the muscular system - hcc learning web

© 2012 Pearson Education, Inc.

PowerPoint® Lecture Presentations prepared by

Jason LaPres

Lone Star College—North Harris

11 The Muscular System


An Introduction to the Muscular System

• The Muscular System

• Consists only of skeletal muscles

• Muscle Organization and Function

• Muscle organization affects power, range, and speed

of muscle movement

• Fascicles

• Muscle cells (fibers) are organized in bundles

(fascicles)


11-1 Fascicle Arrangement

• Classification of Skeletal Muscles

• By the way fascicles are organized

• By relationships of fascicles to tendons



• Organization of Skeletal Muscle Fibers

• Four patterns of fascicle organization

1. Parallel

2. Convergent

3. Pennate

4. Circular



• Parallel Muscles

• Fibers parallel to the long axis of muscle

• For example, biceps brachii

• Most of the skeletal muscles of the human body are

parallel


Figure 11-1a Muscle Types Based on Pattern of Fascicle Organization

Parallel muscle (Biceps brachii muscle)

Fascicle

Cross section

Body (belly)



• Convergent Muscles

• A broad area converges on attachment site (tendon,

aponeurosis, or raphe)

• Muscle fibers pull in different directions, depending on

stimulation

• For example, pectoralis muscles


Figure 11-1b Muscle Types Based on Pattern of Fascicle Organization

Base of muscle

Convergent muscle (Pectoralis muscles)

Tendon

Cross section



• Pennate Muscles

• Form an angle with the tendon

• Do not move as far as parallel muscles

• Contain more myofibrils than parallel muscles

• Develop more tension than parallel muscles


Figure 11-1c Muscle Types Based on Pattern of Fascicle Organization

Extended tendon

Unipennate muscle (Extensor digitorum muscle)



• Circular Muscles

• Also called sphincters

• Open and close to guard entrances of body

• For example, orbicularis oris muscle of the mouth


Figure 11-1f Muscle Types Based on Pattern of Fascicle Organization

Contracted

Relaxed

Circular muscle (Orbicularis oris muscle)


11-2 Levers

• Skeletal Motion

• Skeletal muscles attach to skeleton, produce motion

• Type of muscle attachment affects power, range, and

speed of muscle movement


11-3 Muscle Attachments to Other Tissues

• Origins and Insertions

• Muscles have one fixed point of attachment (origin)

• And one moving point of attachment (insertion)

• Most muscles originate or insert on the skeleton

• Origin is usually proximal to insertion


Skeletal

Muscle

• One bone to another

• Cross at least one movable joint

• Belly

• thicker, middle region of muscle between origin and insertion

• Origin:

• bony attachment at stationary end of muscle

• the less movable attachment

• Insertion:

• bony attachment to mobile end of muscle

• is pulled toward the origin

• Usually one bone moves while the other remains fixed

• In muscles of the limb, origin lies proximal to the insertion (by convention)

• Note: origin and insertion may switch depending on body position and movement produced

11-3 Muscle Attachments



• Actions

• Movements produced by muscle contraction

• Body movements

• For example, flexion, extension, adduction, etc.

• Described in terms of bone, joint, or region



• Muscle Interactions

• Muscles work in groups to maximize efficiency

• Smaller muscles reach maximum tension first, followed by

larger, primary muscles

• Muscle Terminology Based on Function

• Agonist (or prime mover)

• Antagonist

• Synergist



• Agonist (Prime Mover)

• Produces a particular movement

• Antagonist

• Opposes movement of a particular agonist

• Synergist

• A smaller muscle that assists a larger agonist

• Helps start motion or stabilize origin of agonist (fixator)



• Muscle Opposition

• Agonists and antagonists work in pairs

• When one contracts, the other stretches

• Such as flexors–extensors, abductors–adductors, etc.


