chapter 10 lecture outline - palm beach state college · –describe the connective tissue...

1

Chapter 10

Lecture Outline

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Introduction

• Muscles constitute nearly half of the body’s weight and are of central interest in several fields of health care and fitness

10-2

Figure 10.5a

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The Structural and Functional

Organization of Muscles

• Expected Learning Outcomes

– Describe the varied functions of muscles.

– Describe the connective tissue components of a muscle

and their relationship to the bundling of muscle fibers.

– Describe the various shapes of skeletal muscles and

relate this to their functions.

– Explain what is meant by the origin, insertion, belly,

action, and innervation of a muscle.

10-3



(Continued)

– Describe the ways that muscles work in groups to aid,

oppose, or moderate each other’s actions.

– Distinguish between intrinsic and extrinsic muscles.

– Describe, in general terms, the nerve supply to the

muscles and where these nerves originate.

– Explain how the Latin names of muscles can aid in

visualizing and remembering them.

10-4



• About 600 human skeletal muscles

• Constitute about half of our body weight

• Three kinds of muscle tissue

– Skeletal, cardiac, smooth

• Specialized for one major purpose

– Converting the chemical energy in ATP into the

mechanical energy of motion

• Myology—the study of the muscular system

10-5

The Functions of Muscles

• Muscle functions include: movement, stability, control of openings, heat production, and glycemic control

• Movement– Move from place to place; move body parts; move body

contents in breathing, circulation, and digestion

– In communication: speech, writing, facial expressions and other nonverbal communications

• Stability– Maintain posture by preventing unwanted movements

– Antigravity muscles: prevent us from falling over

– Stabilize joints by maintaining tension

10-6

The Functions of Muscles

• Control of openings and passageways– Sphincters: internal muscular rings that control the

movement of food, blood, and other materials within body

• Heat production by skeletal muscles– As much as 85% of our body heat

• Glycemic control– Muscles absorb and store glucose which helps regulate

blood sugar concentration within normal range

10-7

Connective Tissues of a MuscleCopyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Skeletal

muscle

Perimysium

Endomysium

(a)

Muscle

fascicle

Perimysium

Epimysium

Nerve

Blood vessels

Muscle fiber

Tendon

Fascia

Muscle fiber

Muscle fascicle

10-8

Figure 10.1a

Connective Tissues and Fascicles

• Endomysium– Thin sleeve of loose connective tissue around each fiber

– Allows room for capillaries and nerve fibers

– Provides chemical environment for muscle fiber

• Perimysium– Thicker layer of connective tissue that wraps fascicles

• Fascicles: bundles of muscle fibers wrapped together

– Carries nerves, blood vessels, and stretch receptors

• Epimysium– Fibrous sheath surrounding entire muscle

– Outer surface grades into fascia; inner surface projections form perimysium

• Fascia– Sheet of connective tissue that separates neighboring

muscles or muscle groups from each other and the subcutaneous tissue

10-9

Connective Tissues and Fascicles

Figure 10.1c10-10

Fascicles and Muscle Shapes

Figure 10.2

• Strength of a muscle and the direction of its pull are

determined partly by the orientation of its fascicles

Fusiform

Parallel

TriangularUnipennate

Bipennate

Multipennate

Circular

Biceps brachii

Rectus abdominis

Pectoralis majorPalmar interosseous

Rectus femoris

Deltoid

Orbicularis oculi

Tendon

Tendon

Belly

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

10-11

Fascicles and Muscle Shapes

• Fusiform muscles—thick in the middle and tapered at

each end

• Parallel muscles—uniform width and parallel fascicles

• Triangular (convergent) muscles—broad at one end

and narrow at the other

• Pennate muscles—feather shaped- Unipennate—fasciles approach tendon from one side

- Bipennate—fascicles approach tendon from both sides

- Multipennate—bunches of feathers converge to single point

• Circular muscles (sphincters)—form rings around

body openings

10-12

Muscle Compartments

• Muscle compartment—a group of functionally related

muscles enclosed by fascia

– Also contains nerves and blood vessels that supply the muscle group

• Intermuscular septa are very thick fascia that separate one

compartment from another

10-13

Figure 10.3

Anterior

Lateral Medial

Posterior

Key

Posterior compartment,

superficial layer

Posterior compartment,

deep layer

Lateral compartment

Anterior compartmentSubcutaneous

fat

Fasciae

Intermuscular

septa

Artery, veins,

and nerve

Interosseous

membrane

Fibula

Tibia


Muscle Attachments

• Indirect attachment to bone

– Tendons connect muscle to bone

• Collagen fibers of the endo-, peri-, and epimysium

continue into the tendon and from there into periosteum

and matrix of bone

• Aponeurosis—tendon is a broad, flat sheet (palmar

aponeurosis)

• Retinaculum—connective tissue band that tendons from

separate muscles pass under

• Direct (fleshy) attachment to bone

– Little separation between muscle and bone

– Muscle seems to emerge directly from bone

10-14

Muscle Origins and Insertions

• Origin

– Bony attachment at

stationary end of

muscle

• Belly

– Thicker, middle region

of muscle between

origin and insertion

• Insertion

– Bony attachment to

mobile end of muscleFigure 10.4

Scapula

Bellies

Radius

Insertion

Humerus

UlnaInsertion

Origins Origins

Long head

Extensors:

Lateral head

Flexors:Biceps brachii

Brachialis


Triceps brachii

10-15

Muscle Origins and Insertions

• Some anatomists prefer nontraditional descriptions of attachments by proximal vs. distal or superior vs. inferior

• Some muscles insert not on bone but on the fascia or tendon of another muscle or on collagen fibers of the dermis– Example: many facial muscles insert in the skin

10-16

Functional Groups of Muscles

• Action—effect produced by a muscle to produce or

prevent movement

• Four categories of muscle action: prime mover,

synergist, antagonist, and fixator

– Prime mover (agonist)

