Muscular system
elii18
ch_11_lecture_presentation.pptxFundamentals of Anatomy & Physiology
Eleventh Edition
Chapter 11
The Muscular System
Lecture Presentation by
Deborah A. Hutchinson
Seattle University
© 2018 Pearson Education, Inc.
© 2018 Pearson Education, Inc.
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Learning Outcomes
11-1 Describe the arrangement of fascicles in the various types of muscles, and explain the resulting functional differences.
11-2 Describe the classes of levers, and explain how they make muscles more efficient.
11-3 Predict the actions of a muscle on the basis of its origin and insertion, and explain how muscles interact to produce or oppose movements.
11-4 Explain how the name of a muscle can help identify its location, appearance, or function.
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Learning Outcomes
11-5 Compare and contrast the axial and appendicular muscles.
11-6 Identify the principal axial muscles of the body, plus their origins, insertions, actions, and innervation.
11-7 Identify the principal appendicular muscles of the body, plus their origins, insertions, actions, and innervation, and compare the major functional differences between the upper and lower limbs.
11-8 Explain the functional relationship between the muscular system and other body systems, and explain the role of exercise in producing various responses in other body systems.
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An Introduction to the Muscular System
The muscular system
Consists only of skeletal muscles
Muscle organization dramatically affects power, range, and speed of movement
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11-1 Fascicle Arrangement
Skeletal muscle fibers form bundles called fascicles
Muscles are classified based on patterns of fascicle arrangement
Parallel muscles
Convergent muscles
Pennate muscles
Circular muscles
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11-1 Fascicle Arrangement
Parallel muscles
Fascicles are parallel to long axis of muscle
Some are flat
Cylindrical muscles have a central body (belly)
Example: biceps brachii
Tension developed during a contraction depends on total number of myofibrils
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Figure 11–1a Muscle Types Based on Pattern of Fascicle Arrangement.
Parallel Muscles
Parallel muscle
(Biceps brachii)
(a)
Fascicle
Body
(belly)
Cross section
a
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Figure 11–1b Muscle Types Based on Pattern of Fascicle Arrangement.
Parallel Muscles
Parallel muscle
with tendinous
bands
(Rectus abdominis)
(b)
b
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Figure 11–1c Muscle Types Based on Pattern of Fascicle Arrangement.
Parallel Muscles
Wrapping
muscle
(Supinator)
(c)
c
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11-1 Fascicle Arrangement
Convergent muscles
Muscle fibers spread out like a fan and converge on an attachment site
Example: pectoralis muscles
Muscle may pull on
Tendon
Aponeurosis
Raphe (slender band of collagen fibers)
Fibers pull in different directions, depending on activity
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Figure 11–1d Muscle Types Based on Pattern of Fascicle Arrangement.
Convergent Muscles
(d)
Convergent muscle
(Pectoralis)
Tendon
Base of
muscle
Cross
section
d
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11-1 Fascicle Arrangement
Pennate muscles
Muscle fibers pull at an angle relative to tendon
Compared to parallel muscles, pennate muscles
Do not move their tendons as far
Contain more myofibrils
Develop more tension
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11-1 Fascicle Arrangement
Pennate muscles
Unipennate
All fascicles on same side of tendon
Example: extensor digitorum
Bipennate
Fascicles on both sides of a central tendon
Example: rectus femoris
Multipennate
Tendon branches within muscle
Example: deltoid
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Figure 11–1e Muscle Types Based on Pattern of Fascicle Arrangement.
Pennate Muscles
Unipennate
muscle
(Extensor digitorum)
(e)
Extended
tendon
e
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Figure 11–1f Muscle Types Based on Pattern of Fascicle Arrangement.
Pennate Muscles
Bipennate
muscle
(Rectus femoris)
(f)
f
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Figure 11–1g Muscle Types Based on Pattern of Fascicle Arrangement.
Pennate Muscles
Multipennate muscle
(Deltoid)
(g)
Tendons
Cross section
g
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11-1 Fascicle Arrangement
Circular muscles (sphincters)
Act as valves in digestive and urinary tracts
Surround body openings and hollow organs
Contraction makes diameter of opening smaller
Example: orbicularis oris of the mouth
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Figure 11–1h Muscle Types Based on Pattern of Fascicle Arrangement.
(h)
Circular Muscles
Circular muscle
(Orbicularis oris)
Contracted
Relaxed
h
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11-2 Levers
Almost all skeletal muscles attach to bones
Site of connection to a bone affects force, speed, and range of movement
Each bone acts as a lever (a rigid, moving structure)
Moves on a fixed point (fulcrum) when muscles provide applied force to overcome the load
Each joint is a fulcrum
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11-2 Levers
Levers can change
Direction of applied force (AF)
Distance and speed produced by AF
Effective strength of AF
Three classes of levers
Based on relative positions of applied force, fulcrum, and load
First-class lever
Second-class lever
Third-class lever
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11-2 Levers
First-class lever
Fulcrum lies between applied force and load
Like a pry bar or crowbar
Example: extension of the neck and lifting the head
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Figure 11–2a The Three Classes of Levers.
First-class lever
The fulcrum (F) lies between the
applied force (AF) and the load (L).
Splenius capitis and
semispinalis capitis
Example: Pry bar
L
AF
L
Load
L
F
AF
Fulcrum
F
AF
Applied
force
F
a
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11-2 Levers
Second-class lever
Load lies between applied force and fulcrum
Like a wheelbarrow
Small force moves a large weight
Example: ankle extension (plantar flexion) by calf muscles
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Figure 11–2b The Three Classes of Levers.
Second-class lever
The load (L) lies between the applied force
(AF) and the fulcrum (F).
AF
AF
L
Gastrocnemius
Example: Wheelbarrow
Load
AF
Fulcrum
F
L
L
Applied
force
F
F
b
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11-2 Levers
Third-class lever
Applied force is between load and fulcrum
Like a pair of tongs
Most common lever in the body
Maximizes speed and distance traveled at expense of effective force
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Figure 11–2c The Three Classes of Levers.
Third-class lever
The force (F) is applied between
the load (L) and the fulcrum (F).
Applied
force
AF
AF
F
AF
Load
L
L
Biceps brachii
L
Fulcrum
F
Example: Tongs
F
c
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11-3 Origins and Insertions
Origins and insertions
Fixed point of attachment of a muscle to bone is the origin
Movable point of attachment is the insertion
Origin is usually proximal to insertion
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11-3 Origins and Insertions
Actions
Movements produced by muscle contraction
Example: adduction, elevation, pronation, etc.