11-4 Naming Skeletal Muscles

• Names of Skeletal Muscles

• Correct names of muscles include the term muscle

• Exceptions:

• Platysma

• Diaphragm



• Descriptive Names for Skeletal Muscles

• Location in the body

• Origin and insertion

• Fascicle organization

• Relative position

• Structural characteristics

• Action



• Location in the Body

• Identifies body regions

• For example, temporalis muscle

• Origin and Insertion

• First part of name indicates origin

• Second part of name indicates insertion

• For example, genioglossus muscle



• Fascicle Organization

• Describes fascicle orientation within muscle

• For example, rectus (straight), transversus, oblique



• Position

• Externus (superficialis)

• Visible at body surface

• Internus (profundus)

• Deep muscles

• Extrinsic

• Muscles outside an organ

• Intrinsic

• Muscles inside an organ



• Structural Characteristics

• Number of tendons

• bi = 2, tri = 3

• Shape

• Trapezius, deltoid, rhomboid

• Size

• Many terms refer to muscle size



• Action

• Movements

• For example, flexor, extensor, retractor



• Terms Indicating Specific Regions of the Body

• Abdominis (abdomen)

• Anconeus (elbow)

• Auricularis (auricle of ear)

• Brachialis (brachium)

• Capitis (head)

• Carpi (wrist)

• Cervicis (neck)

• Cleido-/-clavius




• Coccygeus (coccyx)

• Costalis (ribs)

• Cutaneous (skin)

• Femoris (femur)

• Genio- (chin)

• Glosso-/-glossal (tongue)

• Hallucis (great toe)

• Ilio- (ilium)

• Inguinal (groin)




• Lumborum (lumbar region)

• Nasalis (nose)

• Nuchal (back of neck)

• Oculo- (eye)

• Oris (mouth)

• Palpebrae (eyelid)

• Pollicis (thumb)

• Popliteus (posterior to knee)

• Psoas (loin)




• Radialis (radius)

• Scapularis (scapula)

• Temporalis (temples)

• Thoracis (thoracic region)

• Tibialis (tibia)

• Ulnaris (ulna)

• Uro- (urinary)



• Terms Indicating Position, Direction, or Fascicle

Organization

• Anterior (front)

• Externus (superficial)

• Extrinsic (outside)

• Inferioris (inferior)

• Internus (deep, internal)

• Intrinsic (inside)

• Lateralis (lateral)

• Medialis/medius (medial, middle)



• Terms Indicating Position, Direction, or Fascicle

Organization

• Oblique

• Posterior

• Profundus (deep)

• Rectus (straight, parallel)

• Superficialis

• Superioris (superior)

• Transversus (transverse)



• Terms Indicating Structural Characteristics of the

Muscle

• Nature of Origin

• Biceps (two heads)

• Triceps (three heads)

• Quadriceps (four heads)




Muscle

• Shape

• Deltoid (triangle)

• Orbicularis (circle)

• Pectinate (comblike)

• Piriformis (pear-shaped)

• Platy- (flat)

• Pyramidal (pyramid)




Muscle

• Shape

• Rhomboid

• Serratus (serrated)

• Splenius (bandage)

• Teres (long and round)

• Trapezius (trapezoid)




Muscle

• Other Striking Features

• Alba (white)

• Brevis (short)

• Gracilis (slender)

• Lata (wide)

• Latissimus (widest)

• Longissimus (longest)

• Longus (long)




Muscle

• Other Striking Features

• Magnus (large)

• Major (larger)

• Maximus (largest)

• Minimus (smallest)

• Minor (smaller)

• Vastus (great)



• Terms Indicating Actions

• General

• Abductor

• Adductor

• Depressor

• Extensor

• Flexor

• Levator

• Pronator

• Rotator

• Supinator

• Tensor



• Terms Indicating Actions

• Specific

• Buccinator (trumpeter)

• Risorius (a laughter)

• Sartorius (like a tailor)



• Divisions of the Muscular System

1. Axial muscles

• Position head and spinal column

• Move rib cage

• 60% of skeletal muscles

2. Appendicular muscles

• Support pectoral and pelvic girdles

• Support limbs

• 40% of skeletal muscles


11-7 Effects of Aging on the Muscular System

• Effects of Aging

• Skeletal muscle fibers become smaller in diameter

• Skeletal muscles become less elastic

• Develop increasing amounts of fibrous tissue (fibrosis)

• Decreased tolerance for exercise

• Decreased ability to recover from muscular injuries


11-8 Muscular System Integration

• Cardiovascular System

• Delivers oxygen and fuel

• Removes carbon dioxide and wastes

• Respiratory System

• Responds to oxygen demand of muscles

• Integumentary System

• Disperses heat from muscle activity

• Nervous and Endocrine Systems

• Direct responses of all systems


Figure 11-3a An Overview of the Major Skeletal Muscles

Axial Muscles

Frontal belly of

occipitofrontalis

Temporoparietalis (reflected)