• Muscle that produces most of force during a particular

joint action

– Synergist: muscle that aids the prime mover

• May contribute additional force, modify the direction of

movement, or stabilize a nearby joint

10-17


(Continued)

– Antagonist: opposes the prime mover

• Prevents excessive movement

• Sometimes relaxes to give prime mover control over

an action

• Antagonistic pairs—muscles that act on opposite

sides of a joint

– Fixator: muscle that prevents movement of bone

10-18


For elbow flexion:

• Prime mover—brachialis

• Synergist—biceps brachii

• Antagonist—triceps brachii

• Fixator—muscle that holds

scapula firmly in place

– Rhomboids

Figure 10.4

Scapula

Bellies

Radius

Insertion

Humerus

UlnaInsertion

Origins Origins

Extensors:

Lateral head

Flexors:Biceps brachii

Brachialis


Long head

Triceps brachii

10-19

Intrinsic and Extrinsic Muscles

• Intrinsic muscle—entirely contained within a region, such as the hand

– Both origin and insertion there

• Extrinsic muscle—acts on a designated region, but has its origin elsewhere

– Fingers: extrinsic muscles in the forearm

Figure 10.28b

Figure 10.31a

(b) Intermediate flexor

Flexor

digitorum

superficialis

Flexor

pollicis longus

Flexor

digitorum

superficialis

tendons

Flexor

digitorum

profundus

tendons

Common

flexor

tendon

Opponens pollicis

Abductor pollicis

brevis

Flexor pollicis

brevis

Adductor

pollicis

Tendon of flexor

digitorum superficialis

Tendon of flexor

digitorum profundus

Abductor pollicis

longus

Palmaris longus

Flexor digitorum

superficialis

Flexor carpi ulnaris

Flexor retinaculum

Abductor digiti

minimi

Flexor digiti

Lumbricals

Opponens

digiti minimi

Tendon sheath

Flexor pollicis

longus

Flexor carpi

radialis

Tendon of flexor

pollicis longus

First dorsal

interosseous

Tendons of:

Tendons of:

(a) Palmar aspect, superficial



10-20

Muscle Innervation

• Innervation of a muscle—refers to the identity of

the nerve that stimulates it

– Knowing innervation enables diagnosis of nerve, spinal

cord, and brainstem injuries from muscle tests

• Spinal nerves arise from the spinal cord

– Emerge through intervertebral foramina

– Immediately branch into posterior and anterior rami

– Innervate muscles below the neck

– Plexus: web-like network of spinal nerves adjacent to

the vertebral column

10-21

Muscle Innervation

• Cranial nerves arise from the base of the brain

– Emerge through skull foramina

– Innervate the muscles of the head and neck

– Numbered CN I to CN XII

10-22

Blood Supply

• Muscular system receives about 1.24 L of

blood per minute at rest (one-quarter of the

blood pumped by the heart)

• During heavy exercise, total cardiac output

rises and the muscular system’s share is

more than three-quarters (11.6 L/min)

• Capillaries branch extensively through the

endomysium to reach every muscle fiber

10-23

How Muscles Are Named

• Latin names– Depressor labii inferioris, flexor digiti minimi brevis

• Describes distinctive aspects of the structure, location, or action of a muscle

• Footnotes throughout chapters show interpreted names of muscles

• Pronunciation of muscles available online at www.aprevealed.com

10-24

The Muscular System

Figure 10.5bFigure 10.5a

Frontalis

Orbicularis oculiMasseter

Orbicularis oris

Trapezius

External abdominal

oblique

Pronator quadratus

Gastrocnemius

Soleus

Adductor longus

Rectus abdominis

Serratus anterior

Sternocleidomastoid

Deltoid

Pectoralis major

Biceps brachii

Brachioradialis

Sartorius

Tensor

fasciae latae

Rectus femoris

Fibularis longus

Extensor digitorum longus

Tibialis anterior

Zygomaticus major

Vastus lateralis

Gracilis

Vastus intermedius

Adductors

Extensor digitorumlongus

Supinator

Flexor digitorum

profundus

Flexor pollicis longus

Transverse abdominal

Brachialis

Coracobrachialis

Platysma

Flexor carpi radialis

(a) Anterior view

Vastus medialis

Pectoralis minor

Internal abdominal

oblique

DeepSuperficial

Vastus lateralis


10-25

A Learning Strategy

• Examine models, cadavers, dissected animals,

or a photographic atlas

• Palpate muscles on yourself if possible

• Locate origins and insertions of muscles on an

articulated skeleton

• Study derivation of each muscle name

– Usually describes the muscle’s location, appearance,

origin, insertion, or action

• Say the names aloud to yourself or study

partner, and spell them correctly

10-26

Muscles of the Head and Neck


– Name and locate the muscles that produce facial

expression.

– Name and locate the muscles used for chewing and

swallowing.

– Name and locate the neck muscles that move the

head.

– Identify the origin, insertion, action, and innervation of

any of these muscles.

