Medical Gross Anatomy
Anatomy Tables - Muscles

Muscles of the Back Region - Listed Alphabetically

Muscle Origin Insertion Action Innervation Artery Notes Image
erector spinae iliac crest, sacrum, transverse and spinous processes of vertebrae and supraspinal ligament angles of the ribs, transverse and spinous processes of vertebrae, posterior aspect of the skull extends and laterally bends the trunk, neck and head segmentally innervated by dorsal primary rami of spinal nerves C1-S5 supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa. the erector spinae m. is separated into 3 columns of muscle: iliocostalis laterally, longissimus in an intermediate position and spinalis medially; each of these columns has multiple named parts
iliocostalis iliac crest and sacrum angles of the ribs extends and laterally bends the trunk and neck dorsal primary rami of spinal nerves C4-S5 supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa. the most lateral part of the erector spinae; it may be subdivided into lumborum, thoracis and cervicis portions
interspinales upper border of spinous process lower border of spinous process above extend trunk and neck dorsal primary rami of spinal nerves C1-L5 supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa. these are small and fairly insignificant muscles
intertransversarii upper border of transverse process lower border of transverse process above laterally bend trunk and neck dorsal primary rami of spinal nerves C1-L5 supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa. these are small and fairly insignificant muscles
longissimus transverse process at inferior vertebral levels transverse process at superior vertebral levels and mastoid process extends and laterally bends the trunk, neck and head dorsal primary rami of spinal nerves C1-S1 supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa. the intermediate part of the erector spinae;it may be subdivided into thoracis, cervicis and capitis portions
multifidus sacrum, transverse processes of C3-L5 spinous processes 2-4 vertebral levels superior to their origin extend and laterally bend trunk and neck, rotate to opposite side dorsal primary rami of spinal nerves C1-L5 supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa. semispinalis, multifidus and rotatores make up the transversospinal muscle group
obliquus capitis inferior spinous process of the axis transverse process of atlas rotates the head to the same side suboccipital nerve (DPR of C1) occipital a. greater occipital nerve (DPR of C2) passes superiorly around the inferior margin of inferior oblique
obliquus capitis superior transverse process of atlas occipital bone above inferior nuchal line extends the head, rotates the head to the same side suboccipital nerve (DPR of C1) occipital a. the suboccipital triangle is formed by obliquus capitis superior and inferior and rectus capitis posterior major
rectus capitis posterior major spinous process of axis inferior nuchal line extends the head, rotate to same side suboccipital nerve (DPR of C1) occipital a. none
rectus capitis posterior minor posterior tubercle of atlas inferior nuchal line medially extends the head suboccipital nerve (DPR of C1) occipital a. rectus capitis posterior minor is deeper and inserts more medial than rectus capitis posterior major
rotatores transverse processes long rotatores: spines 2 vertebrae above origin; short rotatores: spines 1 vertebrae above origin rotates the vertebral column to the opposite side dorsal primary rami of spinal nerves C1-L5 supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa. semispinalis, multifidus and rotatores make up the transversospinal muscle group
semispinalis transverse processes of C7-T12 capitis: back of skull between nuchal lines; cervicis & thoracis: spines 4-6 vertebrae above origin extends the trunk and laterally bends the trunk, rotates the trunk to the opposite side dorsal primary rami of spinal nerves C1-T12 supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa. three parts are named based on their insertions: capitis, cervicis and thoracis; semispinalis, multifidus and rotatores make up the transversospinal muscle group
spinalis spinous processes at inferior vertebral levels spinous processes at superior vertebral levels and base of the skull extends and laterally bends trunk and neck dorsal primary rami of spinal nerves C2-L3 supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa. most medial part of the erector spinae; may be subdivided into thoracis, cervicis and capitis portions
splenius ligamentum nuchae and spines C7-T6 capitis: mastoid process & superior nuchal line laterally; cervicis: posterior tubercles of C1-C3 vertebrae extends and laterally bends neck and head; rotates head to same side dorsal primary rami of spinal nerves C2-C6 supplied segmentally by: deep cervical a., posterior intercostal aa. splenius means bandage; it gets its name from its broad, flat shape
splenius capitis ligamentum nuchae and spines of C7-T6 vertebrae mastoid process and lateral end of the superior nuchal line extends and laterally bends the neck and head, rotates head to the same side dorsal primary rami of spinal nerves C2-C6 supplied segmentally by: deep cervical a., posterior intercostal aa. named for its shape: splenius means bandage and capitis refers to the insertion of this portion of the muscle
splenius cervicis ligamentum nuchae and spines of C7-T6 vertebrae posterior tubercles of the transverse processes of C1-C3 vertebrae extends and laterally bends neck and head, rotates head to the same side dorsal primary rami of spinal nerves C2-C6 supplied segmentally by: deep cervical a., posterior intercostal aa. named for its shape: splenius means bandage and cervicis refers to the insertion of this portion of the muscle

