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THE MUSCULAR SYSTEM
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INTERACTIONS OF SKELETAL
MUSCLES IN THE BODY Muscles only pull; they are not capable of pushing
Generally as a muscle shortens, its insertion(attachment on the movable bone)moves toward itsorigin(its fixed or immovable point of attachment)
Muscles can be classified into four functional groups: 1.Prime Movers:
The muscle that provides the major force for the specific movementis called theprime mover or the agonist, of that movement
The biceps brachii muscle, which fleshes out the anterior arm (and inserts on the radius), is aprime mover of elbow flexion
2.Antagonists: Muscles that oppose or reverse a particular movement
When a prime mover is active, the antagonist muscles are often stretched and may berelaxed
Can also help to regulate the action of a prime mover by contracting to provide someresistance, thus helping to prevent overshoot or to slow or stop the movement
Prime mover and its antagonist are located on opposite sides of the joint acrosswhich they act
Antagonists can also be prime movers in their own right Example: flexion of the forearm by the biceps brachii muscle of the arm is antagonized by the
triceps brachii, the prime mover for extending the forearm
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INTERACTIONS OF SKELETAL
MUSCLES IN THE BODY
3.Synergists: Help the prime movers by:
Adding a little extra force to the same movement
Or reducing undesirable or unnecessary movements that
might occur as the prime mover contracts When a muscle crosses two or more joints, its contraction
causes movement at all of the spanned joints unless othermuscles act as joint stabilizers
Example: the finger flexor muscles cross both the wristand the phalangeal joints, but you can make a fist without
bending your wrist because synergistic muscles stabilizethe wrist
As some flexors act, undesirable rotation movements occur
Synergists can prevent this, allowing all of the primemovers force to be exerted in the desired direction
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INTERACTIONS OF SKELETAL
MUSCLES IN THE BODY
4.Fixators: when synergists immobilize
a bone, or a muscles origin, they are
more specifically called fixators
Examples:
Scapula is held to the axial skeleton only by
muscles and is quite freely movable
The fixator muscles that run from the axial skeleton to the
scapula can immobilize the scapula so that only the
desired movements occur at the mobile shoulder joint
Muscles that help to maintain upright posture
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INTERACTIONS OF SKELETAL
MUSCLES IN THE BODY
Although prime movers seem to get all thecredit for causing certain movements,antagonistic and synergistic muscles are
also important in producing smooth,coordinated, and precise movements
A muscle may act as a prime mover inone movement, an antagonist foranother movement, a synergist for athird movement, and so on
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NAMING SKELETAL MUSCLES
1. Location of the muscle: Some muscle names indicate the bone orbody region with which the muscle is associated Example:
Temporalis muscle overlies the temporal bone
Intercostal muscles run between the ribs
2. Shape of the muscle: Some muscles are named for their shape Example:
Deltoid muscle is roughly triangular
Together the right and left trapezius muscles form a trapezoid
3. Relative size of the muscle: Terms such as maximus (largest),minimus (smallest), longus (long), and brevis (short) are often usedin muscle names to indicate relative size of the muscle Example:
Gluteus maximus
Gluteus minimus
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NAMING SKELETAL MUSCLES
4. Direction of muscle fibers: The names ofsome muscles indicate the direction in whichtheir fibers (and fascicles) run in reference tosome imaginary line, usually the midline of the
body or the longitudinal axis of a limb bone Examples:
Rectus(straight): fibers run parallel to that imaginary line(axis)
Rectus femoris: straight muscle of the thigh, or femur)
Transversus(right angle): muscle fibers run at right angles Transversus abdominis: transverse muscle of the abdomen
