277f compared to thoracic and lumbar, 122–123,

124f–126f joint movement, 165f

Cervical spinal nerves, 283, 283f Cervix, 646, 646f–648f Cheeks, 565, 566f, 567f

wet mount of cells, 28, 28f Chemical digestion, 589–590, 590t Chemical synapse, 264 Chest:

anterior view, 239f

body region, 1 surface anatomy, 238, 239f

Chicken, leg tissue of, 74 Chief (zymogenic) cells, 579, 580f Chondroblasts, 60, 61 Chondrocytes, 60, 61 Chordae tendineae, 436, 436f–437f

sheep heart, 446f Chorion, 664, 667f Chorionic villi, 666, 666f Choroid, 362, 362f, 366f Choroid plexus, 307f, 312, 312f, 313f Chromatin, 32f, 33t Cilia, 33t, 538 Ciliary body, 362, 362f, 366f Ciliary ganglia, 336, 336f Ciliary muscle, 362, 362f Ciliary processes, 362, 362f Ciliated columnar epithelium, 644 Circle of Willis, 482, 482t, 483f Circular folds (small intestine), 569 Circumcision, 633 Circumduction, 164t, 166f Circumfl ex branch, 440, 440f, 441f Cisterna chyli, 508, 509f, 510f, 513f Clavicle (collarbone), 129f, 138, 139f, 207f

anterior and posterior views, 10f surface anatomy, 236, 237f, 246, 246f–247f

Clavicular notch, 129f Cleavage, 662 Clitoris, 648, 648f, 649f CNS, see Central nervous system Coarse focus knobs, 24, 25f Coccygeal spinal nerves, 271f, 282, 282f Coccyx, 120, 121f, 127, 127f, 244, 244f–245f Cochlea, 372, 372f, 373, 373f Cochlear branch, 372, 372f Cochlear duct, 372, 372f, 373, 373f Co-dominance in monohybrid crosses, 679–680,

679f, 680f Cold receptors, 346f, 347t Collagen, 100 Collagen fi bers, 60 Collarbone, see Clavicle Collateral ganglia, 334, 335f Collecting ducts, 602, 603f, 606, 618 Colloid, 394, 395f Colon, see Large intestine Colonoscopy, 570 Color blindness:

inheritance of, 681f red-green, 370, 370f

Columnar epithelial cells, 52, 52f, 56f simple, 52, 56f stratifi ed, 52

Commissural fi bers, 306, 306f Common bile duct, 576, 576f–578f Common carotid artery, 236, 237f, 481f, 516f Common fi bular (peroneal) nerve, 284, 284f,

284t Common hepatic artery, 487f, 487t Common hepatic duct, 576 Common iliac arteries, 240, 488t Common iliac veins, 493, 494f, 495t Communicating artery, 482, 482t, 483f Compact bone, 61, 68f, 68t, 96f, 97, 98f–99f Complete blood count (CBC), 423, 423t

Compound light microscope: magnifi cation in, 24 measuring fi eld of view, 26–27 observation of organs, 27, 27f parts of, 24, 25f transport and storage of, 23, 28 using, 25–26 wet mount of cheek cells, 28, 28f

Concentration gradient, 41, 43 Concentric isotonic contractions, 191 Concentric lamellae, 97, 98f, 99f Condenser, 24, 25f Conduction deafness, 375 Conduction (Purkinje) fi bers, 452, 452f Condylar processes, 113, 115f, 234 Condyles, 113t, 138t Condyloid joint, 168t Cones, 365 Conjunctiva, 360, 360f Connecting (body) stalk, 664, 666f Connective tissue, 51, 60, 78f–79f

blood, 60, 61, 69f, 69t bone, 60, 61, 68f, 68t cartilage, 60, 61, 66f, 67f, 67t dense, 60–61, 64f, 65t loose, 60, 60f, 62f, 63f, 63t

Connective tissue sheath, hair follicle, 85f Contraction of muscles, 185–192, 187t, 192f Contralateral (directional term), 4t Contralateral refl exes, 290 Conus medullaris, 270, 271f Convoluted tubules, 602, 603f, 606, 607f, 617,

618 Coracoid process, 247f Cornea, 362, 362f, 366f Corniculate cartilage, 532, 533f Coronal plane, 5 Coronal sutures, 106, 107f, 108f Corona radiata, 662, 663f Coronary artery, 434, 435f, 437f, 440, 440f,

441f, 456f, 480, 480f, 481t Coronary sinus, 434, 435f, 440, 441f, 490, 490f,

490t Coronary sulcus, 432, 433f, 434f Coronary veins, 434, 434f, 435f, 437f Coronoid fossa of humerus, 140, 141f, 142f Coronoid processes, 113 Coronoid process of humerus, 141f Coronoid process of ulna, 140, 142f Corpora cavernosa (penis), 631f, 633, 634f Corpora quadrigemina, 301, 301f

sheep brain, 316f Corpus albicans, 653, 653f Corpus callosum, 300f, 306, 306f, 307f

sheep brain, 316f Corpuscles of touch (Meissner’s corpuscles),

87f, 346f, 347t, 349f Corpus luteum, 653, 653f Corpus spongiosum (penis), 631f, 633, 634f Cortex:

of hair, 86 of lymph nodes, 514 of ovary, 653 of thymus, 516, 516f

Cortical bone, see Compact bone Cortical nephrons, 602, 603f Cortisol, 396, 400t

I N D E X 725

intestinal section through thorax, 12f length of GI tract and transit time, 572–573,

572t mechanical digestion, 561, 589 overview of, 561, 562f

Digital (term), 2t Dihybrid cross, 676 Dimples, inheritance of, 677f Diploid state, 676 Directional terms, 4, 4t Disaccharides, 590, 590t Distal (directional term), 4f, 4t DNA (deoxyribonucleic acid), 675 Dominant (term), 676 Dorsal:

anatomical term, 2t directional term, 4f, 4t

Dorsal artery: of foot, 488, 488t, 489f of penis, 634f

Dorsal gray horns, 272, 273f Dorsal interossei, 215f Dorsalis pedis, 488, 488t, 489f Dorsal ramus, 280, 281f Dorsal root, 272, 272f, 273f, 279 Dorsal root ganglion, 272, 272f, 273f Dorsal venous arch, 250, 251f, 252 Dorsifl exion, 164t, 167f Ductus arteriosus, 434, 498, 498t, 499f Ductus deferens (vas deferens), 630, 630f–632f Ductus venosus, 498, 498t, 499f Duodenal (Brunner’s) glands, 579, 581f Duodenal papilla, 578f Duodenum, 398f, 565f, 568f, 569, 570f Dural sinuses, 310 Dura mater, 269, 270f, 271f, 274f, 310, 311f Dynamic equilibrium receptors, 375

E Ear:

anatomy of, 371, 371f, 372 auditory and equilibrium tests, 375, 375t cochlea, 373, 373f equilibrium receptors, 374, 374f ossicles of, 105 spiral organ of Corti, 373, 373f

Eccentric isotonic contractions, 191 Eccrine glands, 86, 87f, 88t ECG (electrocardiogram), 453, 453f–455f, 454 Ectoderm, 664 EEG (electroencephalogram), 310, 310f Effectors, 279, 290, 291f Efferent arteriole, 602, 603f, 604f Efferent lymphatic vessels, 514, 514f, 517, 517f Efferent neurons, see Motor neurons Efferent vessels, 514, 514f Egg vitelline membrane, osmosis across, 44–45 Ejaculatory duct, 630, 631f, 632f Elastic arteries, 463–464 Elastic cartilage, 61, 66f, 67t Elastic dense connective tissue, 61, 65f, 65t Elastin fi bers, 60 Elbow, 171f

joint movement, 165f surface anatomy, 248, 248f–249f

Electrical conduction system of heart, 452, 452f Electrical excitation, of muscle fi ber, 186

Deep artery, penis, 634f Deep dorsal vein, penis, 634f Deep inguinal ring, 630 Deep palmar arch, 484, 485f, 485t Defecation, 561 Dehydroepiandrosterone (DHEA), 396 Delta brain waves, 310, 310f Deltoid muscles, 206t, 207f, 208t, 209f, 242,

242f–243f, 246, 246f–247f Deltoid tuberosity of humerus, 140, 141f Demifacets, 123, 125f, 128 Dendrites, 73, 258, 259f, 260f Dens, 122, 123f, 124f Dense connective tissue, 60–61

elastic, 61, 65f, 65t irregular, 60–61, 64f, 65t regular, 60, 64f, 65t

Denticulate ligaments, 269, 270f, 274f Dentin, 573, 575f Deoxyribonucleic acid (DNA), 675 Depolarization, atrial and ventricular, 453 Depression (joint movement), 164t, 167f Depressor anguli oris, 199f Depressor labii inferioris, 199f, 235f Dermal papillae, 84, 85f Dermis, 83, 84, 85f Descending aorta, 396f, 434, 435f, 486, 486f,

487f, 487t Descending colon, 562f, 565f, 570, 570f, 571f Descending limb (loop of Henle), 602, 603f,

606, 607f, 617 Detrusor muscle, 600, 600f DHEA (dehydroepiandrosterone), 396 Dialysis membrane, diffusion across, 43–44, 43f Diaphragm, 14f, 16, 16f, 205, 206t, 396f, 398f,

510f, 516f, 562f heart and, 442, 442f lung volume and, 546, 546t, 547f surface anatomy and, 238

Diaphysis, 96, 96f Diastole, 457 Diastolic blood pressure, 468 Diencephalon, 299, 300f, 304, 304f–305f

epithalamus, 300f, 304, 304f–305f hypothalamus, 300f, 304, 304f–305f, 307f pineal gland, 300f, 304, 304f–305f thalamus, 300f, 304, 304f–305f, 307f

Differential WBC count, 415, 416t Diffusion:

across dialysis membrane, 43–44, 43f as passive process, 41–42, 42f

Digastric anterior belly, 202t, 204f Digastric posterior belly, 202t, 204f Digestion, 589

bile emulsifi cation, 592 chemical, 589–590, 590t mechanical, 589

Digestive system, 14f accessory digestive organs, 561, 562f,

573–574, 574f, 575f, 576, 576f–578f of animals, 582 chemical digestion, 561, 589–590, 590t gastrointestinal tract and peritoneum layers,

563, 563f–565f gastrointestinal tract organs, 561, 562f,

565–567, 566f–568f, 569, 570, 570f, 571f histology of, 579, 580f–582f, 582

Costal (rib) cartilages, 128, 129f Costal margin, 238, 239f Covering and lining epithelia, 52 Cow eye, 364f Cowper’s glands, 632, 632f–634f Coxal (term), 2t Coxal (hip) joint, 144, 147, 160

joint movement, 165f, 166f Cranial (term), 2t Cranial bones, 105, 106, 107f–110f, 116f, 117f,

310 Cranial cavity, 16f Cranial fossae, 310 Cranial meninges, 310, 311f Cranial nerves:

markings of, 112–113, 114f, 115f naming and location of, 323–324, 324t,

325f–326f testing functions of, 327, 327t, 328, 328t

Cranial portion, of skull, 10f Cranial refl exes, 289 Craniosacral division, 336 Creatinine, 619 Cremaster muscle, 627–628, 628f Crenation, 45 Crest, 138t Cribriform plates, 113, 117f, 377, 377f Cricoid cartilage, 236, 237f, 532, 532f, 533f Cricothyroid, 204f Crista (inner ear), 374, 374f Crista galli, 113, 117f, 118f Crossbridges (myosin molecules), 176 Crossed extensor refl ex, 297f Cross-sections of body plane, 5, 5f Crown, of tooth, 573, 575f Cruciate ligaments, 162, 163f Crural (term), 2t Crypts of Lieberkühn, 579, 581f CSF, see Cerebrospinal fl uid Cubital fossa, 248, 248f–249f Cuboidal epithelial cells, 52, 52f

simple, 52, 55f stratifi ed, 52

Cuneiform cartilage, 533f Cupula, 374, 374f Curvature:

of stomach, 568, 568f of vertebrae, 128, 128f

Cutaneous mechanoreceptors, 346f, 347t Cutaneous membrane, 83 Cuticle:

of hair, 86 of nail, 89, 89f

Cystic duct, 576, 576f–578f, 582 Cytokinesis, 35, 35t, 36f Cytoplasm, 32f, 33t Cytoskeleton (of cell), 32f, 33t Cytosol, 32f, 33t Cytotoxic T cells, 518, 524f

