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Pre-Pharm > A&P 10: The Muscular System > Flashcards

A&P 10: The Muscular System Flashcards

1
Q

Skeletal muscles

A

muscle composed of cylindrical multinucleate cells with obvious striations; the muscle(s) attached to the body’s skeleton; voluntary muscle

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2
Q

Prime mover (agonist)

A

a muscle that has the major responsibility for producing a specific movement

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3
Q

Antagonists

A

muscles that oppose/reverse a particular movement

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4
Q

Synergists

A

most movements involve the action of one or more of these; help prime movers by adding a little extra force to the same movement or by reducing undesirable or unnecessary movements that might occur as the prime mover contracts

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5
Q

Fixators

A

when syngergists immobilize a bone, or a muscle’s origin so that the prime mover has a stable base on which to act

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6
Q

Circular

A

fascicular pattern is this when the fascicles are arranged in concentric rings; muscles with this pattern surround external body openings, which they close by contracting (i.e. sphincters)

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7
Q

Convergent

A

muscle with a broad origin with its fascicles converging toward a single tendon of insertion; triangular or fan-shaped

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8
Q

Parallel

A

length of the fascicles run parallel to the long axis of the muscle; straplike or spindle-shaped

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9
Q

Fusiform muscles

A

some authorities classify spindle-shaped muscles into this separate class

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10
Q

Pennate

A

pattern in which the fascicles are short and attach obliquely; 3 forms - uni, bi, or multi

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11
Q

Lever

A

rigid bar that moves on a fulcrum

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12
Q

Fulcrum

A

the fixed point on which a lever moves when a force is applied

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13
Q

Effort

A

applied force used to move a resistance (load)

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14
Q

Load

A

resistance that is trying to be moved by a lever and its fulcrum when effort is applied

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15
Q

Mechanical advantage

A

a power lever; condition that occurs when the load is close to the fulcrum and the effort is applied far from the fulcrum; allows a small effort exerted over a relatively large distance to move a large load over a small distance

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16
Q

Mechanical disadvantage

A

a speed lever; condition that occurs when the load is far from from the fulcrum and the effort is applied near the fulcrum; the effort applied must be greater than the load to be moved

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17
Q

First-class lever

A

effort applied at one end of the lever and the load at the other, with the fulcrum somewhere between (ex. seesaws and scissors)

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18
Q

Second-class lever

A

effort applied at one end of the lever and the fulcrum at the other, with the load between them (ex. wheelbarrow; standing on toes); all of these in the body work at a mechanical advantage; speed and range are sacrificed for strength

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19
Q

Third-class lever

A

effort applied between the load and fulcrum; speedy; always operate at a mechanical disadvantage (ex. tweezers, forceps; most skeletal muscles in the body like biceps in arm)

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20
Q

Epicranius

A

main muscle in the scalp

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21
Q

Frontal belly

A

covers forehead and dome of skull; no bony attachments; raises the eyebrows

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22
Q

Occiptal belly

A

overlies posterior occiput; by pulling on the epicranial aponeurosis, fixes origin of frontal belly; pulls scalp posteriorly

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23
Q

Corrugator supercilli

A

small muscle; activity associated with that of orbicularis oculi; draws eyebrows together and inferiorly

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24
Q

Orbicularis oculi

A

thin, flat sphincter muscle of eyelid; surrounds rim of the orbit; closes eye

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25
Q

Zygomaticus

A

major and minor muscle pair extending diagonally from cheekbone to corner of mouth; raises lateral corners of mouth upward (smiling muscle)

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26
Q

Risorius

A

slender muscle inferior and lateral to zygomaticus; draws corner of lip laterally; tenses lips; synergist of zygomaticus

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27
Q

Levator labii superioris

A

thin muscle between orbicularis oris and inferior eye margin; opens lips

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28
Q

Depressor labii inferioris

A

small muscle running from mandible to lower lip; draws lower lip inferiorly

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29
Q

Depressor anguli oris

A

small muscle lateral to depressor labii inferioris; draws corners of mouth down and laterally; a “tragedy mask” grimace; zygomaticus antagonist

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30
Q

Orbicularis oris

A

complicated, multilayered muscle of the lips with fibers that run in many different directions; most run circularly; closes lips; kissing and whistling muscle