Muscles of the Upper Limb - Listed Alphabetically

Muscle Origin Insertion Action Innervation Artery Notes Image
abductor digiti minimi (hand) pisiform base of the proximal phalanx of the 5th digit on its ulnar side abducts the 5th digit deep branch of the ulnar nerve ulnar a. abductor digiti minimi, flexor digiti minimi brevis, and opponens digiti minimi are located in the hypothenar compartment of the hand
abductor pollicis brevis flexor retinaculum, scaphoid, trapezium base of the proximal phalanx of the first digit abducts thumb recurrent branch of median nerve superficial palmar br. of the radial a. abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis are located in the thenar compartment of the hand (Latin, pollicis = the thumb)
abductor pollicis longus middle one-third of the posterior surface of the radius, interosseous membrane, mid-portion of posterolateral ulna radial side of the base of the first metacarpal abducts the thumb at carpometacarpal joint radial nerve, deep branch posterior interosseous a. the tendons of abductor pollicis longus and extensor pollicis brevis make the lateral border of the anatomical snuffbox (Latin, pollicis = the thumb)
adductor pollicis oblique head: capitate and base of the 2nd and 3rd metacarpals; transverse head: shaft of the 3rd metacarpal base of the proximal phalanx of the thumb adducts the thumb ulnar nerve, deep branch deep palmar arterial arch deep palmar arch and deep ulnar nerve pass between the two heads of adductor pollicis, which is in the adductor-interosseous compartment (Latin, pollicis = the thumb)
anconeus lateral epicondyle of the humerus lateral side of the olecranon and the upper one-fourth of the ulna extends the forearm nerve to anconeus, from the radial nerve interosseous recurrent a. (Greek, anconeus = elbow)
biceps brachii short head: tip of the coracoid process of the scapula; long head: supraglenoid tubercle of the scapula tuberosity of the radius flexes the forearm, flexes arm (long head), supinates musculocutaneous nerve (C5,6) brachial a. a powerful supinator only if the elbow is flexed
brachialis anterior surface of the lower one-half of the humerus and the associated intermuscular septa coronoid process of the ulna flexes the forearm musculocutaneous nerve (C5,6) brachial a., radial recurrent a. a powerful flexor
brachioradialis upper two-thirds of the lateral supracondylar ridge of the humerus lateral side of the base of the styloid process of the radius flexes the elbow, assists in pronation & supination radial nerve radial recurrent a. although brachioradialis is innervated by the nerve for extensors (radial), its primary action is elbow flexion; the neutral position of this muscle is half way between supination and pronation (elbow flexed, thumb up)
coracobrachialis coracoid process of the scapula medial side of the humerus at mid-shaft flexes and adducts the arm musculocutaneous nerve (C5,6) brachial a. the musculocutaneous nerve passes through the coracobrachialis muscle to reach the other arm flexor mm.(biceps brachii and brachialis)
deltoid lateral one-third of the clavicle, acromion, the lower lip of the crest of the spine of the scapula deltoid tuberosity of the humerus abducts arm; anterior fibers flex & medially rotate the arm; posterior fibers extend & laterally rotate the arm axillary nerve (C5,6) from the posterior cord of the brachial plexus posterior circumflex humeral a. the deltoid muscle is the principle abductor of the arm but due to poor mechanical advantage it cannot initiate this action; it is assisted by the supraspinatus m.
dorsal interosseous (hand) four muscles, each arising from two adjacent metacarpal shafts base of the proximal phalanx and the extensor expansion on lateral side of the 2nd digit, lateral & medial sides of the 3rd digit, and medial side of the 4th digit flex the metacarpophalangeal joint, extend the proximal and distal interphalangeal joints of digits 2-4, abduct digits 2-4 (abduction of digits in the hand is defined as movement away from the midline of the 3rd digit) ulnar nerve, deep branch dorsal and palmar metacarpal aa. bipennate muscles; remember DAB & PAD - Dorsal interosseous mm. ABduct and Palmar interosseous mm. ADduct - then you can figure out where they must insert to cause these actions (Latin, inter = between + os = bone)
extensor carpi radialis brevis common extensor tendon (lateral epicondyle of humerus) dorsum of the third metacarpal bone (base) extends the wrist; abducts the hand deep radial nerve radial a. works with the extensor carpi radialis longus and flexor carpi radialis in abduction of the hand (Greek, carpi= the wrist)
extensor carpi radialis longus lower one-third of the lateral supracondylar ridge of the humerus dorsum of the second metacarpal bone (base) extends the wrist; abducts the hand radial nerve radial a. works with the extensor carpi radialis brevis and flexor carpi radialis in abduction of the hand (Greek, carpi= the wrist)
extensor carpi ulnaris common extensor tendon & the middle one-half of the posterior border of the ulna medial side of the base of the 5th metacarpal extends the wrist; adducts the hand deep radial nerve ulnar a. works with the flexor carpi ulnaris in adduction of the hand (Greek, carpi= the wrist)
extensor digiti minimi common extensor tendon (lateral epicondyle of the humerus) joins the extensor digitorum tendon to the 5th digit and inserts into the extensor expansion extends the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints of the 5th digit deep radial nerve interosseous recurrent a. extensor digiti minimi appears to be the ulnar-most portion of extensor digitorum
extensor digitorum common extensor tendon (lateral epicondyle of the humerus) extensor expansion of digits 2-5 extends the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints of the 2nd-5th digits; extends wrist deep radial nerve interosseous recurrent a. and posterior interosseous a. the extensor expansion inserts via a central band on the base of the middle phalanx, while lateral & medial slips insert on the distal phalanx
extensor indicis interosseous membrane and the posterolateral surface of the distal ulna its tendon joins the tendon of the extensor digitorum to the second digit; both tendons insert into the extensor expansion extends the index finger at the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints deep radial nerve posterior interosseous a extensor indicis is a deep forearm extensor, whereas extensor digiti minimi is in the superficial layer of extensors
extensor pollicis brevis interosseous membrane and the posterior surface of the distal radius base of the proximal phalanx of the thumb extends the thumb at the metacarpophalangeal joint deep radial nerve posterior interosseous a the tendons of extensor pollicis brevis and abductor pollicis longus make the lateral border of the anatomical snuffbox, in which the radial arterial pulse can be felt (Latin, pollicis = the thumb)
extensor pollicis longus interosseous membrane and middle part of the posterolateral surface of the ulna base of the distal phalanx of the thumb extends the thumb at the interphalangeal joint deep radial nerve posterior interosseous a the tendon of extensor pollicis longus hooks around the dorsal radial tubercle; it forms the medial border of the anatomical snuffbox, in which the radial arterial pulse can be felt (Latin, pollicis = the thumb)
flexor carpi radialis common flexor tendon from the medial epicondyle of the humerus base of the second and third metacarpals flexes the wrist, abducts the hand median nerve ulnar a. works with the extensor carpi radialis longus and brevis mm. to abduct hand (Greek, carpi = the wrist)
flexor carpi ulnaris common flexor tendon & (ulnar head) from medial border of olecranon & upper 2/3 of the posterior border of the ulna pisiform, hook of hamate, and base of 5th metacarpal flexes wrist, adducts hand ulnar nerve ulnar a. the ulnar nerve passes between the two heads of origin of the flexor carpi ulnaris m. (Greek, carpi = the wrist)
flexor digiti minimi brevis (hand) hook of hamate & the flexor retinaculum proximal phalanx of the 5th digit flexes the carpometacarpal and metacarpophalangeal joints of the 5th digit ulnar nerve, deep branch ulnar a. flexor digiti minimi brevis, abductor digiti minimi, and opponens digiti minimi are in the hypothenar compartment of the hand
flexor digitorum profundus posterior border of the ulna, proximal two-thirds of medial border of ulna, interosseous membrane base of the distal phalanx of digits 2-5 flexes the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints median nerve (radial one-half); ulnar nerve (ulnar one-half) ulnar a., anterior interosseous a. ulnar nerve innervates the portion of profundus that acts on digits 4 & 5 (the ulnar 2 digits)
flexor digitorum superficialis humeroulnar head: common flexor tendon; radial head: middle 1/3 of radius shafts of the middle phalanges of digits 2-5 flexes the metacarpophalangeal and proximal interphalangeal joints median nerve ulnar a. median nerve travels distally in the forearm on the deep surface of the flexor digitorum superficialis m.
flexor pollicis brevis flexor retinaculum, trapezium proximal phalanx of the 1st digit flexes the carpometacarpal and metacarpophalangeal joints of the thumb recurrent branch of the median nerve superficial palmar br. of the radial a. flexor pollicis brevis, abductor pollicis brevis, and opponens pollicis are the three muscles of the thenar compartment of the hand (Latin, pollicis = the thumb)
flexor pollicis longus anterior surface of radius and interosseous membrane base of the distal phalanx of the thumb flexes the metacarpophalangeal and interphalangeal joints of the thumb median nerve anterior interosseous a. the tendon of flexor pollicis longus passes through the carpal tunnel with the other long digital flexor tendons and the median nerve (Latin, pollicis = the thumb)
infraspinatus infraspinatous fossa greater tubercle of the humerus (middle facet) laterally rotates the arm suprascapular nerve suprascapular a. infraspinatus, supraspinatus, teres minor and subscapularis are the rotator cuff muscles
interosseous, dorsal (hand) four muscles, each arising from two adjacent metacarpal shafts base of the proximal phalanx and the extensor expansion on lateral side of the 2nd digit, lateral & medial sides of the 3rd digit, and medial side of the 4th digit flex the metacarpophalangeal joint, extend the proximal and distal interphalangeal joints of digits 2-4, abduct digits 2-4 (abduction of digits in the hand is defined as movement away from the midline of the 3rd digit) ulnar nerve, deep branch dorsal and palmar metacarpal aa. bipennate muscles; remember DAB & PAD - Dorsal interosseous mm. ABduct and Palmar interosseous mm. ADduct - then you can figure out where they must insert to cause these actions (Latin, inter = between + os = bone)
interosseous, palmar four muscles, arising from the palmar surface of the shafts of metacarpals 1, 2, 4, & 5 (the 1st palmar interosseous is often fused with the adductor pollicis m.) base of the proximal phalanx and extensor expansion of the medial side of digits 1 & 2, and lateral side of digits 4 & 5 flexes the metacarpophalangeal, extends proximal and distal interphalangeal joints and adducts digits 1, 2, 4, & 5 (adduction of the digits of the hand is in reference to the midline of the 3rd digit) ulnar nerve, deep branch palmar metacarpal aa. unipennate muscles; remember PAD & DAB: Palmar interossei ADduct and Dorsal interossei ABduct, and you will be able to figure out where they must insert (Latin, inter = between + os = bone)
latissimus dorsi vertebral spines from T7 to the sacrum, posterior third of the iliac crest, lower 3 or 4 ribs, sometimes from the inferior angle of the scapula floor of the intertubercular groove extends the arm and rotates the arm medially thoracodorsal nerve (C7,8) from the posterior cord of the brachial plexus thoracodorsal a. the inserting tendon twists so that fibers originating highest insert lowest (Latin, latissimus = broadest)
levator scapulae transverse processes of C1-C4 vertebrae medial border of the scapula from the superior angle to the spine elevates the scapula dorsal scapular nerve (C5); the upper part of the muscle receives branches of C3 & C4 dorsal scapular a. levator scapulae is named for its action (Latin, levator = to lift)
lumbrical (hand) flexor digitorum profundus tendons of digits 2-5 extensor expansion on the radial side of the proximal phalanx of digits 2-5 flex the metacarpophalangeal joints, extend the proximal and distal interphalangeal joints of digits 2-5 median nerve (radial 2) via palmar digital nerves & ulnar nerve (ulnar 2) via deep branch superficial palmar arterial arch lumbricals, arise from the profundus tendons and have the same pattern of innervation as does the profundus muscle (ulnar and median nn. split the task equally) (Latin, lumbricus = earthworm)
opponens digiti minimi hook of hamate and flexor retinaculum shaft of 5th metacarpal opposes the 5th digit ulnar nerve, deep branch ulnar a. opposition is a rotational movement of the 5th metacarpal around the long axis of its shaft; opponens digiti minimi, abductor digiti minimi, and flexor digiti minimi brevis are in the hypothenar compartment of the hand
opponens pollicis flexor retinaculum, trapezium shaft of 1st metacarpal opposes the thumb recurrent branch of median nerve superficial palmar branch of the radial a. opposition is a rotational movement of the 1st metacarpal around the long axis of its shaft; opponens pollicis, abductor pollicis brevis, and flexor pollicis brevis are in the thenar compartment of the hand (Latin, pollicis = the thumb)
palmar interosseous four muscles, arising from the palmar surface of the shafts of metacarpals 1, 2, 4, & 5 (the 1st palmar interosseous is often fused with the adductor pollicis m.) base of the proximal phalanx and extensor expansion of the medial side of digits 1 & 2, and lateral side of digits 4 & 5 flexes the metacarpophalangeal, extends proximal and distal interphalangeal joints and adducts digits 1, 2, 4, & 5 (adduction of the digits of the hand is in reference to the midline of the 3rd digit) ulnar nerve, deep branch palmar metacarpal aa. unipennate muscles; remember PAD & DAB: Palmar interossei ADduct and Dorsal interossei ABduct, and you will be able to figure out where they must insert (Latin, inter = between + os = bone)
palmaris brevis fascia overlying the hypothenar eminence skin of the palm near the ulnar border of the hand draws the skin of the ulnar side of the hand toward the center of the palm superficial br. of the ulnar n. ulnar a. palmaris brevis improves the grasp
palmaris longus common flexor tendon, from the medial epicondyle of the humerus palmar aponeurosis flexes the wrist median nerve ulnar a. palmaris longus is absent in about 13% of forearms; it may be present on one side only
pectoralis major medial 1/2 of the clavicle, manubrium & body of sternum, costal cartilages of ribs 2-6, sometimes from the rectus sheath of the upper abdominal wall crest of the greater tubercle of the humerus flexes and adducts the arm, medially rotates the arm medial and lateral pectoral nerves (C5-T1) pectoral branch of the thoracoacromial trunk the deep fascia on its anterior surface should not be fused to the fascia of the mammary gland - if it is, this is an important clinical sign indicating breast disease
pectoralis minor ribs 3-5 coracoid process of the scapula draws the scapula forward, medialward, and downward medial pectoral nerve (C8, T1) pectoral branch of the thoracoacromial trunk branches of medial pectoral nerve usually pierce pectoralis minor to reach the pectoralis major muscle
pronator quadratus medial side of the anterior surface of the distal one-fourth of the ulna anterior surface of the distal one-fourth of the radius pronates the forearm median nerve via the anterior interosseous nerve anterior interosseous a. pronator quadratus is the deepest muscle in the distal forearm; it works with pronator teres and has the same nerve supply
pronator teres common flexor tendon and (deep or ulnar head) from medial side of coronoid process of the ulna midpoint of the lateral side of the shaft of the radius pronates the forearm median nerve ulnar a., anterior ulnar recurrent a. median nerve passes between the two heads of origin of pronator teres
rhomboideus major spines of vertebrae T2-T5 medial border of the scapula inferior to the spine of the scapula retracts, elevates and rotates the scapula inferiorly dorsal scapular nerve (C5) dorsal scapular a. named for its shape
rhomboideus minor inferior end of the ligamentum nuchae, spines of vertebrae C7 and T1 medial border of the scapula at the root of the spine of the scapula retracts, elevates and rotates the scapula inferiorly dorsal scapular nerve (C5) dorsal scapular a named for its shape
serratus anterior ribs 1-8 or 9 medial border of the scapula on its costal (deep) surface it draws the scapula forward; the inferior fibers rotate the scapula superiorly long thoracic nerve (from ventral rami C5-C7) lateral thoracic a. a lesion of long thoracic nerve will cause winging of the scapula (i.e., the medial border of the scapula falls away from the posterior chest wall and looks like an angel's wing) (Latin, serratus = to saw)
serratus posterior inferior thoracolumbar fascia, spines of vertebrae T11-T12 and L1-L2 ribs 9-12, lateral to the angles pulls down lower ribs branches of the ventral primary rami of spinal nerves T9-T12 lowest posterior intercostal a., subcostal a., first two lumbar aa. a respiratory muscle, it receives ventral ramus innervation; embryonically related to the intercostal muscles, not the deep back mm. (Latin, serratus = to saw)
serratus posterior superior ligamentum nuchae, spines of vertebrae C7 and T1-T3 ribs 1-4, lateral to the angles elevates the upper ribs branches of the ventral primary rami of spinal nerves T1-T4 posterior intercostal aa. 1-4 a respiratory muscle, it receives ventral ramus innervation; embryonically related to the intercostal muscles, not the deep back mm. (Latin, serratus = to saw)
subclavius first rib and its cartilage inferior surface of the clavicle draws the clavicle (and hence the shoulder) down and forward nerve to subclavius (C5) clavicular br. of the thoracoacromial trunk it serves an important protective function - it cushions the subclavian vessels from bone fragments in clavicular fractures
subscapularis medial two-thirds of the costal surface of the scapula (subscapular fossa) lesser tubercle of the humerus medially rotates the arm; assists extention of the arm upper and lower subscapular nerves (C5,6) subscapular a. subscapularis, supraspinatus, infraspinatus, and teres minor are the rotator cuff muscles
supinator lateral epicondyle of the humerus, supinator crest & fossa of the ulna, radial collateral ligament, annular ligament lateral side of proximal one-third of the radius supinates the forearm deep radial nerve recurrent interosseous a. deep radial nerve passes through the supinator to reach the posterior compartment of the forearm
supraspinatus supraspinatous fossa greater tubercle of the humerus (highest facet) abducts the arm (initiates abduction) suprascapular nerve (C5,6) from the superior trunk of the brachial plexus suprascapular a. supraspinatus initiates abduction of the arm, then the deltoid muscle completes the action; a member of the rotator cuff group
teres major dorsal surface of the inferior angle of the scapula crest of the lesser tubercle of the humerus adducts the arm, medially rotates the arm, assists in arm extension lower subscapular nerve (C5,6) from the posterior cord of the brachial plexus circumflex scapular a. teres major inserts beside the tendon of latissimus dorsi, and assists latissimus in its actions
teres minor upper 2/3 of the lateral border of the scapula greater tubercle of the humerus (lowest facet) laterally rotates the arm axillary nerve (C5,6) from the posterior cord of the brachial plexus circumflex scapular a. fixes the head of the humerus in the glenoid fossa during abduction & flexion of the arm; a member of the rotator cuff group
trapezius medial third of the superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of vertebrae C7-T12 lateral third of the clavicle, medial side of the acromion and the upper crest of the scapular spine, tubercle of the scapular spine elevates and depresses the scapula (depending on which part of the muscle contracts); rotates the scapula superiorly; retracts scapula motor: spinal accessory (XI), proprioception: C3-C4 transverse cervical a. named for its shape; trapezius is an example of a muscle that migrates during development from its level of origin (cervical) to its final position, pulling its nerve and artery along behind
triceps brachii long head: infraglenoid tubercle of the scapula; lateral head: posterolateral humerus & lateral intermuscular septum; medial head: posteromedial surface of the inferior 1/2 of the humerus olecranon process of the ulna extends the forearm; the long head extends and adducts arm radial nerve deep brachial (profunda brachii) a. long head of the triceps separates the triangular and quadrangular spaces (teres major, teres minor and the humerus are the other boundaries); all three heads of origin insert by a common tendon