Temporalis

Sternocleidomastoid

Rectus abdominis

External oblique

Linea alba

Trapezius

Clavicle Deltoid

Pectoralis major

Latissimus dorsi

Serratus anterior

Biceps brachii

Triceps brachii

Brachialis

Pronator teres

Brachioradialis

Extensor carpi radialis brevis

Palmaris longus

Flexor carpi radialis

Flexor digitorum superficialis

Flexor carpi ulnaris

Extensor carpi radialis longus

Sternum

Appendicular Muscles

An anterior view. ATLAS: Plates 1a; 39a–d


Figure 11-3a An Overview of the Major Skeletal Muscles

Iliotibial tract

Patella

Tibia

Inferior extensor

retinaculum

Superior extensor

retinaculum

Medial malleolus of tibia

Lateral malleolus of fibula

An anterior view. ATLAS: Plates 1a; 39a–d

Gluteus medius

Tensor fasciae latae

Iliopsoas

Pectineus

Adductor longus

Gracilis

Sartorius

Rectus femoris

Vastus lateralis

Vastus medialis

Gastrocnemius

Fibularis longus

Tibialis anterior

Soleus

Extensor digitorum longus



Figure 11-3b An Overview of the Major Skeletal Muscles

Trapezius

Deltoid

Teres major

Latissimus dorsi

Infraspinatus

Triceps brachii (long head)

Brachioradialis

Extensor carpi ulnaris

Anconeus



External oblique

Occipital belly of

occipitofrontalis

Sternocleidomastoid

Extensor digitorum


Triceps brachii (lateral head)

Teres minor

Rhomboid major

Axial Muscles

A posterior view

ATLAS: Plates 1b; 40a,b


Figure 11-3b An Overview of the Major Skeletal Muscles

Calcaneal

tendon

Iliotibial tract

Calcaneus

Gluteus maximus


Semitendinosus

Plantaris

Adductor magnus

Gracilis

Sartorius

Biceps femoris

Semimembranosus

Gastrocnemius

Soleus

Gluteus medius

A posterior view

ATLAS: Plates 1b; 40a,b



Figure 11-4a Muscles of Facial Expression

Epicranial aponeurosis

Depressor labii inferioris

Orbicularis oris

Mentalis (cut)

Zygomaticus major

Levator anguli oris

Zygomaticus minor

Levator labii superioris

Nasalis

Orbicularis oculi

Procerus

Frontal belly of

occipitofrontalis

Depressor anguli oris

Omohyoid

Platysma (cut and reflected) Lateral view

Temporoparietalis

(cut and reflected)

Temporalis

Occipital belly of

occipitofrontalis

Masseter

Buccinator

Sternocleidomastoid

Trapezius


Figure 11-4b 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

Platysma

(cut and

reflected)

Anterior view


Figure 11-6a Muscles of Mastication

Superior temporal line

Temporalis

Capsule of

temporomandibular joint

Zygomatic

arch

Masseter

Lateral view. The temporalis muscle 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.


Figure 11-6b Muscles of Mastication

Lateral pterygoid

Medial pterygoid

Cut edge of mandible

Lateral view, pterygoid muscles

exposed. The location and orientation of

the pterygoid muscles can be seen after

the overlying muscles, along with a

portion of the mandible, are removed.


Figure 11-8 Muscles of the Pharynx

Palatal Muscles

Levator veli

palatini

Tensor veli

palatini

Laryngeal elevators

Pharyngeal

Constrictors

Superior

Middle

Inferior

Esophagus


11-5 Axial Musculature

• Oblique and Rectus Muscles

• Lie within the body wall

• Oblique muscles

• Compress underlying structures

• Rotate vertebral column

• Rectus muscles

• Flex vertebral column

• Oppose erector spinae



• Oblique Muscles

• Cervical region

• Scalene muscles

• Flex the neck

• Thoracic region

• Intercostal muscles (external and internal)

• Respiratory movements of ribs

• Transversus thoracis

• Cross inner surface of ribs



• Oblique Muscles

• Abdominopelvic region (same pattern as thoracic)