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31
Q

Mentalis

A

one of the muscle pair forming a V-shaped muscle mass on the chin; wrinkles chin

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32
Q

Buccinator

A

thin, horizontal cheek muscle; principal muscle of cheek; deep to masseter; compresses cheek (as in whistling and sucking)

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33
Q

Platysma

A

unpaired, thin, sheetlike superficial neck muscle; not strictly a head muscle - plays a role in facial expression; tenses skin of neck

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34
Q

Masseter

A

powerful muscle that covers lateral aspect of mandibular ramus; prime mover of jaw closure

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35
Q

Temporalis

A

fan-shaped muscle that covers parts of the temporal, frontal, and parietal bones; closes jaw

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36
Q

Medial pterygoid

A

deep 2-headed muscle that runs along internal surface of mandible and is largely concealed by that bone; acts with the lateral pterygoid muscle to protrude (pull anteriorly) the mandible and promote side-to-side (grinding) movements

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37
Q

Lateral pterygoid

A

deep 2-headed muscle; lies superior to medial pterygoid muscle; provides forward sliding and side-to-side grinding movements of the lower teeth

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38
Q

Genioglossus

A

fan-shaped muscle; forms bulk of inferior part of tongue; its attachment to mandible prevents tongue from falling backward and obstructing breathing; protracts tongue

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39
Q

Hypoglossus

A

flat, quadrilateral muscle; depresses tongue and draws its sides inferiorly

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40
Q

Styloglossus

A

slender muscle running superiorly to and at right angles to hypoglossus; retracts and elevates tongue

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41
Q

Suprahyoid

A

muscles above the hyoid bone that help form floor of oral cavity, anchor tongue, elevate hyoid, and move larynx superiorly during swallowing

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42
Q

Infrahyoid

A

muscles below the hyoid bone; straplike muscles that depress the hyoid bone and larynx during swallowing and speaking

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43
Q

Pharyngeal constrictor muscles

A

muscles in the wall of the pharynx that propel food inferiorly into the esophagus

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44
Q

Stylohyoid

A

Slender muscle below angle of jaw; parallels posterior belly of digastric muscle; elevates & retracts hyoid

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44
Q

Stylohyoid

A

Slender muscle below angle of jaw; parallels posterior belly of digastric muscle; elevates & retracts hyoid

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45
Q

Mylohyoid

A

Flat, triangular muscle just deep to digastric muscle; this muscle pair makes a sling that forms the floor of the anterior mouth; elevates hyoid & floor of mouth

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46
Q

Geniohyoid

A

Narrow muscle in contact with its partner medially; runs from chin to hyoid bone deep to mylohyoid; pulls hyoid bone superiorly & anteriorly

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47
Q

Sternohyoid

A

Most medial muscle of the neck; thin; superficial except inferiorly, where covered by sternocleidomastoid; depresses larynx & hyoid bone if mandible is fixed

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48
Q

Sternothyroid

A

Lateral & deep to sternohyoid; pulls larynx & hyoid bone inferiorly

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49
Q

Omohyoid

A

Strap like muscle with 2 bellies united by an intermediate tendon; lateral to sternohyoid; depresses & retracts hyoid bone

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50
Q

Thyrohyoid

A

Appears as a superior continuation of sternothyroid muscle; depresses hyoid bone or elevates larynx if hyoid is fixed

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51
Q

Superior, middle, & inferior pharyngeal constrictor muscles

A

3 paired muscles whose fibers run circularly in pharynx wall; superior muscle is innermost & inferior one is outermost; substantial overlap; constrict pharynx during swallowing

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52
Q

Sternocleidomastoid

A

2-headed muscle located deep to plates a on anterolateral surface of neck; fleshy parts on either side of neck delineate limits of anterior & posterior triangles; key muscular landmark in neck; spasms of one of these muscles may cause torticollis (wryneck); fixes & laterally rotates the head

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53
Q

Scalenes

A

Located more laterally than anteriorly on the neck; deep to platysma & sternocleidomastoid; elevates 1st 2 ribs

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55
Q

Splenius

A

Broad bipartite superficial muscle (capitis & cervicis parts) extending from upper thoracic vertebrae to skull; capitis portion known as “bandage muscle” because it covers & holds down deeper neck muscles; extends or hyperextends head