D Dactyloscopy, 89 Dartos muscle, 627, 628f Decidua, 664 Deciduas basalis, 664, 666, 667f Deciduous (primary) teeth, 573 Deep (directional term), 4t

726 I N D E X

F Facets, 122, 122f, 123 Facial (term), 2t Facial bones, 105, 106, 107f, 109f, 111f, 112f,

116f markings of, 113, 114f, 115f

Facial muscles, 198, 198t, 199f–201f expressions and, 198, 199f

Facial nerves: function, distribution, action of, 327, 327t,

328t location of, 323, 324t, 325f, 326f, 336f

Facial portion of skull, 10f Falciform ligament, 563, 576, 576f–578f Fallopian (uterine) tubes, 643–644, 644f,

645f, 648f False ribs, 128 Falx cerebelli, 310 Falx cerebri, 310, 311f Fascicles, 173, 174f, 175f, 279, 280f Fast glycolytic (FG) muscle fi bers, 188, 189f Fast oxidative-glycolytic (FOG) muscle fi bers,

188, 189f Fatty acids, 590, 590t Fauces, 565, 566f, 567f Female pelvis, 144, 146f Female reproductive system:

external genitalia, 648, 648f–649f histology of, 653, 653f–655f mammary glands, 650, 650f oogenesis, 652, 652f ovaries and uterine tubes, 643–644, 645f, 651f overview, 648f, 649f, 651, 651f uterus, 644f–647f, 646, 651f vagina, 646, 646f, 647f

Female urinary system, 598f, 600, 600f, 601f Femoral (term), 2t Femoral artery, 488, 488t, 489f, 515f Femoral nerve, 284, 284f, 284t Femoral triangle, 252 Femoral veins, 496, 496f, 497t Femur (thigh bone), 147, 148f, 149f, 151t

anterior and posterior views, 10f longitudinally sectioned, 99f

Fenestrations (capillary), 466, 467f Fertilization, 661, 662 Fetuses and newborns:

blood circulation of, 498, 498t, 499f development period of, 661, 668, 668f–670f ductus arteriosus, 434 foramen ovale, 436, 498, 499f hemolytic disease of, 420 intermediate pituitary lobe, 392 skull, 106, 119, 119f vertebral column curves, 120f

FEV1 (forced expiratory volume in 1 second), 553, 553t

FG muscle fi bers, see Fast glycolytic muscle fi bers

Fibroblasts, 60 Fibrocartilage, 61, 67f, 67t Fibrous capsule, 161, 161f Fibrous joint, 160, 160f Fibrous pericardium, 442, 442f Fibrous tunic, 362 Fibula (leg bone), 147, 148f, 149f

anterior and posterior views, 10f

stratifi ed epithelia, 52, 57f transitional cells, 52, 58f

Eponychium (cuticle) of nail, 89, 89f Equilibrium:

receptors, 374, 374f tests of, 375, 375t

Erector spinae, 205, 210f, 210t, 242, 242f–243f ERV, see Expiratory reserve volume Erythrocytes, see Red blood cells (RBCs) Esophagus, 14f, 562f, 567, 567f, 568f, 580f Estrogen, 399, 644 Ethmoidal sinus, 118, 118f, 529f Ethmoid bone, 106, 107f, 110f–112f, 112, 113,

114f, 115f Eustachian tube, 371, 371f, 530, 531f Eversion (joint movement), 164t, 167f Excitation-contraction coupling, 186 Expiratory reserve volume (ERV), 550, 550t Extension, 164t, 165f Extensor carpi radialis brevis, 211, 216t, 217f Extensor carpi radialis longus, 211, 216t,

217f Extensor carpi ulnaris, 211, 216t, 217f Extensor digiti minimi, 217f Extensor digitorum, 211, 216t, 217f, 250, 251f,

252, 253f Extensor digitorum longus, 222, 222t, 223f,

224f Extensor digitorum minimi, 211, 216t Extensor hallucis longus, 252, 253f Extensor pollicis brevis, 217f Extensor pollicis longus, 216t, 217f Extensor retinaculum, 217f External anal sphincter, 570, 571f, 648f External auditory canal, 371, 371f External auditory meatus, 112, 115f External carotid artery, 116f, 482, 482t, 483f External ear, 371, 371f External elastic lamina, 464, 465f External iliac artery, 488, 488t, 489f External iliac vein, 493, 494f, 495t, 496, 496f External intercostal muscles, 205, 206t, 207f,

208f, 546, 546t, 547f External jugular veins, 236, 491, 491f, 491t External nares, 528, 529f External oblique, 206t, 207f–209f, 240,

240f–241f, 546, 546t, 547f External occipital protuberance, 116f, 234,

234f–235f External os, 646, 647f External respiration, 545 External urethral orifi ce, 600, 600f, 601f, 630,

631f, 633 External urethral sphincter, 600, 600f Extracellular matrix, 60 Extrinsic eye muscles, 360, 361f Eye and vision:

accessory eye structures, 360, 360f cow eye, 364f eyeball structure, 360–361, 362f, 363f,

366f inheritance of color blindness, 681f orbit of, 106, 112, 112f pupillary light refl ex, 337 retinal anatomy, 365, 367f, 387f visual acuity tests, 368–369, 368f, 369f visual fi elds, 388f

Electrocardiogram (ECG), 453, 453f–455f, 454 Electroencephalogram (EEG), 310, 310f Electrolytes, 619 Elevation (joint movement), 164t, 167f Embryonic membrane, 664, 665f Embryonic period, of development, 661–664,

663f, 665f–667f, 666. See also Fetuses and newborns

Emmetropic vision, 368 Emphysema, 535 Emulsifi cation, 592 Enamel, 573, 575f Encapsulated nerve endings, 345 Encephalography, 310, 310f Endocardium, 442, 442f Endocrine system, 14f, 391, 392f

adrenal glands, 391, 392f, 396, 396f–397f, 400t–401t

of animals, 401 and hormone functions, 400, 400t–401t, 401 hypothalamus, 391, 392, 392f, 393f, 408f ovaries, 391, 392f, 399, 401t pancreas, 391, 392f, 398, 398f–399f, 401t parathyroid glands, 391, 392f, 394,

394f–395f, 400t pineal gland, 391, 392f, 399, 401t pituitary gland, 391, 392, 392f, 393f, 400t testes, 391, 392f, 399, 401t thymus, 391, 392f, 399, 401t thyroid gland, 391, 392f, 394, 394f–395f, 400t

Endoderm, 664 Endolymph, 372 Endometrial (uterine) glands, 655, 655f Endometrium, 646, 647f, 655f, 665f Endomysium, 173, 174f, 175f Endoneurium, 279, 280f Endosteum, 96, 96f Enzymes, 590, 590t Eosinophils, 412, 413, 413t, 414f, 416t Ependymal cells, 256, 257f Epicardium, 442, 442f Epicondyle, 138t Epicranial aponeurosis, 199f Epidermal ridges, 84 Epidermis, 83, 84, 85f Epididymis, 628, 630, 630f, 631f Epidural space, 269, 270f Epigastric region, 18 Epiglottis, 379f, 532, 532f, 533f, 566 Epimysium, 173, 174f Epinephrine, 396, 401 Epineurium, 279, 280f Epiphyses, 96, 96f, 99f Epiphyseal line, 96, 96f Epiphyseal plate, 96 Epiploic appendages, 570, 571f Epithalamus, 300f, 304, 304f–305f Epithelial tissues, 51–52, 78f–79f

columnar cells, 52, 52f, 56f covering/lining, 52 cuboidal cells, 52, 52f, 55f glandular, 52 pseudostratifi ed columnar epithelia, 33, 34f,

52, 59f respiratory system, 538, 538t, 539f simple epithelia, 52, 54f–56f squamous cells, 52, 52f, 54f

I N D E X 727

Glomerulus, 602, 603f, 607f Glossopharyngeal nerve:

function, distribution, action of, 327, 327t, 328t location of, 323, 324t, 325f, 326f, 336f

Glottis, 532, 533f Glucagon, 398, 401t Glucocorticoids, 396 Glucose, blood, 401 Glucosuria, 620t Gluteal (term), 2t Gluteal (natal) cleft, 244, 244f–245f Gluteal region, surface anatomy, 244, 244f–245f Gluteal tuberosity, 147, 148f Gluteus maximus muscle, 220f, 220t, 221f, 244,

244f–245f Gluteus medius muscle, 220f, 220t, 221f, 244,

244f–245f Gluteus minimus muscle, 220f, 220t Glycerination, 186 Glycerol, 590 Glycolysis, 188 Goblet cells:

digestive system, 579, 581f respiratory system, 538

Golgi complex, 32f Gonadal arteries, 486, 486f, 487t Gonadal veins, 493, 494f, 495t Graafi an follicle, 653, 653f Gracilis muscle, 218, 218t, 219f, 220f, 252, 253f Graded potential, 264 Granular cast, in urine, 622f Granular leukocytes, 412 Granulosa cells, 653, 654f Gray commissure, 272, 273f Gray matter, 263, 263f

cerebrum, 306, 307f spinal column, 272

Gray rami communicantes, 334 Great cardiac vein, 440f Greater omentum, 563, 564f Greater sciatic notch, 144, 145f Greater trochanter, 147, 148f, 220f, 244, 244f–245f Greater tubercle of humerus, 246, 246f–247f Greater wings of sphenoid, 113, 117f Great saphenous veins, 496, 496f, 497t, 515f Groin (body region), 1 Ground substance, 60 Gustation, 378–379, 379f Gustatory hairs, 378, 379f Gustatory receptor cell, 378, 379f Gyrus, 308, 308f

sheep brain, 315f

H Hair, 86, 87f Hair bulb, 86 Hair bundle, ear, 373, 373f, 374, 374f Hair follicles, 86 Hair root plexuses, 346f, 347t Hamstring muscle group, 218, 220t Hand, 104f

muscles that move, 214t, 215f, 216t, 217f surface anatomy, 250, 251f

Haploid state, 676 Hard palate, 106, 116f, 118, 529, 529f, 565,

566f, 567f Haustra, 570, 571f

FRC, see Functional residual capacity Free edge, of nail, 89, 89f Free nerve ending, 345 Frog:

arteriole, 464f gastrocnemius muscle, 192f

Frontal (term), 2t Frontal bone, 106, 107f, 108f, 110f–112f, 112,

114f, 115f Frontalis, 198t, 199f, 200f, 234, 234f–235f Frontal lobe, 308, 308f

sheep brain, 315f Frontal plane, 5, 5f, 6f Frontal section, 5 Frontal sinus, 118, 118f, 529f FSH, see Follicle-stimulating hormone Functional residual capacity (FRC), 550, 550t Fundus:

of stomach, 567, 568f of uterus, 644f, 646, 647f, 648f

Fungiform papillae, 378, 379f Fused tetanus, 190 FVC, see Forced vital capacity

G Gallbladder, 240, 398f, 562f, 565f, 576,

576f–578f, 582 Gametes, 627 Ganglia:

dorsal root, 272, 273f prevertebral, 334, 335f submandibular, 336, 336f sympathetic, 281f sympathetic trunk, 280, 334, 335f terminal, 336, 336f

Ganglion cell layer, 365, 367f Gap junctions, 443 Gastric artery, 486f, 487f, 487t Gastric glands, 579, 580f Gastric lipase, 590t Gastric pits, 579, 580f Gastric veins, 495f Gastrocnemius muscle, 222, 222t, 223f, 224f,

254, 254f frog, 192f

Gastrointestinal (GI) tract, 561. See also specifi c organs

layers of, 563, 563f–565f organs of, 561, 562f, 565–567, 566f–568f,

569, 570, 570f, 571f transit time and length of, 572–573, 572t

Gender, determining with femur, 151t General senses, see Sensory receptors Genetics, see Heredity Genome, 675 Genotype, 676 Germinal epithelium, 653 Gingiva, 565, 566f, 567f, 573, 575f GI tract, see Gastrointestinal tract Glandular epithelia, 52 Glans (penis), 631f, 633, 634f Glaucoma, 363 Glenoid cavity, 138, 139f Gliding joint movement, 164t, 168t Globus pallidus, 307f Glomerular (Bowman’s) capsule, 54f, 602, 603f,

606, 607f

Fibular (term), 2t Fibular (peroneal) arteries, 488, 488t, 489f Fibularis (peroneus) brevis, 223f, 224f Fibularis (peroneus) longus, 222, 222t, 223f,