10-27

Muscles of Facial Expression

• Muscles that insert in the dermis and

subcutaneous tissues

• Tense the skin and produce facial

expressions

• Innervated by facial nerve (CN VII)

• Paralysis causes face to sag

• Found in scalp, forehead, around the eyes,

nose, and mouth, and in the neck

10-28


Figure 10.8a

Frontalis

Galea aponeurotica

Orbicularis oculi

Platysma

(a) Anterior view

Mentalis (cut)

Orbicularis oris

Masseter

Zygomaticus minor

Levator labii superioris

Zygomaticus major

Risorius

Depressor anguli oris

Depressor labii inferioris

Nasalis

Corrugator supercilii

Buccinator

Modiolus

Levator anguli oris

Superficial Deep


10-29


Frontalis (cut)Galea aponeurotica

Orbicularis oculi

Sternohyoid

Orbicularis oris

Occipitalis

Omohyoid

Sternothyroid

Inferior pharyngeal

constrictor

Sternocleidomastoid

Masseter

Thyrohyoid

Zygomatic arch

Levator labii superioris

Zygomaticus minor

Zygomaticus major

Depressor labii

inferioris

Depressor anguli oris

Buccinator

Risorius (cut)

Nasalis

Corrugator supercilii

Mentalis

Levator scapulae

(b) Lateral view

Modiolus

Temporalis


Figure 10.8b10-30

Muscles of Chewing and Swallowing• Extrinsic muscles of the tongue

– Tongue is very agile organ

– Pushes food between molars for chewing (mastication)

– Forces food into the pharynx for swallowing (deglutition)

– Crucial importance to speech

• Intrinsic muscles of tongue

– Vertical, transverse, and longitudinal fascicles

Figure 10.9

Genioglossus

Styloglossus

Palatoglossus

Posterior belly of digastric (cut)

Stylohyoid

Superior pharyngeal constrictor (cut)

Middle pharyngeal constrictor

Inferior pharyngeal constrictor

Hyoglossus

Hyoid bone

Styloid process

Mastoid process

Mylohyoid (cut)

Geniohyoid

Esophagus

Inferior longitudinal

muscle of tongue

Larynx


Trachea

10-31

Muscles of Chewing and Swallowing

• Four pairs of muscles produce biting and chewing movements of the mandible– Depression: to open mouth

– Elevation: biting and grinding

– Protraction: incisors can cut

– Retraction: make rear teeth meet

– Lateral and medial excursion: grind food

• Temporalis, masseter, medial pterygoid, and lateral pterygoid

• Innervated by mandibular nerve, a branch of the trigeminal (CN V) Figure 10.10a,b

Temporalis

Orbicularis oris

Masseter (cut)

(a) Lateral view

Buccinator


(b) Posterior view

Medial pterygoid muscle

Medial pterygoid plate

Lateral pterygoid plate

Interior of oral cavity

Lateral pterygoid muscle

10-32

Muscles of Chewing and Swallowing• Hyoid muscles—suprahyoid group

• Aspects of chewing, swallowing, and vocalizing

• Eight pairs of hyoid muscles associated with hyoid bone

• Digastric—opens mouth widely

• Geniohyoid—depresses mandible

• Mylohyoid—elevates floor of mouth at beginning of swallowing

• Stylohyoid—elevates hyoid

Figure 10.11a

Levator scapulae

Sternocleidomastoid

Digastric:Anterior bellyPosterior belly

StylohyoidMylohyoid

Sternohyoid

Omohyoid:

Suprahyoid

group

Infrahyoid

group

(a) Anterior view

Hyoid bone

Common carotid artery

Internal jugular vein

Clavicle

Thyrohyoid

Superior bellyInferior belly

Superficial Deep

Infrahyoid

groupSternothyroid


10-33

Muscles of Chewing and Swallowing• Hyoid muscles—infrahyoid group

• Fix hyoid bone from below, allowing suprahyoid muscles to open mouth

• Omohyoid—depresses hyoid after elevation

• Sternohyoid—depresses hyoid after elevation

• Thyrohyoid—depresses hyoid and elevates larynx

• Sternothyroid—depresses larynx after elevation

Figure 10.11b 10-34

Stylohyoid

Hyoglossus

Mylohyoid

Digastric

(anterior belly)

Hyoid bone

Thyrohyoid

Omohyoid

(superior belly)

Sternothyroid

Sternohyoid

(b) Lateral view

Digastric (posterior belly)

Splenius capitis


Sternocleidomastoid

Trapezius

Levator scapulae

Scalenes

Omohyoid (inferior belly)


Muscles of Chewing and Swallowing

• Pharynx: three pairs pharyngeal constrictors

– Encircle pharynx forming a muscular funnel

– During swallowing, drive food into the esophagus

Figure 10.9

Genioglossus

Styloglossus

Palatoglossus

Posterior belly of digastric (cut)

Stylohyoid

Superior pharyngeal constrictor (cut)

Middle pharyngeal constrictor


Hyoglossus

Hyoid bone

Styloid process

Mastoid process

Mylohyoid (cut)

Geniohyoid

Esophagus

Inferior longitudinal

muscle of tongue

Larynx


Trachea

10-35

Muscles Acting on the Head

• Originate on vertebral column, thoracic cage,

and pectoral girdle

• Insert on the cranial bones

• Actions

– Flexion (tipping head forward)

– Extension (holding the head erect)

– Lateral flexion (tipping head to one side)

– Rotation (turning the head to the left and right)

10-36


• Neck flexors

– Sternocleidomastoid

– Scalenes

• Neck extensors

– Trapezius

– Splenius capitis

– Semispinalis capitis

10-37

Figure 10.12


• May cause contralateral movement:

movement of the head toward the opposite

side

• May cause ipsilateral movement: movement

of the head toward the same side

10-38

Muscles of the Trunk


– Name and locate the muscles of respiration and

explain how they affect airflow and abdominal

pressure.

– Name and locate the muscles of the abdominal wall,

back, and pelvic floor.

– Identify the origin, insertion, action, and innervation of

any of these muscles.