• External oblique muscles

• Internal oblique muscles

• Transversus abdominis



• Rectus Muscles

• Rectus abdominis

• Between xiphoid process and pubic symphysis

• Divided longitudinally by linea alba

• Divided transversely by tendinous inscriptions



• Rectus Muscles

• Diaphragmatic muscle or diaphragm

• Divides thoracic and abdominal cavities

• Performs respiration


Figure 11-11b Oblique and Rectus Muscles and the Diaphragm

Anterior view

Linea alba

Tendinous

inscription

External

oblique

Rectus abdominis

Cut edge of

rectus sheath

Internal oblique

External oblique (cut)

External intercostal

Internal intercostal

Serratus

anterior


11-6 Appendicular Musculature

• Appendicular Muscles

• Position and stabilize pectoral and pelvic girdles

• Move upper and lower limbs

• Two divisions of appendicular muscles

1. Muscles of the shoulders and upper limbs

2. Muscles of the pelvis and lower limbs


Figure 11-13a An Overview of the Appendicular Muscles of the Trunk

Deltoid

Superficial Dissection

Axial Muscles

Platysma


Pectoralis major

Latissimus dorsi

Serratus anterior

ATLAS: Plates

25; 39b

Anterior view



Deep Dissection

Axial Muscles


Sternocleidomastoid

Trapezius

Subclavius

Deltoid (cut

and reflected)

Pectoralis minor

Subscapularis

Pectoralis major

(cut and reflected)

Coracobrachialis

Biceps brachii

Teres major

Serratus anterior

ATLAS: Plates

25; 39b

Anterior view



ATLAS: Plates

25; 39b

Anterior view

Axial Muscles


External oblique

Rectus sheath


Superficial inguinal ring

Sartorius

Rectus femoris




ATLAS: Plates

25; 39b

Anterior view

Axial Muscles


External intercostal

Internal intercostal

Internal oblique (cut)

External oblique

(cut and reflected)

Rectus abdominis

Transversus abdominis

Gluteus medius

Iliopsoas

Pectineus

Adductor longus

Gracilis

Deep Dissection


Figure 11-13b An Overview of the Appendicular Muscles of the Trunk


Axial Muscles


Sternocleidomastoid

Trapezius

Deltoid

Infraspinatus

Teres minor

Teres major

Triceps

brachii

ATLAS: Plate 40a,b

Posterior view



ATLAS: Plate 40a,b

Posterior view

Deep Dissection

Axial Muscles


Semispinalis capitis

Splenius capitis

Levator scapulae

Supraspinatus

Rhomboid minor

Rhomboid major



ATLAS: Plate 40a,b

Posterior view

Latissimus dorsi

Thoracolumbar

fascia

Iliac crest

Gluteus medius

Gluteus maximus





ATLAS: Plate 40a,b

Posterior view

Deep Dissection

Erector spinae

muscle group

External oblique

Axial Muscles



• Muscles of the Shoulders and Upper Limbs

• Four groups

1. Muscles that position the pectoral girdle

2. Muscles that move the arm

3. Muscles that move the forearm and hand

4. Muscles that move the hand and fingers



• Muscles That Position the Pectoral Girdle

• Trapezius

• Superficial

• Covers back and neck to base of skull

• Inserts on clavicles and scapular spines


Figure 11-14a Muscles That Position the Pectoral Girdle

Muscles That Position

the Pectoral Girdle

Trapezius

Levator scapulae

Subclavius

Pectoralis minor

Pectoralis major

(cut and reflected)

Internal intercostals

External intercostals

T12

Anterior view ATLAS: Plates 39a-d; 40a–b


Figure 11-14b Muscles That Position the Pectoral Girdle


the Pectoral Girdle

Trapezius


Posterior view

ATLAS: Plates 27b; 40a–b




• Rhomboid and levator scapulae

• Deep to trapezius

• Attach to cervical and thoracic vertebrae

• Insert on scapular border


Figure 11-14b Muscles That Position the Pectoral Girdle


the Pectoral Girdle

Deep Dissection

Levator scapulae

Rhomboid minor

Rhomboid major Scapula

Serratus anterior

Triceps

brachii

T12 vertebra

Posterior view

ATLAS: Plates 27b; 40a–b




• Serratus anterior

• On the chest

• Originates along ribs

• Inserts on anterior scapular margin




• Subclavius

• Originates on ribs

• Inserts on clavicle

• Pectoralis minor

• Attaches to scapula




the Pectoral Girdle

Trapezius

Levator scapulae

Subclavius

Pectoralis minor

Pectoralis major

(cut and reflected)