Oblique(oblique angle): muscle fibers run at oblique angles External oblique: oblique muscle of the abdomen
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NAMING SKELETAL MUSCLES
5. Number of origins: The number of
origins a muscle has may be indicated by
the word biceps, triceps, or quadriceps
Example:
Biceps brachii: muscle of the arm has two origins
(heads)
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NAMING SKELETAL MUSCLES
6. Location of the attachments: Some
muscles are named according to the
location of their origin and insertion
Origin is always named first
Example:
Sternocleidomastoid: muscle of the neck
Has a dual origin on the sternum (sterno) and
clavicle (cleido), and it inserts on the mastoid
process of the temporal bone
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NAMING SKELETAL MUSCLES
7. Action: A muscle may be named for its actionby using such words as flexor (flex), extensor(extend), adductor (brought toward), or supinate(bend backward) in its name Example:
Adductor longus: located in the medial thigh
Brings about thigh adduction (toward the main axis of the bodyor a limb)
Supinator muscle:
Supinates the forearm:
Turn the forearm or hand so that the palm faces upward
Supinates the leg and foot:
To rotate the foot and leg outward
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NAMING SKELETAL MUSCLES
Several criteria are combined in the
naming of some muscles
Example: extensor carpi radialis longus Action of the muscle: the muscles action (extensor)
Location of attachment: joint it acts on (carpi = wrist)
Location of muscle: lies close to the radius of the
forearm (radialis)
Relative size of muscle: relative to other wrist extensormuscles (longus)
Unfor tunately, no t al l musc le names are this
descript ive
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MUSCLE MECHANICS:
IMPORTANCE OF FASCICLE ARRANGEMENT
AND LEVERAGE
In skeletal muscles the common
arrangement of the fascicles varies,
resulting in muscles with different shapes
and functional capabilities
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Arrangement of Fascicles
Fascicle: bundle of
nerve or muscle fibers
(cells) bound together
by connective tissue
All skeletal muscles
consist of fascic les, but
fascicle arrangement
vary, resulting in
muscles with differentshapes and functional
capabilities
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SKELETAL MUSCLE
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Arrangement of Fascicles
(a): Circular pattern: Fascicles arranged in
concentric rings
Muscles with thisarrangement surround
external openings, whichthey close by contracting
General term for thesemuscles is sphincters(squeezers)
Examples:
Orbicularis musclessurrounding the eyes(Orbicularis oculi) andthe mouth (Orbicularisoris)
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Arrangement of Fascicles
(b): Convergent pattern:
Muscle has a broad
origin, and its fascicles
converge toward a single
tendon of insertion Such a muscle is triangular
or fan shaped like the
pectoralis majormuscle
of the anterior thorax
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Arrangement of Fascicles
(c)(f): Parallel pattern: The long axes of the
fascicles run parallel tothe long axis of themuscle
Such muscles are either: straplike (c: parallel)
spindle (f: fusiform)
shaped with anexpanded belly(midsection)
Examples:
Sartoriusof thigh (c)
Biceps brachiimuscle ofthe arm (f)
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Arrangement of Fascicles
(d)(e)(g): Pennate pattern:
In a pennate (feather) pattern ofarrangement the fascicles are short andattach obliquely to a central tendon thatruns the length of the muscle
Types:
Unipennate: d
Fascicles insert into only oneside of the tendon
Example: extensor digitorummuscle of the leg
Bipennate: g
Fascicles insert into the tendonfrom opposite sides (musclegrains resemble a feather)
Example: rectus femoris muscleof the thigh
Multipennate: e
Arrangement looks like many
feathers situated side by side,with all their quills inserted intoone large tendon
Example: deltoid muscle, whichforms the roundness of theshoulder
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FASCICLE ARRANGEMENT
TO
MUSCLE STRUCTURE
