Anamtomy And physiclogy Labs 1,3,and 4

EXPERIMENT 6: PHYSICAL SKELETON - THE APPENDICULAR SKELETON The appendicular skeleton is composed of bodily appendages, better known as extremities. The appendicular skeleton is divided into two regions: the upper extremity and the lower extremity. In this experiment, you will take a closer look at the bones within each of these regions along with their functionality.

PROCEDURE

The Upper Extremity The upper extremity can be divided into four parts: the pectoral girdle, the arm, the forearm, and the hand.

Pectoral Girdle 1. The pectoral girdle is composed of a pair of clavicles and scapulae (one on each side of the body). These bones are the

attachment point between the upper extremities and the axial skeleton.

2. The clavicles are thinner bones with two prominent curves. The medial (or sternal) end has a triangular shape and is convex anteriorly. It attaches to the manubrium of the sternum. The flat lateral (or acromial) end of the clavicle is convex posteriorly and attaches to the scapula. On the virtual model, locate the clavicles and note their curvatures and attachment sites. Then, use Table 16 to locate the specific features of the clavicle on your skeleton.

3. The scapulae, or shoulder blades, have a distinct, flat, triangular shape, almost appearing as “wings.” Use Table 17 to locate the specific features of the scapulae.

4. On your own body, palpate the clavicles and scapulae. Though it may be hard to palpate these on your own body, attempt to palpate the acromioclavicular joint (this will be the very top point of the shoulder) as well as the sternoclavicular joint (right before the jugular notch).

Experiment 6Physical Skeleton - The Appendicular Skeleton Materials Virtual Model

Experiment Inventory

Table 16: Clavicle Feature Locations

Clavicle Features Location

Sternoclavicular Joint Articulation between the manubrium of the sternum and the clavicle of the pectoral girdle. This is the only articulation point between the upper extremities and the axial skeleton, which provides a great deal of mobility but forgoes a great deal of stability.

Conoid Tubercle Bony projection on the inferior portion of the clavicle that serves as an attachment point for ligaments.

Acromioclavicular Joint Articulation between the acromial end of the clavicle and the acromion process of the scapula.

Table 17: Scapula Feature Locations

The Arm 1. The arm is composed of one bone, the humerus. This long bone articulates with the glenoid cavity of the scapula on its

proximal end, and with the radius and ulna of the forearm on its distal end. Locate the humerus on the virtual model, and examine both articulations.

2. Use Table 18 to locate the specific features of the humerus.

3. On your own body, palpate the shaft of the humerus. Then, palpate the lateral and medial epicondyle.

Table 18: Humerus Feature Locations

The Forearm 1. There are two bones located in the forearm: the radius and the ulna. The radius is located on the lateral portion of the

forearm, and the ulna is located on the medial portion. Locate the radius and ulna on your skeleton.

2. Focusing on the radius, locate the specific features specified in Table 19. Refer to Figure 17 (next page) as a guide.

3. Moving to the ulna, use Table 20 to locate the specific features on your skeleton. Refer to Figure 17 (next page) as a guide.

4. The wrist is composed of eight bones called the carpals that are arranged in two rows. The proximal row of carpals, from lateral to medial, is composed of the scaphoid, lunate, triangular, and pisiform carpals. This distal row of carpals, from lateral to medial, is composed of the trapezium, trapezoid, capitate, and hamate carpals. Locate these bones on the virtual model. Note also that the scaphoid and lunate carpals articulate with the distal portion of the radius.

Scapula Features Location

Acromion Process Triangular, enlarged end of the scapula that articulates with the acromial end of the clavicle.

Coracoid Process Hook-like structure on the superior anterior portion of the scapula, which serves as an attachment site for certain muscles. Suprascapular Notch Small notch at the base of the coracoid process that allows nerves to pass.

Glenoid Cavity On the lateral portion of the scapula, this small cavity articulates with the head of the humerus.

Humerus Features Location

Head Located on the proximal end, this rounded edge articulates with the glenoid cavity. Anatomical Neck Separates the head and shaft.

Shaft Long, cylindrical portion of the bone. Greater Tubercle Projection on the lateral proximal end opposite to the head. Lesser Tubercle Projection on the medial proximal end opposite the head.

Intertubercular Groove Groove that separates the greater and lesser tubercles, allowing tendons of the bicep to pass through. Trochlea Located on the distal end; articulates with the trochlear notch on the ulna.

Capitulum Located on the distal end; articulates with the radial head of the radius. Medial Epicondyle Located medially off the trochlea and capitulum; also known as the “funny bone.” Lateral Epicondyle Located laterally off the trochlea and capitulum.

Coronoid Fossa Located on the anterior surface, superior to the trochlea; depression that allows for greater mobility in the elbow.

Olecranon Fossa Located on the posterior surface, superior to the trochlea; depression that allows for greater mobility in the elbow.