Muscles of the Head and Neck - Listed Alphabetically

Muscle Origin Insertion Action Innervation Artery Notes Image
anterior scalene anterior tubercles of the transverse processes of vertebrae C3-C6 scalene tubercle of the first rib elevates the first rib; flexes and laterally bends the neck brachial plexus, C5-C7 ascending cervical a., a branch of the thyrocervical trunk a muscle of inspiration; an important landmark of the neck; it is located between the subclavian vein and the subclavian artery; the roots of the brachial plexus pass posterior to it; the phrenic nerve crosses its anterior surface (Greek, scalene = uneven)
aryepiglottic apex (superior part) of the arytenoid cartilage epiglottis draws the epiglottis posteriorly and downward during swallowing inferior laryngeal nerve, from recurrent laryngeal nerve, a branch of the of vagus (X) laryngeal br. of the superior thyroid a. the mucosa is raised by the underlying aryepiglottic m. to form the aryepiglottic fold
arytenoid, oblique muscular process of the arytenoid cartilage posterior surface of the contralateral arytenoid cartilage, near its apex draws arytenoid cartilages together, adducting the vocal folds inferior laryngeal nerve, from recurrent laryngeal nerve, a branch of the of vagus (X) laryngeal br. of the superior thyroid a. the oblique arytenoid m. lies posterior to the transverse arytenoid m.; the arytenoideus is often considered to be one muscle with oblique and transverse fibers (
arytenoid, transverse posterior surface of the arytenoid cartilage posterior surface of the contralateral arytenoid cartilage draws arytenoid cartilages together, adducting the vocal folds inferior laryngeal nerve, from recurrent laryngeal nerve, a branch of the vagus nerve (X) laryngeal br. of the superior thyroid a. the transverse arytenoid m.lies anterior to the oblique arytenoid m.; the arytenoideus is often considered to be one muscle with oblique and transverse parts
auricular anterior: galea aponeurotica anterior to ear; superior: galea aponeurotica superior to ear; posterior: mastoid process auricle anteriorly, superiorly and posteriorly wiggle the ears anterior & superior: temporal branches of facial nerve (VII); posterior: posterior auricular branch of facial nerve (VII) superficial temporal a., posterior auricular a. the auricular muscles are derived from the mesenchyme of the second pharyngeal arch, as are the muscles of facial expression
buccinator pterygomandibular raphe, mandible, and the maxilla lateral to the molar teeth angle of mouth and the lateral portion of the upper and lower lips pulls the corner of mouth laterally; presses the cheek against the teeth buccal branches of the facial nerve (VII) facial a. although the buccinator is important in mastication, it is innervated by the buccal branch of the facial nerve and NOT by the buccal nerve from V3 (a sensory nerve) (Latin, buccinator = trumpeter)
chondroglossus medial side of the lesser horn and body of the hyoid bone ascends to blend with the intrinsic tongue musculature pulls the sides of the tongue down hypoglossal nerve (XII) lingual a. chondroglossus is often considered to be part of the hyoglossus muscle
ciliary meridional fibers: scleral spur; circular fibers: encircle the ciliary process meridional fibers: ciliary process; circular fibers: encircle the ciliary process relaxes the suspensory ligament of the lens parasympathetic fibers in the oculomotor nerve (III), synapsing in the ciliary ganglion ophthalmic a. relaxation of the suspensory ligament allows the lens to thicken for accommodation (near vision)
constrictor, inferior pharyngeal oblique line of the thyroid cartilage, lateral surface of cricoid cartilage midline pharyngeal raphe constricts pharyngeal cavity vagus (X), via the pharyngeal plexus, with aid from the superior laryngeal and recurrent laryngeal nerves ascending pharyngeal a., superior thyroid a., inferior thyroid a. the most external of the three pharyngeal constructor mm.
constrictor, middle pharyngeal lesser and greater horns of the hyoid bone and the inferior part of the stylohyoid ligament midline pharyngeal raphe constricts the pharyngeal cavity vagus (X), via the pharyngeal plexus ascending pharyngeal a. of the three pharyngeal constrictors, this one is intermediate in both superior/inferior position and depth
constrictor, superior pharyngeal medial pterygoid plate, pterygoid hamulus, pterygomandibular raphe, mylohyoid line of mandible pharyngeal tubercle and midline pharyngeal raphe constricts the pharyngeal cavity vagus (X), via the pharyngeal plexus ascending pharyngeal a. the most internal of the three pharyngeal constructor mm.
corrugator medial part of the supercillary arch skin of the medial half of the eyebrow pulls eyebrows together medially temporal branch of the facial nerve (VII) supratrochlear a. this muscle causes the furrowed brow of the worried look (Latin, corrugator= to wrinkle)
cricoarytenoid, lateral arch of the cricoid cartilage muscular process of the arytenoid cartilage draws the muscular process of the arytenoid cartilage anteriorly, which pivots the arytenoid cartilage and adducts the vocal folds inferior laryngeal nerve, from the recurrent laryngeal nerve, a branch of the vagus nerve (X) superior laryngeal a., cricothyroid branch of the superior thyroid a. an antagonist of the posterior cricoarytenoid m.; the arteries that supply the larynx anastomose within the larynx to supply the mucous membranes and muscles
cricoarytenoid, posterior posterior surface of the lamina of the cricoid cartilage muscular process of the arytenoid cartilage draws the muscular process posteriorly, which pivots the arytenoid cartilage and abducts the vocal folds inferior laryngeal nerve, from the recurrent laryngeal nerve, a branch of the vagus nerve (X) superior laryngeal a., cricothyroid branch of the superior thyroid a. the posterior cricoarytenoid is the only ABductor of the vocal folds; the arteries that supply the larynx anastomose within the larynx to supply the mucous membranes and muscles
cricopharyngeus lateral surface of the cricoid cartilage midline pharyngeal raphe constricts the pharyngeal cavity and the entrance to the esophagus recurrent laryngeal nerve, a branch of the vagus nerve (X) cricothyroid branch of the superior thyroid a., ascending pharyngeal a. cricopharyngeus represents the lowest fibers of the inferior pharyngeal constrictor; it is continuous with the esophagus below and marks the beginning of it
cricothyroid arch of the cricoid cartilage inferior border of the thyroid cartilage draws the thyroid cartilage forward, lengthening the vocal ligaments external branch of superior laryngeal nerve, a branch of the vagus nerve (X) cricothyroid branch of the superior thyroid a. this is the only intrinsic muscle of the larynx that is not supplied by the recurrent laryngeal n.; ALL other laryngeal muscles are innervated by recurrent laryngeal nerve, via its inferior laryngeal branch
depressor anguli oris oblique line of the mandible angle of the mouth pulls the corner of the mouth downward marginal mandibular & buccal branches of the facial nerve (VII) inferior labial branch of the facial a., mental a. a "frown" muscle
depressor labii inferioris anterior surface of the mandible skin of the lower lip depresses the lower lip marginal mandibular branch of the facial nerve (VII) inferior labial branch of the facial a., mental a. this muscle is used to bare the lower incisor teeth
depressor septi maxilla near the midline above the incisor teeth nasal septum depresses the nasal septum; involved in flaring the nostrils buccal branch of facial nerve (VII) superior labial branch of the facial a. depressor septi is considered a part of the nasalis m.
digastric anterior belly: digastric fossa of the mandible; posterior belly: mastoid notch of the temporal bone body of the hyoid via a fibrous loop over an intermediate tendon elevates the hyoid bone; depresses the mandible anterior belly: mylohyoid nerve, from the mandibular division of the trigeminal nerve (V); posterior belly: facial nerve (VII) anterior belly: submental a.; posterior belly: occipital a. the digastric m. forms two sides of the submandibular triangle; it is formed from mesenchyme derived from the first two pharyngeal arches, hence its dual innervation
dilator pupillae outer margin of iris inner margin of iris dilates the pupil sympathetic fibers via short ciliary nerves, synapsing in superior cervical sympathetic ganglion ophthalmic a. none
epicranius frontalis: galea aponeurotica; occipitalis: superior nuchal line frontalis: skin of the eyebrows; occipitalis: galea aponeurotica elevates the eyebrows and wrinkles the forehead frontalis: temporal branches of the facial nerve (VII); occipitalis: posterior auricular branch of the facial nerve (VII)

frontalis: supraorbital and supratrochlear aa.; occipitalis: occipital a.