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MUSCLE MECHANICS:
IMPORTANCE OF FASCICLE ARRANGEMENT
AND LEVERAGE The operation of most skeletal
muscles involves the use ofleverage and lever systems,partnerships between themuscular and skeletal systems Aleveris a rigid bar thatmoves
on a fixed point, or a fulcrum,
when a force is applied to it The applied force, or effort is used
to move a resistance or load
In your body, yourjoints act asthe fulcrums, the bones as thelevers, and the musclecontraction as the effort (force)
Load (resistance) is the boneitself, along with overlyingtissues and anything else youare trying to move with thatlever
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Lever Systems
A lever allows a given effort(force)to lift a heavier load(resistance),or to move aload (resistance) farther orfaster, than it otherwisecould
(a):First-Class: the load isclose to the fulcrum and theeffort is applied far from thefulcrum
A small effort exerted over arelatively large distance canbe used to move a large load
over a small distance Such a lever is said to
operate at a mechanic aladvantage and iscommonly ca lled a pow erlever
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Lever Systems
(b): Third-Class: Load is far from the
fulcrumand the effort isapplied near the fulcrum,the force exerted by themuscle must be greaterthan the load moved orsupported
This lever system operatesat a mechanicaldisadvantage and is aspeed lever
These levers are usefulbecause they providerapid contract ions wi th awide range of mot ion
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MUSCLE LEVERAGE
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Lever Systems
All levers follow the same basic principle: Effort fartherthan load from fulcrum = mechanical
advantage
Effort nearerthan load to fulcrum = mechanical
disadvantage Lever systems that operate at a mechanical
disadvantage (speed levers),force is lost butspeed and range of movement are gained,and this c an be a dist in ct benef i t
Lever systems that operate at a mechanicaladvantage (power levers) are slower, morestable, and used where streng th is a pr ior i ty
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Lever Systems
There are three
types of levers:
First-class
Second-class
Third-class
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Lever Systems
First-Class Levers (a): Effort is applied at one
end of the lever and the loadis at the other, with thefulcrum somewhere between
Examples:
Seesaws Scissors
Lift your head off your chest
Some operate at amechanical advantage
Others operate at amechanical disadvantage
Action of the triceps muscle inextending the forearm againstresistance (pushing)
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Lever Systems
Second-Class Levers (b): Effort is applied at one end
of the lever and the fulcrum islocated at the other, with theload between them
All second-class levers in the bodywork at a mechanical advantagebecause the muscle insertion(effort) is always farther from thefulcrum than is the load to bemoved
Levers of strength, but speedand range are sacrificed for thatstrength
Examples: Wheelbarrow
Uncommon in the human body Best example is the act of
standing on your toes
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Lever Systems
Third-Class Levers (c): Effort is applied between
the load and the fulcrum
Operate with great speed andalways at a mechanicaldisadvantage
Most skeletal muscles of the
body Tend to be thicker and more
powerful
Permits a muscle to be insertedvery close to the joint acrosswhich movement occurs
Allows rapid, extensivemovements with relatively little
shortening of the muscle Examples:
Tweezers (forceps)
biceps
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MUSCLE LEVERAGE
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Skeletal Muscles
Over 600
Book only list approximately 125 pairs of them
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ANTERIOR SUPERFICIAL
MUSCLES
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DIAGRAMMATIC VIEW
OF
ANTERIOR MUSCLES
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POSTERIOR VIEW
OF
SUPERFICIAL MUSCLES
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DIAGRAMMATIC VIEW
OF
POSTERIOR MUSCLES