Radius Features Location

Head Located on the proximal end, the circular-shaped head articulates with the capitulum of the humerus.

Radial Tuberosity Projection on the medial portion of the radius that serves as an attachment site for mus-cles and tendons.

Ulnar Notch Located on the distal end, this small cavity articulates with the medial distal end of the ulna.

Styloid Process Located on the distal end, this downward projection serves as an attachment site for ten-dons and muscles of the wrist.

Table 19: Radius Feature Locations

Figure 17: The bones of the arm and hand.

Table 20: Ulna Feature Locations

Ulna Features Location

Olecranon Process Located on the proximal end, this projection forms the bump felt on the posterior por-tion of the elbow.

Coronoid Process Located on the proximal end, this triangular projection forms the lower portion of the trochlear notch.

Radial Notch Located on the proximal end, this small cavity articulates with the medial portion of the radial head.

Styloid Process Located on the distal end, this small inferior projection serves as an attachment site for ligaments of the wrist.

The Hand 1. The hand is composed of two different sets of bones: the

metacarpals and the phalanges. The metacarpals are located in the palm, whereas the phalanges compose the fingers. There are five metacarpal bones, labeled one through five beginning on the thumb side of the palm. There are 14 phalanges, three in each finger except the thumb, where there are only two. Locate the metacarpals and phalanges on the virtual model.

2. Palpate the metacarpals and phalanges in your hands. Refer to Figure 17 as a guide.

The Lower Extremity The lower extremity can also be divided into four regions: the pelvic girdle, the thigh, the leg, and the foot.

The Pelvic Girdle 1. The pelvic girdle contains two coxal bones that articulate posteriorly with the sacrum and anteriorly with one another,

resulting in a circular appearance. Locate the pelvic girdle on the virtual model.

2. Each coxal bone is composed of three bones: the ilium, the ischium, and the pubis. These bones fuse together during puberty. Note that the fusion of these bones occurs near the center of an indent on the lateral surface of the coxal bones called the acetabulum.

3. The ilium is the largest and most superior of the three bones and articulates directly with the sacrum. Use Table 21 to locate the specified features of the ilium.

4. On your own body, palpate the iliac crest. To locate it, place your hands on your hips. The bony prominence you feel is the iliac crest.

5. The ischium is located inferior and posterior to the ilium. The ischium bears the weight of the body when seated. Locate the ischium. Use Table 22 to locate the specified features.

6. The anterior portion of the coxal bone is comprised of the pubis. Locate the pubis on the virtual model. Use Table 23 to locate the specified features of the pubis.

7. The pelvic girdle, sacrum, and coccyx compose the bony pelvis. Locate the bony pelvis on the virtual model.

8. The bony pelvis can be divided into two regions by the pelvic brim. The pelvic brim is a circular border beginning at the sacral promontory, traveling along the arcuate lines, and ending at the superior portion of the pubic crest. Locate the pelvic brim on the virtual model. The pelvic brim divides the pelvis into the false, or greater, pelvis and the true, or lesser, pelvis.

9. The false pelvis is superior to the pelvic brim, and the true pelvis is inferior to the pelvic brim. Locate the true and false pelvis. Refer to Figure 18 as a guide.

Ilium Features Location

Iliac Crest Superior region of the Ilium, flares out creating bony prominences. Auricular Surface Medially located, articulates with sacrum. Sacroiliac Joint Articulation between the sacrum and the auricular surface of the ilium.

Anterior Superior Iliac Spine Anterior end of iliac crest; important landmark of surface anatomy.

Posterior Superior Iliac Spine Posterior end of iliac crest; important landmark with an overlying dimple that can be seen on very thin individuals.

Greater Sciatic Notch Small opening located on the posterior side of the ilium that allows the sciatic nerve to pass through. Arcuate Lines Rounded edges on the medial surface of the ilium.

Iliac Fossa Concave region on the internal surface of the ilium.

Table 21: Ilium Feature Locations

Figure 18: The pelvis.

Table 22: Ischium Feature Locations

Ischium Features Location

Ischial Tuberosity Bony bulge on the posterior portion of the ischium that bears the majority of the weight when sitting; also an attachment point for muscles of the up- per leg.

Ischial Spine Superior to the ischial tuberosity, this triangular posterior projection is an important landmark; shorter and farther apart in females.

Lesser Sciatic Notch Small opening inferior to the ischial spine that allows blood vessels and nerves to pass through.

Pubis Features Location

Pubic Symphysis Cartilaginous articulation between the two pubis bones of the two coxae. Pubic Crest Anterior border of the pubis bone; site of pubic symphysis.

Obturator Foramen Oval opening bordered by the ischium and pubis that allows blood vessels and nerves to pass through.

