muscle (redirected from muscle rupture)

muscle /mus·cle/ (mus´'l) an organ which by contraction produces movement of an animal organism.

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abductor muscle of great toe  origin, medial tubercle of calcaneus, plantar fascia; insertion, medial surface of base of proximal phalanx of great toe; innervation, medial plantar; action, abducts, flexes great toe.

abductor muscle of little finger  origin, pisiform bone, tendon of ulnar flexor muscle of wrist; insertion, medial surface of base of proximal phalanx of little finger; innervation, ulnar; action, abducts little finger.

abductor muscle of little toe  origin, medial and lateral tubercles of calcaneus, plantar fascia; insertion, lateral surface of base of proximal phalanx of little toe; innervation, superficial branch of lateral plantar; action, abducts little toe.

abductor muscle of thumb, long  origin, posterior surfaces of radius and ulna; insertion, radial side of base of first metacarpal bone; innervation, posterior interosseous; action, abducts, extends thumb.

abductor muscle of thumb, short  origin, scaphoid, ridge of trapezium, transverse carpal ligament; insertion, lateral surface of base of proximal phalanx of thumb; innervation, median; action, abducts thumb.

adductor muscle, great  origin, deep part—inferior ramus of pubis, ramus of ischium, superficial part—ischial tuberosity; insertion, deep part—linea aspera of femur, superficial part—adductor tubercle of femur; innervation, deep part—obturator, superficial part—sciatic; action, deep part—adducts thigh, superficial part—extends thigh.

adductor muscle, long  origin, crest and symphysis of pubis; insertion, linea aspera of femur; innervation, obturator; action, adducts, rotates, flexes thigh.

adductor muscle, short  origin, outer surface of inferior ramus of pubis; insertion, upper part of linea aspera of femur; innervation, obturator; action, adducts, rotates, flexes thigh.

adductor muscle, smallest  a name given the anterior portion of the great adductor muscle; insertion, ischium, body and ramus of pubis; innervation, obturator and sciatic; action, adducts thigh.

adductor muscle of great toe  : origin, oblique head—bases of second, third, and fourth metatarsals, and sheath of peroneus longus, transverse head— capsules of metatarsophalangeal joints of three lateral toes; insertion, lateral side of base of proximal phalanx of great toe; innervation, lateral plantar; action, adducts great toe.

agonistic muscle  one opposed in action by another muscle (the antagonistic m.).

anconeus muscle  origin, back of lateral epicondyle of humerus; insertion, olecranon and posterior surface of ulna; innervation, radial; action, extends forearm.

antagonistic muscle  one that counteracts the action of another muscle (the agonistic m.).

antitragicus muscle  origin, outer part of antitragus; insertion, caudate process of helix and anthelix; innervation, temporal and posterior auricular.

arrector muscle of hair  origin, papillary layer of skin; insertion, a hair follicle; innervation, sympathetic; action, elevate a hair of skin.

articular muscle  one that has one end attached to a joint capsule.

articular muscle of elbow  a few fibers of the deep surface of the triceps brachii that insert into the posterior ligament and synovial membrane of the elbow joint.

articular muscle of knee  origin, distal fourth of anterior surface of shaft of femur; insertion, synovial membrane of knee joint; innervation, femoral; action, lifts capsule of knee joint.

aryepiglottic muscle  an inconstant fascicle of the oblique arytenoid muscle, originating from the apex of the arytenoid cartilage and inserting on the lateral margin of the epiglottis.

arytenoid muscle, oblique  one of the intrinsic muscles of the larynx; origin, dorsal aspect of muscular process of arytenoid cartilage; insertion, apex of opposite arytenoid cartilage; innervation, recurrent laryngeal; action, closes inlet of larynx.

arytenoid muscle, transverse  one of the intrinsic muscles of the larynx; origin, dorsal aspect of muscular process of arytenoid cartilage; insertion, continuous with thyroarytenoid, apex of opposite cartilage; innervation, recurrent laryngeal; action, approximates arytenoid cartilages.

auricular muscles 

1. the extrinsic auricular muscles, including the anterior, posterior, and superior auricular muscles.