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Facial Muscles
Muscles of the Head: Facial
Expression
Muscles of the scalp include
the epicranius consisting of
the frontalisand the
occipitalis Muscles of the face include
corrugator supercilii,
orbicularis oculi,
zygomaticus, risorius, levator
labii superioris, depressor labii
inferioris, depressor angulioris, orbicularis oris,
mentalis, buccinator, and
platysma
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MAJOR SKELETAL MUSCLES
OF
THE FACE Frontalis:cranial (facial nerve)
VII Raises the eyebrows (as in
surprise)
Wrinkles forehead skinhorixzontally
Cranial nerve VII
Orbicularis oculi:cranial (facialnerve) VII Protects eyes from intense light
and injury
Produces blinking, squinting
Draws the eyebrows inferiorly
Orbicularis oris:cranial (facialnerve) VII Closes lips
Purses (pucker) and protrudes(stick out) lips
Kissing and whistling muscle
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HEAD MUSCLES
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Muscles of the Head
Mastication and Tongue
Movement:
Muscles of mastication
include the masseter,
temporalis, medialpterygoid, lateral pterygoid,
and the buccinator
Muscles promoting tongue
movement are the
genioglossus,hypoglossus, and the
styloglossus
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Mastication Muscles
Masseter:Temporalis:cranial(trigeminal) nerve V
Prime mover of jaw closure
Elevates mandible
Temporalis:cranial (trigeminal)
nerve V Closes jaw
Elevates and retractsmandible
Buccinator:cranial (facial)nerve VII
Trampoline-like action
Keeps food between grindingsurfaces of teeth duringchewing
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Mastication Muscles
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HEAD MUSCLES
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Mastication Muscles
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Tongue Muscles
Genioglossus:cranial
(hypoglossal) nerve
XII
Primarily protrudestongue, but in concert
with other extrinsic
muscles to retract
tongue
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TONGUE MUSCLES
MAJOR SKELETAL MUSCLES
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MAJOR SKELETAL MUSCLES
OF
THE BODY
Muscles of the AnteriorNeck and Throat:Swallowing Suprahyoid muscles
include digastric,stylohyoid, mylohyoid, andgeniohyoid
Infrahyoid muscles includesternohyoid, sternothyroid,omohyoid, thyrohyoid, and
the pharyngealconstrictor muscles(superior, middle, andinferior)
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Neck and Throat Muscles
Mylohyoid:cranial
(trigeminal) nerve V
Elevates hyoid bone
and floor of mouth Enables the tongue to
exert backward and
upward pressure that
forces food bolus into
pharynx
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Neck and Throat Muscles
Pharyngealconstrictor muscles(superior, middle, andinferior):cranial
(vagus) nerve X Working as a group
and in sequence, allconstrict pharynx
during swallowing Propels food bolus
to esophagus peristalsis
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NECK MUSCLES
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NECK MUSCLES
MAJOR SKELETAL MUSCLES
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MAJOR SKELETAL MUSCLES
OF
THE BODY
Muscles of the Neck and Vertebral
Column: Head and Trunk Movement
Anterolateral neck muscles include the
sternocleidomastoid, and scalenes(anterior, middle, and posterior)
Intrinsic muscles of the back include splenius
capitis, erector spinae or sacrospinalis,iliocostals, longissimus, spinalis, semispinalis,
and the quadratus lumborum
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Neck Muscles
Sternocleidomastoid:cranial
(accessory) nerve XI and
branches of cervical nerves 2-
4:
Prime mover of head
flexion
Neck flexion
Head movement side-to-
side
NECK AND VERTEBRAL
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NECK AND VERTEBRAL
COLUMN MUSCLES
NECK AND VERTEBRAL
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NECK AND VERTEBRAL
COLUMN MUSCLES
NECK AND VERTEBRAL
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NECK AND VERTEBRAL
COLUMN MUSCLES
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Neck and Vertebral Column Muscles
Longissimus:
thoracis, cervicis, and
capitis: spinal nerves:
Capitis: extends headand turns face side to
side
Thoracis and
cervicis: extend
vertabral column side
to side
NECK AND VERTEBRAL
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NECK AND VERTEBRAL
COLUMN MUSCLES
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Thorax and Abdominal Muscles
Muscles of the Thorax: Breathing Muscles of the thorax include the external
intercostals, internal intercostals,and thediaphragm
Muscles of the Abdominal Wall: TrunkMovement and Compression of AbdominalViscera
Muscles of the anterolateral abdominal wallinclude the rectus abdominis, externaloblique, and the transversus abdominis
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Thorax Muscles
External intercostals:
intercostal nerves:
Elevate rib cage
Aids in inspiration
Internal intercostals:intercostal nerves:
Depress rib cage
Aids in expiration
Diaphragm:cervical(phrenic) nerve (C3-C5)
Breathing
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RESPIRATORY MUSCLES
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RESPIRATORY MUSCLES
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Abdominal Muscles
Rectus abdominis:Intercostal (thoracic)nerves: Flex and rotate lumbar
region
External oblique:Intercostal (thoracic)nerves: Compression of abdominal
wall
Transversus abdominis:Intercostal (thoracic)nerves: Compression of abdominal
wall
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ABDOMINAL MUSCLES
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ABDOMINAL MUSCLES
MAJOR SKELETAL MUSCLES
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MAJOR SKELETAL MUSCLES
OF
THE BODY
Muscles of the Pelvic Floor and Perineum:Support of Abdominopelvic Organs:
Muscles of the pelvic diaphragm include the
levator ani and the coccygeus Muscles of the urogenital diaphragm include
the deep transverse perineus and thesphincter urethrae
Muscles of the superficial space include theischiocavernosus, bulbospongiosus, andthe superficial transverse perineus
PELVIC FLOOR
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PELVIC FLOOR
AND
PERINEUM MUSCLES
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Pelvic Floor Muscles
Ischiocavernosus:pudendal (sacral) nerve:
Retards venou s d rainage
and maintains erect ion o f
penis or c l i tor is Bulbospongiosus:
pudendal (sacral) nerve:
Empties male urethra
Assist in erect ion of
penis in males and of
cl i tor is in females
PELVIC FLOOR
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AND
PERINEUM MUSCLES
MAJOR SKELETAL MUSCLES
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OF
THE BODY
Superficial Muscles of the Anterior and
Posterior Thorax: Movements of the
Scapula
Muscles of the anterior thorax include thepectoralis minor, serratus anterior, and the
subclavius
Muscles of the posterior thorax include thetrapezius, levator scapulae, and the
rhomboids (major and minor)
MAJOR SKELETAL MUSCLES
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OF
THE BODY
Muscles Crossing the Shoulder Joint:
Movement of the Arm
Muscles moving the arm include the
pectoralis major, latissimus dorsi, deltoid,subscapularis, supraspinatous,
infraspinatous, teres minor, teres major, and
the coracobrachialis
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Thorax Muscles
Deltoid: cervical nerves: Prime mover of arm abduction
Antagonists of pectoralis majorand latissimus dorsi
Pectoralis major: cervical andthoracic nerves: Prime mover of arm flexion
Adduction
Trapezius: cervical nerves: Stabilizes, raises, retracts, and
rotates scapula
Latissimus dorsi: cervical nerves Prime mover of arm extension
Powerful arm adductor Striking a blow
Swimming
Rowing
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THORAX MUSCLES
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SHOULDER MUSCLES
MAJOR SKELETAL MUSCLES
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OF
THE BODY
Muscles crossing the Elbow Joint: Flexion
and Extension of the Forearm
Posterior muscles include the t r iceps
brachii, and the anconeus Anterior muscles include the biceps
brach i i , brach ial is , and the b rachioradialis
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SHOULDER MUSCLES
Triceps brachii: cervicalnerves:
Powerful forearm extensor
Biceps brachii: cervicalnerves:
Flexes elbow joint andsupinates forearm
Brachialis: musculocutaneousnerve:
Major forearm flexor
Lifts ulna as biceps lifts the
radius Brachioradialis: radial nerve:
Synergist in forearm flexion
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SHOULDER MUSCLES
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SHOULDER MUSCLES
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O SC S
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ANTERIOR ARM MUSCLES
F M l
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Forearm Muscles
Extensor carpiradialis brevis: radialnerve: Extends and abducts
wrist Extensor digitorum:
branch of radialnerve:
Prime mover of fingerextension
Extends wrist
POSTERIOR ARM MUSCLES
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POSTERIOR ARM MUSCLES
ARM MUSCLES
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ARM MUSCLES
ARM MUSCLE ACTIONS
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ARM MUSCLE ACTIONS
ARM MUSCLE ACTIONS
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ARM MUSCLE ACTIONS
MAJOR SKELETAL MUSCLES
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OF
THE BODY
Muscles of the Forearm: Movements of the Wrist,Hand, and Fingers Anterior superficial muscles include the pronator teres, flexor
carpi radialis, palmaris longus, flexor carpi ulnaris, and the flexordigitorum superficialis
Anterior deep muscles include the flexor pollicis longus, flexordigitorum profundus, and the pronator quadratus
Posterior superficial muscles include the brachioradialis,extensor carpi radialis longus, extensor carpi radialis brevis,extensor digitorum, and the extensor carpi ulnaris
Posterior deep muscles include the supinator, abductor pollicislongus, extensor pollicis longus, and the extensor pollicis brevis
MAJOR SKELETAL MUSCLES
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OF
THE BODY
Intrinsic muscles of the Hand: FineMovements of the Fingers Thenar muscles in ball of thumb include the
abductor pollicis brevis, flexor pollicis brevis,opponnens pollicis, and the adductor pollicis
Hypothenar muscles in ball of little fingerinclude the abductor digiti minimi, flexor digiti
minimi brevis, and the opponens digiti minimi Midpalmar muscles include the lumbricals,
palmar interossei, and the dorsal interossei
H d M l
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Hand Muscles
Abductor pollicisbrevis: median nerve
(cervical.thoracic)
Abducts thumb
Flexor digiti minimi
brevis: ulnar nerve:
Flexes little finger
HAND MUSCLES
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HAND MUSCLES
HAND MUSCLES
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HAND MUSCLES
MAJOR SKELETAL MUSCLES
OF
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OF
THE BODY
Muscles Crossing the Hip and Knee Joints: Movements of the Thighand Leg Anteromedial muscles include the iliopsoas, which is composed of the
iliacus, the psoas major, and the sartorius
Muscles of the medial compartment of the thigh include the adductorgroup, which is made up of the adductor magnus, adductor longus andthe adductor brevis, the pectineus, and the gracilis
Muscles of the anterior compartment of the thigh include the quadricepsfemoris group, which is made up of the rectus femoris, vastus lateralis,vastus medialis and vastus intermedius, and the tensor fasciae latae
Posterior Muscles: gluteal muscles (origin on pelvis) include the gluteusmaximus, gluteus medius, and the gluteus minimus
Lateral rotators include the piriformis, obturator externus, obturator
internus, gemellus, and the quadratus femoris Muscles of the posterior compartment of the thigh include the hamstring
group, which consist of the biceps femoris, semitendinosus, and thesemimembranosus
Thi h M l
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Thigh Muscles
Adductor longus:obturator nerve: Adducts, flexes, and
medially rotates thigh
Gracilis: obturator nerve: Adducts thigh, flexes, and
medially rotates thigh,especially during walking
Quadriceps femoris: Rectus femoris: femoral
nerve: Extends knee and flexes
thigh at hip
ANTERIOR THIGH MUSCLES
-
8/12/2019 AP 10 Muscular System
91/115
ANTERIOR THIGH MUSCLES
ANTERIOR THIGH MUSCLES
-
8/12/2019 AP 10 Muscular System