223t, 224f, 252, 253f Fibular (peroneal) veins, 496, 496f, 497t Field of view, 26–27 Filiform papillae (tongue), 378, 379f Filtrate, 616 Filtration, 615 Filtration membrane, 616 Filum terminale, 270, 271f Fimbriae, 644, 644f, 645f, 648f Fine focus knobs, 24, 25f Fingerprints, 89–90, 90f First polar body, 652, 652f Fissure (term), 113t Fixed macrophages, 579 Flagella, 32f, 33t Flat bones, 95 Flexion, 164t, 165f Flexor carpi radialis, 211, 214t, 215f, 250, 251f Flexor carpi ulnaris, 211, 214t, 215f, 250, 251f Flexor digiti minimi brevis, 215f Flexor digitorum longus, 222, 222t, 223f, 224f Flexor digitorum profundus, 215f Flexor digitorum superfi cialis, 211, 214t, 215f,

250, 251f Flexor hallucis longus, 222t, 224f Flexor pollicis brevis, 215f Flexor pollicis longus, 214t, 215f Flexor refl ex, 297f Floating ribs, 128, 129f FOG muscle fi bers, see Fast oxidative-glycolytic

muscle fi bers Folia, 303, 303f Foliate papillae, 378, 379f Follicle-stimulating hormone (FSH), 392, 400t Follicular cells, 394, 395f Follicular fl uid, 654f Fontanels, 106, 119, 119f Foot:

dorsum of, 252 joint movement, 167f skeletal muscles of, 222, 222t, 223f–224f surface anatomy of, 252

Foramen, 113t, 138t cranial nerves, 354t transverse, 122, 124f, 277f vertebral, 122, 122f

Foramen lacerum, 112, 116f, 117f Foramen magnum, 113, 116f, 117f Foramen ovale, 116f, 117f, 326f, 436, 498, 499f Foramina ovale, 113 Foramina rotundum, 113, 117f, 326f Forced expiratory volume in 1 second (FEV1),

553, 553t Forced vital capacity (FVC), 553, 553t Forearm (body region), 1 Formed elements, blood, 412, 412f Fornix, 300f, 306, 307f

sheep brain, 316f of vagina, 648f

Fossa, 113t, 138t Fossa ovalis, 436, 499f Fourth ventricle, 312, 312f, 313f

sheep brain, 316f

728 I N D E X

Inferior nasal conchae, 106, 111f, 529, 529f Inferior nasal meatus, 529, 529f Inferior oblique eye muscle, 361f Inferior orbital fi ssure, 114f Inferior rectus eye muscle, 360, 361f Inferior vena cava, 14f, 396f, 434, 435f, 441f,

490, 490f, 490t, 493, 494f, 582f Infraspinatus muscle, 205, 208t, 209f, 242,

242f–243f Infundibulum, 300f, 304, 305f, 392, 393f

sheep brain, 315f uterine tube, 644

Inguinal (term), 2t Inguinal canals, 630 Inguinal ligament, 207f, 219f, 515f Inguinal lymph nodes, 513f Inguinal ring, 207f, 630 Inner cell mass, 662 Insertion point of muscle, 197 Inspiratory capacity (IC), 550, 550t Inspiratory reserve volume (IRV), 550t Insula, 307f, 308, 308f Insulin, 398, 401t Integrating center, 290, 291f Integument, 83 Integumentary system, 14f, 83, 89f fi ngerprints, 89–90, 90f hair and hair follicles, 86, 87f nails, 89, 89f skin, 83–89, 85f sudoriferous and sebaceous glands, 86, 87f

Interatrial septum, 436 Intercalated discs, 442, 443, 443f Intercellular (capillary) clefts, 466, 467f Intercondylar fossa, 147, 148f Interior (directional term), 4t Interior mesenteric ganglia, 334 Interior orbital fi ssures, 113 Intermediate (directional term), 4t Intermediate mass of thalamus, 305f Internal anal sphincter, 570, 571f Internal auditory meatus, 112, 117f, 326f Internal capsule, 306, 307f Internal carotid arteries, 482, 482t, 483f Internal elastic lamina, 463–464, 465f Internal iliac artery, 488, 488t, 489f Internal iliac veins, 493, 494f, 495t Internal intercostal muscles, 205, 206t, 207f,

208f, 546, 546t, 547f Internal jugular vein, 236, 491, 491f, 491t Internal nares, 529, 529f, 530f Internal naris, 566 Internal oblique muscles, 206t, 207f, 208f, 546,

546t, 547f Internal os, 646, 647f Internal respiration, 545 Internal sphincter, 569, 570 Internal urethral orifi ce, 600, 600f Internal urethral sphincter, 600, 600f Interneurons (association neurons), 260, 261f,

268f, 348, 349f Interosseous membrane, 142f Interphase, in somatic cell division, 35, 35f,

35t, 36f Interstitial endocrinocytes, 636 Interstitial fl uid, 507, 508f Interstitial lamellae, 97, 98f

Hips: bones of, see Pelvic girdle coxal joint, 144, 147, 160 joint movement, 165f, 166f

Homeostasis, 13, 478f Homologous chromosomes, 675 Homozygous trait, 676 Hormones, 392, 394, 400t, 618, 618f

and blood pressure, 478f Human chorionic gonadotropin (hCG), 664 Human development:

embryonic period, 661–664, 663f, 665f–667f, 666

fetal period, 668, 668f–670f Human gene pool, 675 Human growth hormone (hGH), 392, 400t Humerus, 140, 141f, 142f, 248 Hyaline cartilage, 61, 66f, 67t Hyaline cast, in urine, 622f Hymen, 648, 649f Hyoid bone, 107f, 120, 204f, 235f

muscles that move, 198, 202t, 204f surface anatomy, 236, 237f

Hyperextension, 164t, 165f Hyperopic vision, 368 Hypertonic (term), 43 Hypodermis, 83, 85f Hypogastric (pubic) region, 18 Hypoglossal canal, 326f Hypoglossal foramina, 113, 116f, 117f Hypoglossal nerve:

function, distribution, action of, 327, 327t, 328t location of, 323, 324t, 325f, 326f

Hyponychium, of nail, 89, 89f Hypophysis, see Pituitary gland Hypothalamus, 300f, 304, 304f–305f, 307f, 391,

392, 392f, 393f, 408f Hypothenar eminence, 250, 251f Hypotonic (term), 43 H zone, 178, 178f, 179f

I I bands, 178, 178f, 179f IC, see Inspiratory capacity Ileocecal sphincter, 569, 571f Ileum, 562f, 565f, 569, 570f, 571f Iliac arteries, 486, 486f, 487t, 489f Iliac crest, 240, 240f–241f, 244, 244f–245f Iliac fossa, 144, 145f Iliac lymph nodes, 513f Iliac region, 18 Iliacus, 218t, 219f Iliac veins, 493, 494f, 495t Iliocostalis lumborum, 210f Iliocostalis thoracis, 210f Iliopsoas, 218t, 219f Iliotibial tract, 219f, 220f Immune cells, 518, 518f, 519f, 524f Implantation of blastocyst, 664, 665f Incisors, 573, 575f Incomplete dominance, 678, 678f Incus, 371, 371f Inferior (directional term), 4f, 4t Inferior colliculi, 301, 301f, 303f

sheep brain, 316f Inferior mesenteric artery, 486, 486f, 487t Inferior mesenteric vein, 493, 495f, 495t

Haversian (central) canal, 97, 98f, 99f hCG (human chorionic gonadotropin),

664 Head:

arteries of, 482, 482t, 483f MRI of, 22f skeletal muscles of, 198, 198t, 199f–201f,

200t, 202, 203f surface anatomy of, 234, 235f veins to, 491, 491f, 491t

Head (microscope), 24, 25f Head (term), 138t Heads (myosin molecules), 176 Hearing, tests of, 375–376, 375t Heart, 14f, 431. See also Cardiac cycle

coronary circulation, 440, 441f great vessels of, 434, 434f, 435f internal features of, 436, 436f–437f location and surface features of, 432 location of, 432f murmurs of, 456 pericardium and layers of heart wall, 442,

442f, 443f section through thorax, 12f serous pericardium, 17f, 443f sheep, 444, 444f–446f, 446 sounds of, 456–457 surface anatomy and, 238 surface features of, 433f systemic and pulmonary circulations, 438,

439f valves of, 456–457, 456f veins to, 490, 490f, 490t

Height, determining with femur, 151t Helix, 371, 371f Helper T cells, 518, 524f Hematocrit, 417, 417f Hematuria, 620t Hemiazygos vein, 493, 494f, 494t Hemoglobin, 412, 622f Hemolysis, 45 Hemolytic disease of the newborn, 420 Hepatic artery, 579, 582, 582f Hepatic ducts, 576, 576f–578f, 582, 582f Hepatic portal circulation, 493, 494f, 495t Hepatic portal vein, 579, 582, 582f Hepatocytes, 579, 581f, 582, 582f Hepatopancreatic ampulla (sphincter of Oddi),

576, 576f–578f Heredity, 675

co-dominance in monohybrid crosses, 679–680, 679f, 680f

genetic language, 675–676 incomplete dominance, 678, 678f monohybrid crosses and Punnett Square,

676–677, 677f sex-linked inheritance, 681, 681f

Herniated disc, 126f Heterozygous trait, 676 hGH, see Human growth hormone High-dry objective, 26 Hilus:

lung, 536, 537f lymph node, 514, 514f renal, 597, 599f spleen, 517

Hinge, 168t

I N D E X 729

Ligamentum teres, 499f Ligamentum venosum, 499f Light intensity knob, 25f Line (term), 138t Linea alba, 207f, 240, 240f–241f Linea aspera, 147, 148f Linea semilunaris, 240, 240f–241f Lingual frenulum, 573, 574f, 575f Lingual lipase, 590t Lingual tonsil, 379f, 511, 511f, 530, 530f, 531f Lips, 565, 566f, 567f Lipids, 590 Liver, 14f, 241, 398f, 562f, 565f, 576, 576f–578f

histology of, 579, 581f, 582f section through thorax, 12f

LLQ (left lower quadrant), 18 Lobar bronchi, 534, 534f, 535f Lobes, of lungs, 536, 536f, 537f Lobule, 371, 371f, 579 Long bones, 95, 96, 96f, 103f Longissimus capitis, 210f Longissimus cervicis, 210f Longissimus thoracis, 210f Longitudinal fi ssure, 308, 308f

sheep brain, 315f Longitudinal section, 5, 5f Loops, fi ngerprint pattern, 90, 90f Loop of Henle, 602, 603f, 606, 607f, 617 Loose connective tissue, 60, 63t

adipose, 60, 63f, 63t areolar, 60, 60f, 62f, 63t reticular, 60, 62f, 63t

Lordosis, 128, 128f Lower esophageal sphincter, 568f Lower limb (term), 2t Lower limbs, 137, 147, 148f–151f, 151–152,

151t, 488, 488t. See also Foot; Leg anterior and posterior views, 10f arteries of, 488, 488t, 489f surface anatomy, 252, 253f, 254, 254f veins of, 496, 496f, 497t

Low-power objective lens, 26 Lumbar (term), 2t Lumbar arteries, 486 Lumbar enlargement, 270, 271f Lumbar nerves, 282, 282f Lumbar plexus, 282, 282f, 284, 284f, 284t Lumbar trunk, 513f Lumbar vertebral region, 120, 121f, 271f

compared to cervical and thoracic, 123, 124f–126f

Lungs, 12f, 14f, 238, 516f, 528f, 535f–537f, 536, 539f. See also Pulmonary ventilation

Lunula, of nail, 89, 89f LUQ (left upper quadrant), 18 Luteinizing hormone (LH), 392, 400t Lymphatic system, 14f, 507, 519f

immune cells, 518, 518f, 519f lymph and lymphatic vessels, 507–508,

508f–510f, 513f, 515f lymph nodes, 511, 512f, 514, 514f, 515f organs and tissues of, 511, 511f, 512f spleen, 511, 512f, 517, 517f, 519f thymus, 516, 516f

Lymphocytes, 412, 413, 413t, 414f, 416t Lymph trunks, 508, 509f, 510f, 513f Lysosome, 32f, 33t