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56
Q

Erector spinae

A

AKA sacrospinalis; prime mover of back extension; each consists of 3 columns - the iliocostalis, longissimus, and spinalis muscles - forming intermediate layer of intrinsic back muscles; provide resistance that helps control action of bending forward at the waist and act as powerful extensors to promote return to erect position

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57
Q

Iliocostalis

A

most lateral muscle group of erector spinae muscles; extend from pelvis to neck; extend and laterally flex the vertebral column

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58
Q

Longissimus

A

intermediate tripartite muscle group of erector spinae; extend by many muscle slips from lumbar region to skull; mainly pass between transverse processes of vertebrae; thoracis and cervicis act together to extend and laterally flex vertebral column; capitis extends head and turns the face toward same side

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59
Q

Spinalis

A

most medial muscle column of erector spinae; cervicis usually rudimentary and poorly defined; extends vertebral column

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60
Q

Semispinalis

A

composite muscle forming part of deep layer of intrinsic back muscles; extends from thoracic region to head; extends vertebral column and head and rotates them to opposite side

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61
Q

Quadratus lumborum

A

fleshy muscle forming part of posterior abdominal wall; flexes vertebral column laterally

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62
Q

External intercostals

A

11 pairs lie between ribs; fibers run obliquely (down and forward) from each rib to rib below; in lower spaces, fibers are continuous with external oblique muscle, forming part of abdominal wall; pull ribs toward one another to elevate rib cage

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63
Q

Internal intercostals

A

11 pairs lie between ribs; fibers run deep to and at right angles to those of external _____; lower ones are continuous with fibers of internal obliques of the abdominal wall; draw ribs together and depress rib cage

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64
Q

Diaphragm

A

broad muscle pierced by the aorta, inferior vena cava, and esophagus; forms floor of thoracic cavity; dome shaped in relaxed state; fibers converge from margins of thoracic cage toward a boomerang-shaped central tendon; prime mover of inspiration; flattens on contraction

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65
Q

Linea alba

A

white line; a tendinous raphe (seam) that runs from the sternum to the pubic symphysis

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66
Q

Rectus abdominis

A

medial superficial muscle pair; extend from pubis to rib cage; ensheathed by aponeuroses of lateral muscles; segmented by 3 tendinous intersections; flex and rotate lumbar region of vertebral column

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67
Q

External oblique

A

largest and most superficial of the 3 lateral muscles; fibers run downward and medially (same direction outstretched fingers take when hands are in pants pockets); aponeurosis turns under inferiorly, forming inguinal ligament; flex vertebral column and compress abdominal wall; rotates trunk & flexes laterally

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68
Q

Internal oblique

A

most fibers run upward and medially; muscle fans so its inferior fibers run downward and medially; flexes vertebral column and compresses abdominal wall; rotates trunk and flexes laterally

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69
Q

Transverse abdominis

A

deepest (innermost) muscle of abdominal wall; fibers run horizontally; compresses abdominal contents

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70
Q

Levator ani

A

broad, thin, tripartite muscle (pubococcygeus, puborectalis, and iliococcygeus); its fibers extend inferomedially, forming a muscular “sling” around male prostrate (or female vagina), urethra, and anorectal junction before meeting in the median plane; supports and maintains position of pelvic viscera

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71
Q

Coccygeus

A

small triangular muscle lying posterior to levator ani; forms posterior part of pelvic diaphragm; supports pelvic viscera

72
Q

Deep transverse perineal muscle

A

together the pair spans distance between ischial rami; in females, lies posterior to the vagina; supports pelvic organs

73
Q

External urethral sphincter

A

muscle encircling urethra and vagina (female); constricts urethra; allows voluntary inhibition of urination; helps support pelvic organs

74
Q

Ischiocavernosus

A

runs from pelvis to base of penis or clitoris; retards venous drainage and maintains erection of penis or clitoris

75
Q

Bulbospongiosus

A

encloses base of penis (bulb) in males and lies deep to labia in females; empties male urethra; assists in erection of penis and of clitoris

76
Q

Superficial transverse perineal muscles

A

paired muscle bands posterior to urethral (and in females, vaginal) opening; variable; sometimes absent; strengthens central tendon of perineum