92/115
ANTERIOR THIGH MUSCLES
Hip Muscles
-
8/12/2019 AP 10 Muscular System
93/115
Hip Muscles
Gluteus maximus:inferior gluteal nerve:
Major extensor of thigh
Complex, powerful, and
most effective when thighis flexed and force is
necessary, as in rising from
a forward flexed position
and in thrusting the thigh
posteriorly in climbing
stairs and running
Inactive during standing
POSTERIOR THIGH MUSCLES
-
8/12/2019 AP 10 Muscular System
94/115
POSTERIOR THIGH MUSCLES
Hamstrings: sciaticnerve
Biceps femoris
Semitendinosus
Semimembranosus
Extends thigh and
flexes knee
POSTERIOR THIGH MUSCLES
-
8/12/2019 AP 10 Muscular System
95/115
POSTERIOR THIGH MUSCLES
POSTERIOR THIGH MUSCLES
-
8/12/2019 AP 10 Muscular System
96/115
POSTERIOR THIGH MUSCLES
MAJOR SKELETAL MUSCLES
OF
-
8/12/2019 AP 10 Muscular System
97/115
OF
THE BODY
Muscles of the Leg: Movements of the Ankle andToes Muscles of the anterior compartment include the tibialis anterior,
extensor digitorum longus, fibularis (peroneus) tertius, and theextensor hallucis longus
Muscles of the lateral compartment include the fibularis(peroneus) longus and the fibularis (peroneus) brevis
Superficial muscles of the posterior compartment include thetriceps surae, which is composed of the gastrocnemius and thesoleus, and the plantaris
Deep muscles of the posterior compartment include thepopliteus, flexor digitorum longus, flexor hallucis longus, and thetibialis posterior
ANTERIOR LEG MUSCLES
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8/12/2019 AP 10 Muscular System
98/115
ANTERIOR LEG MUSCLES
Tibialis anterior: fibularnerve (lumbar): Prime mover of dorsiflexion
Inverts foot
Assists in supporting
medial longitudinal arch offoot
Fibularis longus: fibularnerve (lumbar): Plantar flexes and everts
foot May help keep foot flat on
ground
ANTERIOR LEG MUSCLES
-
8/12/2019 AP 10 Muscular System
99/115
ANTERIOR LEG MUSCLES
ANTERIOR LEG MUSCLES
-
8/12/2019 AP 10 Muscular System
100/115
ANTERIOR LEG MUSCLES
LATERAL LEG MUSCLES
-
8/12/2019 AP 10 Muscular System
101/115
LATERAL LEG MUSCLES
LATERAL LEG MUSCLES
-
8/12/2019 AP 10 Muscular System
102/115
LATERAL LEG MUSCLES
POSTERIOR LEG MUSCLES
-
8/12/2019 AP 10 Muscular System
103/115
POSTERIOR LEG MUSCLES
Gastrocnemius: tibialnerve (sacral): Plantar flexes foot when
knee is extended
Since it also crosses knee
joint, it can flex knee whenfoot is dorsiflexed
Soleus: tibial nerve(sacral): Plantar flexes foot
Important locomotor andpostural muscle duringwalking, running, anddancing
POSTERIOR LEG MUSCLES
-
8/12/2019 AP 10 Muscular System
104/115
POSTERIOR LEG MUSCLES
POSTERIOR LEG MUSCLES
-
8/12/2019 AP 10 Muscular System
105/115
POSTERIOR LEG MUSCLES
POSTERIOR LEG MUSCLES
-
8/12/2019 AP 10 Muscular System
106/115
POSTERIOR LEG MUSCLES
POSTERIOR LEG MUSCLES
-
8/12/2019 AP 10 Muscular System
107/115
POSTERIOR LEG MUSCLES
LEG MUSCLE ACTIONS
-
8/12/2019 AP 10 Muscular System
108/115
LEG MUSCLE ACTIONS
LEG MUSCLE ACTIONS
-
8/12/2019 AP 10 Muscular System
109/115
LEG MUSCLE ACTIONS
MAJOR SKELETAL MUSCLES
OF
-
8/12/2019 AP 10 Muscular System
110/115
OF
THE BODY
Intrinsic Muscles of the Foot: Toe Movement andArch Support The muscle found on the dorsum of the foot is the extensor
digitorum brevis
Muscles on the sole of the foot found in the first layer are the
flexor digitorum brevis, abductor hallucis, and the abductor digitiminimi
Muscles on the sole of the foot found in the second layer are theflexor accessorius (quadratus plantae) and the lumbricals
Muscles of the sole of the foot found in the third layer include theflexor hallicis brevis, adductor hallucis, and the flexor digitiminimi brevis
Muscles of the sole of the foot found in the fourth layer includethe plantar and the dorsal interossei
Foot Muscles
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8/12/2019 AP 10 Muscular System
111/115
Dorsum
Extensor digitorumbrevis: fibular nerve
(sacral):
Helps extend toes
Foot Muscles
-
8/12/2019 AP 10 Muscular System
112/115
Sole
Flexor digitorumbrevis: medial plantar
nerve (sacral):
Helps flex toes
FOOT MUSCLES
-
8/12/2019 AP 10 Muscular System
113/115
FOOT MUSCLES
FOOT MUSCLES
-
8/12/2019 AP 10 Muscular System
114/115
FOOT MUSCLES
FOOT MUSCLES
-
8/12/2019 AP 10 Muscular System
115/115
FOOT MUSCLES