Table 23: Pubis Feature Locations

The Thigh 1. The thigh lies inferior to the pelvic girdle. The thigh contains only one bone, the femur

(Figure 19). The femur is the longest, heaviest, and strongest bone in the body. Locate the femur on the virtual model and use Table 24 to locate the specified features.

2. Observe the articulation of distal edge of the femur with the patella. The patella is a sesamoid bone located within the tendon of the quadriceps femoris muscle group. It articulates with the femur in a depression between the medial and lateral condyles. Locate the patella on the virtual model. Then, palpate your patella.

Figure 19: Thigh bones

Femur Features Location

Head Round prominence on the proximal end of the femur that articulates with the acetab-ulum of the pelvic girdle. Neck Short, angled process that connects the head and the shaft of the femur.

Shaft Long, cylindrical body of the femur.

Greater Trochanter Attachment site for muscles located laterally to the head and neck.

Lesser Trochanter Smaller attachment site for muscles located inferiorly to the head and neck.

Medial Condyles Located on the medial distal end of the femur; articulates with the tibia.

Lateral Condyles Located on the lateral distal end of the femur; articulates with the tibia.

Medial Epicondyles Attachment site for ligaments; located proximal to the medial condyle.

Lateral Epicondyles Attachment site for ligaments; located proximal to the lateral condyle.

Table 24: Femur Feature Locations

The Leg 1. The leg is composed of two bones: the tibia and the fibula (Figure 20, next page). The tibia, or the shin bone, is the larger

of the two leg bones and is located medially to the fibula. Locate the tibia on your skeleton and use Table 25 to locate the specified features.

2. On your own body, palpate your tibial tuberosity and medial malleolus. The tibial tuberosity is located just below the kneecap and has a rough, bumpy feel. The medial malleolus is the protrusion you feel on the medial distal portion of the ankle.

3. The fibula is the smaller and more lateral of the two leg bones and does not articulate with the femur. Locate the fibula on the model skeleton and use Table 26 to locate the specified features.

4. On your own body, palpate the lateral malleolus. It can be located by the large “bump” on the lateral side of your ankle.

Femur Features Location

Head Round prominence on the proximal end of the femur that articulates with the acetab-ulum of the pelvic girdle. Neck Short, angled process that connects the head and the shaft of the femur.

Shaft Long, cylindrical body of the femur.

Greater Trochanter Attachment site for muscles located laterally to the head and neck.

Lesser Trochanter Smaller attachment site for muscles located inferiorly to the head and neck.

Medial Condyles Located on the medial distal end of the femur; articulates with the tibia.

Lateral Condyles Located on the lateral distal end of the femur; articulates with the tibia.

Medial Epicondyles Attachment site for ligaments; located proximal to the medial condyle.

Lateral Epicondyles Attachment site for ligaments; located proximal to the lateral condyle.

Table 24: Femur Feature Locations

Figure 20: Leg bones

Tibia Features Location

Medial Condyle Located on the medial proximal end of the tibia; articu-lates with the femur.

Lateral Condyle Located on the lateral proximal end of the tibia; articu-lates with the femur.

Tibial Tuberosity Rough prominence located slightly inferior to the con- dyles; attachment site for the quadriceps femoris mus- cle group.

Anterior Crest Anterior surface of the tibia.

Medial Malleolus Bony projection on the medial distal end of the tibia, articulates with the foot.

Table 25: Tibia Feature Locations

Table 26: Fibula Feature Locations

Fibula Features Location

Head Located on the proximal end of the fibula; articulates with the lateral condyle of the tibia.

Lateral Malleolus Bony projection on the lateral distal end of the fibula; articulates with the foot.

The Foot 1. The foot consists of seven tarsal bones, five metatarsal bones, and 14 phalanges (Figure 21, next page). Use Table 27 to

locate the seven different tarsal bones.

2. Locate the metatarsals on the virtual model. These bones are traditionally numbered 1 – 5, beginning on the medial side of the foot.

3. Locate the foot phalanges. Notice, similar to the thumb and fingers, that the big toe contains only two phalanges, while the other toes contain three.

4. On your own body, palpate the calcaneus, metatarsals, and phalanges of the foot.

Table 27: Tarsal Bone Locations

Tarsal Bones Location Talus

(ankle bone) Most superior; articulates with the distal end of the tibia and fibula to form the ankle joint.

Calcaneus (heel bone) Largest of the tarsals; located inferior to the talus.

Navicular Medially located; articulates proximally with the talus and distally with the cunei-forms.

Cuboid Laterally located, cube-shaped; articulates proximally with the calcaneus and distal-ly with the metatarsals.

Medial Cuneiform Medially located; articulates proximally with the navicular and distally with the metatarsals.

Intermediate Cuneiform Located between the medial and lateral cuneiform; articulates proximally with the navicular and distally with the metatarsals.

Lateral Cuneiform Laterally located, articulates proximally with the navicular, laterally with the cuboid, and distally with the metatarsals.

Figure 21: Foot bones