Described in terms of effect on bone or joint
Example: flexion of the forearm, or flexion at the elbow
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11-3 Origins and Insertions
Muscle interactions
Muscles work in groups to maximize efficiency
Smaller muscles reach maximum tension first, followed by larger, primary muscles
Four terms refer to how muscles work together
Agonist
Antagonist
Synergist
Fixator
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11-3 Origins and Insertions
Agonist (prime mover)
Mostly responsible for producing a particular movement
Antagonist
Opposes movement of a particular agonist
Synergist
A smaller muscle that assists a larger agonist
Fixator
A synergist that assists an agonist by preventing movement at another joint
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11-3 Origins and Insertions
Muscle opposition
Agonists and antagonists work in pairs
When one contracts, the other stretches
Such as flexors–extensors and abductors–adductors
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Figure 11–3 Muscle Action (Part 1 of 3).
Flexion and Extension
At joints that permit flexion and extension, muscles whose
lines of action cross the anterior side of a joint are flexors
of that joint, and muscles whose lines of action cross the
posterior side of a joint are
extensors of that joint.
ANTERIOR
Flexor
The biceps brachii
crosses on the
anterior side of the
elbow joint. So it is
a flexor of the
elbow joint.
FLEXION
Elbow joint
POSTERIOR
Extensor
The triceps brachii
crosses on the
posterior side of
the elbow joint. So
it is an extensor of
the elbow joint.
EXTENSION
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Figure 11–3 Muscle Action (Part 2 of 3).
Abduction and Adduction
At joints that permit adduction and abduction, muscles whose
lines of action cross the medial side of a joint are adductors
of that joint, and muscles whose lines of action cross the lateral
side of a joint are abductors
of that joint.
LATERAL
Abductor
The gluteus medius
and minimus cross
the lateral side of
the hip joint. So
they are abductors
of the hip joint.
Hip joint
MEDIAL
Adductor
The adductor
magnus crosses
on the medial
side of the hip
joint. So it is an
adductor of the
hip joint.
ABDUCTION
ADDUCTION
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Figure 11–3 Muscle Action (Part 3 of 3).
Medial and Lateral Rotation
Shoulder joint
POSTERIOR
Lateral rotator
The teres minor
crosses the posterior
side of the shoulder
joint. When it
contracts, it rotates
the shoulder laterally.
ANTERIOR
Medial rotator
The subscapularis
crosses on the
anterior side of the
shoulder joint. When it
contracts, it rotates
the shoulder medially.
Scapula
Humerus
At joints that permit rotation,
movement or turning of the body
part occurs around its axis. The
shoulder joint is a
ball-and-socket joint that
permits rotation. The
subscapularis has lines of action
that cross the anterior aspect of
the shoulder joint. When the subscapularis contracts it produces medial rotation at the joint. The teres minor has lines of action that cross the posterior aspect of the shoulder joint. When the teres minor contracts, it produces lateral rotation at the shoulder.
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11-4 Naming Skeletal Muscles
The body has approximately 700 skeletal muscles
Names of muscles include descriptive information about
Region of the body (e.g., temporalis)
Position, direction, or fascicle arrangement
Structural characteristics
Action
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11-4 Naming Skeletal Muscles
Terms indicating specific regions of the body
Abdominal (abdomen)
Ancon (elbow)
Auricular (ear)
Brachial (arm)
Capitis (head)
Carpi (wrist)
Cervicis (neck)
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11-4 Naming Skeletal Muscles
Terms indicating specific regions of the body
Coccygeal (coccyx)
Costal (rib)
Cutaneous (skin)
Femoris (thigh)
Glossal (tongue)
Hallux (great toe)
Ilium (groin)
Inguinal (groin)
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11-4 Naming Skeletal Muscles
Terms indicating specific regions of the body
Lumbar (lumbar region)
Nasalis (nose)
Nuchal (back of neck)
Ocular (eye)
Oris (mouth)
Palpebra (eyelid)
Pollex (thumb)
Popliteal (posterior to knee)
Psoas (loin)
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11-4 Naming Skeletal Muscles
Terms indicating specific regions of the body
Radial (forearm)
Scapular (scapula)
Temporal (temple)
Thoracic (thorax)
Tibial (tibia; shin)
Ulnar (ulna)
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11-4 Naming Skeletal Muscles
Position, direction, or fascicle arrangement
Externus (superficialis)
Muscles visible at body surface
Internus (profundus)
Deeper muscles
Extrinsic muscles
Position or stabilize an organ
Intrinsic muscles
Located entirely within an organ
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11-4 Naming Skeletal Muscles
Position, direction, or fascicle arrangement
Transversus muscles
Run across the long axis of the body
Oblique muscles
Run at a slant to long axis
Rectus (straight) muscles
Run along the long axis
Example: rectus abdominis
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11-4 Naming Skeletal Muscles
Terms indicating position, direction, or fascicle arrangement
Anterior (front)
External (on the outside)
Extrinsic (outside the structure)
Inferior (below)
Internal (away from the surface)
Intrinsic (within the structure)
Lateral (on the side)
Medial (middle)
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11-4 Naming Skeletal Muscles
Terms indicating position, direction, or fascicle arrangement
Oblique (slanting)
Posterior (back)
Profundus (deep)
Rectus (straight)
Superficial (toward the surface)
Superior (toward the head)
Transverse (crosswise)
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11-4 Naming Skeletal Muscles
Structural characteristics
Origin and insertion
First part of name indicates origin
Second part indicates insertion
Example: genioglossus
Number of tendons
Example: biceps brachii
Shape and size
Example: trapezius, deltoid, rhomboid
Many terms refer to muscle size
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11-4 Naming Skeletal Muscles
Terms indicating structural characteristics
Nature of origin
Biceps (two heads)
Triceps (three heads)
Quadriceps (four heads)
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11-4 Naming Skeletal Muscles
Terms indicating structural characteristics
Shape
Deltoid (triangle)
Orbicularis (circle)
Pectinate (comblike)
Piriformis (pear shaped)
Platysma (flat plate)
Pyramidal (pyramid)
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11-4 Naming Skeletal Muscles
Terms indicating structural characteristics
Shape
Rhomboid (parallelogram)
Serratus (serrated)
Splenius (bandage)
Teres (round and long)
Trapezius (trapezoid)
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11-4 Naming Skeletal Muscles
Terms indicating structural characteristics
Other striking features
Alba (white)
Brevis (short)
Gracilis (slender)
Latae (wide)
Latissimus (widest)
Longissimus (longest)
Longus (long)
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11-4 Naming Skeletal Muscles
Terms indicating structural characteristics
Other striking features
Magnus (large)
Major (larger)
Maximus (largest)
Minimus (smallest)
Minor (smaller)
Vastus (great)
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11-4 Naming Skeletal Muscles
Action
Movements
Example: flexor, extensor, pronator, etc.