10-39

Muscles of the Trunk

• Three functional groups

– Muscles of respiration

– Muscles that support abdominal wall and pelvic floor

– Movement of vertebral column

10-40

Muscles of Respiration

• Breathing requires the use of muscles enclosing thoracic cavity– Diaphragm, external intercostal, internal intercostal,

and innermost intercostal muscles

• Inspiration—air intake

• Expiration—expelling air

10-41


• Other muscles of chest and abdomen that contribute to breathing– Sternocleidomastoid, scalenes of neck

– Pectoralis major and serratus anterior of chest

– Latissimus dorsi of back

– Abdominal muscles: internal and external obliques, and transverse abdominis

– Even some anal muscles

10-42


Figure 10.13b

Xiphoid process

of sternum

Esophagus

Aorta

Inferior

vena cava

Central

tendon

of diaphragm

(b) Inferior view of diaphragm

Vertebral

column

Ribs

• Diaphragm—muscular

dome between thoracic and

abdominal cavities

• Muscle fascicles extend to

a fibrous central tendon

• Contraction flattens

diaphragm

– Enlarges thoracic cavity

(inspiration)

• In relaxation of diaphragm it

rises

– Shrinks the thoracic cavity

(expiration)


10-43


• External intercostals

– Elevate ribs

– Expand thoracic cavity

– Create partial vacuum causing

inflow of air

• Internal intercostals

– Depresses and retracts ribs

– Compresses thoracic cavity

– Expelling air

• Innermost intercostals

– Same action as internal

intercostals

Figure 10.13a

External

intercostals

Internal

intercostals

(a) Lateral view of intercostal muscles


10-44

Muscles of the Anterior Abdominal Wall

• Internal abdominal oblique

– Intermediate layer of lateral abdominal muscles

– Unilateral contraction causes ipsilateral rotation of waist

– Aponeurosis

• Tendons of oblique and transverse muscles

• Broad, fibrous sheets

Subclavius

Pectoralis minor (cut)

Internal intercostals

External intercostals

Rectus abdominis (cut)

External abdominal

oblique (cut)

Internal abdominal

oblique (cut)

Transverse abdominal (cut)

Posterior wall of rectus sheath

(rectus abdominis removed)

Internal abdominal

oblique

Inguinal ligament

Rectus sheath

Serratus anterior

Pectoralis minor

(b) Deep


Figure 10.15b 10-45


• Transverse abdominal

– Deepest of lateral abdominal muscles

– Horizontal fibers

– Compresses abdominal contents

– Contributes to movements of vertebral column

Subclavius





External abdominal

oblique (cut)

Internal abdominal

oblique (cut)




Internal abdominal

oblique

Inguinal ligament

Rectus sheath

Serratus anterior

Pectoralis minor

(b) Deep


Figure 10.15b 10-46


• Rectus abdominis– Flexes lumbar region of vertebral column

– Produces forward bending at the waist

– Extends from sternum to pubis

– Rectus sheath encloses muscle

– Three transverse tendinous intersections divide rectus abdominis

into segments, sometimes called a “six pack”

Figure 10.15a

Pectoralis major

Tendinous

intersections

Linea alba

Latissimus dorsi

Rectus abdominis

Inguinal ligament

Rectus sheath (cut edges)

Serratus anterior

Aponeurosis of

external abdominal

oblique

Umbilicus

Linea semilunaris

Transverse abdominal

Internal abdominal

oblique (cut)

External abdominal

oblique (cut)

Rectus sheath

(a) Superficial


10-47

Muscles of Back

• Back muscles extend,

rotate, and laterally

flex vertebral column

• Most prominent

superficial back

muscles:

latissimus dorsi and

trapezius

• Upper limb movement

Figure 10.1710-48

Muscles of the Back

• Deep muscles

• Erector spinae– Iliocostalis, longissimus,

spinalis

– From cranium to sacrum

– Extension and lateral flexion of vertebral column

• Semispinalis thoracis– Extension and

contralateral rotation of vertebral column

Figure 10.18

Longissimus capitisSemispinalis capitis

Internal abdominal

oblique

Erector spinae:

Semispinalis

thoracis

Multifidus

Quadratus lumborum

Superior nuchal line

Splenius capitis

Serratus posterior

superior

Splenius cervicis

External abdominal

oblique (cut)

Semispinalis cervicis

Serratus posterior inferior

Iliocostalis

Longissimus

Spinalis


10-49

Muscles of the Back

(Continued)

• Quadratus lumborum– Aids respiration

– Ipsilateral flexion of lumbar vertebral column

• Multifidus– Stabilizes adjacent vertebrae

– Maintains posture

10-50

Muscles of the Pelvic Floor

• Layers of muscles and fasciae that span pelvic outlet– Penetrated by anal canal, urethra, and vagina

• Perineum—diamond-shaped region between the thighs – Bordered by four bony landmarks

• Pubic symphysis anteriorly

• Coccyx posteriorly

• Ischial tuberosities laterally

– Urogenital triangle: anterior half of perineum

– Anal triangle: posterior half of perineum

10-51


• Layers or compartments of the perineum

– Superficial perineal space• Ischiocavernosus, bulbospongiosus

– Deep perineal space• Deep transverse perineal, compressor urethrae

– Anal triangle• External anal sphincter

– Pelvic diaphragm: deepest (most superior) layer • Levator ani

10-52


• Superficial perineal space

– Ischiocavernosus—maintains erection

– Bulbospongiosus—aids in erection, expels remaining urine

Figure 10.20a

10-53


• Deep perineal space

– Urogenital triangle—contains deep transverse perineal muscle

and compressor urethrae in females

• Anal triangle—external anal sphincter

Figure 10.20b

10-54


• Pelvic diaphragm: deepest compartment of the perineum

– Levator ani: supports viscera and defecation

– Coccygeus muscle(s)

Figure 10.20c

10-55


Aponeurosis of external

abdominal oblique

muscle

Inguinal canal

External inguinal ring

Herniated loop of

small intestineUpper scrotum

Hernias• Hernia—any condition in which

the viscera protrudes through a

weak point in the muscular wall of

the abdominopelvic cavity

• Inguinal hernia

– Most common type of hernia (rare

in women)

– Viscera enter inguinal canal or

even the scrotum

• Hiatal hernia

– Stomach protrudes through

diaphragm into thorax

– Overweight people over 40

• Umbilical hernia

– Viscera protrude through the

navel 10-56

Figure 10.21

Muscles Acting on the Shoulder

and Upper Limb


– Name and locate the muscles that act on the pectoral

girdle, shoulder, elbow, wrist, and hand.