2. the intrinsic auricular muscles that extend from one part of the auricle to another, including the helicis major, helicis minor, tragicus, antitragicus, transverse auricular, and oblique auricular muscles.

auricular muscle, anterior  origin, superficial temporal fascia; insertion, cartilage of ear; innervation, facial; action, draws the auricle forward.

auricular muscle, posterior  origin, mastoid process; insertion, cartilage of ear; innervation, facial; action, draws auricle backward.

auricular muscle, superior  origin, galea aponeurotica; insertion, cartilage of ear; innervation, facial; action, raises auricle.

Bell's muscle  the muscular strands between the ureteric orifices and the uvula vesicae, bounding the trigone of the urinary bladder.

biceps muscle of arm  origin, long head—upper border of glenoid cavity, short head—apex of coracoid process; insertion, radial tuberosity and fascia of forearm; innervation, musculocutaneous; action, flexes forearm, supinates hand.

biceps muscle of thigh  origin, long head—ischial tuberosity, short head—linea aspera of femur; insertion, head of fibula, lateral condyle of tibia; innervation, long head—tibial, short head— peroneal, popliteal; action, flexes leg, extends thigh.

brachial muscle  origin, anterior surface of humerus; insertion, coronoid process of ulna; innervation, radial, musculocutaneous; action, flexes forearm.

brachioradial muscle  origin, lateral supracondylar ridge of humerus; insertion, lower end of radius; innervation, radial; action, flexes forearm.

bronchoesophageal muscle  a name given muscular fasciculi arising from the wall of the left bronchus, reinforcing muscles of the esophagus.

Brücke's muscle  the longitudinal fibers of the ciliary muscle.

buccinator muscle  origin, buccinator ridge of mandible, alveolar process of maxilla, pterygomandibular ligament; insertion, orbicularm muscle of mouth at angle of mouth; innervation, buccal branch of facial; action, compresses cheek and retracts angle of the mouth.

bulbocavernosus muscle , bulbocavernous muscle, bulbospongiosus muscle origin, central point of perineum, median raphe of bulb; insertion, fascia of penis (male) or clitoris (female); innervation, pudendal; action, constricts spongy urethra.

canine muscle  levator m. of angle of mouth.

cardiac muscle  the muscle of the heart, composed of striated but involuntary muscle fibers, comprising the chief component of the myocardium and lining the walls of the adjoining large vessels.

ceratocricoid muscle  a muscular fasciculus arising from the cricoid cartilage and inserted on the inferior cornu of the thyroid cartilage, considered one of the intrinsic muscles of the larynx.

cervical muscles  the muscles of the neck, including the sternocleidomastoid, longus colli, suprahyoid, infrahyoid, and scalene muscles.

chin muscle  origin, incisive fossa of mandible; insertion, skin of chin; innervation, facial; action, wrinkles skin of chin.

chondroglossus muscle  origin, medial side and base of lesser cornu of hyoid bone; insertion, substance of tongue; innervation, hypoglossal; action, depresses, retracts tongue.

ciliary muscle  origin, scleral spur; insertion, outer layers of choroid and ciliary processes; innervation, oculomotor, parasympathetic; action, affects shape of lens in visual accommodation.

coccygeal muscle , coccygeus muscle origin, ischial spine; insertion, lateral border of lower part of sacrum, upper coccyx; innervation, third and fourth sacral; action, supports and raises coccyx.

constrictor muscle of pharynx, inferior  origin, undersurfaces of cricoid and thyroid cartilages; insertion, median raphe of posterior wall of pharynx; innervation, glossopharyngeal, pharyngeal plexus, and external and recurrent laryngeal; action, constricts pharynx. It is divided into a cricopharyngeal part and a thyropharyngeal part.