Occupations or habits
Example: buccinator means “trumpeter”
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11-4 Naming Skeletal Muscles
Terms indicating general actions
Abductor (movement away)
Adductor (movement toward)
Depressor (lowering movement)
Extensor (straightening movement)
Flexor (bending movement)
Levator (raising movement)
Pronator (turning into prone position)
Supinator (turning into supine position)
Tensor (tensing movement)
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11-4 Naming Skeletal Muscles
Terms indicating specific actions
Buccinator (trumpeter)
Risorius (laugher)
Sartorius (like a tailor)
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11-5 Axial and Appendicular Muscles
Divisions of the muscular system
Axial muscles
60 percent of skeletal muscles
Position head and vertebral column
Move rib cage
Form pelvic floor
Appendicular muscles
Move and support pectoral and pelvic girdles and limbs
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Figure 11–4a An Overview of the Major Skeletal Muscles (Part 1 of 6).
Axial Muscles
Frontal belly of occipitofrontalis
Temporoparietalis (reflected)
Temporalis
Sternocleidomastoid
Rectus abdominis
External oblique
Clavicle
Sternum
Appendicular Muscles
Trapezius
Deltoid
Pectoralis major
Latissimus dorsi
Serratus anterior
Biceps brachii
Triceps brachii
Brachialis
Pronator teres
Brachioradialis
Extensor carpi radialis longus
Extensor carpi radialis brevis
Palmaris longus
Flexor carpi radialis
Flexor digitorum superficialis
Flexor carpi ulnaris
Linea alba
Anterior view
ATLAS: Plates 1a; 39a–d
a
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Figure 11–4a An Overview of the Major Skeletal Muscles (Part 2 of 6).
Appendicular Muscles
Gluteus medius
Tensor fasciae latae
Pectineus
Adductor longus
Gracilis
Sartorius
Rectus femoris
Vastus lateralis
Vastus medialis
Gastrocnemius
Fibularis longus
Tibialis anterior
Soleus
Extensor digitorum longus
Medial malleolus of tibia
Lateral malleolus of fibula
Iliopsoas
Iliotibial tract
Patella
Tibia
Superior extensor retinaculum
Inferior extensor retinaculum
Anterior view
ATLAS: Plates 1a; 39a–d
a
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Figure 11–4b An Overview of the Major Skeletal Muscles (Part 1 of 6).
Axial Muscles
Occipital belly of
occipitofrontalis
Sternocleidomastoid
Appendicular Muscles
Trapezius
Deltoid
Infraspinatus
Teres minor
Teres major
External oblique
Triceps brachii (long head)
Latissimus dorsi
Brachioradialis
Anconeus
Rhomboid major
Triceps brachii (lateral head)
Extensor carpi radialis longus
Flexor carpi ulnaris
Extensor digitorum
Extensor carpi ulnaris
Posterior view
ATLAS: Plates 1b; 40a,b
b
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Figure 11–4b An Overview of the Major Skeletal Muscles (Part 2 of 6).
Appendicular Muscles
Gluteus medius
Tensor fasciae latae
Gluteus maximus
Adductor magnus
Semitendinosus
Iliotibial tract
Semimembranosus
Gracilis
Biceps femoris
Sartorius
Plantaris
Gastrocnemius
Soleus
Calcaneal tendon
Calcaneus
Posterior view
ATLAS: Plates 1b; 40a,b
b
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11-6 Axial Muscles
Axial muscles
Grouped based on location and function
Muscles of the head and neck
Muscles of the vertebral column
Oblique and rectus muscles
Muscles of the pelvic floor
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11-6 Axial Muscles
Muscles of the head and neck
Muscles of facial expression
Originate on skull
Muscles of mastication
Move the mandible
Muscles of the tongue
Names end in glossus
Muscles of the pharynx
Begin swallowing process
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11-6 Axial Muscles
Muscles of the head and neck
Extrinsic eye muscles
Originate on surface of orbit
Control position of eyes
Muscles of the anterior neck
Control position of larynx
Depress the mandible and tense floor of mouth
Support muscles of tongue and pharynx
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11-6 Axial Muscles
Muscles of facial expression
Orbicularis oris
Constricts the mouth opening
Buccinator
Moves food across the teeth
In infants, provides suction for nursing
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11-6 Axial Muscles
Muscles of facial expression
Muscles of the epicranium (scalp)
Temporoparietalis
Occipitofrontalis
Frontal belly and occipital belly are separated by epicranial aponeurosis
Platysma
Covers anterior surface of neck
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Figure 11–5a Muscles of Facial Expression.
Epicranial aponeurosis
Frontal belly of occipitofrontalis
Procerus
Orbicularis oculi
Nasalis
Levator labii superioris
Zygomaticus minor
Levator anguli oris
Zygomaticus major
Mentalis (cut)
Orbicularis oris
Depressor labii inferioris
Depressor anguli oris
Omohyoid
Temporoparietalis
(cut and reflected)
Temporalis
Occipital belly of
occipitofrontalis
Masseter
Buccinator
Sternocleidomastoid
Trapezius
Platysma (cut and reflected)
Lateral view
a
63
Figure 11–5b Muscles of Facial Expression.
Frontal belly of
occipitofrontalis
Corrugator supercilii
Temporalis
(temporoparietalis removed)
Orbicularis oculi
Nasalis
Zygomaticus minor
Zygomaticus major
Orbicularis oris
Risorius
Platysma
Mentalis (cut)
Thyroid cartilage of the larynx
Epicranial aponeurosis
Temporoparietalis
(cut and reflected)
Temporalis
Procerus
Levator labii superioris
Levator anguli oris
Masseter
Buccinator
Depressor anguli oris
Depressor labii inferioris
Sternal head of
sternocleidomastoid
Clavicular head of
sternocleidomastoid
Trapezius
Clavicle
Platysmae (cut and
reflected)
Anterior view
b
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11-6 Axial Muscles
Extrinsic eye muscles (oculomotor muscles)
Inferior rectus
Medial rectus
Superior rectus
Lateral rectus
Inferior oblique
Superior oblique
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Figure 11–6a Extrinsic Eye Muscles.
Optic
nerve
Frontal
bone
Levator
palpebrae
superioris
Trochlea
(ligamentous sling)
Extrinsic Eye
Muscles
Superior oblique
Superior rectus
Lateral rectus
Inferior oblique
Inferior rectus
Maxilla
Lateral surface, right eye
a
66
Figure 11–6b Extrinsic Eye Muscles.
Trochlea
Extrinsic Eye
Muscles
Superior oblique
Superior rectus
Levator
palpebrae
superioris
Optic
nerve
Medial rectus
Inferior rectus
Medial surface, right eye
b
67
Figure 11–6c Extrinsic Eye Muscles.
Superior
rectus
Trochlea
Superior
oblique
Lateral
rectus
Inferior
oblique
Medial
rectus
Inferior
rectus
Anterior view, right eye
c
68
Figure 11–6d Extrinsic Eye Muscles.