Internal intercostals

External intercostals

T12





T12


the Pectoral Girdle

Pectoralis minor

(cut)

Serratus anterior

Biceps brachii, short head

Biceps brachii, long head



• Muscles That Move the Arm

• Deltoid

• The major abductor

• Supraspinatus

• Assists deltoid


Figure 11-15a Muscles That Move the Arm


Muscles That Move the Arm

Deltoid

Sternum

Clavicle

Pectoralis major

Anterior view


Figure 11-15b Muscles That Move the Arm



Posterior view

Supraspinatus

Deltoid

Latissimus dorsi

Thoracolumbar

fascia

Vertebra T1




• Subscapularis and teres major

• Produce medial rotation at shoulder



Deep Dissection


Ribs (cut)

Subscapularis

Coracobrachialis

Teres major

Biceps brachii,

short head

Biceps brachii,

long head

Vertebra T12

Anterior view




• Infraspinatus and teres minor

• Produce lateral rotation at shoulder

• Coracobrachialis

• Attaches to scapula

• Produces flexion and adduction at shoulder



Deep Dissection


Supraspinatus

Infraspinatus

Teres minor

Teres major

Triceps brachii,

long head

Triceps brachii,

lateral head

Posterior view



Deep Dissection


Ribs (cut)

Subscapularis

Coracobrachialis

Teres major

Biceps brachii,

short head

Biceps brachii,

long head

Vertebra T12

Anterior view




• 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





Deltoid

Sternum

Clavicle

Pectoralis major

Anterior view





Posterior view

Supraspinatus

Deltoid

Latissimus dorsi

Thoracolumbar

fascia

Vertebra T1



• The Rotator Cuff

• Muscles involved in shoulder rotation

• Supraspinatus, subscapularis, infraspinatus, teres

minor, and their tendons



Deep Dissection


Ribs (cut)

Subscapularis

Coracobrachialis

Teres major

Biceps brachii,

short head

Biceps brachii,

long head

Vertebra T12

Anterior view



Deep Dissection


Supraspinatus

Infraspinatus

Teres minor

Teres major

Triceps brachii,

long head

Triceps brachii,

lateral head

Posterior view



• Muscles That Move the Forearm and Hand

• Originate on humerus and insert on forearm

• Exceptions:

• The major flexor (biceps brachii)

• The major extensor (triceps brachii)