the frontalis and occipitalis muscles are two bellies of the epicranius muscle; also known as: occipitofrontalis m.
frontalis galea aponeurotica skin of the eyebrow elevates the eyebrows and wrinkles the forehead temporal branches of the facial nerve (VII) supraorbital and supratrochlear aa. frontalis is the anterior belly of the epicranius muscle
genioglossus mental spine on the inner aspect of the mental symphysis fans out to insert into the tongue from the tip to the base protrudes the tongue (inferior fibers); depresses tongue (middle fibers) hypoglossal nerve (XII) lingual a. an extrinsic muscle of the tongue; XII innervates all tongue muscles except palatoglossus [innervated by vagus (X), as are most of the palate and pharynx muscles]; genioglossus is used to test the function of cranial nerve XII
geniohyoid mental spines of the mandible body of the hyoid bone elevates the hyoid bone; depresses the mandible ventral primary ramus of spinal nerve C1 via fibers carried by the hypoglossal nerve lingual a., submental a. thyrohyoid and geniohyoid receive ansa cervicalis fibers that travel with the hypoglossal nerve distal to the superior limb of the ansa cervicalis
hyoglossus upper border of the greater horn of the hyoid and body of the hyoid bone spreads out into the intrinsic muscles of the tongue depresses the sides of the tongue; retracts the tongue hypoglossal nerve (XII) lingual a. an extrinsic muscle of the tongue
inferior oblique floor of the orbit lateral to the lacrimal groove sclera on the inferior surface of the eyeball elevates and abducts the corneal part of the eye; rotates the superior pole of the iris laterally; when the eye is adducted, this muscle elevates the cornea oculomotor nerve (III), inferior division ophthalmic a. clinicians examining the eye will ask the patient to look toward the bridge of the nose to test the function of this muscle
inferior pharyngeal constrictor oblique line of the thyroid cartilage, lateral surface of cricoid cartilage midline pharyngeal raphe constricts pharyngeal cavity vagus (X), via the pharyngeal plexus, with aid from the superior laryngeal and recurrent laryngeal nerves ascending pharyngeal a., superior thyroid a., inferior thyroid a. the most external of the three pharyngeal constructor mm.
inferior rectus common tendinous ring at the apex of the orbit sclera on the inferior surface of the eyeball depresses and adducts the corneal part of the eyeball; rotates the superior pole of the iris laterally oculomotor nerve (III), inferior division ophthalmic a. because this muscle approaches the eyeball from a medial direction, it has a rotational action on the iris
lateral cricoarytenoid arch of the cricoid cartilage muscular process of the arytenoid cartilage draws the muscular process of the arytenoid cartilage anteriorly, which pivots the arytenoid cartilage and adducts the vocal folds inferior laryngeal nerve, from the recurrent laryngeal nerve, a branch of the vagus nerve (X) superior laryngeal a., cricothyroid branch of the superior thyroid a. an antagonist of the posterior cricoarytenoid m.; the arteries that supply the larynx anastomose within the larynx to supply the mucous membranes and muscles
lateral pterygoid superior head: greater wing of the sphenoid bone; inferior head: lateral surface of the lateral pterygoid plate superior head: capsule and & articular disk of the temporomandibular joint; inferior head: neck of the mandible protracts the mandible; opens the mouth; active in grinding actions of chewing lateral pterygoid branch of the mandibular division of the trigeminal nerve (V) pterygoid branch of the maxillary a. the only one of the muscles of mastication that opens the mouth; the superior head of lateral pterygoid is sometimes called sphenomeniscus due to its insertion into the disc of the temporomandibular joint (Greek, pterygoid = wing-shaped)
lateral rectus common tendinous ring at the apex of the orbit sclera on the lateral surface of the eyeball abducts the corneal part of the eyeball abducens nerve (VI) ophthalmic a. loss of function of the abducens nerve will cause the eye to be abducted
levator anguli oris canine fossa of the maxilla angle (corner) of the mouth elevates the angle of the mouth buccal branch of the facial nerve (VII) infraorbital a., superior labial branch of the facial a. a "smile" muscle
levator labii superioris inferior margin of the orbit skin of the upper lip elevates the upper lip buccal branch of the facial nerve (VII) infraorbital a., superior labial branch of the facial a. levator labii superioris is used to bare the upper incisor teeth, as in a sneer (Latin, levator = to lift + labial = lips)
levator labii superioris alaque nasi frontal process of the maxilla ala of the nose and skin of the upper lip elevates the upper lip and flares the nostril buccal branch of the facial nerve (VII) infraorbital a., superior labial branch of the facial a. (Latin, levator = to lift + labial = lips)
levator palpebrae superioris apex of the orbit above the optic canal skin and fascia of upper eyelid and the superior tarsal plate elevates the upper eyelid oculomotor nerve (III) and sympathetics (to the superior tarsal portion) ophthalmic a. fibers inserting into the superior tarsal plate are called superior tarsal muscle and are smooth muscle; lesion of the sympathetic supply causes slight ptosis (drooping of the eyelid) (Latin, levator = to lift + palpebrae = eyelid)
levator scapulae transverse processes of C1-4 vertebrae medial border of the scapula from the superior angle to the spine elevates scapula dorsal scapular nerve (C5); the upper part of the muscle receives branches of C3 & C4 spinal nerves dorsal scapular a. named for its action (Latin, levator = to lift)
levator veli palatini apex of the petrous part of the temporal bone and the medial surface of the auditory tube cartilage muscles and fascia of the soft palate; palatine aponeurosis elevates the soft palate vagus nerve (X) via the pharyngeal plexus ascending pharyngeal a. a derivative of the fourth pharyngeal arch (Latin, levator = to lift)
linguae, longitudinalis within tongue within tongue near the apex shapes the tongue for speech and mastication hypoglossal nerve (XII) lingual a. an intrinsic muscle of the tongue; longitudinalis has superior and inferior subdivisions that span the length of the tongue
linguae, transversus within tongue within tongue compresses the sides of the tongue; shapes the tongue for speech and mastication hypoglossal nerve (XII) lingual a. an intrinsic muscle of the tongue whose fibers run transversely
linguae, verticalis within tongue within tongue shapes the tongue for speech and mastication hypoglossal nerve (XII) lingual a. an intrinsic muscle of the tongue whose fibers run superoinferiorly
longus capitis anterior tubercles of vertebrae C3-6 basilar portion of the occipital bone flex the head and neck cervical plexus, ventral primary rami of spinal nerves C1-4 deep cervical a. none
longus colli anterior tubercles and anterior surfaces of the bodies of vertebrae C3-T3 anterior arch of atlas, anterior tubercles of C5-6, anterior surfaces of bodies of vertebrae C2-4 flex neck, rotate and laterally bend neck cervical and brachial plexus, C2-7 deep cervical a. none
masseter zygomatic arch and zygomatic bone lateral surface of the ramus and angle of the mandible elevates the mandible nerve to the masseter, from the mandibular division of the trigeminal nerve (V) masseteric branch of the maxillary a. (Greek, masseter = the chewer)
medial pterygoid medial surface of the lateral pterygoid plate, pyramidal process of the palatine bone, tuberosity of the maxilla medial surface of the ramus and angle of the mandible elevates and protracts the mandible medial pterygoid branch of the mandibular division of the trigeminal nerve (V) pterygoid branch of the maxillary a. this muscle mirrors the masseter m. in position and action with the ramus of the mandible between the two mm. (Greek, pterygoid = wing-shaped)
medial rectus common tendinous ring at the apex of the orbit sclera on the medial surface of the eyeball adducts the corneal part of the eyeball oculomotor nerve (III) (inferior division) ophthalmic a. this muscle directly opposes the action of the lateral rectus m.
mentalis anterior surface of the mandible near the mental symphysis (midline) skin of the chin elevates the lower lip and skin of chin marginal mandibular branch of the facial nerve (VII) mental a., inferior labial branch of the facial a.
middle pharyngeal constrictor lesser and greater horns of the hyoid bone and the inferior part of the stylohyoid ligament midline pharyngeal raphe constricts the pharyngeal cavity vagus (X), via the pharyngeal plexus ascending pharyngeal a. of the three pharyngeal constrictors, this one is intermediate in both superior/inferior position and depth
middle scalene posterior tubercles of the transverse processes of vertebrae C2-C7 upper surface of the first rib behind the subclavian artery elevates the first rib; flexes and laterally bends the neck brachial plexus, C3-C8 ascending cervical a. a muscle of respiration (inspiratory); also called scalenus medius; penetrated by the dorsal scapular n. and long thoracic n. (Greek, scalene = uneven)
musculus uvulae posterior nasal spine mucosa of the uvula shortens the uvula vagus nerve (X) via pharyngeal plexus lesser palatine a. the soft palate and uvula resist the upward pressure of the tongue during swallowing
mylohyoid mylohyoid line of mandible midline raphe and body of the hyoid bone elevates the hyoid bone and the tongue; depresses the mandible mylohyoid nerve from the inferior alveolar nerve, a branch of the mandibular division of the trigeminal nerve (V) mylohyoid branch of the inferior alveolar a. the nerve to mylohyoid also innervates the anterior belly of digastric m.; both muscles are derivatives of the second pharygneal arch
nasalis maxilla above the incisor teeth and the canine teeth ala of the nose and midline aponeurosis flattens the nose, flare the nostrils buccal branch of the facial nerve (VII) superior labial branch of the facial a. nasalis has two subsidiary parts: nasalis pars alaris and pars transversa
nasalis pars alaris maxilla above the canine teeth ala of the nose flares the nostrils buccal branch of facial nerve (VII) superior labial branch of the facial a. a subdivision of the nasalis m. (Latin, pars = a part)
nasalis pars transversa maxilla above the incisor teeth midline aponeurosis flattens the nose buccal branch of facial nerve (VII) superior labial branch of the facial a. a subdivision of the nasalis m. (Latin, pars = a part)
oblique arytenoid muscular process of the arytenoid cartilage posterior surface of the contralateral arytenoid cartilage, near its apex draws arytenoid cartilages together, adducting the vocal folds inferior laryngeal nerve, from recurrent laryngeal nerve, a branch of the of vagus (X) laryngeal br. of the superior thyroid a. the oblique arytenoid m. lies posterior to the transverse arytenoid m.; the arytenoideus is often considered to be one muscle with oblique and transverse fibers
oblique, inferior floor of the orbit lateral to the lacrimal groove sclera on the inferior surface of the eyeball elevates and abducts the corneal part of the eye; rotates the superior pole of the iris laterally; when the eye is adducted, this muscle elevates the cornea oculomotor nerve (III), inferior division ophthalmic a. clinicians examining the eye will ask the patient to look toward the bridge of the nose to test the function of this muscle
oblique, superior apex of the orbit above the optic canal sclera on the posterior superior surface of the eyeball depresses and abducts the eyeball; rotates the superior pole of the iris medially trochlear nerve (IV) ophthalmic a. passes through a fibrocartilagenous pulley known as the trochlea; when the eye is adducted, this muscle moves the cornea inferiorly
occipitalis superior nuchal line galea aponeurotica pulls the scalp posteriorly; elevates the eyebrows posterior auricular branch of the facial nerve (VII) occipital a. occipitalis is the posterior belly of the epicranius muscle
occipitofrontalis frontalis: galea aponeurotica; occipitalis: superior nuchal line frontalis: skin of the eyebrows; occipitalis: galea aponeurotica elevates the eyebrows and wrinkles the forehead frontalis: temporal branches of the facial nerve (VII); occipitalis: posterior auricular branch of the facial nerve (VII)

frontalis: supraorbital and supratrochlear aa.; occipitalis: occipital a.