Trochlear
nerve (IV)
Levator palpebrae
superioris
Superior rectus
Oculomotor
nerve (III)
Trochlea
Superior
oblique
Medial rectus
Optic nerve (II)
Inferior rectus
Lateral rectus
Abducens
nerve (VI)
Inferior oblique
Anterior view, right orbit
d
69
11-6 Axial Muscles
Muscles of mastication
Masseter
Strongest jaw muscle
Temporalis
Helps elevate the mandible
Pterygoid muscles
Elevate, depress, and protract mandible
Slide mandible from side to side (lateral excursion)
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Figure 11–7a Muscles of Mastication.
Superior temporal line
Muscles of
Mastication
Temporalis
Masseter
Capsule of
temporomandibular joint
Lateral view. The temporalis passes medial to the zygomatic
arch to insert on the coronoid process of the mandible. The
masseter inserts on the angle and lateral surface of the mandible.
a
71
Figure 11–7b Muscles of Mastication.
Muscles of
Mastication
Lateral pterygoid
Medial pterygoid
Cut edge of mandible
Lateral view, pterygoid muscles exposed. The location
and orientation of the pterygoid muscles are seen after the
overlying muscles and a portion of the mandible are removed.
b
72
11-6 Axial Muscles
Muscles of the tongue
All named for origin and insertion
Palatoglossus
Styloglossus
Genioglossus
Hyoglossus
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Figure 11–8 Muscles of the Tongue.
Muscles of the
Tongue
Palatoglossus (cut)
Styloglossus
Hyoglossus
Mandible
(cut)
Genioglossus
Hyoid bone
Styloid
process
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11-6 Axial Muscles
Muscles of the pharynx
Pharyngeal constrictor muscles
Move food into esophagus
Palatal muscles
Elevate the soft palate and adjacent portions
Pull open entrance to auditory tube
Laryngeal elevators
Raise the larynx
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Figure 11–9 Muscles of the Pharynx.
Palatal Muscles
Tensor veli
palatini
Levator veli
palatini
Laryngeal elevators
Pharyngeal
Constrictors
Superior
Middle
Inferior
Esophagus
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11-6 Axial Muscles
Muscles of the anterior neck
Digastric
Controls position of larynx
Extends from chin to hyoid bone
And from hyoid to mastoid portion of temporal bone
Mylohyoid
Elevates floor of the mouth
Depresses jaw
Geniohyoid
Extends between hyoid bone and chin
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11-6 Axial Muscles
Muscles of the anterior neck
Stylohyoid
Between hyoid bone and styloid process of skull
Sternocleidomastoid
Extends from clavicle and sternum to mastoid
Turns head obliquely to opposite side
Omohyoid
Attaches scapula, clavicle, first rib, and hyoid
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Figure 11–10a Muscles of the Anterior Neck.
Mylohyoid
(cut and
reflected)
Mandible
Mylohyoid
Digastric
Anterior belly
Posterior belly
Sternocleidomastoid
(cut)
Omohyoid
Superior belly
Inferior belly
Clavicle
Sternocleidomastoid
(cut heads)
Geniohyoid
Stylohyoid
Hyoid bone
Thyrohyoid
Thyroid cartilage
of larynx
Sternothyroid
Sternohyoid
Sternocleidomastoid
Clavicular head
Sternal head
Sternum
Anterior view
a
79
Figure 11–10b Muscles of the Anterior Neck.
Genioglossus
(cut)
Mylohyoid
Geniohyoid
Mandible
Hyoid bone
Superior view
b
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11-6 Axial Muscles
Muscles of the vertebral column
Erector spinae muscles
Superficial and deep layers
Spinal flexors
81
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11-6 Axial Muscles
Muscles of the vertebral column
Erector spinae, superficial layer
Spinalis group
Longissimus group
Iliocostalis group
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11-6 Axial Muscles
Muscles of the vertebral column
Erector spinae, deep layer
Semispinalis group
Multifidus
Interspinales
Intertransversarii
Rotatores
83
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Figure 11–11 Muscles of the Vertebral Column (Part 1 of 2).
Erector Spinae, Deep Layer
Semispinalis Group
Semispinalis capitis
Semispinalis cervicis
Semispinalis thoracis
Erector Spinae, Superficial Layer
Splenius capitis
Spinalis, Longissimus, and
Iliocostalis Groups
Longissimus capitis
Spinalis cervicis
Longissimus cervicis
Iliocostalis cervicis
Multifidus
Iliocostalis thoracis
Longissimus thoracis
Spinalis thoracis
Iliocostalis lumborum
84
11-6 Axial Muscles
Muscles of the vertebral column
Spinal flexors
Neck
Longus capitis and longus colli
Rotate and flex the neck
Lumbar region
Quadratus lumborum
Flexes vertebral column and depresses ribs
85
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Figure 11–11 Muscles of the Vertebral Column (Part 2 of 2).
Intervertebral Muscles,
Posterior View
Rotatores
Quadratus lumborum
Flexors of the Anterior
Cervical and Thoracic Spine
Spinal Flexors
Spinous
process
of
vertebra
Interspinales
Transverse
process of
vertebra
Longus
capitis
Thoracodorsal
fascia
Posterior view
Longus
colli
Intertransversarii
86
11-6 Axial Muscles
Oblique and rectus muscles
Lie within body wall
Oblique muscles
Compress underlying structures
Rotate vertebral column
Rectus muscles
Flex vertebral column
Oppose erector spinae
87
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11-6 Axial Muscles
Oblique muscles
Cervical region
Scalene muscles
Flex the neck and elevate ribs
Thoracic region
External and internal intercostal muscles
Aid in breathing movements of ribs
Transversus thoracis
Crosses posterior surface of sternum
88
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11-6 Axial Muscles
Oblique muscles
Abdominopelvic region (same pattern as thoracic)
External oblique
Internal oblique
Transversus abdominis
89
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11-6 Axial Muscles
Rectus muscles
Rectus abdominis
Between xiphoid process and pubic symphysis
Divided longitudinally by linea alba
Divided transversely by tendinous inscriptions
90
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11-6 Axial Muscles
The diaphragm
Divides thoracic and abdominopelvic cavities
Major muscle used in breathing
91
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Figure 11–12a Oblique and Rectus Muscles and the Diaphragm.
Scalenes
Anterior
Middle
Posterior
Anterior view,
cervical region
a
92
Figure 11–12b Oblique and Rectus Muscles and the Diaphragm.
Serratus
anterior
External
oblique
Tendinous
inscription
Internal intercostal
External intercostal
External oblique (cut)
Internal oblique
Cut edge of
rectus sheath
Rectus abdominis
Anterior view
Linea alba
b
93
Figure 11–12c Oblique and Rectus Muscles and the Diaphragm.
Transversus
thoracis
Xiphoid
process
Costal
cartilages
External
oblique
Inferior
vena cava
T10
External
intercostal
Internal
intercostal
Esophagus
Serratus
anterior
Diaphragm
Thoracic aorta
Spinal cord
Central tendon
of diaphragm
Erector spinae group
Superior view of the diaphragm
Rectus
abdominis
c
94
Figure 11–12d Oblique and Rectus Muscles and the Diaphragm.