77
Q

Pectoralis minor

A

flat, thin muscle directly beneath and obscured by the pectoralis major; with ribs fixed, draws scapula forward and downward

78
Q

Serratus anterior

A

fan-shaped muscle; lies deep to scapula, deep and inferior to pectoral muscles on lateral rib cage; forms medial wall of axilla; origins have serrated (sawtooth) appearance; paralysis results in “winging” of vertebral border of scapula away from chest wall, making arm elevation impossible; rotates scapula so its inferior angle moves laterally and upward

79
Q

Subclavius

A

small, cylindrical muscle extending from rib 1 to clavicle; helps stabilize and depress pectoral girdle

80
Q

Trapezius

A

most superficial muscle of posterior thorax; flat and triangular in shape; upper fibers run inferiorly to scapula; middle fibers run horizontally to scapula; lower fibers run superiorly to scapula; stabilizes, raises, retracts, and rotates scapula

81
Q

Levator scapulae

A

located at back and side of neck, deep to trapezius; thick, straplike muscle; elevates/adducts scapula

82
Q

Rhomboids

A

2 roughly diamond-shaped muscles lying deep to trapezius and inferior to levator scapulae; minor is the more superior muscle; stabilize scapula

83
Q

Pectoralis major

A

large, fan-shaped muscle covering superior portion of chest; forms anterior axillary fold; divided into clavicular and sternal parts; prime mover of arm flexion; rotates arm medially; adducts arm

84
Q

Deltoid

A

thick, multipennate muscle forming rounded shoulder muscle mass; a common site for intramuscular injection, particularly in males, where it tends to be quite fleshy; prime mover of arm abduction when all its fibers contract simultaneously

85
Q

Lattisimus dorsi

A

broad, flat, triangular muscle of lower back; extensive superficial origins; covered by trapezius superiorly; contributes to the posterior wall of axilla; prime mover of arm extension; powerful arm adductor; medially rotates arm at shoulder

86
Q

Subscapularis

A

forms part of posterior wall of axilla; tendon of insertion passes in front of shoulder joint; a rotator cuff muscle; chief medial rotator of humerus

87
Q

Supraspinatus

A

named for its location on posterior aspect of scapula; deep to trapezius; a rotator cuff muscle

88
Q

Infraspinatus

A

partially covered by deltoid and trapezius; named for its scapular location; a rotator cuff muscle; rotates humerus laterally

89
Q

Teres minor

A

rotates humerus laterally; small, elongated muscle; lies inferior to infraspinatus and may be inseparable from that muscle; a rotator cuff muscle

90
Q

Teres major

A

thick, rounded muscle; located inferior to teres minor; helps form posterior wall of axilla (along with latissimus dorsi and subscapularis); extends, medially rotates, and adducts humerus

91
Q

Coracobrachialis

A

small, cylindrical muscle; flexes and adducts humerus

92
Q

Triceps brachii

A

large, fleshy muscle; the only muscle of posterior compartment of arm; 3-headed origin; long and lateral heads lie superficial to medial head; powerful forearm extensor

93
Q

Anconeus

A

short, triangular muscle; partially blended with distal end of triceps on posterior humerus; may control ulnar abduction during forearm pronation

94
Q

Biceps brachii

A

two-headed fusiform muscle; bellies unite as insertion point is approached; tendon of long head helps stabilize shoulder joint; flexes elbow joint and supinates forearm

95
Q

Brachialis

A

strong muscle that is immediately deep to biceps brachii on distal humerus; a major forearm flexor

96
Q

Brachioradialis

A

superficial muscle of lateral forearm; forms lateral boundary of cubital fossa; extends from distal humerus to distal forearm; synergist in flexing forearm

97
Q

Pronator teres

A

2-headed muscle; seen in superficial view between proximal margins of brachioradialis and flexor carpi radialis; forms medial boundary of cubital fossa; pronates forearm

98
Q

Flexor carpi radialis

A

runs diagonally across forearm; midway, its fleshy belly is replaced by a flat tendon that becomes cordlike at wrist; powerful flexor of wrist; abducts hand