the frontalis and occipitalis muscles are two bellies of the occipitofrontalis muscle; also known as: epicranius m.
omohyoid inferior belly: upper border of the scapula medial to the scapular notch; superior belly: intermediate tendon inferior belly: intermediate tendon; superior belly: lower border of the hyoid bone lateral to the sternohyoid insertion depresses/stabilizes the hyoid bone ansa cervicalis transverse cervical a. the intermediate tendon of omohyoid is tethered to the clavicle by a fascial sling
orbicularis oculi orbital part: medial orbital margin and the medial palpebral ligament; palpebral part: medial palpebral ligament orbital part: skin of the lateral cheek; palpebral part: lateral palpebral raphe closes the eyelids temporal & zygomatic branches of the facial nerve (VII) supraorbital a., supratrochlear a., infraorbital a., angular branch of the facial a. activated involuntarily in the blink reflex; the palpebral part is active in normal blinking and the orbital part is used to forcefully close the eye
orbicularis oris skin and fascia of lips and the area surrounding the lips skin and fascia of the lips purses the lips buccal branch of the facial nerve (VII) superior and inferior labial branches of the facial a., mental a., infraorbital a. the "kissing" muscle
palatoglossus palatine aponeurosis side of the tongue, entering it from above elevates and retracts the tongue vagus nerve (X) via the pharyngeal plexus tonsilar branch of the facial a., ascending pharyngeal a. although palatoglossus sounds like a tongue muscle (and would therefore be innervated by XII), it is a palatal muscle innervated by X
palatopharyngeus posterior margin of the bony palate and the palatine aponeurosis posterior wall of the pharynx and the posterior margin of the thyroid cartilage elevates the larynx vagus nerve (X) via pharyngeal plexus ascending pharyngeal a. palatopharyngeus is part of the inner longitudinal muscle layer of the pharynx
platysma fascia overlying the pectoralis major and deltoid muscles inferior border of the mandible and skin of lower face draws the corners of the mouth down; it aids in depression of the mandible cervical branch of the facial nerve (VII) facial a. platysma is derived from the mesenchyme of the second pharyngeal arch (Greek, platysma = a flat plate)
posterior cricoarytenoid posterior surface of the lamina of the cricoid cartilage muscular process of the arytenoid cartilage draws the muscular process posteriorly, which pivots the arytenoid cartilage and abducts the vocal folds inferior laryngeal nerve, from the recurrent laryngeal nerve, a branch of the vagus nerve (X) superior laryngeal a., cricothyroid branch of the superior thyroid a. the posterior cricoarytenoid is the only ABductor of the vocal folds; the arteries that supply the larynx anastomose within the larynx to supply the mucous membranes and muscles
posterior scalene posterior tubercles of the transverse processes of vertebrae C5-C7 lateral surface of the second rib elevates the second rib; flexes and laterally bends the neck brachial plexus, C7-C8 ascending cervical a. a muscle of respiration (inspiratory); it is the longest of the scalene muscles (Greek, scalene = uneven)
procerus nasal bone skin between the eyebrows depresses the medial corners of the eyebrows temporal branch of the facial nerve (VII) supratrochlear a. (Latin, procerus = long and streched out)
pterygoid, lateral superior head: greater wing of the sphenoid bone; inferior head: lateral surface of the lateral pterygoid plate superior head: capsule and & articular disk of the temporomandibular joint; inferior head: neck of the mandible protracts the mandible; opens the mouth; active in grinding actions of chewing lateral pterygoid branch of the mandibular division of the trigeminal nerve (V) pterygoid branch of the maxillary a. the only one of the muscles of mastication that opens the mouth; the superior head of lateral pterygoid is sometimes called sphenomeniscus due to its insertion into the disc of the temporomandibular joint (Greek, pterygoid = wing-shaped)
pterygoid, medial medial surface of the lateral pterygoid plate, pyramidal process of the palatine bone, tuberosity of the maxilla medial surface of the ramus and angle of the mandible elevates and protracts the mandible medial pterygoid branch of the mandibular division of the trigeminal nerve (V) pterygoid branch of the maxillary a. this muscle mirrors the masseter m. in position and action with the ramus of the mandible between the two mm. (Greek, pterygoid = wing-shaped)
pupillae, dilator outer margin of iris inner margin of iris dilates the pupil sympathetic fibers via short ciliary nerves, synapsing in superior cervical sympathetic ganglion ophthalmic a. none
pupillae, sphincter encircles iris encircles iris constricts the pupil parasympathetic fibers of oculomotor nerve (III), synapsing in ciliary ganglion ophthalmic a. none
rectus capitis anterior lateral mass of atlas basilar portion of occipital bone flexes the head ventral primary ramus of spinal nerve C1 deep cervical a. none
rectus capitis lateralis transverse process of atlas occipital bone anterolateral to foramen magnum laterally bends the head ventral primary ramus of spinal nerve C1 deep cervical a. none
rectus, inferior common tendinous ring at the apex of the orbit sclera on the inferior surface of the eyeball depresses and adducts the corneal part of the eyeball; rotates the superior pole of the iris laterally oculomotor nerve (III), inferior division ophthalmic a. because this muscle approaches the eyeball from a medial direction, it has a rotational action on the iris
rectus, lateral common tendinous ring at the apex of the orbit sclera on the lateral surface of the eyeball abducts the corneal part of the eyeball abducens nerve (VI) ophthalmic a. loss of function of the abducens nerve will cause the eye to be abducted
rectus, medial common tendinous ring at the apex of the orbit sclera on the medial surface of the eyeball adducts the corneal part of the eyeball oculomotor nerve (III) (inferior division) ophthalmic a. this muscle directly opposes the action of the lateral rectus m.
rectus, superior common tendinous ring at the apex of the orbit sclera on the superior surface of the eyeball elevates and adducts the eyeball; rotates the superior pole of the iris medially oculomotor nerve (III), superior division ophthalmic a. because this muscle approaches the eye from a medial position, it causes the iris to rotate medially
risorius fascia of the lateral cheek skin of the angle (corner) of the mouth draws the corner of the mouth laterally buccal branches of the facial nerve (VII) transverse facial a., facial a. risorius is active in expressions of mirth (Latin, risorius = to laugh)
salpingopharyngeus inferior surface of the anteromedial end of the auditory tube cartilage pharyngeal wall and superior border of the thyroid cartilage along with the palatopharyngeus m. elevates the larynx vagus nerve (X) via the pharyngeal plexus ascending pharyngeal a. like other muscles of the pharyngeal wall, salpingopharyngeus is derived from the fourth pharyngeal arch
scalene, anterior anterior tubercles of the transverse processes of vertebrae C3-C6 scalene tubercle of the first rib elevates the first rib; flexes and laterally bends the neck brachial plexus, C5-C7 ascending cervical a., a branch of the thyrocervical trunk a muscle of inspiration; an important landmark of the neck; it is located between the subclavian vein and the subclavian artery; the roots of the brachial plexus pass posterior to it; the phrenic nerve crosses its anterior surface (Greek, scalene = uneven)
scalene, middle posterior tubercles of the transverse processes of vertebrae C2-C7 upper surface of the first rib behind the subclavian artery elevates the first rib; flexes and laterally bends the neck brachial plexus, C3-C8 ascending cervical a. a muscle of respiration (inspiratory); also called scalenus medius; penetrated by the dorsal scapular n. and long thoracic n. (Greek, scalene = uneven)
scalene, posterior posterior tubercles of the transverse processes of vertebrae C5-C7 lateral surface of the second rib elevates the second rib; flexes and laterally bends the neck brachial plexus, C7-C8 ascending cervical a. a muscle of respiration (inspiratory); it is the longest of the scalene muscles (Greek, scalene = uneven)
sphenomeniscus greater wing of the sphenoid capsule and articular disk of the temporomandibular joint pulls the articular disk forward in opening of the mouth lateral pterygoid branch of mandibular division of trigeminal nerve (V) pterygoid branch of the maxillary a. sphenomeniscus is another name for the superior belly of the lateral pterygoid m.
sphincter pupillae encircles iris encircles iris constricts the pupil parasympathetic fibers of oculomotor nerve (III), synapsing in ciliary ganglion ophthalmic a. none
splenius ligamentum nuchae and spines C7-T6 capitis: mastoid process & superior nuchal line laterally; cervicis: posterior tubercles of C1-3 extends and laterally bends neck and head; rotates head to same side dorsal primary rami of spinal nerves C2-6 supplied segmentally by: deep cervical a., posterior intercostal aa. it gets its name from its broad, flat shape (Greek, splenius = a bandage)
stapedius walls of the pyramidal eminence neck of the stapes dampens vibration of the stapes facial nerve (VII) anterior tympanic a. entirely enclosed in bone, except for its tendon; a derivative of the second pharyngeal arch
sternocleidomastoid sternal head: anterior surface of the manubrium; clavicular head: medial 1/3rd of the clavicle mastoid process and lateral 1/2 of the superior nuchal line draws the mastoid process down toward the same side which causes the chin to turn up toward the opposite side; acting together, the muscles of the two sides flex the neck spinal accessory nerve (XI), with sensory supply from C2 & C3 (for proprioception) sternocleidomastoid branch of the occipital a. carotid sheath structures lie deep to it
sternohyoid posterior surfaces of both the manubrium and sternal end of the clavicle lower border of the hyoid bone, medial to the omohyoid m. insertion depresses/stabilizes the hyoid bone ansa cervicalis superior thyroid a. sternohyoid overlies the sternothyroid and thyrohyoid mm.
sternothyroid posterior surface of the manubrium below the origin of the sternohyoid m. oblique line of the thyroid cartilage depresses/stabilizes the hyoid bone ansa cervicalis superior thyroid a. sternothyroid lies deep to the sternohyoid m.
styloglossus anterior side of the styloid process posterolateral side of the tongue retracts and elevates the tongue hypoglossal nerve (XII) ascending pharyngeal a., ascending palatine branch of the facial a. an extrinsic muscle of the tongue
stylohyoid posterior side of the styloid process splits around the intermediate tendon of the digastric m. to insert on the body of the hyoid bone elevates and retracts the hyoid bone facial nerve (VII) ascending pharyngeal a. facial nerve innervates both the stylohyoid m. and the posterior belly of the digastric m. shortly after exiting from the stylomastoid foramen
stylopharyngeus medial side of the styloid process superior border of the thyroid cartilage and also into the pharyngeal wall elevates the larynx glossopharyngeal nerve (IX) ascending pharyngeal a. stylopharyngeus, the only muscle innervated by IX, is the only muscle of the pharyngeal wall NOT innervated by the vagus (X) nerve; it is a derivative of the third pharyngeal arch
superior oblique apex of the orbit above the optic canal sclera on the posterior superior surface of the eyeball depresses and abducts the eyeball; rotates the superior pole of the iris medially trochlear nerve (IV) ophthalmic a. passes through a fibrocartilagenous pulley known as the trochlea; when the eye is adducted, this muscle moves the cornea inferiorly
superior pharyngeal constrictor medial pterygoid plate, pterygoid hamulus, pterygomandibular raphe, mylohyoid line of mandible pharyngeal tubercle and midline pharyngeal raphe constricts the pharyngeal cavity vagus (X), via the pharyngeal plexus ascending pharyngeal a. the most internal of the three pharyngeal constructor mm.
superior rectus common tendinous ring at the apex of the orbit sclera on the superior surface of the eyeball elevates and adducts the eyeball; rotates the superior pole of the iris medially oculomotor nerve (III), superior division ophthalmic a. because this muscle approaches the eye from a medial position, it causes the iris to rotate medially
temporalis temporal fossa and the temporal fascia coronoid process of the mandible and the anterior surface of the ramus of the mandible elevates the mandible; retracts the mandible (posterior fibers) anterior and posterior deep temporal nerves from the mandibular division of the trigeminal nerve (V) anterior and posterior deep temporal aa. a powerful chewing muscle; a derivative of the first pharyngeal arch
tensor tympani cartilagenous auditory tube and the greater wing of the sphenoid bone which lies adjacent to it manubrium of the malleus dampens vibrations of the tympanic membrane medial pterygoid branch of the mandibular division of the trigeminal nerve (V) superior tympanic branch of the middle meningeal a. V3 innervates both tensor muscles of the head (tympani and veli palatini) which are derivatives of the first pharyngeal arch (Latin, tympanum = a kettle drum)
tensor veli palatini scaphoid fossa, lateral wall of the auditory tube cartilage palatine aponeurosis opens the auditory tube; tenses the soft palate mandibular division of the trigeminal nerve (V) ascending pharyngeal a. remember: V3 innervates both tensor muscles (tympani and veli palatini); ALL other palatal muscles are innervated by vagus
thyroarytenoid inner surface of the thyroid cartilage anteriorly lateral border of the arytenoid cartilage draws the arytenoid cartilage forward, relaxing and adducting the vocal folds inferior laryngeal nerve, from recurrent laryngeal nerve, a branch of the vagus nerve (X) laryngeal branch of the superior thyroid a. its subsidiary parts are the thyroepiglottic m. and the vocalis m.; the medial most fibers of thyroarytenoid that insert along the vocal ligament are called the vocalis muscle
thyroepiglottic inner surface of the thyroid cartilage near the laryngeal prominence lateral surface of the epiglottic cartilage draws the epiglottic cartilage downward inferior laryngeal nerve, from recurrent laryngeal nerve, a branch of the vagus nerve (X) laryngeal branch of the superior thyroid a. represents the superior fibers of thyroarytenoid muscle which fan out to the quadrangular membrane and epiglottis
thyrohyoid oblique line of the thyroid cartilage lower border of the hyoid bone elevates the larynx; depresses/stabilizes the hyoid bone ansa cervicalis (via fibers running with the hypoglossal nerve that leave XII distal to the superior limb of ansa) superior thyroid a. thyrohyoid lies deep to the sternohyoid
trachealis posterior edge of the tracheal cartilage posterior edge of the tracheal cartilage of other side (joins tracheal rings posteriorly) constricts the bronchi and trachea preganglionic parasympathetic fibers from the vagus (X) nerve inferior thyroid a., bronchial aa. smooth muscle, found in the submucosal layer
transverse arytenoid posterior surface of the arytenoid cartilage posterior surface of the contralateral arytenoid cartilage draws arytenoid cartilages together, adducting the vocal folds inferior laryngeal nerve, from recurrent laryngeal nerve, a branch of the vagus nerve (X) laryngeal br. of the superior thyroid a. the transverse arytenoid m.lies anterior to the oblique arytenoid m.; the arytenoideus is often considered to be one muscle with oblique and transverse parts
transverse arytenoid posterior surface of the arytenoid cartilage posterior surface of the contralateral arytenoid cartilage draws arytenoid cartilages together, adducting the vocal folds inferior laryngeal nerve, from recurrent laryngeal nerve, a branch of the vagus nerve (X) laryngeal br. of the superior thyroid a. the transverse arytenoid m.lies anterior to the oblique arytenoid m.; the arytenoideus is often considered to be one muscle with oblique and transverse parts
vocalis surface of the thyroid cartilage, vocal process of the arytenoid cartilage vocal ligament relaxes segments of the vocal ligament, thereby adjusting pitch inferior laryngeal nerve, from the recurrent laryngeal nerve, a branch of the vagus nerve (X) laryngeal br. of the superior thyroid a. represents the innermost fibers of the thyroarytenoid muscle; the cricothyroid m. grossly tenses the vocal ligaments, while the vocalis muscle provides the mechanism for fine tuning the vibrations of the vocal folds
zygomaticus major upper lateral surface of the zygomatic bone skin of the angle of the mouth elevates and draws the corner of the mouth laterally zygomatic and buccal branches of the facial nerve (VII) transverse facial a., facial a. a "smile" muscle
zygomaticus minor lower surface of the zygomatic bone lateral part of the upper lip elevates the upper lip buccal branch of the facial nerve (VII) transverse facial a., facial a. a "smile" muscle