Rectus abdominis
Linea alba
External
oblique
Transversus
abdominis
Internal
oblique
L3
Quadratus
lumborum
Thoracolumbar
fascia
Transverse section through
the abdominal cavity
Rectus sheath
d
95
11-6 Axial Muscles
Muscles of the pelvic floor
Function to
Support organs of pelvic cavity
Flex sacrum and coccyx
Control movement of materials through urethra and anus
96
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11-6 Axial Muscles
Muscles of the pelvic floor
Perineum
Region bounded by inferior margins of pelvis
Divided by ischial tuberosities into
Anterior urogenital triangle
Posterior anal triangle
Pelvic diaphragm
Forms muscular foundation of anal triangle
Extends to pubic symphysis
97
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11-6 Axial Muscles
Perineum
Urogenital and pelvic diaphragms
Do not completely close pelvic outlet
Urethra, anus, vagina (in females), muscles, nerves, and blood vessels pass through
Sphincters permit voluntary control of urination and defecation
98
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Figure 11–13a Muscles of the Pelvic Floor (Part 1 of 2).
Superficial Dissections
Vagina
Urogenital Triangle
Ischiocavernosus
Bulbospongiosus
Superficial
transverse perineal
muscle
Anus
Gluteus maximus
Female
a
99
Figure 11–13a Muscles of the Pelvic Floor (Part 2 of 2).
Deep Dissections
UROGENITAL TRIANGLE
OF PERINEUM
Urethra
External urethral sphincter
Deep transverse perineal
muscle
Central tendon of perineum
Pelvic Diaphragm
Pubococcygeus
Iliococcygeus
Coccygeus
Sacrotuberous ligament
Levator
ani
External anal sphincter
Female
ANAL TRIANGLE
a
100
Figure 11–13b Muscles of the Pelvic Floor (Part 1 of 2).
Superficial Dissections
Testis
Urethra (connecting
segment removed)
Urogenital Triangle
Bulbospongiosus
Ischiocavernosus
Superficial
transverse perineal
muscle
Anus
Gluteus maximus
Male
b
101
Figure 11–13b Muscles of the Pelvic Floor (Part 2 of 2).
Deep Dissections
UROGENITAL TRIANGLE
OF PERINEUM
External urethral sphincter
Deep transverse perineal
muscle
Pelvic Diaphragm
Pubococcygeus
Central tendon of perineum
Levator
ani
Iliococcygeus
External anal sphincter
Coccygeus
Sacrotuberous ligament
Male
ANAL TRIANGLE
b
102
11-7 Appendicular Muscles
Appendicular muscles
Position and stabilize pectoral and pelvic girdles
Move upper and lower limbs
Two groups of appendicular muscles
Muscles of the shoulders and upper limbs
Muscles of the pelvis and lower limbs
103
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Figure 11–14a An Overview of the Appendicular Muscles of the Trunk.
Superficial Dissection
Deep Dissection
Axial Muscles
Axial Muscles
Platysma
Sternocleidomastoid
Appendicular Muscles
Appendicular Muscles
Deltoid
Pectoralis major
Latissimus dorsi
Trapezius
Subclavius
Deltoid (cut
and reflected)
Pectoralis minor
Subscapularis
Pectoralis major
(cut and reflected)
Coracobrachialis
Biceps brachii
Teres major
Serratus anterior
Axial Muscles
Serratus anterior
Axial Muscles
External oblique
Rectus sheath
External intercostal
Internal intercostal
External oblique
(cut and reflected)
Rectus abdominis
Internal oblique (cut)
Superficial inguinal ring
Transversus abdominis
Anterior view
ATLAS: Plates 25; 39b
a
104
Figure 11–14b An Overview of the Appendicular Muscles of the Trunk.
Superficial Dissection
Axial Muscles
Sternocleidomastoid
Deep Dissection
Axial Muscles
Semispinalis capitis
Splenius capitis
Appendicular Muscles
Trapezius
Deltoid
Infraspinatus
Teres minor
Teres major
Triceps
brachii
Appendicular Muscles
Levator scapulae
Supraspinatus
Rhomboid minor
(cut and reflected)
Serratus posterior
superior
Rhomboid major
(cut and relflected)
Serratus anterior
Latissimus dorsi
(cut and reflected)
Latissimus dorsi
(right side cut
and reflected)
Thoracolumbar
fascia
Iliac crest
Axial Muscles
Erector spinae
muscle group
Serratus posterior
inferior
External oblique
Internal oblique
Posterior view
ATLAS: Plate 40a,b
b
105
11-7 Appendicular Muscles
Muscles of the shoulders and upper limbs
Four groups
Muscles that position the pectoral girdle
Muscles that move the arm
Muscles that move the forearm and hand
Muscles that move the fingers
106
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11-7 Appendicular Muscles
Muscles that position the pectoral girdle
Trapezius
Large and superficial
Covers back and portions of the neck
Extends to base of skull
Originates on midline of neck and back
Inserts on clavicles and scapular spines
107
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Figure 11–15b Muscles That Position the Pectoral Girdle (Part 1 of 2).
Superficial Dissection
Muscles That Position
the Pectoral Girdle
Trapezius
Posterior view
ATLAS: Plates 27b; 40a–b
b
108
11-7 Appendicular Muscles
Muscles that position the pectoral girdle
Serratus anterior
Fan-shaped muscle on chest
Originates along ribs
Inserts on anterior margin of scapula
109
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11-7 Appendicular Muscles
Muscles that position the pectoral girdle
Subclavius
Originates on ribs
Inserts on clavicle
Pectoralis minor
Originates on ribs
Attaches to coracoid process of scapula
110
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Figure 11–15a Muscles That Position the Pectoral Girdle (Part 1 of 2).
Muscles That Position
the Pectoral Girdle
Trapezius
Levator scapulae
Subclavius
Pectoralis minor
Pectoralis major
(cut and reflected)
Internal intercostal
muscles
External intercostal
muscles
T12
Anterior view
ATLAS: Plates 39a–d; 40a–b
a
T12
111
Figure 11–15a Muscles That Position the Pectoral Girdle (Part 2 of 2).
Muscles That Position
the Pectoral Girdle
Pectoralis minor
(cut)
Serratus anterior
Biceps brachii, short head
Biceps brachii, long head
T12
Anterior view
ATLAS: Plates 39a–d; 40a–b
a
T12
112
11-7 Appendicular Muscles
Muscles that position the pectoral girdle
Rhomboid major, rhomboid minor, and levator scapulae
Deep to trapezius
Attach to cervical and thoracic vertebrae
Insert on vertebral border of each scapula
113
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Figure 11–15b Muscles That Position the Pectoral Girdle (Part 2 of 2).