– Relate the actions of these muscles to the joint

movements described in chapter 9.

– Describe the origin, insertion, and innervation of each

muscle.

10-57


and Upper Limb

• Compartments—spaces where muscles are separated by fibrous connective tissue sheets (fasciae)

– Each compartment contains one or more functionally related muscles along with their nerve and blood supplies

• Muscles of upper limbs divided into anterior and posterior compartments

• Intermuscular septa (thick fascia) separates compartments

• Compartment syndrome—one of the muscles or blood vessels in a compartment is injured

10-58

Compartment Syndrome• If a blood vessel in a compartment is damaged, blood

and tissue fluid accumulate

• Fasciae enclose muscle compartments snugly and prevent expansion

• Compartment syndrome—mounting pressure triggers a sequence of degenerative events– Blood flow to compartment is obstructed by pressure

– If ischemia (poor blood flow) persists for more than 2 to 4 hours, nerves begin to die

– After 6 hours, muscles begin to die

• Nerves can regenerate after pressure relieved, but muscle damage is permanent

• Myoglobin in urine indicates compartment syndrome

• Treatment: immobilization of limb and fasciotomy (incision to relieve compartment pressure)

10-59


and Upper Limb

• Upper limb is used for a broad range of powerful

and subtle actions

– Climbing, grasping, throwing, writing, playing musical

instruments, and manipulating small objects

• Muscles that act on the scapula

• Muscles that act on the humerus and shoulder

joint

• Muscles that act on the forearm and elbow joint

• Muscles that act on the wrist, hand, and fingers

10-60


• A group of muscles originate on the axial

skeleton and insert on clavicle or scapula

• Scapula loosely attached to thoracic cage

– Capable of great movement

– Rotation, elevation, depression, protraction, retraction

• Clavicle braces the shoulder and moderates

movements

10-61

Muscles Acting on the Scapula

Figure 10.22

10-62


• Pectoralis minor

– Ribs 3–5 to coracoid process of scapula

– Draws scapula laterally

• Serratus anterior

– All ribs to medial

border of scapula

– Draws scapula laterally

and forward; prime

mover for reaching and

pushing

Subclavius





Inguinal ligament

Rectus sheath

Serratus anterior

Pectoralis minor

(b) Deep

Internal abdominal

oblique




Internal abdominal

oblique (cut)

External abdominal

oblique (cut)


Figure 10.15b 10-63

• Anterior group of muscles of pectoral girdle


• Four muscles of posterior group

– Trapezius: superficial

– Levator scapulae, Rhomboid minor, and Rhomboid major: deep

• Trapezius

– Stabilizes scapula and shoulder

– Elevates and depresses shoulder apex

Figure 10.17

Semispinalis capitis

Sternocleidomastoid

Deltoid

Levator scapulae

Rhomboid minor

Rhomboid major

Infraspinatus

Gluteus maximus

Gluteus medius Gluteus minimus

Lateral rotators

Serratus anterior

Supraspinatus

Erector spinae

Splenius capitis

Superficial Deep

Trapezius

Latissimus

dorsi

External abdominal

obliqueThoracolumbar

fascia

Teres minor

Teres major

Serratus posterior

inferior

External abdominal

oblique

Internal abdominal

oblique


10-64

• Posterior group of muscles

of pectoral girdle


(Continued from slide 170)

• Levator scapulae

– Elevates scapula

– Flexes neck laterally

• Rhomboid minor

– Retracts scapula and braces shoulder

• Rhomboid major

– Same as Rhomboid minor

10-65


Figure 10.17

Semispinalis capitis

Sternocleidomastoid

Deltoid

Levator scapulae

Rhomboid minor

Rhomboid major

Infraspinatus

Gluteus maximus

Gluteus medius Gluteus minimus

Lateral rotators

Serratus anterior

Supraspinatus

Erector spinae

Splenius capitis

Superficial Deep

Trapezius

Latissimus

dorsi

External abdominal

oblique

Thoracolumbar

fascia

Teres minor

Teres major

Serratus posterior

inferior

External abdominal

oblique

Internal abdominal

oblique


10-66

• Posterior scapular muscles

Muscles Acting on the Arm

• Nine muscles cross the shoulder joint and insert on

humerus

• Two are axial muscles originating on axial skeleton

– Pectoralis major: flexes, adducts, and medially rotates humerus

– Latissimus dorsi: adducts and medially rotates humerus

Figure 10.23a Figure 10.23b

Clavicle

Deltoid

Sternum

Pectoralis major

Coracobrachialis

Lateral head

Long head

Medial head

Biceps brachii

Brachialis

Brachioradialis

Triceps brachii:

(a) Anterior view


(b) Posterior view

Supraspinatus

Spine of scapula

Infraspinatus

Lateral head

Long head

Latissimus dorsi

Humerus

Greater tubercle

of humerus

Teres minor

Teres major

Triceps brachii:


10-67

Anterior View of Cadaver Chest

Figure 10.24a10-68

Back Muscles of Cadaver

Figure 10.24b 10-69

• Seven muscles with

scapular origin

– Deltoid

• Rotates and abducts arm

• Intramuscular injection site

– Teres major

• Extension and medial

rotation of humerus

– Coracobrachialis

• Flexes and medially rotates

arm

– Remaining four form the

rotator cuff that reinforce

the shoulder joint


Figure 10.23b

Figure 10.23a

Clavicle

Deltoid

Sternum

Pectoralis major

Coracobrachialis

Lateral head

Long head

Medial head

Biceps brachii

Brachialis

Brachioradialis

Triceps brachii:

(a) Anterior view


(b) Posterior view

Supraspinatus

Spine of scapula

Infraspinatus

Lateral head

Long head

Latissimus dorsi

Humerus

Greater tubercle

of humerus

Teres minor

Teres major

Triceps brachii:


10-70


• Rotator cuff muscles

• Tendons of the remaining four scapular muscles form the

rotator cuff

• Acronym “SITS muscles”

– Supraspinatus

– Infraspinatus

– Teres minor

– Subscapularis

• Tendons of these muscles merge with the joint capsule of

the shoulder as they cross it in route to the humerus

• Holds head of humerus into glenoid cavity

• Supraspinatus tendon easily damaged10-71

Rotator Cuff Muscles

Figure 10.25

Acromion

Inferior angle

Clavicle

Infraspinatus

Subscapularis

Glenoid cavity

Supraspinatus

Anterior Posterior

Rotator cuff (SITS)

muscles:

Teres minor

Coracoid

process


10-72

Muscles Acting on the Forearm

• Elbow and forearm capable of flexion, extension,

pronation, and supination

– Carried out by muscles in both brachium (arm) and

antebrachium (forearm)

• Muscles with bellies in the arm (brachium)

– Principal elbow flexors: anterior compartment

• Brachialis and biceps brachii

– Brachialis produces 50% more power than biceps brachii

– Brachialis is prime mover of elbow flexion

– Principal elbow extensor: posterior compartment

• Triceps brachii

– Prime mover of elbow extension

10-73


• Principal flexor

– Brachialis

• Synergistic

flexors

– Biceps brachii

– Brachioradialis

• Principal extensor

– Triceps brachii

Figure 10.23b

Figure 10.23a

Clavicle

Deltoid

Sternum

Pectoralis major

CoracobrachialisLateral headLong head

Medial head

Biceps brachii

Brachialis

Brachioradialis

Triceps brachii:

(a) Anterior view


(b) Posterior view

Supraspinatus

Spine of scapula

Infraspinatus

Lateral headLong head

Latissimus dorsi

Humerus

Greater tubercleof humerus

Teres minor

Teres major

Triceps brachii:


Biceps brachii:

Long head

Short head

(c) Anterior view


Figure 10.23c

10-74


• Muscles with bellies in the forearm

(antebrachium)

– Brachioradialis: flexes elbow

– Anconeus: extends elbow

– Pronator quadratus: prime mover in forearm

pronation

– Pronator teres: assists pronator quadratus in

pronation

– Supinator: supinates the forearm

10-75


• Supination– Supinator muscle

– Palm facing anteriorly or superiorly

• Pronation– Pronator quadratus and

pronator teres

– Palm faces posteriorly or inferiorly

Figure 10.26a Figure 10.26c


Medial epicondyle

Lateral epicondyle

Ulna

Pronator quadratus

Pronator teres

Supinator

Radius

Radius

(a) Supination

Ulna

Bursa

Biceps

brachii

Supinator

(b) Muscle actions

in supination


Medial epicondyle

Lateral epicondyle

Ulna

Pronator quadratus

Pronator teres

Supinator

Radius

Radius

(c) Pronation

Ulna

Bursa

Biceps

brachii

Supinator

(b) Muscle actions

in supination

10-76

Muscles Acting on the Wrist and Hand• Anterior group

• Extrinsic muscles of the forearm

• Intrinsic muscles in the hand itself

• Extrinsic muscle actions

– Flexion and extension of wrist and digits

– Radial and ulnar flexion

– Finger abduction and adduction

– Thumb opposition

Figure 10.28a,b,c


(c) Deep flexors(b) Intermediate flexor(a) Superficial flexors

Flexor

digitorum

superficialis

Flexor

digitorum

profundus

Supinator

Flexor

pollicis

longus

Biceps brachii

Brachialis

Pronator teres

Brachioradialis


Palmaris longus

Flexor digitorum

superficialis

Extensor carpi radialis

longus and brevis

Triceps brachii

Common flexor tendon

Aponeurosis of biceps

brachii


Interosseous

membrane

Flexor

pollicis longus

Flexor

digitorum

superficialis

tendons

Flexor

digitorum

profundus

tendons

Common flexor

tendon

Palmar

aponeurosis

Flexor

digitorum

superficialis

tendons

Flexor

digitorum

profundus

tendons

Flexor

retinaculum

Anterior view

10-77

• Anterior (flexor) compartment—superficial

layer

– Flexor carpi radialis

– Flexor carpi ulnaris

– Flexor digitorum superficialis

– Palmaris longus

• Anterior (flexor) compartment—deep layer

– Flexor digitorum profundus

– Flexor pollicis longus

Muscles Acting on the Wrist and Hand

10-78

Cross Section of Upper Limb

Figure 10.27a,b,c




Palmaris longus

Flexor pollicis longus

Flexor digitorum profundus

Extensor carpi radialis longus

Extensor carpi radialis brevis

Extensor digitorum

Extensor digiti minimi

Extensor carpi ulnaris

(c)

Pronator teres

Radius

Ulna

Anconeus

Brachioradialis

Flexor digitorum superficialis

Supinator

Short headLong head

Pectoralis major

Triceps brachii:

Coracobrachialis

Humerus

Deltoid

Teres major

Latissimus dorsi tendon

Biceps brachii:

Lateral headLong head

(a)

Brachialis

Biceps brachii

Triceps brachii:

Medial head

Long head

Lateral head

(b)

Anterior (flexor)

compartment, superficial

Anterior (flexor)

compartment, deep

Posterior (extensor)

compartment

Other muscles

Key

(a)

(b)

(c)

Posterior

Anterior

Lateral Medial

10-79

Muscles Acting on the Wrist and Hand• Posterior group

• Extension of wrist and fingers, adduct/abduct wrist

• Extension and abduction of thumb (pollicis)