Muscles of the Thoracic Region - Listed Alphabetically

Muscle Origin Insertion Action Innervation Artery Notes Image
diaphragm xiphoid process, costal margin, fascia over the quadratus lumborum and psoas major mm.(lateral & medial arcuate ligaments), vertebral bodies L1-L3 central tendon of the diaphragm pushes the abdominal viscera inferiorly, increasing the volume of the thoracic cavity (inspiration) phrenic nerve (C3-C5) musculophrenic a., superior phrenic a., inferior phrenic a. left crus attaches to the L1-L2 vertebral bodies, the right crus attaches to the L1-L3 vertebral bodies
external intercostal lower border of a rib within an intercostal space upper border of the rib below, coursing, downward and medially keeps the intercostal space from blowing out or sucking in during respiration intercostal nerves (T1-T11) intercostal a. 11 in number; they extend from the tubercle of the rib to the costochondral junction; continuous with the external intercostal membrane anteriorly
innermost intercostal upper borders of a rib fibers course up and medially to insert on the inferior margin of the rib above keeps the intercostal space from blowing out or sucking in during respiration intercostal nerves (T1-T11) intercostal a. innermost intercostal mm. have the same fiber direction as the internal intercostal mm., the only difference being that they lie deep to the intercostal neurovascular bundle
internal intercostal upper border of a rib lower border of rib above, coursing up and medially keeps the intercostal space from blowing out or sucking in during respiration intercostal nerves (T1-T11) intercostal a. 11 in number; they extend from the margin of the sternum to the angle of the rib; continuous posteriorly with the internal intercostal membrane
levatores costarum transverse processes C7-T11 rib below its origin, medial to the angle elevates the rib dorsal primary rami of spinal nerves C7-T11 deep cervical a., intercostal aa. these are fairly small and insignificant muscles
subcostalis angle of ribs angle of a rib 2-3 ribs above origin compresses the intercostal spaces intercostal nerves intercostal a. subcostalis, transversus thoracis & innermost intercostal mm. make up the deepest intercostal muscle layer
transversus thoracis posterior surface of the sternum inner surfaces of costal cartilages 2-6 compresses the thorax for forced expiration intercostal nerves 2-6 internal thoracic a. transversus thoracis, subcostalis & innermost intercostal mm. make up the innermost intercostal muscle layer

Muscles of the Abdominal Region - Listed Alphabetically

Muscle Origin Insertion Action Innervation Artery Notes Image
cremaster inguinal ligament forms thin network of muscle fascicles around the spermatic cord and testis (or around the distal portion of the round ligament of the uterus) elevates testis (not well developed in females) genital branch of the genitofemoral nerve cremasteric a., a branch of the inferior epigastric a. the cremaster m. is internal abdominal oblique muscle's contribution to the coverings of the spermatic cord and testis; the cremasteric reflex may be elicited by stroking the medial thigh (where the femoral branch of the genitofemoral n. distributes cutaneously) (Greek, cremaster = suspender)
dartos subcutaneous connective tissue of the scrotum and the penis (or labium majus and clitoris) skin of the scrotum and penis (or labium majus and clitoris) elevates testis (tenses the skin of the pudendal region in the female) postganglionic sympathetic nerve fibers arriving via the ilioinguinal nerve and the posterior scrotal nerve cremasteric a., posterior scrotal (labial) a. the dartos elevates the testis in response to cold (it is modified arrector pili fibers, or the goose-bump muscles) (Latin, dartos = leather)
external abdominal oblique lower 8 ribs linea alba, pubic crest & tubercle, anterior superior iliac spine & anterior half of iliac crest flexes and laterally bends the trunk intercostal nerves 7-11, subcostal, iliohypogastric and ilioinguinal nerves musculophrenic a., superior epigastric a., intercostal aa. 7-11, subcostal a., lumbar aa., superficial circumflex iliac a., deep circumflex iliac a., superficial epigastric a., inferior epigastric a., superficial external pudendal a. the inguinal ligament is a specialization of the external abdominal oblique aponeurosis; the external spermatic fascia is the external abdominal oblique muscle's contribution to the coverings of the testis and spermatic cord
interfoveolar transversus abdominis fibers that lie superficial to the inferior epigastric vessels anterior lamina of femoral sheath, immediately distal to origin of inferior epigastric vessels compresses abdominal contents iliohypogastric and ilioinguinal nerves inferior epigastric a. an inconstant part of the transversus abdominis m. which may be replaced by a ligament (interfoveolar ligament) Image Not Available
internal abdominal oblique thoracolumbar fascia, anterior 2/3 of the iliac crest, lateral 2/3 of the inguinal ligament lower 3 or 4 ribs, linea alba, pubic crest flexes and laterally bends the trunk intercostal nerves 7-11, subcostal, iliohypogastric and ilioinguinal nerves musculophrenic a., superior epigastric a., intercostal aa. 7-11, subcostal a., lumbar aa., superficial circumflex iliac a., deep circumflex iliac a., superficial epigastric a., inferior epigastric a., superficial external pudendal a. anterior fibers of internal abdominal oblique course up and medially, perpendicular to the fibers of external abdominal oblique; the cremaster muscle and fascia is the internal abdominal oblique muscle's contribution to the coverings of the testis and spermatic cord
oblique, external abdominal lower 8 ribs linea alba, pubic crest & tubercle, anterior superior iliac spine & anterior half of iliac crest flexes and laterally bends the trunk intercostal nerves 7-11, subcostal, iliohypogastric and ilioinguinal nerves musculophrenic a., superior epigastric a., intercostal aa. 7-11, subcostal a., lumbar aa., superficial circumflex iliac a., deep circumflex iliac a., superficial epigastric a., inferior epigastric a., superficial external pudendal a. the inguinal ligament is a specialization of the external abdominal oblique aponeurosis; the external spermatic fascia is the external abdominal oblique muscle's contribution to the coverings of the testis and spermatic cord
oblique, internal abdominal thoracolumbar fascia, anterior 2/3 of the iliac crest, lateral 2/3 of the inguinal ligament lower 3 or 4 ribs, linea alba, pubic crest flexes and laterally bends the trunk intercostal nerves 7-11, subcostal, iliohypogastric and ilioinguinal nerves musculophrenic a., superior epigastric a., intercostal aa. 7-11, subcostal a., lumbar aa., superficial circumflex iliac a., deep circumflex iliac a., superficial epigastric a., inferior epigastric a., superficial external pudendal a. anterior fibers of internal abdominal oblique course up and medially, perpendicular to the fibers of external abdominal oblique; the cremaster muscle and fascia is the internal abdominal oblique muscle's contribution to the coverings of the testis and spermatic cord
psoas major bodies and transverse processes of lumbar vertebrae lesser trochanter of femur (with iliacus) via iliopsoas tendon flexes the thigh; flexes & laterally bends the lumbar vertebral column branches of the ventral primary rami of spinal nerves L2-L4 subcostal a., lumbar aa. the genitofemoral nerve pierces the anterior surface of the psoas major m. (Greek, psoas = the muscles of the loins)
psoas minor bodies of the T12 & L1 vertebrae iliopubic eminence at the line of junction of the ilium and the superior pubic ramus flexes & laterally bends the lumbar vertebral column branches of the ventral primary rams of spinal nerves L1-L2 lumbar aa. absent in 40% of cases (Greek, psoas = the muscles of the loins)
pyramidalis pubis, anterior to the rectus abdominis linea alba draws the linea alba inferiorly subcostal nerve subcostal a., inferior epigastric a. the pyramidalis m. is not always present
quadratus lumborum posterior part of the iliac crest and the iliolumbar ligament transverse processes of lumbar vertebrae 1-4 and the 12th rib laterally bends the trunk, fixes the 12th rib subcostal nerve and ventral primary rami of spinal nerves L1-L4 subcostal a., lumbar aa. the lateral arcuate ligament of the diaphragm crosses the anterior surface of the quadratus lumborum m.
rectus abdominis pubis and the pubic symphysis xiphoid process of the sternum and costal cartilages 5-7 flexes the trunk intercostal nerves 7-11 and subcostal nerve superior epigastric a. intercostal aa., subcostal a., inferior epigastric a. rectus sheath contains rectus abdominis and is formed by the aponeuroses of external and internal oblique and transversus abdominis mm.
transversus abdominis lower 6 ribs, thoracolumbar fascia, anterior 3/4 of the iliac crest, lateral 1/3 of inguinal ligament linea alba, pubic crest and pecten of the pubis flexes and laterally bends trunk intercostal nerves 7-11, subcostal, iliohypogastric and ilioinguinal nerves musculophrenic a., superior epigastric a., intercostal aa. 7-11, subcostal a., lumbar aa., superficial circumflex iliac a., deep circumflex iliac a., superficial epigastric a., inferior epigastric a., superficial external pudendal a. transversus abdominis muscle does not contribute to the coverings of the spermatic cord and testis; transversalis fascia, the deep fascia that covers the inner surface of the transversus abdominis, forms the internal spermatic fascia