Deep Dissection
Muscles That Position
the Pectoral Girdle
Levator scapulae
Rhomboid minor
Scapula
Rhomboid major
Serratus anterior
Triceps
brachii
T12 vertebra
Posterior view
ATLAS: Plates 27b; 40a–b
b
114
11-7 Appendicular Muscles
Muscles that move the arm
Deltoid
The major abductor
Supraspinatus
Assists deltoid
115
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Figure 11–16b Muscles That Move the Arm (Part 1 of 2).
Superficial Dissection
Muscles That Move
the Arm
Supraspinatus*
Deltoid
Latissimus dorsi
Vertebra T1
(*Rotator cuff muscle)
Thoracolumbar fascia
Posterior view
b
116
11-7 Appendicular Muscles
Muscles that move the arm
Subscapularis and teres major
Produce medial rotation at shoulder
Infraspinatus and teres minor
Produce lateral rotation at shoulder
Coracobrachialis
Produces flexion and adduction at shoulder
117
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Figure 11–16a Muscles That Move the Arm (Part 2 of 2).
Deep Dissection
Ribs (cut)
Muscles That Move
the Arm
Subscapularis*
Coracobrachialis
Teres major
(*Rotator cuff muscle)
Biceps brachii, short head
Biceps brachii, long head
Vertebra T12
Anterior view
a
118
Figure 11–16b Muscles That Move the Arm (Part 2 of 2).
Deep Dissection
Muscles That Move
the Arm
Supraspinatus*
Teres minor*
Teres major
(*Rotator cuff muscles)
Triceps brachii, long head
Triceps brachii, lateral head
Infraspinatus*
Posterior view
b
119
11-7 Appendicular Muscles
Muscles that move the arm
Pectoralis major
Between anterior chest and greater tubercle of humerus
Produces flexion at shoulder joint
Latissimus dorsi
Between thoracic vertebrae and humerus
Produces extension at shoulder joint
120
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Figure 11–16a Muscles That Move the Arm (Part 1 of 2).
Superficial Dissection
Sternum
Clavicle
Muscles That Move
the Arm
Deltoid
Pectoralis major
Anterior view
a
121
Figure 11–16b Muscles That Move the Arm (Part 1 of 2).
Superficial Dissection
Muscles That Move
the Arm
Supraspinatus*
Deltoid
Latissimus dorsi
Vertebra T1
(*Rotator cuff muscle)
Thoracolumbar fascia
Posterior view
b
122
11-7 Appendicular Muscles
Rotator cuff
Muscles involved in shoulder rotation
Supraspinatus, infraspinatus, teres minor, subscapularis, and their tendons
123
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11-7 Appendicular Muscles
Muscles that move the forearm and hand
Most originate on humerus and insert on forearm and wrist
Exceptions
The major flexor (biceps brachii)
The major extensor (triceps brachii)
Biceps brachii and long head of triceps brachii originate on scapula
124
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11-7 Appendicular Muscles
Muscles that move the forearm and hand
Extensors
Mainly on posterior and lateral surfaces of arm
Flexors
Mainly on anterior and medial surfaces
125
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11-7 Appendicular Muscles
Extensors of the elbow
Triceps brachii
Long head originates on scapula
Inserts on olecranon of ulna
Anconeus
126
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Figure 11–17a Muscles That Move the Forearm and Hand.
Muscles That Move
the Forearm
ACTION AT THE
ELBOW
Triceps brachii,
long head
Triceps brachii,
lateral head
Brachioradialis
Anconeus
Olecranon of ulna
Muscles That
Move the Hand
ACTION AT THE
HAND
Flexor
carpi ulnaris
Extensor carpi
radialis longus
Extensor
carpi ulnaris
Extensor carpi
radialis brevis
ANTERIOR
Extensor digitorum
Abductor
pollicis longus
Extensor
pollicis brevis
Flexor digitorum
superficialis
Flexor carpi
ulnaris
Flexor digitorum
profundus
Ulna
Extensor carpi
ulnaris
Extensor digiti minimi
POSTERIOR
Flexor carpi radialis
Brachioradialis
Flexor pollicis
longus
Radius
Extensor carpi
radialis longus
Extensor carpi
radialis brevis
Abductor pollicis
longus
Extensor digitorum
Extensor pollicis
longus
Ulna
Extensor retinaculum
Posterior view, superficial layer
Palmaris longus
a
127
11-7 Appendicular Muscles
Flexors of the elbow
Biceps brachii
Flexes elbow and supinates forearm
Stabilizes shoulder joint
Originates on scapula
Inserts on radial tuberosity of radius
Brachialis and brachioradialis
Flex the elbow
128
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Figure 11–17b Muscles That Move the Forearm and Hand.
POSTERIOR
Lateral head
Long head
Medial head
Triceps
brachii
Coracoid process
of scapula
Humerus
Coracobrachialis
Muscles That Move
the Forearm
ACTION AT THE ELBOW
LATERAL
Humerus
Vein
Artery
Nerve
Brachialis
Biceps brachii
ANTERIOR
Biceps brachii, short head
Biceps brachii, long head
Triceps brachii, long head
Triceps brachii,
medial head
Brachialis
Brachioradialis
Medial epicondyle
of humerus
Pronator teres
Muscles That Move the Hand
ACTION AT THE HAND
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Flexor digitorum superficialis
Pronator quadratus
Flexor retinaculum
Anterior view, superficial layer
b
129
11-7 Appendicular Muscles
Muscles involved in supination and pronation
Supinator and pronator teres
Originate on humerus and ulna
Rotate radius
Pronator quadratus
Originates on ulna
Assists pronator teres in opposing actions of supinator or biceps brachii
130
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Figure 11–18e Muscles That Move the Hand and Fingers.
Muscles That
Move the Forearm
SUPINATOR AND
PRONATORS
Supinator
Pronator teres
Pronator quadratus
Ulna
Radius
Supination
Pronation
Supination and pronation
e
131
11-7 Appendicular Muscles
Flexors of the wrist
Flexor carpi ulnaris
Flexes and adducts wrist
Flexor carpi radialis
Flexes and abducts wrist
Palmaris longus
Flexes wrist
132
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Figure 11–17b Muscles That Move the Forearm and Hand.
POSTERIOR
Lateral head
Long head
Medial head
Triceps
brachii
Coracoid process
of scapula
Humerus
Coracobrachialis
Muscles That Move
the Forearm
ACTION AT THE ELBOW
LATERAL
Humerus
Vein
Artery
Nerve
Brachialis
Biceps brachii
ANTERIOR
Biceps brachii, short head
Biceps brachii, long head
Triceps brachii, long head
Triceps brachii,
medial head
Brachialis
Brachioradialis
Medial epicondyle
of humerus
Pronator teres
Muscles That Move the Hand
ACTION AT THE HAND
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Flexor digitorum superficialis
Pronator quadratus
Flexor retinaculum
Anterior view, superficial layer
b
133
11-7 Appendicular Muscles
Extensors of the wrist
Extensor carpi radialis
Extends and abducts wrist
Extensor carpi ulnaris
Extends and adducts wrist
134
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Figure 11–17a Muscles That Move the Forearm and Hand.