99
Q

Palmaris longus

A

small, fleshy muscle with a long insertion tendon; often absent; may be used as a guide to find median nerve that lies lateral to it at wrist; tenses skin and fascia of palm during hand movements

100
Q

Flexor carpi ulnaris

A

most medial muscle of this group; 2-headed; ulnar nerve lies lateral to its tendon; powerful flexor of wrist; also adducts hand

101
Q

Flexor digitorum superficialis

A

2-headed muscle; more deeply placed (therefore, actually forms an intermediate layer); overlain by muscles above but visible at distal end of forearm; flexes wrist and middle phalanges of fingers 2-5

102
Q

Flexor pollicis longus

A

partly covered by flexor digitorum superficialis; parallels flexor digitorum profundus laterally; flexes distal phalanx of thumb

103
Q

Flexor digitorum profundus

A

extensive origin; overlain entirely by flexor digitorum superficialis; flexes distal interphalangeal joints

104
Q

Pronator quadratus

A

deepest muscle of distal forearm; passes downward and laterally; only muscle that arises solely from ulna and inserts solely into radius; prime mover of forearm pronation

105
Q

Extensor carpi radialis longus

A

parallels brachioradialis on lateral forearm and may blend with it; extends/abducts wrist

106
Q

Extensor carpi radialis brevis

A

shorter than extensor carpi radialis longus and lies deep to it; extends and abducts wrist

107
Q

Extensor digitorum

A

lies medial to extensor carpi radialis brevis; a detached portion of this muscle (exensor digiti minimi) extends little finger; prime mover of finger extension

108
Q

Extensor carpi ulnaris

A

most medial of superficial posterior muscles; long, slender muscle; extends/adducts wrist

109
Q

Supinator

A

deep muscle at posterior aspect of elbow; largely concealed by superficial muscles; assists biceps brachii to forcibly supinate forearm

110
Q

Abductor pollicis longus

A

lateral and parallel to extensor pollicis longus; just distal to supinator; abducts/extends thumb

111
Q

Extensor pollicis brevis & longus

A

deep muscle pair with a common origin and action; overlain by extensor carpi ulnaris; extends thumb

112
Q

Extensor indicis

A

tiny muscle arising close to wrist; extends index finger

113
Q

Abductor pollicis brevis

A

lateral muscle of thenar group; superficial; abducts thumb at carpometacarpal joint

114
Q

Flexor pollicis brevis

A

medial and deep muscle of thenar group; flexes thumb

115
Q

Opponens pollicis

A

deep to abductor pollicis brevis, on metacarpal I; opposition

116
Q

Adductor pollicis

A

fan-shaped with horizontal fibers; distal to other thenar muscles; oblique and transverse heads; adducts and helps to oppose thumb

117
Q

Abductor digiti minimi

A

medial muscle of hypothenar group; superficial; abducts little finger

118
Q

Flexor digiti minimi brevis

A

lateral deep muscle of hypothenar group; flexes little finger

119
Q

Opponens digiti minimi

A

deep to abductor digiti minimi; helps in opposition

120
Q

Lumbricals

A

4 worm-shaped muscles in palm, one to each finger (except thumb); unusual because they originate from the tendons of another muscle; flex fingers at metacarpophalangeal joints but extend fingers at interphalangeal joints

121
Q

Palmar interossei

A

4 long, cone-shaped muscles in the spaces between the metacarpals; lie ventral to the dorsal interossei; adducts fingers

122
Q

Dorsal interossei

A

4 bipennate muscles filling spaces between the metacarpals; deepest palm muscles, also visible on dorsal side of hand

123
Q

Illiopsoas

A

composite of 2 closely related muscles (Iliacus and psoas major) whose fibers pass under the inguinal ligament to insert via a common tendon on the femur

124
Q

Iliacus

A

large, fan-shaped, more lateral muscle; prime mover for flexing thigh or for flexing trunk on thigh as during a bow

125
Q

Psoas major

A

longer, thicker, more medial muscle of the pair; “tenderloin”; with iliacus, prime mover for flexing thigh or for flexing trunk on thigh; also flexes vertebral column laterally

126
Q

Sartorius

A

straplike superficial muscle running obliquely across anterior surface of thigh to knee; longest muscle in body; crosses both hip and knee joints; flexes, abducts, and laterally rotates thigh

