Muscular System

Fundamentals of Anatomy & Physiology

Fundamentals of Anatomy & Physiology

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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.

3

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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

4

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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

6

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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

7

Figure 11–1b Muscle Types Based on Pattern of Fascicle Arrangement.

Parallel Muscles

Parallel muscle

with tendinous

bands

(Rectus abdominis)

(b)

b

8

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

11

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

14

Figure 11–1f Muscle Types Based on Pattern of Fascicle Arrangement.

Pennate Muscles

Bipennate

muscle

(Rectus femoris)

(f)

f

15

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

18

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

54

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

56

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

57

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

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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

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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

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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

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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

156

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11-7 Appendicular Muscles

Iliopsoas

Two hip flexors that insert on the same tendon

Psoas major

Iliacus

157

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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

159

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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

165

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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

168

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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

169

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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

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Figure 11–22c Extrinsic Muscles That Move the Foot and Toes.

Patella

Patellar

ligament

Ankle Flexors

Tibialis anterior

Medial surface

of tibial shaft

Ankle Extensors

Gastrocnemius,

medial head

Soleus

Tibialis posterior

Digital Extensors

Tendon of extensor

hallucis longus

Superior extensor

retinaculum

Calcaneal tendon

Flexor retinaculum

Inferior extensor

retinaculum

Tendon of tibialis

anterior

Medial view

c

171

Figure 11–22d Extrinsic Muscles That Move the Foot and Toes.

Patellar

ligament

Fibularis

longus

Tibialis

anterior

Tibia

Extensor

digitorum

longus

Extensor

hallucis

longus

Tendon of

extensor

digitorum

longus

Superior extensor

retinaculum

Inferior extensor

retinaculum

Tendon of tibialis

anterior

Anterior view

d

172

11-7 Appendicular Muscles

Extrinsic muscles that produce flexion at toes

Flexor digitorum longus

Flexor hallucis longus

173

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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

174

11-7 Appendicular Muscles

Intrinsic muscles of the foot

Originate on tarsal and metatarsal bones

Move toes and maintain longitudinal arch of foot

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Figure 11–23a Intrinsic Muscles of the Foot.

Tendon of

fibularis brevis

Superior extensor

retinaculum

Medial malleolus

of tibia

Lateral malleolus of fibula

Inferior extensor retinaculum

Tendon of fibularis tertius

Tendons of extensor

digitorum longus

Intrinsic Muscles of

the Foot

Dorsal interossei

Tendons of extensor

digitorum brevis

Tendon of

tibialis anterior

Intrinsic Muscles

of the Great Toe

Extensor hallucis

brevis

Abductor hallucis

Tendon of extensor

hallucis longus

Dorsal view

a

176

Figure 11–23b Intrinsic Muscles of the Foot.

Superficial Muscles of the

Sole of the Foot

Fibrous tendon

sheaths

Intrinsic Muscles of

the Foot

Lumbricals

Tendons of

flexor digitorum

brevis overlying

tendons of flexor

digitorum longus

Flexor hallucis brevis

Flexor digiti minimi brevis

Abductor hallucis

Flexor digitorum brevis

Abductor digiti minimi

Plantar aponeurosis (cut)

Calcaneus

Plantar view, superficial layer

b

177

Figure 11–23c Intrinsic Muscles of the Foot.

Deep Muscles of the

Sole of the Foot

Tendons of flexor digitorum brevis

Intrinsic Muscles of

the Foot

Lumbricals

Flexor hallucis brevis

Flexor digiti minimi brevis

Abductor hallucis

Quadratus plantae

Flexor digitorum brevis

Abductor digiti minimi

Tendon of

flexor digitorum

longus

Tendon of tibialis

posterior

Tendon of

fibularis longus

Tendons of flexor

digitorum longus

Tendon of flexor

hallucis longus

Plantar aponeurosis (cut)

Calcaneus

Plantar view, deep layer

c

178

11-8 Effects of Exercise

Muscular system is supported by other systems

Cardiovascular system

Delivers oxygen and nutrients

Removes carbon dioxide

Respiratory system

Responds to oxygen demand of muscles

Integumentary system

Disperses heat from muscle activity

Nervous and endocrine systems

Direct responses of all systems

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Figure 11–24 Integration of the MUSCULAR system with the other body systems presented so far.