Muscles That Move
the Forearm
ACTION AT THE
ELBOW
Triceps brachii,
long head
Triceps brachii,
lateral head
Brachioradialis
Anconeus
Olecranon of ulna
Muscles That
Move the Hand
ACTION AT THE
HAND
Flexor
carpi ulnaris
Extensor carpi
radialis longus
Extensor
carpi ulnaris
Extensor carpi
radialis brevis
ANTERIOR
Extensor digitorum
Abductor
pollicis longus
Extensor
pollicis brevis
Flexor digitorum
superficialis
Flexor carpi
ulnaris
Flexor digitorum
profundus
Ulna
Extensor carpi
ulnaris
Extensor digiti minimi
POSTERIOR
Flexor carpi radialis
Brachioradialis
Flexor pollicis
longus
Radius
Extensor carpi
radialis longus
Extensor carpi
radialis brevis
Abductor pollicis
longus
Extensor digitorum
Extensor pollicis
longus
Ulna
Extensor retinaculum
Posterior view, superficial layer
Palmaris longus
a
135
11-7 Appendicular Muscles
Tendons of forearm muscles that cross the wrist pass through synovial tendon sheaths
Extensor retinaculum
Wide band of connective tissue
Posterior surface of wrist
Stabilizes tendons of extensor muscles
Flexor retinaculum
Anterior surface of wrist
Stabilizes tendons of flexor muscles
136
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Figure 11–19b Intrinsic Muscles of the Hand.
Tendon of extensor indicis
Intrinsic Muscles of the Hand
First dorsal interosseus
Abductor digiti minimi
Tendon of extensor pollicis longus
Tendon of extensor pollicis brevis
Tendon of extensor carpi radialis longus
Tendon of extensor carpi radialis brevis
Tendons of extensor digitorum
Tendon of extensor digiti minimi
Tendon of extensor carpi ulnaris
Extensor retinaculum
Right hand, posterior view
b
137
Figure 11–19a Intrinsic Muscles of the Hand.
Tendon of flexor digitorum profundus
Tendon of flexor digitorum superficialis
Synovial sheaths
Intrinsic Muscles of
the Hand
Lumbricals
Palmar interosseus
First dorsal interosseus
Abductor digiti minimi
Flexor digiti minimi brevis
Opponens digiti minimi
Palmaris brevis (cut)
Flexor retinaculum
Tendon of palmaris longus
Tendon of flexor carpi ulnaris
Tendons of flexor digitorum
Tendon of flexor pollicis longus
Intrinsic Muscles of
the Thumb
Adductor pollicis
Flexor pollicis brevis
Opponens pollicis
Abductor pollicis brevis
Tendon of flexor
carpi radialis
Right hand, anterior (palmar) view
a
138
11-7 Appendicular Muscles
Muscles that move the fingers
Extrinsic muscles of the hand
Lie in forearm
Only tendons cross wrist
Provide strength and gross movement of hand and fingers
139
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Figure 11–18a Muscles That Move the Hand and Fingers.
Tendon of
biceps brachii
Radius
Brachioradialis
(retracted)
Median nerve
Brachial artery
Flexor carpi ulnaris
(retracted)
Pronator teres (cut)
Muscles That Flex the
Fingers and Thumb
Flexor digitorum
superficialis
Flexor pollicis longus
Flexor digitorum
profundus
LATERAL
MEDIAL
Anterior view, middle layer
a
140
Figure 11–18b Muscles That Move the Hand and Fingers.
Supinator
Brachialis
Muscles That Flex the
Fingers and Thumb
Flexor pollicis longus
Flexor digitorum
profundus
Cut tendons
of flexor
digitorum
superficialis
Pronator
quadratus
Anterior view, deepest layer
b
141
Figure 11–18c Muscles That Move the Hand and Fingers.
Anconeus
Muscles That
Extend the Fingers
Extensor digitorum
Extensor digiti
minimi
Abductor pollicis
longus
Tendon of
extensor
pollicis longus
Extensor pollicis
brevis
MEDIAL
LATERAL
Posterior view, middle layer
c
142
Figure 11–18d Muscles That Move the Hand and Fingers.
Anconeus
Supinator
Muscles That
Move the Thumb
Extensor pollicis longus
Abductor pollicis longus
Extensor
indicis
Ulna
Tendon of extensor
digiti minimi (cut)
Tendon of
extensor
digitorum (cut)
Extensor pollicis brevis
Radius
Posterior view, deepest layer
d
143
11-7 Appendicular Muscles
Muscles that move the fingers
Intrinsic muscles
Originate on carpal and metacarpal bones
No muscles originate on phalanges
Only tendons extend across distal joints of fingers
Provide fine motor movement of the hand
144
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Figure 11–19a Intrinsic Muscles of the Hand.
Tendon of flexor digitorum profundus
Tendon of flexor digitorum superficialis
Synovial sheaths
Intrinsic Muscles of
the Hand
Lumbricals
Palmar interosseus
First dorsal interosseus
Abductor digiti minimi
Flexor digiti minimi brevis
Opponens digiti minimi
Palmaris brevis (cut)
Flexor retinaculum
Tendon of palmaris longus
Tendon of flexor carpi ulnaris
Tendons of flexor digitorum
Tendon of flexor pollicis longus
Intrinsic Muscles of
the Thumb
Adductor pollicis
Flexor pollicis brevis
Opponens pollicis
Abductor pollicis brevis
Tendon of flexor
carpi radialis
Right hand, anterior (palmar) view
a
145
Figure 11–19b Intrinsic Muscles of the Hand.
Tendon of extensor indicis
Intrinsic Muscles of the Hand
First dorsal interosseus
Abductor digiti minimi
Tendon of extensor pollicis longus
Tendon of extensor pollicis brevis
Tendon of extensor carpi radialis longus
Tendon of extensor carpi radialis brevis
Tendons of extensor digitorum
Tendon of extensor digiti minimi
Tendon of extensor carpi ulnaris
Extensor retinaculum
Right hand, posterior view
b
146
11-7 Appendicular Muscles
Muscles of the pelvis and lower limbs
Pelvic girdle is tightly bound to axial skeleton
Permits little movement
Few axial muscles influence position of pelvis
A range of movements is possible in lower limbs
147
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11-7 Appendicular Muscles
Muscles that position the lower limbs
Three functional groups
Muscles that move the thigh
Muscles that move the leg
Muscles that move the foot and toes
148
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11-7 Appendicular Muscles
Muscles that move the thigh
Gluteal muscles
Lateral rotators
Adductors
Iliopsoas
149
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11-7 Appendicular Muscles
Gluteal muscles
Gluteus maximus
Largest, most posterior gluteal muscle
Produces extension and lateral rotation at hip
Tensor fasciae latae
Works with gluteus maximus
To pull on iliotibial tract of lateral surface of thigh
Gluteus medius and gluteus minimus
Originate anterior to gluteus maximus
Insert on greater trochanter of femur
150
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Figure 11–20a Muscles That Move the Thigh.