127
Q

Adductors

A

large muscle mass consisting of 3 muscles (magnus, longus, and brevis) forming medial aspect of thigh; arise from inferior part of pelvis and insert at various levels on femur; all used in movements that press thighs together; important in pelvic tilting movements that occur during walking and in fixing the hip when the knee is flexed and the foot is off the ground

128
Q

Adductor magnus

A

triangular muscle with a broad insertion; a composite muscle that is part adductor and part hamstring in action; anterior part adducts and medially rotates and flexes thigh; posterior part is a synergist of hamstrings to extend thigh

129
Q

Adductor longus

A

overlies middle aspect of adductor magnus; most anterior of adductor muscles; adducts, flexes, and medially rotates thigh

130
Q

Adductor brevis

A

in contact with obturator externus muscle; largely concealed by adductor longus and pectineus; adducts, flexes, and medially rotates thigh

131
Q

Pectineus

A

short, flat muscle; overlies adductor brevis on proximal thigh; abuts adductor longus medially; adducts, flexes, and medially rotates thigh

132
Q

Gracilis

A

long, thin, superficial muscle of medial thigh; adducts thigh, flexes and rotates leg

133
Q

Quadriceps femoris

A

4 separate heads that form the flesh of front and sides of thigh; common insertion tendon which inserts into the patella and then into the tibial tuberosity; powerful knee extensor used in climbing, jumping, running, and rising from seated position; important role in strengthening the knee joint

134
Q

Rectus femoris

A

superficial muscle of anterior thigh; runs straight down thigh; longest head and only muscle of group to cross hip joint; extends knee and flexes thigh at hip

135
Q

Vastus lateralis

A

largest head of the group; forms lateral aspect of thigh; common intramuscular injections site, particularly in infants, who have poorly developed buttock and arm muscles; extends and stabilizes knee

136
Q

Vastus medialis

A

forms inferomedial aspect of thigh; extends knee

137
Q

Vastus intermedius

A

obscured by rectus femoris; lies between vastus lateralis and vastus medialis on anterior thigh; extends knee

138
Q

Tensor fasciae latae

A

enclosed between fascia layers of anterolateral aspect of thigh; functionally associated with medial rotators and flexors of thigh; functionally associated with medial rotators and flexors of thigh; steadies the knee and trunk on thigh by making iliotibial tract taut

139
Q

Gluteus maximus

A

largest and most superficial gluteus muscle; forms bulk of buttock mass; fibers are thick and coarse; important site of IM injection (dorsal); overlies large sciatic nerve; covers ischial tuberosity only when standing; when sitting, moves superiorly, leaving ischial tuberosity exposed in the SQ position; major extensor of thigh

140
Q

Gluteus medius

A

thick muscle largely covered by gluteus maximus; important site for IM injections (ventral); considered safer than dorsal site b/c less chance of injuring sciatic nerve; abducts and medially rotates thigh

141
Q

Gluteus minimus

A

smallest and deepest gluteal muscle; important site for IM injections (ventral); considered safer than dorsal site b/c less chance of injuring sciatic nerve; abducts and medially rotates thigh

142
Q

Piriformis

A

pyramidal muscle located on posterior aspect of hip joint; inferior to gluteus minimus; issues from pelvis via greater sciatic notch; rotates extended thigh laterally

143
Q

Obturator externus

A

flat, triangular muscle deep in superomedial aspect of thigh; rotates extended thigh laterally

144
Q

Obturator internus

A

surrounds obturator foramen within pelvis; leaves pelvis via lesser sciatic notch and turns acutely forward to insert on femur; rotates extended thigh laterally

145
Q

Gemellus

A

2 small muscles with common insertions and actions; considered extrapelvic portions of obturator internus; rotates extended thigh laterally

146
Q

Quadratus femoris

A

short, thick muscle; most inferior lateral rotator muscle; extends laterally from pelvis; rotates thigh laterally and stabilizes hip joint

147
Q

Hamstrings

A

fleshy muscles of the posterior thigh; cross hip and knee joints; prime movers of thigh extension and knee flexion

148
Q

Biceps femoris

A

most lateral muscle of the group; arises from 2 heads; extends thigh and flexes knee