Integumentary System

• The Integumentary System removes excess body heat, synthesizes vitamin D3 for calcium and phosphate absorption, and protects underlying muscles.

• The muscular system includes facial muscles that pull on the skin of the face to produce facial expressions

Skeletal System

• The Skeletal System provides mineral reserves for maintaining normal calcium and phosphate levels in body fluids, supports skeletal muscles, and provides sites of muscle attachment.

• The muscular system provides skeletal movement and support, and stabilizes bones and joints. Stresses exerted by tendons maintain normal bone structure and bone mass.

Muscular System

The muscular system performs these

primary functions for the human body:

• It produces skeletal movement

• It helps maintain posture and body position

• It supports soft tissues

• It guards entrances and exits to the body

• It helps maintain body temperature

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Eleventh Edition

Chapter 11

The Muscular System

Lecture Presentation by

Deborah A. Hutchinson

Seattle University

© 2018 Pearson Education, Inc.

© 2018 Pearson Education, Inc.

1

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.

2

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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.

3

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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

4

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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

5

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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

6

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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

7

Figure 11–1b Muscle Types Based on Pattern of Fascicle Arrangement.

Parallel Muscles

Parallel muscle

with tendinous

bands

(Rectus abdominis)

(b)

b

8

Figure 11–1c Muscle Types Based on Pattern of Fascicle Arrangement.

Parallel Muscles

Wrapping

muscle

(Supinator)

(c)

c

9

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

10

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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

11

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

12

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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

13

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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

14

Figure 11–1f Muscle Types Based on Pattern of Fascicle Arrangement.

Pennate Muscles

Bipennate

muscle

(Rectus femoris)

(f)

f

15

Figure 11–1g Muscle Types Based on Pattern of Fascicle Arrangement.

Pennate Muscles

Multipennate muscle

(Deltoid)

(g)

Tendons

Cross section

g

16

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

17

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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

18

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

19

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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

20

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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

21

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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

22

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

23

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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

24

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

25

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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

26

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

27

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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

32

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

33

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.

34

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

35

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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)

42

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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

53

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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

54

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

55

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

56

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

57

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

58

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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

59

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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

60

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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

61

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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

62

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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

64

11-6 Axial Muscles

Extrinsic eye muscles (oculomotor muscles)

Inferior rectus

Medial rectus

Superior rectus

Lateral rectus

Inferior oblique

Superior oblique

65

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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)

70

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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

73

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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

74

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

75

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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

76

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

77

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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

78

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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

80

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

82

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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

© 2018 Pearson Education, Inc.

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

© 2018 Pearson Education, Inc.

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

© 2018 Pearson Education, Inc.

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

© 2018 Pearson Education, Inc.

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

© 2018 Pearson Education, Inc.

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

© 2018 Pearson Education, Inc.

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

© 2018 Pearson Education, Inc.

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

© 2018 Pearson Education, Inc.

11-7 Appendicular Muscles

Muscles that move the thigh

Gluteal muscles

Lateral rotators

Adductors

Iliopsoas

149

© 2018 Pearson Education, Inc.

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

© 2018 Pearson Education, Inc.

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

© 2018 Pearson Education, Inc.

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

156

© 2018 Pearson Education, Inc.

11-7 Appendicular Muscles

Iliopsoas

Two hip flexors that insert on the same tendon

Psoas major

Iliacus

157

© 2018 Pearson Education, Inc.

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

159

© 2018 Pearson Education, Inc.

11-7 Appendicular Muscles

Flexors of the knee

Hamstrings

Biceps femoris

Semitendinosus

Semimembranosus

Sartorius

Popliteus

160

© 2018 Pearson Education, Inc.

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

162

© 2018 Pearson Education, Inc.

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

165

© 2018 Pearson Education, Inc.

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

168

© 2018 Pearson Education, Inc.

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

169

© 2018 Pearson Education, Inc.

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

Figure 11–22c Extrinsic Muscles That Move the Foot and Toes.