Lacteal, 579 Lactiferous ducts, 650, 650f Lactiferous sinuses, 650 Lacunae, 61, 97, 98f, 99f, 666 LAD, see Left anterior descending branch Lambdoid suture, 106, 107f, 108f, 110f Lamella, 61 Lamellated (Pacinian) corpuscle, 87f, 346f, 347t Lamina of vertebrae, 122, 122f Lamina propria, 579, 580f, 581f Laminectomy, 123 Langerhans cells, 84 Large intestine, 14f, 562f, 570, 570f, 571f Laryngopharynx, 530, 530f, 531f, 538t, 566,

567f Larynx, 198, 528f, 532, 532f–533f, 538t, 544f Latent period, in muscle contraction, 190 Lateral (directional term), 4t Lateral aperture, 312, 312f Lateral cerebral sulcus, 308, 308f Lateral collateral ligament, 162, 163f Lateral condyle:

of femur, 147, 148f, 252, 253f of tibia, 149f, 252, 253f

Lateral epicondyle: of femur, 147, 148f of humerus, 140, 141f, 246, 246f–247f

Lateral gray horns, 272, 273f Lateral malleolus of fi bula, 149f, 252, 253f Lateral meniscus, 163f Lateral pterygoid, 201f Lateral rectus eye muscle, 360, 361f Lateral ventricles, 305f–307f, 312, 312f, 313f

sheep brain, 316f Lateral white column (spinal cord), 272, 273f Latissimus dorsi muscle, 207f, 208t, 209f, 242,

242f–243f Left anterior descending branch (LAD), 440,

440f, 441f Left colic (splenic) fl exure, 570, 571f Left hypochondriac region, 18 Left inguinal region, 18 Left lower quadrant (LLQ), 18 Left lumbar region, 18 Left upper quadrant (LUQ), 18 Leg:

body region, 1 chicken, 74 skeletal muscles of, 222, 222t, 223f–224f surface anatomy of, 252, 254

Lens, 363f, 366f Lesser omentum, 563, 564f Lesser sciatic notch, 144, 145f Lesser trochanter, 147, 148f Lesser wing of sphenoid, 113, 117f Leukocytes, see White blood cells (WBCs) Leukocytosis, 412 Leukopenia, 412 Levator labii superioris, 199f Levator scapulae, 202t, 203f, 204f, 208t, 209f,

237f Leydig cells, 636, 637f, 638f LH, see Luteinizing hormone Lie detector test, 339f Ligamentum arteriosum, 434, 434f, 435f, 437f,

499f sheep heart, 444f

Interstitial spaces, 636, 638f Intertubercular sulcus of humerus, 140, 141f Interventricular foramen, 312, 313f Interventricular septum, 436, 436f–437f

sheep heart, 446f Intervertebral discs, 121f, 123, 126f Intervertebral foramina, 279, 281f Intervillus spaces, 666, 666f, 667f Intestines, see Large intestine; Small intestine Intramural ganglia, 336, 336f Intrapleural pressure, 548 Intrinsic stimulation (heart), 452 Intrinsic tongue muscles, 573 Inversion, 164t, 167f Ipsilateral (directional term), 4t Ipsilateral refl ex arc, 290 Iris, 362, 362f, 366f Iris diaphragm, 24, 25f Irregular bones, 95 Irregular dense connective tissue, 60–61, 64f,

65t IRV, see Inspiratory reserve volume Ischial spine, 144, 145f Ischial tuberosity, 144, 145f, 244, 244f–245f Ischium, 144, 145f Islets of Langerhans, 398, 399f, 579, 581f Isometric contractions, 191 Isotonic contractions, 191 Isotonic solutions, 43 Isthmus of uterine tube, 644, 644f, 645f

J Jejunum, 562f, 565f, 569, 570f, 577f Joints. See also Synovial joints

structural classifi cation of, 159–160, 160f Jugular foramen, 112, 116f, 117f, 326f Jugular (suprasternal) notch, 128, 129f, 236,

237f, 239f Jugular veins, 491, 491f, 491t, 513f Juxtamedullary nephrons, 602, 603f

K Keratinized stratifi ed squamous epithelium, 84 Keratinocytes, 84 Ketonuria, 620t Kidneys, 14f, 597–598, 598f, 599f, 604, 604f

blood fl ow through, 604, 604f histology of, 606, 607f section through thorax, 12f surface anatomy, 244

Knee, 103f, 162, 163f joint movement, 165f patellar refl ex, 291, 292f

Knee cap, see Patella Korotkoff sounds, 468 Kupffer’s cells, 579 Kyphosis, 128, 128f

L Labial frenulum, 565, 566f, 567f Labia majora and minora, 648, 648f, 649f Lachrymal bones, 106, 107f, 111f, 112, 112f,

113, 115f Lacrimal canals, 360, 360f Lacrimal fossa, 113, 115f Lacrimal gland, 360, 360f Lacrimal sac, 360, 360f

730 I N D E X

Motor end plate, 180, 180f Motor (efferent) neurons, 33, 34f, 180, 180f,

260, 261f, 268f, 290, 291f Motor unit, 180, 180f, 190 Mouth, 562f, 565, 566f, 567f Movement, at synovial joints, 164, 165f–167f MSH, see Melanocyte-stimulating hormone Mucosa, 563, 563f, 579, 580f, 608, 608f Mucosa-associated lymphoid tissue (MALT),

511 Mucous neck cells, 579 Multipolar neurons, 73, 260, 261f Muscles, see specifi c muscles Muscle fatigue, 190 Muscle spindles, 291, 346f, 347f Muscle tissues, 51, 70, 70f–72f, 70t, 80f. See

also Skeletal muscles Muscular arteries, 464, 465f Muscularis, 563, 563f, 579, 580f, 608, 608f Muscular system, 14f Musculocutaneous nerve, 283, 283f, 283t Myelinated fi bers, 262, 262f, 263f Myelin sheaths, 256, 257f, 259f, 262, 262f, 280f Mylohyoid, 202t, 204f Myocardium, 442, 442f Myofi brils, 176, 177f Myofi laments, 176, 177f Myograph, 191 Myometrium, 646, 646f, 647f, 655f Myopic vision, 368 Myosin molecules, 176

N Nails, 89, 89f Nasal (term), 2t Nasal bones, 106, 107f, 111f, 114f, 115f, 118f,

234, 234f–235f Nasal cartilage, 234 Nasal cavity, 538t Nasal concha, 529, 529f Nasal septum, 106, 118, 118f, 528, 529f Nasolacrimal duct, 360, 360f Nasopharynx, 530, 530f, 531f, 538t, 566, 567f Natal cleft, 244, 244f–245f NE, see Norepinephrine Near point of vision, 368 Neck:

arteries, 482, 482t, 483f MRI of, 22f skeletal muscles of, 198, 200t, 202t, 203f,

204f surface anatomy of, 236, 237f veins, 491, 491f, 491t

Nephrons, 598, 602, 603f, 615–618, 618f Nerves, see specifi c nerves, e.g.: Spinal nerves Nervous system, 14f, 255, 268f. See also Central

nervous system (CNS); Nervous tissue Nervous tissue, 51, 73, 73f, 80f, 255

gray and white matter, 263, 263f myelination of axons, 262, 262f, 263f neuroglia, 73, 256, 256t, 257f neurons, 73, 257f, 258, 259f, 260, 261f structure of, 256, 257f–259f, 258 synapses, 264, 264f

Neural portion of retina, 362, 367f Neuroglia, 73, 256, 256t, 257f Neurohypophysis, 392, 393f, 400t

Medullary sinuses, 514, 514f Megakaryocytes, 412 Meiosis, 636, 637f, 652, 652f Meissner’s corpuscles, 87f, 346f, 347t, 349f Melanocytes, 84 Melanocyte-stimulating hormone (MSH), 392,

400t Melatonin, 399, 401t Membranous labyrinth, 372, 372f Membranous urethra, 600, 601f, 630, 631f, 632f,

634f Memory B cells, 518, 524f Memory T cells, 524f Mendel, Gregor, 676 Meninges, 269 Meningeal branch, 281f Meningeal layer, 310 Meniscus, 162, 163f Mental (term), 2t, 114f Mental foramina, 113 Mental protuberance, 234, 234f–235f Merkel cells, 84 Merkel discs, 346f, 347t Mesentery, 563, 564f Mesocolon, 563, 564f Mesoderm, 664 Mesothelium, 53f, 54f Metabolic end products, 619 Metacarpals, 10f, 166f Metacarpus, 143, 143f Metaphase, of mitosis, 35, 35t, 36f Metaphyses, 96, 99f Metatarsals, 10f Metatarsus, 150, 150f Microglia, 256, 257f Micrometer, 24 Microscope, see Compound light microscope Microscopic anatomy, 538, 538t, 539f Microvilli, 32f, 33t, 257f, 569, 579, 581f Micturition, 600 Midbrain, 300f–302f, 301 Middle cerebral arteries, 482, 482t, 483f Middle cranial fossae, 310 Middle ear, 371, 371f Middle nasal conchae, 113, 114f, 529, 529f Middle nasal meatus, 529, 529f Middle scalene, 202t Midsagittal plane, 5, 5f, 6f Mineralcorticoids, 396 Mineral salts, 100 Minor calyces, 598, 599f Mitochondria, 32f, 33t, 259f Mitosis, 35, 35f, 35t, 36f Mitral valve, see Bicuspid valve Mixed nerves, 272, 279 M line, 178, 178f, 179f Molars, 573, 575f Monocytes, 412, 413, 413t, 414f, 416t Monohybrid crosses, 676, 677f, 679–680,

679f, 680f Monosaccharides, 590, 590t Monosynaptic integrating center, 291 Monosynaptic refl ex arc, 290 Mons pubis, 648, 649f Morula, 662, 663f Motor areas, of cerebral cortex, 309, 309f Motor axons, 279

M McBurney’s point, 240, 240f–241f Macrophages, 518, 519f Maculae (ear), 374, 374f Macula lutea, 365, 365f Magnifi cation, calculating microscope’s, 24 Major calyces, 598, 599f Major duodenal papilla, 576, 577f, 578f Male pelvis, 144, 146f Male reproductive system, 627

accessory structures, 632, 632f–635f duct system, 630, 630f, 631f penis, 627, 631f, 633f, 634f scrotum, 627–628, 628f sperm, 627, 636, 638f testes, 627–628, 628f–631f, 636, 637f, 638f

Male urinary system, 600, 601f Malleus, 371, 371f MALT (mucosa-associated lymphoid tissue),

511 Mammary (term), 2t Mammary glands, 86, 650, 650f Mammillary body, 304, 305f

sheep brain, 315f, 316f Mandible, 106, 107f, 111f, 113, 115f Mandibular fossa, 112, 116f Manual (term), 2t Manubrium, 128, 129f, 238, 239f Marginal branch, 440, 440f, 441f Masseter muscle, 200f, 204f, 234, 234f–235f Mastication, 565, 589 Mastoid process, 112, 115f, 116f, 234, 234f–235f Matrix:

of hair, 86 of nail, 89, 89f

Maxillae, 106, 107f, 109f, 111f, 112, 112f, 113, 115f

Maxillary sinus, 118, 118f, 529f Maximal force, 190 Maximal stimulus, 190 Meatus, 113t, 529, 529f Mechanical stage, 24, 25f Medial (directional term), 4t Medial collateral ligament, 162, 163f Medial condyle:

of femur, 147, 148f, 252, 253f of tibia, 252, 253f

Medial epicondyle, 215f, 217f femur, 147, 148f humerus, 140, 141f, 248, 248f–249f

Medial malleolus of tibia, 149f, 252, 253f Medial meniscus, 162, 163f Medial pterygoid, 201f Medial rectus eye muscle, 360, 361f Median aperture, 312, 312f Median cubital veins, 248, 248f–249f, 492,

492f, 493t Median nerve, 283, 283f, 283t Mediastinum, 16, 432, 442, 442f, 537f Medulla:

of hair, 86 of lymph node, 514 of ovary, 653 of thymus, 516, 516f

Medulla oblongata, 282f, 300f–303f, 301 sheep brain, 315f, 316f

Medullary cavity, 96, 96f, 99f

I N D E X 731

Palatoglossal arch, 565 Palatopharyngeal arch, 565 Palmar (term), 2t Palmaris longus, 214t Palmaris longus tendon, 211, 215f, 250, 251f Palpabrae, 360, 360f Palpation, 233 Palpebral conjunctiva, 360, 360f Pancreas, 14f, 391, 392f, 398, 398f–399f, 401t,

562f, 576, 576f–578f histology of, 579, 581f

Pancreatic amylase, 590t Pancreatic duct, 398, 398f, 576, 576f–578f Pancreatic islets (islets of Langerhans), 398,