Muscles of the Pelvis and Perineum - Listed Alphabetically

Muscle Origin Insertion Action Innervation Artery Notes Image
anal sphincter, external perineal body or central tendinous point of the perineum encircles the anal canal; superficial fibers attach to the coccyx constricts the anal canal inferior rectal nerves (from the pudendal nerve) inferior rectal a. skeletal (voluntary) muscle, as contrasted with sphincter ani internus, which is smooth (involuntary) muscle; the external anal sphincter is considered part of the pelvic diaphragm
anal sphincter, internal encircles the anal canal encircles the anal canal constricts the anal canal parasympathetic fibers from S4 middle rectal a. smooth muscle (involuntary), as contrasted with sphincter ani externus, which is skeletal muscle (voluntary)
bulbospongiosus, in female perineal body and fascia of the bulb of the vestibule perineal membrane and corpus cavernosum of the clitoris compresses the vestibular bulb and constricts the vaginal orifice deep branch of the perineal nerve (from pudendal nerve) perineal a. skeletal muscle
bulbospongiosus, in male central tendinous point and the midline raphe on the bulb of the penis perineal membrane, dorsal surface of the corpus spongiosum, deep penile fascia compresses the bulb of the penis, compresses the spongy urethra deep branch of the perineal nerve (from pudendal nerve) perineal a. expels the last drops of urine from urethra; expels semen during ejaculation
coccygeus ischial spine side of the coccyx and lower sacrum elevates the pelvic floor branches of the ventral primary rami of spinal nerves S3-S4 inferior gluteal a. coccygeus and levator ani combined form the pelvic diaphragm
deep transverse perineus medial surface of the ischial ramus contralateral muscle and perineal body/central tendinous point fixes and stabilizes the perineal body/central tendinous point deep branch of perineal nerve from pudendal nerve internal pudendal a. superficial and deep transverse perineus muscles are separated by the perineal membrane
detruser of bladder smooth muscle in the wall of the urinary bladder fascicles are arranged roughly in three layers compresses the urinary bladder parasympathetic nerve fibers from the pelvic splanchnic nerves (S2-S4 spinal cord levels) superior and inferior vesical aa. muscles in the neck of bladder must contract and cause the internal urethral orifice to open before the detruser muscle can void the bladder (Latin, detruser = to push down)
iliococcygeus arcus tendineus levator ani and the ischial spine anococcygeal raphe and the coccyx elevates the pelvic floor branches of the ventral primary rami of spinal nerves S3-S4 inferior gluteal a. the combination of puborectalis, pubococcygeus and iliococcygeus is called the levator ani m.
ischiocavernosus medial surface of the ischial tuberosity and the ischiopubic ramus corpus cavernosum and crus of the penis/clitoris compresses the corpus cavernosum deep branch of the perineal nerve (from pudendal nerve) perineal a. ischiocavernosus m. is closely applied to the surface of the crus penis/clitoris
levator ani posterior surface of the body of the pubis, fascia of the obturator internus m. (arcus tendineus levator ani), ischial spine anococcygeal raphe and coccyx elevates the pelvic floor branches of the ventral primary rami of spinal nerves S3-S4 inferior gluteal a. the combination of puborectalis, pubococcygeus & iliococcygeus is the levator ani m.; coccygeus and levator ani combined form the pelvic diaphragm (Latin, levator = to lift)
levator prostatae posterior aspect of the pubis fascia of the prostate elevates the prostate branches of the ventral primary rami of spinal nerves S3-S4 inferior gluteal a. levator prostatae is part of the puborectalis m. (Latin, levator = to lift)
pubococcygeus posterior aspect of the superior pubic ramis coccyx elevates the pelvic floor branches of the ventral primary rami of spinal nerves S3-S4 inferior gluteal a. the combination of puborectalis, pubococcygeus and iliococcygeus is called the levator ani m.
puborectalis posterior aspect of the body of the pubis unites with the puborectalis m. of other side posterior to the rectum draws the distal rectum forward and superiorly; aids in voluntary retention of feces branches of the ventral primary rami of spinal nerves S3-S4 inferior gluteal a. the combination of puborectalis, pubococcygeus and iliococcygeus is called the levator ani m.
pubovaginalis posterior aspect of the body of the pubis fascia of the vagina and perineal body draws the vagina forward and superiorly branches of the ventral primary rami of spinal nerves S3-S4 inferior gluteal a. pubovaginalis is part of the levator ani muscle
sphincter ani externus perineal body or central tendinous point of the perineum encircles the anal canal; superficial fibers attach to the coccyx constricts the anal canal inferior rectal nerves (from the pudendal nerve) inferior rectal a. skeletal (voluntary) muscle, as contrasted with sphincter ani internus, which is smooth (involuntary) muscle; the external anal sphincter is considered part of the pelvic diaphragm
sphincter ani internus encircles the anal canal encircles the anal canal constricts the anal canal parasympathetic fibers from S4 middle rectal a. smooth muscle (involuntary), as contrasted with sphincter ani externus, which is skeletal muscle (voluntary)
sphincter urethrae, in female encircles the urethra encircles urethra and vagina; extends superiorly along the urethra as far as the inferior surface of the bladder compresses urethra and vagina deep branch of perineal nerve from pudendal nerve internal pudendal a. skeletal muscle
sphincter urethrae, in male encircles the urethra encircles urethra, reaches lateral surface of prostate and inferior bladder compresses urethra deep branch of perineal nerve from pudendal nerve internal pudendal a. skeletal muscle
superficial transverse perineus medial surface of the ischial ramus contralateral muscle and the perineal body/central tendinous point fixes and stabilizes perineal body/central tendinous point deep branch of perineal nerve from pudendal nerve perineal a. superficial and deep transverse perineus muscles are separated by the perineal membrane
transverse perineus, deep medial surface of the ischial ramus contralateral muscle and perineal body/central tendinous point fixes and stabilizes the perineal body/central tendinous point deep branch of perineal nerve from pudendal nerve internal pudendal a. superficial and deep transverse perineus muscles are separated by the perineal membrane
transverse perineus, superficial medial surface of the ischial ramus contralateral muscle and the perineal body/central tendinous point fixes and stabilizes perineal body/central tendinous point deep branch of perineal nerve from pudendal nerve perineal a. superficial and deep transverse perineus muscles are separated by the perineal membrane