• Extensors

• Mainly on posterior and lateral surfaces of arm

• Flexors

• Mainly on anterior and medial surfaces



• Flexors of the Elbow

• Biceps brachii

• Flexes elbow

• Stabilizes shoulder joint

• Originates on scapula

• Inserts on radial tuberosity

• Brachialis and brachioradialis


Figure 11-16b Muscles That Move the Forearm and Hand

Coracoid process

of scapula

Humerus

Coracobrachialis

Biceps brachii,

short head

Biceps brachii,

long head

Triceps brachii,

long head

Triceps brachii,

medial head

Brachialis

Medial epicondyle

of humerus

Pronator teres

Brachioradialis


Palmaris longus



Pronator quadratus

Flexor retinaculum

Anterior view, superficial layer



• Extensors of the Elbow

• Triceps brachii

• Extends elbow

• Originates on scapula

• Inserts on olecranon

• Anconeus

• Opposes brachialis


Figure 11-16a Muscles That Move the Forearm and Hand

Triceps brachii, long head

Triceps brachii, lateral head

Brachioradialis

Olecranon of ulna

Anconeus




Extensor digitorum

Ulna

Extensor retinaculum


Abductor pollicis longus

Extensor pollicis brevis

Posterior view, superficial layer



• Flexors of the Wrist

• Palmaris longus

• Superficial, flexes wrist

• Flexor carpi ulnaris

• Superficial, flexes wrist, adducts wrist

• Flexor carpi radialis

• Superficial, flexes wrist, abducts wrist



Coracoid process

of scapula

Humerus

Coracobrachialis

Biceps brachii,

short head

Biceps brachii,

long head

Triceps brachii,

long head

Triceps brachii,

medial head

Brachialis

Medial epicondyle

of humerus

Pronator teres

Brachioradialis


Palmaris longus



Pronator quadratus

Flexor retinaculum




• Extensors of the Wrist

• Extensor carpi radialis

• Superficial, extends wrist, abducts wrist

• Extensor carpi ulnaris

• Superficial, extends wrist, adducts wrist


Figure 11-16a Muscles That Move the Forearm and Hand

Triceps brachii, long head

Triceps brachii, lateral head

Brachioradialis

Olecranon of ulna

Anconeus




Extensor digitorum

Ulna

Extensor retinaculum




Posterior view, superficial layer




• Pronation and supination

• Pronator teres and supinator

• Originate on humerus and ulna

• Rotate radius

• Pronator quadratus

• Originates on ulna

• Assists pronator teres



Coracoid process

of scapula

Humerus

Coracobrachialis

Biceps brachii,

short head

Biceps brachii,

long head

Triceps brachii,

long head

Triceps brachii,

medial head

Brachialis

Medial epicondyle

of humerus

Pronator teres

Brachioradialis


Palmaris longus



Pronator quadratus

Flexor retinaculum



Figure 11-17b Muscles That Move the Hand and Fingers

Supinator

Muscles That Flex the

Fingers and Thumb

Flexor pollicis longus

Flexor digitorum profundus

Anterior view, deepest layer

Brachialis

Cut tendons of

flexor digitorum

superficialis

Pronator

quadratus


Figure 11-17d Muscles That Move the Hand and Fingers

Anconeus

Supinator

Muscles That Move

the Thumb


Extensor pollicis longus


Radius

Tendon of extensor

digitorum (cut)

Posterior view, deepest layer

Tendon of extensor

digiti minimi (cut)

Ulna

Extensor indicis



• Muscles That Move the Hand and Fingers

• Also called extrinsic muscles of the hand

• Lie entirely within forearm

• Only tendons cross wrist (in synovial tendon sheaths)


Figure 11-17a Muscles That Move the Hand and Fingers

Median nerve

Pronator teres (cut)

Brachial artery

Radius

Flexor carpi ulnaris (retracted)


Fingers and Thumb




Tendon of

biceps

brachii

Brachioradialis

(retracted)

MEDIAL LATERAL

Anterior view, middle layer


Figure 11-17b Muscles That Move the Hand and Fingers

Supinator


Fingers and Thumb



Anterior view, deepest layer

Brachialis

Cut tendons of

flexor digitorum

superficialis

Pronator

quadratus


Figure 11-17c Muscles That Move the Hand and Fingers

Posterior view, middle layer

Anconeus

Muscles That

Extend the Fingers

Extensor digitorum

Extensor digiti minimi



Tendon of extensor

pollicis longus

LATERAL MEDIAL


Figure 11-17d Muscles That Move the Hand and Fingers

Anconeus

Supinator

Muscles That Move

the Thumb


Extensor pollicis longus


Radius

Tendon of extensor

digitorum (cut)

Posterior view, deepest layer

Tendon of extensor

digiti minimi (cut)

Ulna

Extensor indicis



• Muscles of the Pelvis and Lower Limbs

• Pelvic girdle is tightly bound to axial skeleton

• Permits little movement

• Has few muscles



• Muscles That Position the Lower Limbs

• Three Groups

1. Muscles that move the thigh

2. Muscles that move the leg

3. Muscles that move the foot and toes



• Muscles That Move the Thigh

• Gluteal muscles

• Lateral rotators

• Adductors

• Iliopsoas



• Gluteal Muscles

• Gluteus maximus

• Largest, most posterior gluteal muscle

• Produces extension and lateral rotation at hip

• Tensor fasciae latae

• Works with gluteus maximus

• Stabilizes iliotibial tract

• Gluteus medius and gluteus minimus

• Originate anterior to gluteus maximus

• Insert on trochanter


Figure 11-19a Muscles That Move the Thigh

Sacrum Iliac crest

Gluteus

medius (cut)

Gluteus

maximus

(cut)