Iliac crest
Gluteus
medius (cut)
Gluteus
maximus
(cut)
Sacrum
Gluteal Group
Gluteus medius
Gluteus maximus
Gluteus minimus
Obturator
internus
Gluteal region, posterior view
a
151
Figure 11–20b Muscles That Move the Thigh.
Gluteal Group
Gluteus medius
Gluteus maximus
Tensor fasciae
latae
Rectus
femoris
Sartorius
Iliotibial tract
Vastus lateralis
Biceps femoris,
long head
Biceps femoris,
short head
Semimembranosus
Patella
Plantaris
Head of fibula
Lateral view
Patellar
ligament
b
152
11-7 Appendicular Muscles
Lateral rotators
Group of six muscles, including the dominant
Piriformis
Obturator
153
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Figure 11–20c Muscles That Move the Thigh.
Gluteal Group
Gluteus
maximus
(cut)
Gluteus
medius
(cut)
Gluteus
minimus
Tensor
fasciae
latae
Lateral Rotator Group
Piriformis
Superior gemellus
Obturator internus
Inferior gemellus
Quadratus femoris
Ischial tuberosity
Iliotibial tract
Posterior view, deep muscles
c
154
Figure 11–20d Muscles That Move the Thigh.
Iliopsoas Group
Psoas major
Iliacus
L5
Lateral Rotator Group
Piriformis
Obturator internus
Obturator externus
Inguinal ligament
Adductor Group
Pectineus
Adductor brevis
Adductor longus
Adductor magnus
Gracilis
Anterior view of
the iliopsoas and
adductor groups
d
L5
155
11-7 Appendicular Muscles
Adductors
Pectineus, adductor brevis, adductor longus, and gracilis
Produce hip flexion and adduction
Adductor magnus
Produces adduction and extension or flexion
Also, medial or lateral rotation at hip
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11-7 Appendicular Muscles
Iliopsoas
Two hip flexors that insert on the same tendon
Psoas major
Iliacus
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Figure 11–20d Muscles That Move the Thigh.
Iliopsoas Group
Psoas major
Iliacus
L5
Lateral Rotator Group
Piriformis
Obturator internus
Obturator externus
Inguinal ligament
Adductor Group
Pectineus
Adductor brevis
Adductor longus
Adductor magnus
Gracilis
Anterior view of
the iliopsoas and
adductor groups
d
L5
158
11-7 Appendicular Muscles
Muscles that move the leg
Flexors of the knee
Most originate on edges of pelvis
Insert on tibia and fibula
Knee extensors
Most originate on shaft of femur
Insert on the patella
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11-7 Appendicular Muscles
Flexors of the knee
Hamstrings
Biceps femoris
Semitendinosus
Semimembranosus
Sartorius
Popliteus
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Figure 11–21a Muscles That Move the Leg.
Iliac crest
Gluteus medius
Tensor fasciae
latae
Gluteus maximus
Adductor magnus
Gracilis
Iliotibial tract
Flexors of the Knee
Biceps femoris, long head*
Biceps femoris, short head*
Semitendinosus*
Semimembranosus*
Sartorius
Popliteus
(*Hamstring muscles)
Hip and thigh, posterior view
a
161
11-7 Appendicular Muscles
Knee extensors
Quadriceps femoris consists of
Three vastus muscles
Rectus femoris
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Figure 11–21b Muscles That Move the Leg.
Gluteus medius
Anterior superior iliac spine
Inguinal ligament
Iliacus
Psoas major
Pubic tubercle
Tensor fasciae latae
Pectineus
Adductor longus
Gracilis
Sartorius
Extensors of the Knee
(Quadriceps femoris)
Rectus femoris
Vastus lateralis
Vastus medialis
Quadriceps tendon
Patella
Patellar ligament
Iliotibial tract
Quadriceps femoris and thigh muscles, anterior view
Iliopsoas
b
163
Figure 11–21c Muscles That Move the Leg.
POSTERIOR
Sciatic nerve
Femur
Extensors of the Knee
(Quadriceps femoris)
Vastus lateralis
Vastus intermedius
Vastus medialis
Rectus femoris
ANTERIOR
Sectional view
Flexors of the Knee
Semitendinosus
Semimembranosus
Biceps femoris, long head
Biceps femoris, short head
Gracilis
Adductor magnus
Adductor longus
Sartorius
c
164
11-7 Appendicular Muscles
Muscles that move the foot and toes
Extrinsic muscles that produce plantar flexion
Gastrocnemius
Soleus
Fibularis muscles
Tibialis posterior
Calcaneal tendon (Achilles tendon)
Shared by the gastrocnemius and soleus
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Figure 11–22a Extrinsic Muscles That Move the Foot and Toes (Part 1 of 2).
Superficial Dissection
Ankle Extensors
Plantaris
Gastrocnemius,
medial head
Gastrocnemius,
lateral head
Soleus
Popliteus
Gastrocnemius
(cut and removed)
Calcaneal
tendon
Calcaneus
Posterior views
a
166
Figure 11–22a Extrinsic Muscles That Move the Foot and Toes (Part 2 of 2).
Deep Dissection
Head of fibula
Ankle Extensors
(Deep)
Tibialis posterior
Fibularis longus
Fibularis brevis
Digital Flexors
Flexor digitorum
longus
Flexor hallucis
longus
Tendon of flexor digitorum
longus
Tendon of fibularis brevis
Tendon of fibularis
longus
Tendon of flexor
hallucis longus
Posterior views
a
167
11-7 Appendicular Muscles
Extrinsic muscles that produce flexion at ankle
Tibialis anterior
Opposes the gastrocnemius
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11-7 Appendicular Muscles
Extrinsic muscles that produce extension at toes
Extensor digitorum longus
Extensor hallucis longus
Extensor retinacula stabilize synovial tendon sheaths of these muscles
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Figure 11–22b Extrinsic Muscles That Move the Foot and Toes.
Iliotibial
tract
Ankle Extensors
Gastrocnemius,
lateral head
Fibularis longus
Soleus
Fibularis brevis
Digital Extensors
Extensor digitorum
longus
Tendon of extensor
hallucis longus
Head of
fibula
Ankle Flexors
Tibialis anterior
Superior extensor
retinaculum
Calcaneal tendon
Inferior extensor
retinaculum
Tendon of fibularis
tertius
Lateral view
b
170