399f, 579, 581f Pancreatic lipase, 590t Papillae:

of hair, 86 of tongue, 378, 379f, 573

Papillary ducts, 598, 602, 603f Papillary muscle, 436, 436f–437f

sheep heart, 446f Papillary region, of dermis, 84, 85f Parafollicular cells (C cells), 394, 395f Paranasal sinuses, 106, 118, 118f, 538t Parasagittal plane, 5, 5f Parasympathetic motor division, 333, 336,

336f Parathyroid glands, 391, 392f, 394, 394f–395f,

400t Parathyroid hormone (PTH), 394, 400t Parfocal lenses, 26 Parietal bones, 106, 107f–111f, 311f Parietal cell, 579, 580f Parietal layer, of serous pericardium, 17, 17f,

442, 442f, 516f Parietal lobe, 308, 308f

sheep brain, 315f Parietal peritoneum, 563, 564f Parietal pleura, 536, 537f Parieto-occipital sulcus, 308, 308f Parotid ducts, 573, 574f Parotid glands, 234, 573, 574f Passive processes, 41 Patella, 147, 149f, 252, 253f

anterior and posterior views, 10f Patellar (term), 2t Patellar ligament, 252, 253f Patellar refl ex (knee jerk), 291, 292f Pectinate muscles, 436, 437f Pectineus, 218, 218t, 219f Pectoral (term), 2t Pectoral girdle, 137, 138, 139f

anterior and posterior views, 10f Pectoralis major muscle, 206t, 207f, 238, 239f Pectoralis minor muscle, 206t, 207f, 546, 546t,

547f Pedal (term), 2t Pedicle, 124f, 126f

vertebrae, 122, 122f Pedocytes, 606 Pelvic (term), 2t Pelvic arteries, 488, 488t, 489f Pelvic cavity, 16, 16f Pelvic (hip) girdle, 137, 144, 145f

anterior and posterior views, 10f Pelvic splanchnic nerves, 336

Ophthalmoscope, 365 Opponens digiti minimi, 215f Optic chiasm, 304, 305f

sheep brain, 315f, 316f Optic disc, 365, 365f, 366f Optic foramina, 113, 117f, 326f Optic nerve, 366f

function, distribution, action of, 327, 327t, 328t

location of, 323, 324t, 325f, 326f sheep brain, 315f

Optic tract, 307f sheep brain, 315f

Oral (term), 2t Oral cavity, 565, 566f, 567f Ora serrata, 362, 362f Orbicularis oculi, 198t, 199f, 200f, 235f Orbicularis oris, 198t, 199f, 201f, 235f Orbital (term), 2t Orbit of the eye, 106, 112, 112f Organ systems and body cavities:

abdominopelvic regions and quadrants, 18, 18f

body cavities, 16, 16f organ identifi cation, 15, 22f organs and organ systems, 13–15, 14f of rats, 17 serous membranes, 17, 17f

Origin, of muscle, 197 Oropharynx, 530, 530f, 531f, 538t, 566, 567f Os coxae, 144, 145f Osmosis:

across dialysis membrane, 43–44, 43f across egg vitelline membrane, 44–45 across plasma membrane, 45–46, 46f

Osseous tissue, see Bones Osteoblasts, 60, 96 Osteoclasts, 96 Osteocytes, 60, 61, 97, 98f, 99f Osteons, 61, 97, 98f Osteoporosis, 104f OT, see Oxytocin Otic (term), 2t Otic ganglia, 336, 336f Otoliths, 374, 374f Otolithic membrane, 374, 374f Oval window, of ear, 371, 371f, 372f Ovaries, 643–644, 644f, 645f, 648f

arteries, 486 endocrine system, 391, 392f, 399, 401t histology of, 653, 654f ligaments, 644, 644f, 645f

Oviducts, see Uterine (fallopian) tubes Ovulation, 643–644 Ovum, 652, 652f, 662 Oxyphil cells, 394 Oxytocin (OT), 392, 400t

P Pacinian corpuscles, 87f, 346f, 347t Pain:

receptors of, 346f, 347t referred, 354

Palatine bones, 106, 109f, 112, 116f, 118 Palatine process, 113, 116f, 118 Palatine tonsil, 379f, 511, 511f, 519f, 530, 531f,

565, 566f

Neurolemma, 262, 262f Neuromuscular junction, 180, 180f, 268f Neurons, 73, 257f

classifi cation of, 260, 261f structure of, 258, 259f synapses of, 264, 264f

Neuron cell body, 257f, 260f Neutrophils, 412, 413, 413t, 414f, 416t Newborns, see Fetuses and newborns Nipple, 650, 650f Nociceptors, 346f, 347t Node of Ranvier, 257f, 259f, 262, 262f Nonciliated simple columnar epithelium with

microvilli, 33, 34f Norepinephrine (NE), 396, 401t Normal sinus rhythm (NSR), 454 Nose, 377, 377f, 528–529, 528f, 529f NSR (normal sinus rhythm), 454 Nuclear membrane, 32f Nucleolus, 32f, 33t Nucleus, 32f, 33t, 260f Nucleus pulposus, 123 Nutrient artery, 96, 96f Nutrient foramen, 96 Nystagmus, 375

O Objective lenses, 24, 25f Oblique plane, 5, 5f Oblique vein, 441f Obturator externus, 219f Obturator foramen, 145f Obturator nerve, 284, 284f, 284t Occipital (term), 2t Occipital bone, 106, 107f–110f, 113, 115f Occipital condyles, 113, 116f, 122 Occipitalis, 198t, 199f, 200f, 234, 234f–235f Occipital lobe, 308, 308f

sheep brain, 315f, 316f Ocular lenses, 24, 25f Oculomotor nerve, 337

function, distribution, action of, 327, 327t, 328t

location of, 323, 324t, 325f, 326f, 336f Odontoid process, 122 Olecranal (term), 2t Olecranon fossa of humerus, 140, 141f, 142f Olecranon process, 247f Olecranons of ulna, 140, 141f, 142f, 247f, 248,

248f–249f Olfaction, 377, 377f Olfactory bulb, 377, 377f

sheep brain, 315f Olfactory epithelium, 377, 377f Olfactory foramina, 113, 117f, 326f Olfactory hairs, 377, 377f Olfactory nerves, 377, 377f

function, distribution, action of, 327, 327t, 328t

location of, 323, 324t, 325f, 326f Olfactory tract, 377, 377f

sheep brain, 315f Oligodendrocytes, 256, 257f, 262, 262f Omohyoid, 202t, 204f Oocytes, 643–644 Oogenesis, 652, 652f Oogonia, 652, 652f

732 I N D E X

Primary lymphatic organs, 511 Primary motor area, 309, 309f Primary olfactory area, 309 Primary oocytes, 652, 652f, 653, 654f Primary somatosensory area, 309, 309f Primary spermatocytes, 636, 637f Primary teeth, 573 Primary visual area, 309, 309f Primordial follicles, 653, 653f, 654f Principal cells, of parathyroid, 394 Principle of segregation, 676 PRL, see Prolactin Progesterone, 399, 401t, 644, 653 Projection fi bers, 306, 306f Prolactin (PRL), 392, 400t Pronation, 164t, 167f Pronator teres, 214t, 215f Prone position, 1 Prophase, of mitosis, 35, 35t, 36f Proprioceptors, 346f Prostate gland, 630, 631f–634f, 632 Prostate-specifi c antigen (PSA), 632 Prostatic urethra, 600, 601f, 630, 631f, 634f Proteases, 590 Protraction, 164t Proximal (directional term), 4f, 4t PSA (prostate-specifi c antigen), 632 Pseudostratifi ed ciliated columnar epithelial

cells, 33, 34f, 52, 59f Psoas major muscle, 218t, 219f Pterygoid processes, 113, 116f Pterygopalatine ganglia, 336, 336f PTH, see Parathyroid hormone Pubic (term), 2t Pubic region, 18 Pubic symphysis, 240, 631f, 648f, 649f Pubis, 144, 145f Pudendal nerve, 284, 284f, 284t Pudendum, 648 Pulmonary arteries, 440f, 441f Pulmonary circulation, 438, 439f, 463, 479,

497, 497f Pulmonary embolus, 490 Pulmonary (semilunar) value, 436, 436f–437f Pulmonary veins, 441f Pulmonary ventilation, 545

carbon dioxide and, 554–555 lung and thoracic volumes, 546, 546t, 547f,

548f, 550, 550t, 552t, 553, 553t pressure changes during, 548–549, 549f

Pulp cavity, 573, 575f Pulse, 457 Punnett Square, 676, 677f Pupil, 362, 362f, 366f Pupillary light refl ex, 337 Purkinje fi bers, 452, 452f Putamen, 307f P wave, in ECG, 453, 454f Pyloric antrum, 567, 568f Pyloric canal, 567, 568f Pyloric sphincter, 567, 568f Pylorus, 567, 568f Pyuria, 620t

Q QRS complex, in ECG, 453, 454f Q-T interval, in ECG, 453, 454f

diffusion and osmosis across dialysis mem- brane, 43–44, 43f

osmosis across plasma membrane, 45–46, 46f Platelets (thrombocytes), 69t, 412

characteristics of, 413t structure and function of, 412, 429f

Platysma, 198t, 199f, 200f, 202t, 207f Pleura, 17, 537f Pleural cavity, 17, 536, 537f, 548 Plicae circularis, 569 PNS, see Peripheral nervous system Pointer, 24 Polycythemia, 412, 417 Polygraphs, 191 Polysynaptic refl ex arc, 290, 291 Pons, 300f–303f, 301, 312

sheep brain, 315f, 316f Popliteal (term), 2t Popliteal artery, 488, 488t, 489f Popliteal veins, 496, 496f, 497t Portal triad, 579 Postcentral gyrus, 308, 308f Posterior (directional term), 4f, 4t Posterior cavity (eyeball), 363, 363f Posterior cerebral arteries, 482, 482t, 483f Posterior column-medial lemniscus pathway,

349f Posterior communicating arteries, 482, 482t,

483f Posterior cranial fossae, 310 Posterior cruciate ligament, 163f Posterior (dorsal) gray horns, 272, 273f Posterior inferior iliac spine, 144, 145f Posterior intercostal arteries, 486 Posterior interventricular branch, 441f Posterior interventricular sulcus, 432, 433f Posterior median sulcus, 272, 272f, 273f Posterior pituitary (neurohypophysis), 392,

393f, 400t Posterior ramus, 280, 281f Posterior root, 272, 272f, 273f, 279 Posterior root ganglion, 272, 272f, 273f Posterior superior iliac spine, 144, 145f Posterior tibial artery, 488, 488t, 489f Posterior tibial veins, 496, 496f, 497t Posterior triangle, 198, 236, 237f Posterior white column (spinal cord), 272, 273f Postganglionic motor neurons, 333, 334, 335f,

336 Postsynaptic neuron, 264 Postsynaptic potential, 264 P-Q interval, in ECG, 453, 454f Precentral gyrus, 308, 308f Preganglionic motor neurons, 333, 334, 335f,

336, 336f Premolars, 573, 575f Prepuce, 633, 634f, 648, 649f Presbyopia, 368 Pressure, pulmonary ventilation and, 548–549,

549f Presynaptic neuron, 264 Prevertebral (collateral) ganglia, 334, 335f Primary auditory area, 309, 309f Primary bronchi, 238 Primary follicles, 651, 653f, 654f Primary germ layers, of embryo, 664 Primary gustatory area, 309, 309f

Pelvis, 144, 146f arteries of, 488, 488t, 489f body region, 1 radiograph of, 22f surface anatomy, 244f–245f, 247 veins of, 493, 494f, 495t

Penis, 627, 631f, 633f, 634f Pepsin, 590t Pepsinogen, 590t Peptidases, 590, 590t Peptides, 590, 590t Perforating (Volkmann) canals, 97, 98f Pericardial cavity, 16 Pericardium, 17, 442, 442f, 443f Perilymph, 372 Perimetrium, 646, 647f Perimysium, 173, 174f, 175f Perineurium, 279, 280f Periodontal ligament, 573, 575f Periosteal layer, 310 Periosteum, 96, 96f, 97, 98f, 161f Peripheral nervous system (PNS), 255, 257f,