Muscles of the Lower Limb - Listed Alphabetically

Muscle Origin Insertion Action Innervation Artery Notes Image
abductor digiti minimi (foot) medial and lateral sides of the tuberosity of the calcaneus lateral side of the base of the proximal phalanx of the 5th digit abducts the 5th toe; flexes the metatarsophalageal joint lateral plantar nerve lateral plantar a. abductor digiti minimi forms the lateral margin of the sole of the foot
abductor hallucis medial side of the tuberosity of calcaneus medial side of the base of the proximal phalanx of the great toe (hallux) abducts the great toe; flexes the metatarsophalageal joint medial plantar nerve medial plantar a. abductor hallucis forms the medial margin of the sole of the foot (Latin, hallex = great toe)
adductor brevis inferior pubic ramus pectineal line and linea aspera (deep to the pectineus and adductor longus mm.) adducts, flexes, and medially rotates the femur anterior division of the obturator nerve obturator a., deep femoral a. anterior and posterior divisions of the obturator nerve lie on the anterior and posterior surfaces of adductor brevis
adductor hallucis oblique head: bases of metatarsals 2-4; transverse head: heads of metatarsals 3-5 lateral side of base of the proximal phalanx of the great toe adducts the great toe (moves it toward midline of the foot; i.e.toward the 2nd digit) deep branch of the lateral plantar nerve plantar arterial arch the plantar arterial arch passes superior to the oblique head of adductor hallucis (Latin, hallex = great toe)
adductor longus medial portion of the superior pubic ramus linea aspera of the femur adducts, flexes, and medially rotates the femur anterior division of the obturator nerve obturator a., deep femoral a. the most anterior of the adductor group of muscles
adductor magnus ischiopubic ramus and ischial tuberosity linea aspera of the femur; the ischiocondylar part inserts on the adductor tubercle of the femur adducts, flexes, and medially rotates the femur; extends the femur (ischiocondylar part) posterior division of the obturator nerve; tibial nerve (ischiocondylar part) obturator a., deep femoral a., medial femoral circumflex a. the ischiocondylar part of adductor magnus is a hamstring muscle by embryonic origin and action, so it is innervated by the tibial nerve
adductor minimus lower portion of the inferior pubic ramus gluteal ridge and upper part of the linea aspera of the femur adducts and laterally rotates the femur posterior division of the obturator nerve obturator a., medial femoral circumflex a., deep femoral a. adductor minimus m. is the uppermost fibers of the adductor magnus m.
articularis genu anterior surface of the femur above the patellar surface articular capsule of the knee elevates the articular capsule of the knee joint femoral nerve descending genicular a. articularis genu is formed by muscle fascicles deep to the vastus intermedius m.
biceps femoris long head: ischial tuberosity; short head: lateral lip of the linea aspera head of fibula and lateral condyle of the tibia extends the thigh, flexes the leg long head: tibial nerve; short head: common fibular (peroneal) nerve perforating branches of the deep femoral a. one of the "hamstring" muscles
dorsal interosseous (foot) shafts of adjacent metatarsal bones bases of the proximal phalanges for digit 2 (both sides) & digits 3,4 (lateral side) abduct digits 2-4 (move these digits away from midline as defined by a plane passing through the 2nd digit); flex the metatarsophalangeal joints and extend the interphalangeal joints of those digits deep branch of the lateral plantar nerve dorsal metatarsal aa. four in number; remember DAB (Dorsal interossei ABduct) and PAD (Plantar interossei ADduct), then logic can tell you where these muscles insert (Latin, inter = between + os = bone)
extensor digitorum brevis superolateral surface of the calcaneus extensor expansion of toes 1-4 extends toes 1-4 deep fibular (peroneal) nerve dorsalis pedis a. the part of the extensor digitorum brevis that goes to the great toe is called the extensor hallucis brevis m.
extensor digitorum longus lateral condyle of the tibia, anterior surface of the fibula, lateral portion of the interosseous membrane dorsum of the lateral 4 toes via extensor expansions (central slip inserts on base of middle phalanx, lateral slips on base of distal phalanx) extends the metatarsophalangeal, proximal interphalangeal and distal interphalangeal joints of the lateral 4 toes deep fibular (peroneal) nerve anterior tibial a. one of the muscles involved in anterior compartment syndrome
extensor hallucis brevis superolateral surface of the calcaneus dorsum of base of proximal phalanx of the great toe extends the great toe deep fibular (peroneal) nerve dorsalis pedis a. usually considered to be the medial-most part of the extensor digitorum brevis m. (Latin, hallex = great toe)
extensor hallucis longus middle half of the anterior surface of the fibula and the interosseous membrane base of the distal phalanx of the great toe extends the metatarsophalangeal interphalangeal joints of the great toe deep fibular (peroneal) nerve anterior tibial a. one of the muscles involved in anterior compartment syndrome (Latin, hallex = great toe)
fibularis (peroneus) brevis lower one third of the lateral surface of the fibula tuberosity of the base of the 5th metatarsal extends (plantar flexes) and everts the foot superficial fibular (peroneal) nerve fibular (peroneal) a. stress fracture of the base of the 5th metatarsal bone is a common runner's injury
fibularis (peroneus) longus upper two/thirds of the lateral surface of the fibula after crossing the plantar surface of the foot deep to the intrinsic muscles, it inserts on the medial cuneiform and the base of the 1st metatarsal bone extends (plantar flexes) and everts the foot superficial fibular (peroneal) nerve fibular (peroneal) a. fibularis longus lies superficial to the fibularis brevis m. in the lateral compartment of the leg
fibularis (peroneus) tertius distal part of the anterior surface of the fibula dorsum of the shaft of the 5th metatarsal bone everts the foot deep fibular (peroneal) nerve anterior tibial a. fibularis tertius is in the anterior compartment of the leg, not the lateral compartment (which contains fibularis longus and brevis)
flexor digiti minimi brevis (foot) base of 5th metatarsal bone lateral side of base of proximal phalanx of 5th digit flexes the metatarsophalangeal joint of the 5th digit lateral plantar nerve lateral plantar a. none
flexor digitorum brevis tuberosity of the calcaneus, plantar aponeurosis, intermuscular septae base of the middle phalanx of digits 2-5 after splitting to allow passage of the flexor digitorum longus tendons flexes the metatarsophalangeal & proximal interphalangeal joints of digits 2-5 medial plantar nerve medial and lateral plantar aa. flexor digitorum brevis in the foot is equivalent to the flexor digitorum superficialis m. of the arm
flexor digitorum longus middle half of the posterior surface of the tibia bases of the distal phalanges of digits 2-5 flexes the metatarsophalangeal, proximal interphalangeal and distal interphalangeal joints of digits 2-5; plantar flexes the foot tibial nerve tibial a. flexor digitorum longus in the leg is equivalent to the flexor digitorum profundus m. of the arm
flexor hallucis brevis cuboid, lateral cuneiform, medial side of the first metatarsal medial belly: medial side of proximal phalanx of the great toe; lateral belly: lateral side of the proximal phalanx of the great toe flexes the metatarsophalangeal joint of the great toe medial plantar nerve (lateral belly occasionally receives innervation from the lateral plantar nerve) medial plantar a. each tendon of insertion contains a sesamoid bone (Latin, hallex = great toe)
flexor hallucis longus lower 2/3 of the posterior surface of the fibula base of the distal phalanx of the great toe flexes the metatarsophalangeal and proximal interphalangeal joints of the great toe; plantar flexes the foot tibial nerve fibular (peroneal) a. and tibial a. flexor hallucis longus is very important in the "push off" part of the normal gait (Latin, hallex = great toe)
gastrocnemius femur; medial head: above the medial femoral condyle; lateral head: above the lateral femoral condyle dorsum of the calcaneus via the calcaneal (Achilles') tendon flexes leg; plantar flexes foot tibial nerve sural aa. (from the popliteal a.), posterior tibial a. the calcaneal tendon of the gastrocnemius and soleus is the thickest and strongest tendon in the body
gemellus, inferior ischial tuberosity obturator internus tendon laterally rotates the femur nerve to the quadratus femoris m. inferior gluteal a. gemellus is a Latin word that means "little twin"
gemellus, superior ischial spine obturator internus tendon laterally rotates the femur nerve to the obturator internus m. inferior gluteal a. gemellus is a Latin word that means "little twin"
gluteus maximus posterior gluteal line, posterior surface of sacrum and coccyx, sacrotuberous ligament upper fibers: iliotibial tract; lowermost fibers: gluteal tuberosity of the femur extends the thigh; laterally rotates the femur inferior gluteal nerve superior and inferior gluteal aa. gluteus maximus is a site of intramuscular injection
gluteus medius external surface of the ilium between the posterior and anterior gluteal lines greater trochanter of the femur abducts the femur; medially rotates the thigh superior gluteal nerve superior gluteal a. the angle at which the gluteus medius tendon approaches the greater trochanter of the femur is anterior to the axis of rotation of the thigh, resulting in medial rotation
gluteus minimus external surface of the ilium between the anterior and inferior gluteal lines greater trochanter of the femur abducts the femur; medially rotates the thigh superior gluteal nerve superior gluteal a. the angle at which the gluteus minimus tendon approaches the greater trochanter of the femur is anterior to the axis of rotation of the thigh, resulting in medial rotation
gracilis pubic symphysis and the inferior pubic ramus medial surface of the tibia (via pes anserinus) adducts the thigh, flexes and medially rotates the thigh, flexes the leg anterior division of the obturator nerve obturator a. the pes anserinus is the common insertion of the gracilis, sartorius, and semitendinosus mm. (Latin, pes anserinus = goose's foot; gracilis = slender)
iliacus iliac fossa and iliac crest; ala of sacrum lesser trochanter of the femur flexes the thigh; if the thigh is fixed it flexes the pelvis on the thigh femoral nerve iliolumbar a. inserts in company with the psoas major m. via the iliopsoas tendon
iliopsoas iliac fossa; bodies and transverse processes of lumbar vertebrae lesser trochanter of the femur flexes the thigh; flexes and laterally bends the lumbar vertebral column branches of the ventral primary rami of spinal nerves L2-L4; branches of the femoral nerve iliolumbar a. a combination of the iliacus and psoas major mm.
inferior gemellus ischial tuberosity obturator internus tendon laterally rotates the femur nerve to the quadratus femoris m. inferior gluteal a. Latin, gemellus = little twin
interosseous, dorsal (foot) shafts of adjacent metatarsal bones bases of the proximal phalanges for digit 2 (both sides) & digits 3,4 (lateral side) abduct digits 2-4 (move these digits away from midline as defined by a plane passing through the 2nd digit); flex the metatarsophalangeal joints and extend the interphalangeal joints of those digits deep branch of the lateral plantar nerve dorsal metatarsal aa. four in number; remember DAB (Dorsal interossei ABduct) and PAD (Plantar interossei ADduct), then logic can tell you where these muscles insert (Latin, inter = between + os = bone)
interosseous, plantar base and medial side of metatarsals 3-5 bases of proximal phalanges and extensor expansions of digits 3-5 adduct digits 3-5 (move these digits toward the midline of the foot as defined by a plane through the second digit); flex the metacarpophalangeal and extend interphalangeal joints of digits 3-5 deep branch of the lateral plantar nerve plantar metatarsal aa. remember PAD (Plantar interossei ADduct) and DAB (Dorsal interossei ABduct), and logic will tell you where these muscles must insert (Latin, inter = between + os = bone)
lumbricals (foot) tendons of the flexor digitorum longus medial side of the extensor expansion of digits 2-5 flex the metatarsophalangeal joint, extend the proximal interphalangeal & distal interphalangeal joints of digits 2-5 medial (1st) lumbrical: medial plantar nerve; lateral three lumbricals: lateral plantar nerve medial and lateral plantar aa. the lumbricals of the foot have the same action on the toes that the lumbricals in the hand have on the fingers (Latin, lumbricus = earthworm)
obturator externus the external surface of the obturator membrane and the superior and inferior pubic rami trochanteric fossa of the femur laterally rotates the thigh obturator nerve obturator a. the tendon of the obturator externus m. passes inferior to the neck of the femur to reach its insertion site
obturator internus the internal surface of the obturator membrane and margin of the obturator foramen greater trochanter on its medial surface above the trochanteric fossa laterally rotates and abducts the thigh nerve to the obturator internus m. obturator a. the obturator internus m. leaves the pelvis by passing through the lesser sciatic foramen; the superior and inferior gemellus mm. insert on the obturator internus tendon
pectineus pecten of the pubis pectineal line of the femur adducts, flexes, and medially rotates the thigh femoral nerve and possibly the anterior division of the obturator nerve medial femoral circumflex a. pectineus often has a dual innervation
peroneus mm. (SEE fibularis mm.)   peroneus is the old terminology used for the fibularis mm.
piriformis anterior surface of sacrum upper border of greater trochanter of femur laterally rotates and abducts thigh ventral rami of S1-S2   piriformis leaves the pelvis by passing through the greater sciatic foramen
plantar interosseous base and medial side of metatarsals 3-5 bases of proximal phalanges and extensor expansions of digits 3-5 adduct digits 3-5 (move these digits toward the midline of the foot as defined by the second digit),flex metatarsophalangeal and extend interphalangeal joints of digits 3-5 deep branch of the lateral plantar nerve plantar metatarsal aa. remember PAD (Plantar interossei ADduct) and DAB (Dorsal interossei ABduct), and logic will tell you where these muscles must insert (Latin, inter = between + os = bone)
plantaris above the lateral femoral condyle (above the lateral head of gastrocnemius) dorsum of the calcaneus medial to the calcaneal tendon flexes the leg; plantar flexes the foot tibial nerve popliteal a. plantaris has a long slender tendon that is equivalent to the tendon of the palmaris longus m. of the arm; its tendon is often called the "freshman nerve" because it is often misidentified by the freshman medical student
popliteus lateral condyle of the femur posterior surface of the tibia above soleal line flexes and rotates the leg medially (with the foot planted, it rotates the thigh laterally) tibial nerve popliteal a. has a round tendon of origin; popliteus unlocks the knee joint to initiate flexion of the leg
psoas major bodies and transverse processes of lumbar vertebrae lesser trochanter of femur (with iliacus) via iliopsoas tendon flexes the thigh; flexes & laterally bends the lumbar vertebral column branches of the ventral primary rami of spinal nerves L2-L4 subcostal a., lumbar aa. the genitofemoral nerve pierces the anterior surface of the psoas major m. (Latin, psoas = the muscles of the loins)
psoas minor bodies of the T12 & L1 vertebrae iliopubic eminence at the line of junction of the ilium and the superior pubic ramus flexes & laterally bends the lumbar vertebral column branches of the ventral primary rams of spinal nerves L1-L2 lumbar aa. absent in 40% of cases (Latin, psoas = the muscles of the loins)
quadratus femoris lateral border of the ischial tuberosity quadrate line of the femur below the intertrochanteric crest laterally rotates the thigh nerve to the quadratus femoris m. inferior gluteal a. the nerve to the quadratus femoris m. also innervates the inferior gemellus m.
quadratus plantae anterior portion of the calcaneus and the long plantar ligament tendons of the flexor digitorum longus m. assists the flexor digitorum longus in flexing the toes lateral plantar nerve lateral plantar a. the quadratus plantae m. changes the line of force of the flexor digitorum longus m. to bring it in line with the long axis of the foot (Latin, quadratus = square)
quadriceps femoris anterior surface of the femur and the anterior side of the medial and lateral intermuscular septa tibial tuberosity via the patellar ligament extends the knee; rectus femoris flexes the thigh femoral nerve lateral circumflex femoral a., deep femoral a. composed of 4 muscles: rectus femoris, vastus lateralis, vastus intermedius and vastus medialis
rectus femoris straight head: anterior inferior iliac spine; reflected head: above the superior rim of the acetabulum patella and tibial tuberosity (via the patellar ligament) extends the leg, flexes the thigh femoral nerve lateral circumflex femoral a. rectus femoris is part of the quadriceps femoris muscle
sartorius anterior superior iliac spine medial surface of the tibia (pes anserinus) flexes, abducts and laterally rotates the thigh; flexes leg femoral nerve lateral femoral circumflex a., saphenous a. its actions put the lower limb in the traditional cross-legged seated position of a tailor (Latin, sartorius = tailor)
semimembranosus upper, outer surface of the ischial tuberosity medial condyle of the tibia extends the thigh, flexes the leg tibial nerve perforating branches of the deep femoral a. one of the "hamstring" muscles
semitendinosus lower, medial surface of ischial tuberosity (common tendon with biceps femoris m.) medial surface of tibia (via pes anserinus) extends the thigh, flexes the leg tibial nerve perforating branches of the deep femoral a. pes anserinus is the common insertion for the gracilis, sartorius, and semitendinosus mm.
soleus posterior surface of head and upper shaft of the fibula, soleal line of the tibia dorsum of the calcaneus via the calcaneal (Achilles') tendon plantar flexes the foot tibial nerve posterior tibial a. soleus and the 2 heads of gastrocnemius are sometimes called the triceps surae muscle
superior gemellus ischial spine obturator internus tendon laterally rotates the femur nerve to the obturator internus m. inferior gluteal a. Latin, gemellus = little twin
tensor fasciae latae anterior part of the iliac crest, anterior superior iliac spine iliotibial tract flexes, abducts, and medially rotates the thigh superior gluteal nerve superior gluteal a. tensor fascia latae redirects the rotational forces of the gluteus maximus m.
tibialis anterior lateral tibial condyle and the upper lateral surface of the tibia medial surface of the medial cuneiform and the 1st metatarsal dorsiflexes and inverts the foot deep fibular (peroneal) nerve anterior tibial a. acts as both an antagonist (dorsiflexion/plantar flexion) and a synergist (inversion) of the tibialis posterior m.
tibialis posterior interosseous membrane, posteromedial surface of the fibula, posterolateral surface of the tibia tuberosity of the navicular and medial cuneiform, metatarsals 2-4 plantar flexes the foot; inverts the foot tibial nerve fibular (peroneal) a. and tibial a. acts as both an antagonist (dorsiflexion/plantar flexion) and a synergist (inversion) of the tibialis anterior m.
vastus intermedius anterior and lateral surface of the femur patella extends the leg femoral nerve lateral femoral circumflex a. vastus intermedius is part of the quadriceps femoris muscle (Latin, vastus = huge)
vastus lateralis lateral intermuscular septum, lateral lip of the linea aspera and the gluteal tuberosity patella and medial patellar retinaculum extends leg femoral nerve lateral femoral circumflex a., perforating branches of the deep femoral a. vastus lateralis is part of the quadriceps femoris muscle (Latin, vastus = huge)
vastus medialis medial intermuscular septum, medial lip of the linea aspera patella and medial patellar retinaculum extends leg femoral nerve lateral femoral circumflex a. vastus medialis is part of the quadriceps femoris muscle (Latin, vastus = huge)

The material presented in these tables is contained in the book:
MedCharts Anatomy by Thomas R. Gest & Jaye Schlesinger
Published by ILOC, Inc., New York
Copyright © 1995, unauthorized use prohibited.
The excellent editorial assistance of
Dr. Pat Tank, UAMS
is gratefully acknowledged.