Gluteal region, posterior view

Gluteal Group

Gluteus medius

Gluteus maximus

Gluteus minimus


Figure 11-19b Muscles That Move the Thigh

Gluteal Group

Gluteus medius

Gluteus maximus

Tensor fasciae

latae

Iliotibial tract

Vastus lateralis

Biceps femoris,

long head

Biceps femoris,

short head

Semimembranosus

Plantaris

Head of fibula

Patella

Patellar

ligament

Sartorius

Rectus

femoris

Lateral view



• Lateral Rotators

• Group of six muscles, including the dominant:

1. Piriformis

2. Obturator


Figure 11-19c Muscles That Move the Thigh

Lateral Rotator

Group

Piriformis

Superior gemellus

Obturator internus

Inferior gemellus

Quadratus femoris

Ischial tuberosity

Iliotibial tract

Gluteal Group

Gluteus

maximus

(cut)

Gluteus

medius

(cut)

Gluteus

minimus

Tensor

fasciae

latae

Posterior view, deep muscles



• Muscles That Move the Leg

• Flexors of the knee

• Originate on the pelvic girdle

• Extensors of the knee

• Originate on the femoral surface

• Insert on the patella



• Flexors of the Knee

• Hamstrings

• Biceps femoris

• Semimembranosus

• Semitendinosus

• Sartorius

• Originates superior to the acetabulum


Figure 11-20a 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

Hip and thigh, posterior view



• Extensors of the Knee

• Four muscles of the quadriceps femoris

• Three vastus muscles

• Rectus femoris muscle


Figure 11-20b Muscles That Move the Leg

Extensors of the Knee

(Quadriceps muscles)

Rectus femoris

Vastus lateralis

Vastus medialis

Quadriceps tendon

Patella

Patellar ligament

Sartorius

Anterior superior iliac spine

Inguinal ligament

Iliacus Psoas major

Iliopsoas

Pubic tubercle

Tensor fasciae

latae

Pectineus

Adductor longus

Gracilis

Quadriceps and thigh muscles, anterior view

Gluteus medius

Iliotibial tract


Figure 11-21a Extrinsic Muscles That Move the Foot and Toes


Ankle Extensors

Plantaris

Gastrocnemius,

medial head

Gastrocnemius,

lateral head

Soleus

Popliteus

Gastrocnemius

(cut and removed)

Calcaneal

tendon

Calcaneus

Posterior views



Deep Dissection

Posterior views

Tibialis posterior

Tendon of

flexor

hallucis

longus

Head of fibula

Ankle Extensors

(Deep)

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


Figure 11-21b Extrinsic Muscles That Move the Foot and Toes

Ankle Extensors

Gastrocnemius,

lateral head

Fibularis longus

Fibularis brevis

Superior extensor

retinaculum

Calcaneal tendon

Inferior extensor

retinaculum

Iliotibial tract

Head of fibula

Lateral view

Soleus

Tibialis anterior

Extensor digitorum

longus

Tendon of extensor

hallucis longus

Ankle Flexors

Digital Extensors


Figure 11-21c Extrinsic Muscles That Move the Foot and Toes

Patella

Medial view

Patellar

ligament

Tibialis anterior

Tendon of extensor

hallucis longus

Tendon of

tibialis anterior

Ankle Flexors

Digital Extensors

Soleus

Ankle Extensors

Superior extensor

retinaculum

Calcaneal tendon

Inferior extensor

retinaculum

Medial surface

of tibial shaft

Gastrocnemius,

medial head

Tibialis posterior

Flexor retinaculum



Deep Dissection

Posterior views

Tibialis posterior

Tendon of

flexor

hallucis

longus

Head of fibula

Ankle Extensors

(Deep)

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


11-7 Effects of Aging on the Muscular System

• Effects of Aging

• Skeletal muscle fibers become smaller in diameter

• Skeletal muscles become less elastic

• Develop increasing amounts of fibrous tissue (fibrosis)

• Decreased tolerance for exercise

• Decreased ability to recover from muscular injuries


11-8 Muscular System Integration

• Cardiovascular System

• Delivers oxygen and fuel

• Removes carbon dioxide and wastes

• Respiratory System

• Responds to oxygen demand of muscles

• Integumentary System

• Disperses heat from muscle activity

• Nervous and Endocrine Systems

• Direct responses of all systems

the muscular system - hcc learning web

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