Patella

Patellar

ligament

Ankle Flexors

Tibialis anterior

Medial surface

of tibial shaft

Ankle Extensors

Gastrocnemius,

medial head

Soleus

Tibialis posterior

Digital Extensors

Tendon of extensor

hallucis longus

Superior extensor

retinaculum

Calcaneal tendon

Flexor retinaculum

Inferior extensor

retinaculum

Tendon of tibialis

anterior

Medial view

c

171

Figure 11–22d Extrinsic Muscles That Move the Foot and Toes.

Patellar

ligament

Fibularis

longus

Tibialis

anterior

Tibia

Extensor

digitorum

longus

Extensor

hallucis

longus

Tendon of

extensor

digitorum

longus

Superior extensor

retinaculum

Inferior extensor

retinaculum

Tendon of tibialis

anterior

Anterior view

d

172

11-7 Appendicular Muscles

Extrinsic muscles that produce flexion at toes

Flexor digitorum longus

Flexor hallucis longus

173

© 2018 Pearson Education, Inc.

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

174

11-7 Appendicular Muscles

Intrinsic muscles of the foot

Originate on tarsal and metatarsal bones

Move toes and maintain longitudinal arch of foot

175

© 2018 Pearson Education, Inc.

Figure 11–23a Intrinsic Muscles of the Foot.

Tendon of

fibularis brevis

Superior extensor

retinaculum

Medial malleolus

of tibia

Lateral malleolus of fibula

Inferior extensor retinaculum

Tendon of fibularis tertius

Tendons of extensor

digitorum longus

Intrinsic Muscles of

the Foot

Dorsal interossei

Tendons of extensor

digitorum brevis

Tendon of

tibialis anterior

Intrinsic Muscles

of the Great Toe

Extensor hallucis

brevis

Abductor hallucis

Tendon of extensor

hallucis longus

Dorsal view

a

176

Figure 11–23b Intrinsic Muscles of the Foot.

Superficial Muscles of the

Sole of the Foot

Fibrous tendon

sheaths

Intrinsic Muscles of

the Foot

Lumbricals

Tendons of

flexor digitorum

brevis overlying

tendons of flexor

digitorum longus

Flexor hallucis brevis

Flexor digiti minimi brevis

Abductor hallucis

Flexor digitorum brevis

Abductor digiti minimi

Plantar aponeurosis (cut)

Calcaneus

Plantar view, superficial layer

b

177

Figure 11–23c Intrinsic Muscles of the Foot.

Deep Muscles of the

Sole of the Foot

Tendons of flexor digitorum brevis

Intrinsic Muscles of

the Foot

Lumbricals

Flexor hallucis brevis

Flexor digiti minimi brevis

Abductor hallucis

Quadratus plantae

Flexor digitorum brevis

Abductor digiti minimi

Tendon of

flexor digitorum

longus

Tendon of tibialis

posterior

Tendon of

fibularis longus

Tendons of flexor

digitorum longus

Tendon of flexor

hallucis longus

Plantar aponeurosis (cut)

Calcaneus

Plantar view, deep layer

c

178

11-8 Effects of Exercise

Muscular system is supported by other systems

Cardiovascular system

Delivers oxygen and nutrients

Removes carbon dioxide

Respiratory system

Responds to oxygen demand of muscles

Integumentary system

Disperses heat from muscle activity

Nervous and endocrine systems

Direct responses of all systems

179

© 2018 Pearson Education, Inc.

Figure 11–24 Integration of the MUSCULAR system with the other body systems presented so far.

Integumentary System

• The Integumentary System removes excess body heat, synthesizes vitamin D3 for calcium and phosphate absorption, and protects underlying muscles.

• The muscular system includes facial muscles that pull on the skin of the face to produce facial expressions

Skeletal System

• The Skeletal System provides mineral reserves for maintaining normal calcium and phosphate levels in body fluids, supports skeletal muscles, and provides sites of muscle attachment.

• The muscular system provides skeletal movement and support, and stabilizes bones and joints. Stresses exerted by tendons maintain normal bone structure and bone mass.

Muscular System

The muscular system performs these

primary functions for the human body:

• It produces skeletal movement

• It helps maintain posture and body position

• It supports soft tissues

• It guards entrances and exits to the body

• It helps maintain body temperature

180

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