149
Q

Semitendinosus

A

lies medial to biceps femoris; quite fleshy; its long slender tendon begins about 2/3 of the way down thigh; extends thigh and flexes knee; with semimembranosus, medially rotates leg

150
Q

Semimembranosus

A

deep to semitendinosus; extends and flexes knee

151
Q

Tibialis anterior

A

superficial muscle of anterior leg; laterally parallels sharp anterior margin of tibia; prime mover of dorsiflexion

152
Q

Extensor digitorum longus

A

unipennate muscle on anterolateral surface of leg; lateral to tibialis anterior; prime mover of toe extension

153
Q

Fibularis (peroneus) tertius

A

small muscle usually continuous and fused with distal part of extensor digitorum longus; not always present; dorsiflexes and everts foot

154
Q

Extensor hallucis longus

A

deep to extensor digitorum longus and tibialis anterior; narrow origin; extends great toe

155
Q

Flexor, extensor, and fibular/peroneal retinacula

A

“ankle brackets” that hold the tendons in place where they run to the foot

156
Q

Fibularis (peroneus) longus

A

superficial lateral muscle; overlies fibula; plantar flexes and everts foot

157
Q

Fibularis (peroneus) brevis

A

smaller muscle; deep to fibularis longus; enclosed in a common sheath; plantar flexes and everts foot

158
Q

Triceps surae

A

refers to muscle pair (gastrocnemius and soleus) that shapes the posterior calf and inserts via a common tendon into the calcaneus of the heel (Achilles/calcaneal tendon)

159
Q

Gastrocnemius

A

superficial muscle of pair; 2 prominent bellies that form proximal curve of calf; plantar flexes foot

160
Q

Soleus

A

broad, flat muscle, deep to gastrocnemius on posterior surface of calf; plantar flexes foot

161
Q

Plantaris

A

generally a small, feeble muscle, but varies in size and extent; may be absent; helps to flex knee and plantar flex foot

162
Q

Popliteus

A

thin, triangular muscle at posterior knee; passes inferomedially to tibial surface; flexes and rotates leg medially to unlock extended knee when flexion begins

163
Q

Flexor digitorum longus

A

long, narrow muscle; runs medial to and partially overlies tibialis posterior; plantar flexes and inverts foot; flexes toes

164
Q

Flexor hallucis longus

A

bipennate muscle; lies lateral to inferior aspect of tibialis posterior; plantar flexes and inverts foot; flexes great toe at all joints

165
Q

Tibialis posterior

A

thick, flat muscle deep to soleus; placed between posterior flexors; prime mover of foot inversion

166
Q

Extensor digitorum brevis

A

small, 4-part muscle on dorsum of foot; deep to the tendons of extensor digitorum longus; corresponds to the extensor indicis and extensor pollicis muscles of forearm; helps extend toes at metatarsophalangeal joints

167
Q

Flexor digitorum brevis

A

bandlike muscle in middle of sole; corresponds to flexor digitorum superficialis of forearm ad inserts into digits in the same way; helps flex toes

168
Q

Abductor hallucis

A

lies medial to flexor digitorum brevis; abducts great toe

169
Q

Abductor digiti minimi

A

most lateral of the 3 superficial sole muscles; abducts and flexes little toe

170
Q

Flexor accesorius (quadratus plantae)

A

rectangular muscle just deep to flexor digitorum brevis in posterior half of sole; 2 heads; straightens out the oblique pull of flexor digitorum longus

171
Q

Lumbricals

A

4 little “worms”; flex toes at metatarsophalangeal joints and extend toes at interphalangeal joints

172
Q

Flexor hallucis brevis

A

covers metatarsal I; splits into 2 bellies; flexes great toe’s metatarsophalangeal joint

173
Q

Adductor hallucis

A

oblique and transverse heads; deep to lumbricals; helps maintain the transverse arch of the foot

174
Q

Flexor digiti minimi brevis

A

covers metatarsal V; flexes little toe at metatarsophalangeal joint

175
Q

Plantar (3) & Dorsal Interossei (4)

A

similar to palmar and dorsal interossei of hand in locations, attachments, and actions; however, these muscles orient around the 2nd digit, not the 3rd

Pre-Pharm (182 decks)

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