261f Peristalsis, 567, 569, 608 Peritoneal cavity, 16, 563, 564f Peritoneal fl uid, 563 Peritoneum, 17, 563, 563f–565f Peritubular capillary network, 602, 603f Perivascular feet, 256 Permanent teeth, 573 Peroneal arteries, 488, 488t, 489f Peroneal veins, 496, 496f, 497t Peroneus brevis, 223f, 224f Peroneus longus, 222, 223f, 223t, 224f, 252,

253f Peroxisome, 32f, 33t Perpendicular plate, 113, 114f, 118f Peyer’s patches, 511, 512f, 519f Phagocytes, 256 Phalanges, 10f, 143, 143f, 150, 150f Pharyngeal tonsil, 511, 511f, 530, 530f, 531f Pharynx, 528f, 530, 531f, 562f, 566, 567f Phenotype, 676 Photoreceptor cell layer, 365, 367f Phrenic nerve, 283, 283f, 283t Pia mater, 257f, 269, 270f, 310, 311f Pigs, kidneys of, 605–606, 605f Pigmented layer of retina, 362, 367f Pineal gland, 300f, 304, 304f–305f, 391, 392f,

399, 401t sheep brain, 316f

Piriformis, 220f, 220t, 221f Pisiform bone, 215f, 250, 251f Pituitary gland (hypophysis), 300f, 304, 305f,

391, 392, 392f, 393f sheep brain, 316f

Pivot joint, 168t Placenta, 666, 667f

blood circulation and, 498, 499f Planes, see Body planes and sections Plantar (term), 2t Plantar fl exion, 164t, 167f, 294 Plantaris, 223f, 224f Plasma, 60, 61, 69t, 412, 412f, 420, 420f Plasma cells, 518, 524f Plasma membrane, transport across, 32f, 33t

active and passive processes, 43

I N D E X 733

Sacroiliac joints, 127, 127f, 144, 244 Sacrum, 120, 121f, 127, 127f, 244, 244f–245f,

271f Saddle joint, 168t Sagittal plane, 5 Sagittal suture, 106, 108f Salivary amylase, 590t Salivary glands, 562f, 573, 574f, 575f SA node, see Sinoatrial node Sarcolemma, 176, 177f Sarcomeres, 176, 177f–179f, 178 Sarcoplasmic reticulum, 176, 177f Sartorius muscle, 218, 218t, 219f, 252, 253f,

515f Satellite cells, 256, 257f, 260f Scala tympani, 373 Scala vestibuli, 373, 373f Scalenes, 202t, 203f, 236, 237f, 546, 546t,

547f Scanning objective lens, 25 Scapula, 129f, 138, 141f, 171f

anterior and posterior views, 10f muscles that move, 202t, 205, 206t, 208t surface anatomy, 242, 242f–243f

Scapular (term), 2t Schwann cells, 256, 257f, 259f, 262, 262f Sciatic nerve, 220f, 284, 284f, 284t Sclera, 362, 362f, 366f Scleral venous sinus (canal of Schlemm), 362,

362f, 363, 363f Scoliosis, 128, 128f Scrotal septum, 627 Scrotum, 627–628, 628f, 631f Sebaceous glands, 86, 87f Secondary (lobar) bronchi, 534, 534f, 535f Secondary follicles, 653, 653f, 654f Secondary lymphatic organs, 511 Secondary oocytes, 652, 652f–654f, 663f Secondary spermatocytes, 636, 637f Secondary teeth, 573 Second polar body, 652, 652f Secretory vesicle, 32f, 33t Segmental bronchi, 534, 534f, 535f Segmentation, 569, 589 Segregation, principle of, 676 Sella turcica, 113, 117f, 118f Semen, 627, 630 Semicircular (ear) canals, 372, 372f Semicircular (ear) ducts, 372, 372f Semilunar valves, 436, 436f–437f, 456, 456f Semimembranosus muscle, 220f, 220t, 221f,

254, 254f Seminal vesicle, 630f–633f, 632 Seminal vesicle duct, 630, 630f–633f, 632 Seminiferous tubules, 628, 629f Semispinalis capitis, 210f Semispinalis cervicis, 210f Semispinalis thoracis, 210f Semitendinosus muscle, 220f, 220t, 221f, 254,

254f Senses, see Sensory receptors Sensorineural deafness, 375 Sensors, 191 Sensory areas, of cerebral cortex, 309, 309f Sensory axons, 279 Sensory (afferent) neurons, 260, 261f, 268f, 289,

291f, 348, 349f

Respiratory system, 14f, 546t, 547f. See also Pulmonary ventilation

of animals, 540 bronchial tree, 528f, 534, 534f, 535f larynx, 528f, 532, 532f–533f, 544f lungs, 528f, 535f–537f, 536, 539f microscopic anatomy of, 538, 538t, 539f muscles and, 205, 206t, 207f, 546 nose, 528–529, 528f, 529f pharynx, 528f, 530, 531f structures of, 527, 528f trachea, 528f, 534, 534f, 535f, 539f

Rete testis, 628, 629f Reticular connective tissues, 60, 62f, 63t Reticular fi bers, 60 Reticular layer, of dermis, 84, 85f Reticular tissue, 514 Reticulocytes, 514 Reticuloendothelial (Kupffer’s) cells, 579 Retina, 362, 362f, 366f

anatomy of, 365, 365f, 367f, 387f Retraction, 164t, 167f Retroperitoneal cavity, 16 Retroperitoneal organs, 563, 564f Revolving nosepiece, 24, 25f Rh blood typing system, 420–422, 420f, 422f Rhomboid major, 208t, 209f Rhomboid minor, 208t, 209f Ribs, 239f Rib cage, 128, 129f, 130f, 238 Ribosome, 32f, 33t Right colic (hepatic) fl exure, 570, 571f Right hypochondriac region, 18 Right lower quadrant (RLQ), 18 Right lumbar region, 18 Right upper quadrant (RUQ), 18 Rinne test, 375t Risorius, 199f RLQ (right lower quadrant), 18 Rods, 365 Root:

of hair, 86 of nail, 89 of spinal nerves, 274, 274f of tooth, 573, 575f

Root canal, 573, 575f Rotation, 164t, 167f Rotator cuff muscles, 205 Rough endoplasmic reticulum, 32f, 33t Round ligaments of uterus, 646, 646f, 647f Round window, of ear, 371, 371f, 372f Ruffi ni’s corpuscles, 346f, 347t Rugae:

of stomach, 567, 568f of vagina, 646, 647f

RUQ (right upper quadrant), 18 RV, see Residual volume

S Saccule, 372, 372f Sacral canal, 127, 127f Sacral foramen, 127, 127f Sacral hiatus, 127, 127f Sacral nerves, 282, 282f Sacral plexus, 282, 282f, 284, 284f, 284t Sacral promontory, 127, 127f Sacral vertebral region, 271f

Quadrants, abdominal pelvic regions and, 18, 18f

Quadriceps femoris group, 218, 218t, 219f

R Radial artery, 250, 251f, 484, 484f–485f, 485t Radial fossa of humerus, 140, 141f Radial nerve, 283, 283f, 283t Radial notch, of ulna, 140, 142f Radial pulse, 457 Radial tuberosity, 140, 142f Radial veins, 492, 492f, 493t Radius, 10f, 140, 141f, 142f Rami communicantes, 280, 281f Ramus, 113t

of mandible, 113, 115f, 234, 234f–235f of spinal nerves, 271f, 274f, 280, 281f

Rats, organ systems and body cavities of, 17 RBCs, see Red blood cells Receptor cells, 345 Recessive (term), 676 Reciprocal innervation, 291 Rectum, 570, 570f, 571f, 631f, 648f Rectus abdominis, 206t, 207f, 208f, 240,

240f–241f, 546, 546t, 547f Rectus femoris, 218, 218t, 219f, 252, 253f, 515f Rectus sheath, 207f Red blood cells (RBCs), 33, 34f, 61, 69t, 412

antigens and anti-bodies and, 420f characteristics of, 413t hematocrit and, 417, 417f osmosis in, 45–46, 46f structure and function of, 412, 429f in urine, 620t

Red bone marrow, 96, 511, 512f Red-green color blindness, 370, 370f Red pulp, of lymphatic system, 517 Referred pain, 354 Refl ex arcs, 289–290, 290t, 291f Refl ex testing:

Achilles refl ex (ankle jerk), 294 biceps refl ex (biceps jerk), 293 patellar refl ex (knee jerk), 291, 292f plantar fl exion, 294 triceps refl ex (triceps jerk), 293

Regular dense connective tissue, 60, 64f, 65t Relaxation, autonomic nervous system

and, 340 Relaxation period, of muscle, 190 Renal arteries, 486, 486f, 487t Renal capsule, 597, 599f Renal columns, 598, 599f Renal corpuscle, 602, 603f, 616 Renal cortex, 597, 599f Renal fascia, 597, 599f Renal hilus, 597, 599f Renal medulla, 597, 599f Renal papilla, 598, 599f Renal pelvis, 598 Renal pyramid, 597, 599f Renal sinus, 598, 599f Renal veins, 493, 494f, 495t Reproductive systems, 14f. See also Female

reproductive system; Male reproductive system

Residual volume (RV), 550, 550t Respiratory membrane, 534

734 I N D E X

protected structures and spinal meninges, 269, 270f

section through thorax, 12f transverse section, 270f, 272, 272f–274f, 277f

Spinalis capitis, 210f Spinalis cervicis, 210f Spinalis thoracis, 210f Spinal nerves, 272, 272f, 277f, 279, 280f, 281f

from cervical and brachial plexuses, 283, 283f, 283t

connective tissue coverings of, 279, 280f divisions and spinal plexuses, 282, 282f from lumbar and sacral plexuses, 284, 284f,

284t rami of, 280, 281f

Spinal organ of Corti, 373, 373f Spinal plexuses, 282, 282f Spinal refl exes, 289 Spine, 113t. See also Vertebral column

of scapula, 242, 246, 246f–247f Spinothalamic pathway, 349f Spinous process of vertebrae, 122, 122f, 124f,

126f, 242, 242f–243f, 270f, 277f Spirometer, 550 Splanchnic nerves, 334, 335f Spleen, 14f, 398f, 510f, 511, 512f, 517, 517f, 519f

section through thorax, 12f Splenic artery, 486f, 487f, 487t, 517, 517f Splenic vein, 493, 495f, 495t, 517, 517f Splenius capitis, 202t, 203f, 209f, 210f Spongy bone, 61, 68f, 68t, 96f, 97, 98f–99f Spongy (penile) urethra, 600, 601f, 630, 631f,

632f, 634f Squamous epithelial cells, 52, 52f

simple, 52, 54f stratifi ed, 52, 57f

Squamous sutures, 106, 107f Stage, microscope, 24, 25f Stapes, 371, 371f Starch, 589–590, 590t Static equilibrium receptors, 375 Sternal (term), 2t Sternal angle, 128, 238, 239f Sternocleidomastoid muscle, 198, 202t, 203f,

204f, 207f, 236, 237f, 546, 546t, 547f Sternohyoid, 202t, 204f Sternum, 128, 129f

anterior and posterior views, 10f section through thorax, 12f

Stomach, 14f, 562f, 565f, 567–568, 568f, 570f histology of, 579, 580f section through thorax, 12f

Stratifi ed epithelia, 52, 57f Stratifi ed squamous epithelium, 538, 538t Stratum basale, 84, 85f, 655f Stratum corneum, 84, 85f Stratum functionalis, 655, 655f Stratum granulosum, 84, 85f Stratum lucidum, 84, 85f Stratum spinosum, 84, 85f Stress, and autonomic nervous system, 340 Striations, in muscle tissue, 70, 175f S-T segment, in ECG, 453, 454f Stylohyoid, 202t, 204f Styloid process, 112, 115f, 116f

radius, 140, 142f, 250, 251f ulna, 140, 142f, 250, 251f

sarcomeres, 176, 177f–179f, 178 shoulder, 246 thigh, 218, 218t, 219f–221f, 220t, 252, 254 tissue of, 70, 70f, 70t, 71f, 173, 174f, 175f trunk, 205, 206t, 207f–210f, 208t, 210t

Skeletal system, 10f, 14f Skin, 87f, 93f

dermis, 83, 84, 85f epidermis, 83, 84, 85f hypodermis, 83, 85f sensory receptors in, 346f

Skull, 105, 135f anterior and posterior views, 10f bone markings, 112–113, 113t, 114f–118f,