• Brevis means “short,” ulnaris indicates “on ulna side of

forearm”Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Anconeus

Supinator

Abductor pollicis

longus

Extensor pollicis

longus

Extensor pollicis

brevis

Extensor indicis

Olecranon

Tendons of extensor

digitorum

(a) Superficial extensors (b) Deep extensors

Posterior view

Extensor carpi

ulnaris

Anconeus

Triceps brachii

Flexor carpi

ulnaris

Extensor digiti

minimi

Tendon of

extensor indicis

Extensor carpi

radialis longus

Extensor carpi

radialis brevis

Extensor digitorum

Abductor pollicis

longus

Extensor pollicis

brevis

Extensor pollicis

longus

Brachioradialis

Tendons of extensor

carpi radialis longus

and brevis

Figure 10.29a,b

10-80

Muscles Acting on the Wrist and Hand

• Posterior (extensor) compartment—superficial layer

– Extensor carpi radialis longus

– Extensor carpi radialis brevis

– Extensor digitorum

– Extensor digiti minimi

– Extensor carpi ulnaris

• Posterior (extensor) compartment—deep layer

– Abductor pollicis longus

– Extensor pollicis brevis

– Extensor pollicis longus

– Extensor indicis

10-81

Carpal Tunnel Syndrome

• Flexor retinaculum—bracelet-like fibrous sheet,

passed under by flexor tendons crossing the wrist

• Carpal tunnel—tight space between the flexor

retinaculum and the carpal bones

– Flexor tendons passing through the tunnel are enclosed

in tendon sheaths

• Enable tendons to slide back and forth quite easily

10-82


• Carpal tunnel syndrome—prolonged, repetitive

motions of wrist and fingers cause tissues in the

carpal tunnel to become inflamed, swollen, or fibrotic

– Puts pressure on median nerve of wrist that passes

through the carpal tunnel along with flexor tendons

– Tingling and muscular weakness in the palm and medial

side of the hand

– Pain may radiate to arm and shoulder

– Treatment: anti-inflammatory drugs, immobilization of the

wrist, and sometimes surgery to remove part or all of

flexor retinaculum

10-83


Repetitive motions

cause inflammation

and pressure on

median nerve

Figure 10.31a

Figure 10.31b


Opponens pollicis

Abductor pollicis

brevis

Flexor pollicis

brevis

Adductor

pollicis

Tendon of flexor

digitorum superficialis

Tendon of flexor

digitorum profundus

Palmaris longus

Flexor digitorum

superficialis

Flexor retinaculum

Abductor digiti

minimi

Flexor digiti

minimi brevis

Lumbricals

Opponens

digiti minimi

Tendon sheath

Flexor pollicis

longus

Flexor carpi

radialis

Tendon of flexor

pollicis longus

First dorsal

interosseous


Abductor pollicis

longus

(a) Palmar aspect, superficial

Tendons of:

Tendons of:

10-84

Intrinsic Muscles of the Hand

• Thenar group—form thick, fleshy mass at base of thumb– Adductor pollicis

– Abductor pollicis brevis

– Flexor pollicis brevis

– Opponens pollicis

• Hypothenar group—fleshy base of the little finger– Abductor digiti minimi

– Flexor digiti minimi brevis

– Opponens digiti minimi

• Midpalmar group—hollow of palm– Dorsal interosseous muscles (4)

– Palmar interosseous muscles (3)

– Lumbricals (4 muscles)

10-85

Muscles Acting on the Hip

and Lower Limb


– Name and locate the muscles that act on the hip,

knee, ankle, and toe joints.

– Relate the actions of these muscles to the joint

movements described in chapter 9.

– Describe the origin, insertion, and innervation of each

muscle.

10-86

Muscles Acting on the Hip

and Lower Limb

• Body’s largest muscles found in lower limb

• Less for precision, more for strength needed

to stand, maintain balance, walk, and run

• Several cross and act on two or more joints

• Leg—the part of the limb between the knee and

ankle

• Foot—includes tarsal region (ankle),

metatarsal region, and the toes

10-87

Muscles Acting on the Hip and Femur

• Anterior muscles of the hip– Iliacus

• Flexes thigh at hip

• Iliacus portion arises from iliac crest and fossa

– Psoas major• Flexes thigh at hip

• Arises from lumbar vertebrae

– They share a common tendon on the femur

Figure 10.32


Iliopsoas:

IliacusPsoas

major

Adductor

longus

Adductor

brevis

Pectineus

Gracilis

Insertion of

gracilis on

tibia

Piriformis

Obturator

externusAdductor

magnus

10-88


• Lateral and posterior muscles of the hip– Tensor fasciae latae

• Extends knee, laterally rotates knee

– Gluteus maximus• Forms mass of the buttock

• Prime hip extensor

• Provides most of lift when you climb stairs

– Gluteus medius andminimus

• Abduct and medially rotate thigh

Figure 10.3310-89

Muscles Acting on the Hip and

Femur

• Posterior group

• Lateral rotators—six muscles inferior to gluteus minimus

• Deep to the two other gluteal muscles– Gemellus superior

– Gemellus inferior

– Obturator externus

– Obturator internus

– Piriformis

– Quadratus femoris

10-90


• Medial (adductor) compartment of thigh

• Five muscles act as primary adductors of the thigh– Adductor brevis

– Adductor longus

– Adductor magnus

– Gracilis

– Pectineus

Figure 10.32


Iliopsoas:

IliacusPsoas

major

Adductor

longus

Adductor

brevis

Pectineus

Gracilis

Insertion of

gracilis on

tibia

Piriformis

Obturator

externusAdductor

magnus

10-91

Muscles Acting on the Knee and Leg

• Anterior (extensor) compartment of the thigh

– Contains large quadriceps femoris muscle• Prime mover of knee extension

• Most powerful muscle in the body

• Has four heads—rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius

– All converge on single quadriceps (patellar) tendon

– Extends to patella

– Then continues as patellar ligament

– Inserts on tibial tuberosity

– Sartorius: longest muscle in the body• “Tailor’s muscle”

10-92

Anterior Thigh Cadaver Muscles

Figure 10.34 10-93


Figure 10.35a,b10-94


• Posterior (flexor) compartment of the thigh– Contains hamstring muscles

– From lateral to medial:

Biceps femoris

Semitendinosus

Semimembranosus

Figure 10.33 10-95

Muscles Acting on the Foot

• Crural muscles, acting on the foot, are separated into three compartments– Anterior compartment (red)

– Fibular (lateral) compartment (green)

– Posterior compartments (superficial = pink) (deep = purple)

Figure 10.40b


(a)

(b)

Fibularis longus

Fibularis brevis

(b)

Gastrocnemius

(medial head)

Gastrocnemius

(lateral head)

Fibula

Extensor hallucis longus

Extensor digitorum longus

Soleus

Flexor hallucis longus

Tibialis posterior

Tibia

Tibialis anterior

Flexor digitorum longusAnterior (extensor)

compartment

Lateral (fibular) compartment

Posterior (flexor)

compartment, superficial

Posterior (flexor

compartment, deep)

Key b

Anterior

Posterior

Lateral Medial

10-96


• Anterior (extensor) compartment of the leg– Dorsiflex the ankle

– Prevent toes from scuffing ground when walking

– Fibularis (peroneus) tertius

– Extensor digitorum longus

– Extensor hallucis longus

– Tibialis anterior


Tibialis

anterior

Extensor

digitorum

brevis

Extensor

hallucis

brevis

Fibularis

tertius

Extensor

digitorum

longus

Tibialis

anterior

Fibularis

longus

Extensor

digitorum longus

Fibularis

brevis

Patella

Patellar

ligament

Gastrocnemius

Soleus

Tibia

Extensor retinacula

Extensor

hallucis

longus

(a) (b) (c) (d)

Figure 10.38a–d

10-97


• Posterior compartment—three muscles of the superficial group

– Gastrocnemius: plantar flexes foot, flexes knee

– Soleus: plantar flexes foot

– Plantaris: weak synergist of triceps surae

• Triceps surae—collective name for gastrocnemius and soleus

– Inserts on calcaneus by way of the calcaneal (Achilles) tendon

– Strongest tendon in the body


Gastrocnemius:

Heads ofgastrocnemius(cut)

Calcaneal tendon

Calcaneus

Medial head

Lateral head

Popliteus

Flexor

digitorum

longus

Plantaris

Soleus

Flexor

hallucis

longus

Tendon of

plantaris

Fibularis

brevis

Fibularis

longus

Fibularislongus

Gastrocnemius

(cut)

Tendon of

gastrocnemius

(a) (b)

Figure 10.38a,b

10-98


• Posterior compartment—four muscles in the deep group

– Flexor digitorum longus: flexes phalanges

– Flexor hallucis longus: flexes great toe

– Tibialis posterior: inverts foot

– Popliteus: acts on knee


Calcaneal tendon

(cut)

Calcaneus(a)

(b) (c)

(d)

Flexor digitorum

longus

Flexor

digitorum

longus

Flexor hallucis

longus

Flexor

hallucis

longus

Popliteus

Popliteus

Plantaris (cut)

Soleus (cut)

Fibula

Fibularis

longus

Fibularis

brevis

Gastrocne

-mius (cut)

Plantar surface

of the foot

Tibialis

posterior

Tibialis

posterior

Figure 10.39

10-99


• Lateral (fibular)

compartment—two

muscles

– Fibularis longus

– Fibularis brevis

• Both plantar flex and

evert the foot

• Provide lift and

forward thrust


Calcaneal tendon

(cut)

Calcaneus

(a)

Flexor digitorum

longus

Flexor hallucis

longus

Popliteus

Plantaris (cut)

Soleus (cut)

Fibula

Fibularis

longus

Fibularis

brevis

Gastrocnemius (cut)

Tibialis

posterior

Figure 10.39a

10-100

Intrinsic Muscles of Foot

• One dorsal

muscle

– Extensor

digitorum

brevis extends

toes

• Four ventral

muscle layers

– Support arches

– Abduct and

adduct the toes

– Flex the toes

Figure 10.41a–e

Dorsal

view

(a) Layer 1, plantar view (b) Layer 2, plantar view

Abductor hallucis

Calcaneus

Lumbricals

Quadratus plantae

(c) Layer 3, plantar view (d) Layer 4, plantar view (e) Layer 4, dorsal view

Adductor hallucis

Flexor hallucis brevis

Abductor hallucis (cut)

Flexor digiti

minimi brevis

Abductor digiti

minimiFlexor digitorum

brevis

Plantar aponeurosis

(cut)

Flexor digitorum

brevis (cut)

Flexor hallucis

longus tendon

Flexor digitorum

longus tendonAbductor hallucis

(cut)

Flexor hallucis

longus tendon (cut)

Flexor digitorum

longus tendon (cut)

Plantar

interosseous

Dorsal

interosseous


Flexor digiti

minimi brevis

Quadratus plantae

(cut)

10-101

Common Athletic Injuries

• Muscles and tendons are vulnerable to sudden and intense stress

• Proper conditioning and warm-up needed

• Common injuries include:– Compartment syndrome

– Shin splints

– Pulled hamstrings

– Tennis elbow

– Pulled groin

– Rotator cuff injury

• Treat with rest, ice, compression, and elevation

• “No pain, no gain” is a dangerous misconception

10-102

chapter 10 lecture outline - palm beach state college · –describe the connective tissue...

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