134f, 136f cranial bones, 105, 106, 107f–110f, 116f,

117f facial bones, 105, 106, 107f, 109f, 111f, 112f,

116f fetal and newborn, 106, 119, 119f hard palate, 106, 118 nasal septum, 106, 118, 118f orbit of the eye, 106, 112, 112f paranasal sinuses, 106, 118, 118f sutures, 106, 108f, 110f

Slow oxidative (SO) muscle fi bers, 188, 189f Small intestine, 14f, 562f, 569, 569f–571f

histology of, 579, 581f Small saphenous veins, 496, 496f, 497t Smooth endoplasmic reticulum, 32f, 33t Smooth muscle tissue, 70, 70t, 72f Snellen acuity card, 369f Soft palate, 530, 530f, 531f, 565, 566f, 567f Soleus muscle, 222, 222t, 223f, 224f, 254, 254f Somatic cell division, 35, 35f, 35t, 36f Somatic refl exes, 289

refl ex arcs, 289–290, 290t, 291f refl ex testing, 291–294, 292f, 297f

Somatic sensory receptors, 345, 346f, 347t Somatosensory cortex, 357f Somatotropin, 392, 400t SO muscle fi bers, see Slow oxidative muscle

fi bers Special senses:

ear and hearing/equilibrium, 371–376, 371f–374f, 375t

eye and vision, 360–365, 360f–370f, 368–370 nose and olfaction, 377–378, 377f taste buds and gustation, 378–380, 379f

Special sensory receptors, 345 Specifi c gravity, of urine, 619, 619t Sperm, 33, 34f, 627, 628, 636, 637f, 638f, 652f,

662, 663f Spermatic cord, 630, 630f Spermatic fascia, 628 Spermatids, 636, 637f Spermatogenesis, 628, 636, 637f Spermatogonia, 636, 637f Spermiogenesis, 636, 637f Sphenoidal sinus, 118, 118f, 529f Sphenoid bone, 106, 107f, 109f–112f, 112, 113,

114f, 115f Sphincter of Oddi, 576, 576f–578f Sphygmomanometer, 468, 469f Spinal cord, 269, 274f, 300f

dissection of, 274, 274f external features, 270, 271f

Sensory receptors, 268f, 289, 291f adaptation of, 352–353 and referred pain, 354 sensory pathways, 348, 349f somatic (general), 345, 346f, 347t special, 345 tactile sensitivity, 350–351 visceral, 345

Septa, 628, 629f Septal cartilage, 118f Septum pellucidum, 312 Serosa, 563, 563f, 579, 580f Serous fl uid, 17, 442 Serous membranes, 17, 17f Serous pericardium, 442, 442f, 443f Serratus anterior muscle, 206t, 207f, 238, 239f,

240, 240f–241f Sertoli cells, 636, 637f Serum, 412, 412f Sesamoid bones, 95 Sex chromosomes, 675, 681, 681f Sex-linked genes, 681 Sex-linked inheritance, 681, 681f Shaft, of hair, 86 Sheep:

brain of, 314, 315f, 316f heart of, 444, 444f–446f, 446 kidneys of, 605–606

Short bones, 95 Shoulder:

bones of, see Pectoral girdle joint movement, 165f–167f, 171f, 206t, 207f,

208t, 209f surface anatomy of, 246, 247f

Shoulder blade, see Scapula Sickle-cell anemia, 680, 680f Sickle-cell trait, 680 Sigmoid colon, 565f, 570, 571f Sigmoidoscopy, 570 Simple epithelia:

columnar, 52, 56f cuboidal, 52, 55f squamous, 52, 54f

Sinoatrial (SA) node, 452, 452f Sinuses, see Paranasal sinuses Sinusoids, 579, 582, 582f Skeletal muscles, 33, 34f, 173

abdomen, 241 antecubital region, 248 arm, 205, 206t, 211, 211t, 212f–213f, 214t,

215f, 216t, 217f, 246 arm and elbow, 246, 248 back, 242 chest, 238 connective tissue coverings, 173, 174f, 175f contraction of, 185–192, 187t, 192f control of muscle tension, 190–191 fi bers of, 176, 176f–177f, 188–189, 189f force generated by, 191–192, 192f head, 198, 198t, 199f–201f, 200t, 203f, 234 isotonic and isometric contractions, 191 leg and ankle, 252, 254 leg and foot, 222, 222t, 223f–224f naming criteria, 197 neck, 198, 200t, 202t, 203f, 204f, 236 neuromuscular junction, 180, 180f, 268f pelvis and gluteal region, 244

I N D E X 735

Thalamus, 268f, 300f, 304, 304f–305f, 307f sheep brain, 316f

Thenar eminence, 250, 251f Theta brain waves, 310, 310f Thick skin, 84 Thigh:

body region, 1 lymph nodes and vessels, 515f skeletal muscles of, 218, 218t, 219f–221f, 220t surface anatomy of, 252, 254

Thin skin, 84 Third-order neurons, 348, 349f Third ventricle, 305f–307f, 312, 312f, 313f Thoracic (term), 2t Thoracic aorta, 14f, 481f, 486, 486f, 487t Thoracic cage, 128, 129f, 130f, 238 Thoracic cavity, 16, 16f Thoracic duct, 508, 509f, 510f, 513f Thoracic nerves, 282, 282f Thoracic vertebral region, 120, 121f, 271f

compared to cervical and lumbar, 123, 124f–126f

Thoracolumbar division, 334 Thorax:

anterior and posterior views, 10f body sections through, 12f radiograph of, 22f veins of, 493, 494f, 494t

Threshold stimulus, of muscles, 190 Thrombocytes, see Platelets Thrombocytopenia, 412 Thrombus, 490 Thymosin, 399, 401t Thymus, 391, 392f, 399, 401t, 511, 512f, 516,

516f, 519f, 524f Thyroglobulin, 394 Thyrohyoid, 204f Thyroid cartilage, 236, 237f, 532f Thyroid gland, 236, 237f, 391, 392f, 394,

394f–395f, 400t, 516f Thyroid hormones (TH), 394 Thyroid-stimulating hormone (TSH), 392, 400t Thyroxine (T4), 394, 400t Tibia, 147, 148f, 149f

anterior and posterior views, 10f Tibialis anterior muscle, 222, 222t, 223f, 252,

253f Tibialis posterior muscle, 224f Tibial nerves, 284, 284f, 284t Tibial tuberosity, 252, 253f Tidal volume (TV), 550, 550t Tight junctions, capillary, 466, 467f Tissues:

of chicken leg, 74 connective, see Connective tissue epithelial, see Epithelial tissues muscle, see Muscle tissues nervous, see Nervous tissue

TLC, see Total lung capacity TMJ, see Temporomandibular joint Tongue, 562f, 573, 574f, 575f, 677f Total lung capacity (TLC), 550, 550t Trabeculae:

of bone, 61, 97, 98f, 99f of lymph nodes, 514 of spleen, 517, 517f of thymus, 516, 516f

Surgical neck, of humerus, 140 Suspensory ligaments:

of eye, 362, 362f of uterus, 644, 645f

Sutures, 106, 108f, 110f Sweat (sudoriferous) glands, 86, 87f Sympathetic ganglion, 280, 281f Sympathetic motor division, 333, 334, 335f Sympathetic nerves, 478f Sympathetic trunk (chain) ganglia, 334, 335f Synapses, 264, 264f Synaptic cleft, 180, 180f Synaptic end bulbs, 180, 180f Synaptic vesicles, 180, 180f Synovial cavity, 161, 161f Synovial fl uid, 161, 161f Synovial joints, 160, 160f, 161, 161f, 171f, 172f.

See also Joints knee, 162, 163f structure of, 161, 161f types of, 168t types of movement, 164, 165f–167f

Synovial membrane, 161, 161f Systemic circulation, 438, 439f, 463, 479 Systole, 457 Systolic blood pressure, 468

T T3, see Triiodothyronine T4, see Thyroxine Tachycardia, 454 Tactile sensitivity, 350 Talus, 149f Tarsal (term), 2t Tarsals, 10f Tarsus, 150, 150f Taste buds, 378–379, 379f Taste pore, 378, 379f T cells (lymphocytes), 518, 519f, 524f Tectorial membrane, 373, 373f Teeth, 562f, 573, 574f, 575f Telephase, of mitosis, 35, 35t, 36f Temporal bone, 106, 107f, 109f–111f, 114f, 115f Temporalis muscle, 201f, 234, 234f–235f Temporal lobe, 308, 308f Temporal process, 113 Temporomandibular joint (TMJ), 167f, 234,

234f–235f Tendinous intersection, 240, 240f–241f Tendons, 173, 174f, 250 Tendon of semitendinosus muscles, 254, 254f Tendon organs, 346f, 347f Teniae coli, 570, 571f Tensor fasciae latae, 218t, 219f Tentorium cerebelli, 310 Teres major muscle, 208t, 209f, 242, 242f–243f Teres minor muscle, 205, 208t, 209f Terminal cisternae, 176, 177f Terminal (intramural) ganglia, 336, 336f Tertiary (segmental) bronchi, 534, 534f, 535f Testes, 627–628, 628f–631f

endocrine system, 391, 392f, 399, 401t histology of, 636, 637f, 638f

Testicular arteries, 486 Testosterone, 399, 401t, 636 Tetraiodothyronine, 394 TH (thyroid hormones), 394

Stylomastoid foramen, 112, 116f, 326f Subarachnoid space, 269, 270f, 310, 311f–313f,

312 Subcapsular sinus, 514, 514f Subclavian artery, 237f, 480, 480f, 481f, 481t,

484, 484f–485f, 485t Subclavian vein, 491, 491f, 491t, 492, 492f,

493t, 513f Sublingual glands, 573, 574f Submandibular ducts, 573, 574f Submandibular ganglia, 336, 336f Submandibular glands, 573, 574f Submucosa, 563, 563f, 579, 580f Suborbital margins, 234, 234f–235f Subscapularis muscle, 171f, 205, 206t, 207f Substage light, 24, 25f Sudoriferous glands, 86, 87f Sulcus, 308, 308f

sheep brain, 315f Superfi cial (directional term), 4t Superfi cial inguinal ring, 630 Superfi cial palmar arch, 484, 485f, 485t Superior (directional term), 4f, 4t Superior cervical sympathetic ganglion, 336f Superior colliculi, 301, 301f, 303f

sheep brain, 316f Superior iliac spine, 244, 244f–245f Superior mesenteric artery, 486, 486f, 487t Superior mesenteric ganglia, 334 Superior mesenteric vein, 493, 495f, 495t Superior nasal conchae, 113, 529, 529f Superior nasal meatus, 529, 529f Superior oblique eye muscle, 360, 361f Superior orbital fi ssures, 113, 114f, 326f Superior rectus eye muscle, 360, 361f Superior sagittal sinus, 310, 311f, 312, 313f Superior vena cava, 434, 434f, 435f, 437f,

441f, 490, 490f, 490t, 491, 494f, 513f, 516f

sheep heart, 444f Supination, 164t, 167f Supinator, 214t, 215f, 216t, 217f Supine position, 1 Supraorbital foramen, 112, 114f Supraorbital margin, 114f Supraorbital ridges, 112 Suprarenal arteries, 486, 486f, 487t Suprarenal veins, 493, 494f, 495t Supraspinatus muscle, 171f, 205, 208t, 209f,

242, 242f–243f Suprasternal notch, 128, 129f, 236, 237f, 238,

239f Sural (term), 2t Surface anatomy, 233

abdomen, 240, 240f–241f arm and elbow, 246, 246f–249f, 248 back, 242, 242f–243f chest, 238, 239f foot, 252 head, 234, 235f leg and ankle, 252, 254 lower limb, 252, 253f, 254, 254f neck, 236, 237f pelvis and gluteal region, 244, 244f–245f shoulder, 246, 246f–247f thigh, 252, 254 wrist and hand, 250, 251f

736 I N D E X

Urogenital diaphragm, 601f Uterine cavity, 646, 646f–648f Uterine (fallopian) tubes, 643–644, 644f, 645f,

648f Uterus, 644f–647f, 646, 651f

histology of, 655, 655f UTI (urinary tract infection), 620t Utricle, 372, 372f Uvula, 530, 531f, 565, 566f, 567f

V Vagina, 646, 646f–649f Vaginal canal, 646, 646f Vaginal orifi ce, 646, 649f Vagus nerve:

function, distribution, action of, 327, 327t, 328t

location of, 323, 324t, 325f, 326f, 336f Vallate papillae, 378, 379f Vasa recta, 602, 603f, 604f Vascular tunic, 362 Vas deferens, 630, 630f–632f Vasoconstriction, 463 Vasodilation, 463 Vastus intermedius muscle, 218t, 219f Vastus lateralis muscle, 218t, 219f, 252, 253f,

515f Vastus medialis muscle, 218t, 219f, 252, 253f VC, see Vital capacity Veins, 431, 463–465, 465f, 466f, 490

abdomen, 493 blood pressure in, 468 cardiac, 440, 441f, 490, 490f, 490t coronary, 434, 434f, 435f, 437f cranial, 491, 491f, 491t hepatic, 493, 494f, 495f, 495t lower extremities, 496, 496f, 497t neck, 491, 491f, 491t pelvic, 493, 494f, 495t pulmonary, 497, 497f thoracic, 493, 494f, 494t upper extremities, 492, 492f, 493t valves, 465, 465f

Vena cava, 434, 434f, 435f, 437f, 510f. See also Inferior vena cava; Superior vena cava

sheep heart, 444f Ventral (directional term), 4f, 4t Ventral gray horns, 272, 273f Ventral ramus, 280, 281f Ventral root, 272, 272f, 273f, 279 Ventricles:

of brain, 312, 312f–313f human heart, 432, 433f, 434f, 437f, 440f, 441f sheep heart, 444f–446f

Ventricular depolarization, 453 Ventricular fi brillation, 454 Ventricular folds, 532, 533f Ventricular repolarization, 453 Venules, 463, 464 Vermis, 303, 303f

sheep brain, 315f Vertebral (term), 2t Vertebral arteries, 482, 482t, 483f Vertebral border, of scapula, 242 Vertebral canal, 16f Vertebral column, 120, 135f

abnormal curvatures, 128, 128f

Tunica albuginea, 628, 628f, 629f Tunica externa, 463, 465f, 466f

frog, 464f Tunica interna, 463, 465f, 466f

frog, 464f Tunica media, 463, 465f, 466f

frog, 464f Tunica vaginalis, 628, 629f TV, see Tidal volume T wave, in ECG, 453, 454f Twitch contraction, 190 Two-point discrimination test, 350 Tympanic membrane, 371, 371f Type AB blood, 420, 420f, 422f Type A blood, 420, 420f, 422f Type B blood, 420, 420f, 422f Type O blood, 420, 420f, 422f Tyrosine crystals, 622f

U Ulna, 140, 141f, 142f, 248

anterior and posterior views, 10f dorsal surface, 250, 251f

Ulnar artery, 484, 484f–485f, 485t Ulnar nerve, 248, 283, 283f, 283t Ulnar veins, 492, 492f, 493t Umbilical (term), 2t Umbilical arteries, 498, 498t, 499f Umbilical cord, 666, 667f Umbilical region, 18 Umbilical veins, 498, 498t, 499f Umbilicus, 18f, 240, 240f–241f, 666 Unfused tetanus, 190 Unipolar neurons, 260, 261f Unmyelinated fi bers, 262, 262f Upper esophageal sphincter, 567 Upper limbs. See also Arm

appendicular skeleton, 137, 140, 141f–143f, 143

arteries of, 484, 484f–485f, 485t veins of, 492, 492f, 493t

Upper limb (term), 2t Urea, 619 Ureters, 14f, 598, 598f, 600, 600f, 601f Ureteral openings, 600, 600f Urethra, 598, 600, 600f, 601f, 648f Uric acid, 619, 622f Urinalysis, 619–621, 619t–620t, 622f Urinary bladder, 14f, 598, 598f, 600, 600f, 601f,

631f, 648f Urinary system, 14f, 597, 598f

of animals, 606 female organs, 598f, 600, 600f, 601f histology of, 606–608, 607f, 608f kidneys, 597–598, 598f, 599f, 604–605, 604f,

605f male organs, 600, 601f nephrons, 598, 602, 603f, 615–618, 618f ureters/urinary bladder/urethra, 598, 600,

600f, 601f urinalysis, 619, 620t, 622f, 626t urine formation, 615–618, 618f, 619t, 620t

Urinary tract infection (UTI), 620t Urine:

and function of nephrons, 615–618, 616f, 618f

urinalysis, 619–621, 619t–620t, 622f

Trabeculae carneae, 436, 436f–437f sheep heart, 446f

Trabecular bone, see Spongy bone Trabecular sinuses, 514, 514f Trachea, 12f, 14f, 238, 516f, 528f, 534, 534f,

535f, 538t, 539f Tracheal cartilage, 534f Trachealis muscle, 534 Transcytosis, 466, 467f Transitional epithelial cells, 52, 58f Transit time, digestive system, 572–573, 572t Transport across the plasma membrane:

diffusion and osmosis across dialysis mem- brane, 43–44, 43f

diffusion as passive transport, 41–42 osmosis across plasma membrane, 45–46, 46f osmosis across vitelline membrane, 44–45

Transverse colon, 562f, 565f, 570, 570f, 571f Transverse fi ssure, 308, 308f

sheep brain, 316f Transverse foramina, 122, 123, 124f, 277f Transverse plane, 5, 5f, 6f Transverse process, 124f, 126f

vertebrae, 122, 122f Transverse section, 5 Transversus abdominis, 206t, 207f, 208f, 546,

546t, 547f Trapezius muscle, 202t, 203f, 207f, 208t, 209f,

236, 237f, 242, 242f–243f Triad, 176, 177f Triangle of auscultation, 242f–243f Triceps brachii, 211t, 213f, 246, 246f–249f, 248 Triceps refl ex (triceps jerk), 293 Tricuspid valve, 436, 436f–437f

sheep heart, 446f Trigeminal nerve:

function, distribution, action of, 327, 327t, 328t

location of, 323, 324t, 325f, 326f, 336f sheep brain, 315f

Trigger zone, 259f Trigone, 600, 600f Trihybrid cross, 676 Triiodothyronine (T3), 394, 400t Trilaminar embryonic disc, 664 Triple phosphate crystals, 622f Trochanter, 138t Trochlea of humerus, 140, 141f, 142f, 171f Trochlear nerve:

function, distribution, action of, 327, 327t, 328t

location of, 323, 324t, 325f, 326f Trochlear notch of ulna, 140 Trophoblast, 662, 663f, 664 Tropic hormones, 392 Tropomyosin, 176 Troponin molecules, 176 Trunk, skeletal muscles of, 205, 206t,

207f–210f, 208t, 210t Trypsin, 590t TSH, see Thyroid-stimulating hormone T tubules, 176, 177f Tubercle, 128, 138t

of humerus, 140, 141f, 246, 246f–247f Tuberosity, 138t, 142f Tubular reabsorption, 615, 617 Tubular secretion, 615

I N D E X 737

Working distance, 26 Wrist, see Carpus

X Xiphisternal joint, 238, 239f Xiphoid process of sternum, 128, 129f, 238,

239f

Y Yellow marrow, 96, 96f Yolk sac, 664, 665f, 666f

Z Z discs, 178, 178f, 179f Zona fasciculata, 396, 397f Zona glomerulosa, 396, 397f Zona pellucida, 662, 663f Zona reticularis, 396, 397f Zonular fi bers, 362, 362f Zygomatic bone, 106, 107f, 109f, 111f, 112,

112f, 113 Zygomatic process, 112, 115f Zygomaticus major muscle, 198t, 199f, 200f,

234, 234f–235f Zygomaticus minor muscle, 198t, 199f, 200f Zygote, 644, 652, 652f, 661, 662, 663f Zymogenic cells, 579, 580f

Visceral sensory receptors, 345 Vision, see Eye and vision Vital capacity (VC), 550, 550t Vitelline membrane, osmosis across, 44–45 Vitreous body, 363 Vitreous chamber, 363, 363f Vocal folds, 533f Volkmann canals, 97, 98f Vomer, 106, 109f, 111f, 118f Vulva, 648

W Warm receptors, 346f, 347t Wave summation, 190 Waxy cast, in urine, 622f WBCs, see White blood cells Weber test, 375, 375t Wernicke’s area, 309, 309f Whiplash, 122 White blood cells (WBCs), 33, 34f, 61, 69t,

412, 414f characteristics of, 413t differential WBC count, 415, 415f, 416t structure and function of, 412, 429f in urine, 620t

White fi brous tissue, see Dense connective tissue

White matter, 263, 263f brain, 306, 307f, 311f spinal column, 272

White pulp, of lymphatic system, 517, 517f White rami communicantes, 334 Whorls, fi ngerprint pattern, 90, 90f

anterior and posterior views, 10f cervical, thoracic, lumbar compared,

122–123, 124f–126f muscles that move, 205, 210f, 210t regions and natural curvature, 120, 121f sacrum and coccyx, 127, 127f section through thorax, 12f vertebrae parts, 122, 122f

Vertebral curvature, abnormal, 128, 128f Vertebral foramen, 122, 122f Vertebral vein, 491, 491f, 491t Vertebra prominens, 122, 123f, 242 Vertebrochondral ribs, 128 Vertebrosternal ribs, 128 Vertigo, 375 Vesicles:

in capillaries, 467f secretory, 32f, 33t seminal, 630f–633f, 632

Vestibular membrane, 373, 373f Vestibule:

of ear, 372, 372f of female external genitalia, 648 of mouth, 565, 566f, 567f

Vestibulocochlear nerve, 372, 372f, 374f function, distribution, action of, 327, 327t,

328t location of, 323, 324t, 325f, 326f, 336f

Villi, 569, 579, 581f Visceral cavity, 536, 537f Visceral epithelial layer, 606 Visceral layer, 17, 17f Visceral peritoneum, 563, 564f

Cover
Title Page
Copyright Page
Preface
Acknowledgments
Contents
INTRODUCTION

EXERCISE 1 Anatomical Language
EXERCISE 2 Organ Systems and Body Cavities

CELL AND TISSUES

EXERCISE 3 Compound Light Microscope
EXERCISE 4 Cell Structure and Cell Cycle
EXERCISE 5 Transport Across the Plasma Membrane
EXERCISE 6 Tissues

INTEGUMENTARY SYSTEM

EXERCISE 7 The Integumentary System Structure and Function

SKELETAL SYSTEM AND JOINTS

EXERCISE 8 Bone Structure and Function
EXERCISE 9 Axial Skeleton
EXERCISE 10 Appendicular Skeleton
EXERCISE 11 Joints and Synovial Joint Movements

MUSCULAR SYSTEM: SKELETAL MUSCLES

EXERCISE 12 Skeletal Muscle Structure
EXERCISE 13 Contraction of Skeletal Muscle
EXERCISE 14 Skeletal Muscles and Their Actions

SURFACE ANATOMY

EXERCISE 15 Surface Anatomy

NERVOUS SYSTEM

EXERCISE 16 Nervous Tissue
EXERCISE 17 Spinal Cord Structure and Function
EXERCISE 18 Spinal Nerves
EXERCISE 19 Somatic Reflexes
EXERCISE 20 Brain Structure and Function
EXERCISE 21 Cranial Nerves
EXERCISE 22 Autonomic Nervous System Structure and Function
EXERCISE 23 General Senses
EXERCISE 24 Special Senses

ENDOCRINE SYSTEM

EXERCISE 25 Endocrine Structure and Function

CARDIOVASCULAR SYSTEM

EXERCISE 26 Blood Components and Blood Tests
EXERCISE 27 Heart Structure and Function
EXERCISE 28 Cardiac Cycle
EXERCISE 29 Blood Vessel Structure and Function
EXERCISE 30 Blood Vessel Identification

LYMPHATIC AND IMMUNE SYSTEMS

EXERCISE 31 Lymphatic System Structure and Immune System Function

RESPIRATORY SYSTEM

EXERCISE 32 Respiratory System Structure and Function
EXERCISE 33 Pulmonary Ventilation

DIGESTIVE SYSTEM

EXERCISE 34 Digestive System Structure and Function
EXERCISE 35 Mechanical and Chemical Digestion

URINARY SYSTEM

EXERCISE 36 Urinary System Structure and Function
EXERCISE 37 Urine Formation and Urinalysis

REPRODUCTIVE SYSTEMS

EXERCISE 38 Male Reproductive System Structure and Function
EXERCISE 39 Female Reproductive System Structure and Function

HUMAN DEVELOPMENT AND HEREDITY

EXERCISE 40 Human Development
EXERCISE 41 Heredity

Answer Key to Activities
APPENDIX A: Word Roots
APPENDIX B: Skeletal Muscle Origins and Insertions
APPENDIX C: Measurements
Photo Credits
Index