constrictor muscle of pharynx, middle  origin, cornua of hyoid and stylohyoid ligament; insertion, median raphe of posterior wall of pharynx; innervation, pharyngeal plexus of vagus and glossopharyngeal; action, constricts pharynx. It is divided into a ceratopharyngeal part and an chondropharyngeal part.

constrictor muscle of pharynx, superior  origin, medial pterygoid plate, pterygomandibular raphe, mylohyoid ridge of mandible, and mucous membrane of floor of mouth; insertion, median raphe of posterior wall of pharynx; innervation, pharyngeal plexus of vagus; action, constricts pharynx. It is divided into buccopharyngeal, glossopharyngeal, mylopharyngeal, and pterygopharyngeal parts.

coracobrachial muscle  origin, coracoid process of scapula; insertion, medial surface of shaft of humerus; innervation, musculocutaneous; action, flexes, adducts arm.

corrugator muscle, superciliary  origin, medial end of superciliary arch; insertion, skin of eyebrow; innervation, facial; action, draws eyebrow downward and medially.

cremaster muscle  origin, inferior margin of internal oblique muscle of abdomen; insertion, pubic tubercle; innervation, genital branch of genitofemoral; action, elevates testis.

cricoarytenoid muscle, lateral  one of the intrinsic muscles of the larynx; origin, lateral surface of cricoid cartilage; insertion, muscular process of arytenoid cartilage; innervation, recurrent laryngeal; action, approximates vocal folds.

cricoarytenoid muscle, posterior  one of the intrinsic muscles of the larynx; origin, back of cricoid cartilage; insertion, muscular process of arytenoid cartilage; innervation, recurrent laryngeal; action, separates vocal folds.

cricothyroid muscle  one of the intrinsic muscles of the larynx; origin, front and side of cricoid cartilage; insertion, lamina of thyroid cartilage; innervation, superior laryngeal; action, tenses vocal folds.

dartos muscle 

1. the nonstriated muscle fibers of the tunica dartos, the deeper layers of which help to form the septum of the scrotum.

2. tunica dartos (1).

deltoid muscle  origin, clavicle, acromion, spine of scapula; insertion, deltoid tuberosity of humerus; innervation, axillary; action, abducts, flexes, extends arm.

depressor muscle, superciliary  a name applied to a few fibers of the orbital part of the orbicular muscle of eye that are inserted in the eyebrow, which they depress.

depressor muscle of angle of mouth  origin, lower border of mandible; insertion, angle of mouth; innervation, facial; action, pulls down angle of mouth.

depressor muscle of lower lip  origin, anterior portion of lower border of mandible; insertion, orbicular muscle of mouth and skin of lower lip; innervation, facial; action, depresses lower lip.

depressor muscle of septum of nose  origin, incisor fossa of maxilla; insertion, ala and septum of nose; innervation, facial; action, contracts nostril and depresses ala.

detrusor muscle of bladder , detrusor urinae muscle the bundles of smooth muscle fibers forming the muscular coat of the urinary bladder, which are arranged in a longitudinal and a circular layer and, on contraction, serve to expel urine.

diaphragmatic muscle  diaphragma (1).

digastric muscle  origin, anterior belly—digastric fossa on deep surface of inferior border of mandible near symphysis, posterior belly—mastoid notch of temporal bone; insertion, intermediate tendon on hyoid bone; innervation, anterior belly—mylohyoid, posterior belly—digastric branch of facial; action, elevates hyoid bone, lowers jaw.

dilator muscle of pupil  a name applied to fibers extending radially from the sphincter of pupil to the ciliary margin; innervation, sympathetic; action, dilates iris.

epicranial muscle  a name given the muscular covering of the scalp, including the occipitofrontal and temporoparietal muscles, and the galea aponeurotica.

erector muscle of spine  a name given the fibers of the more superficial of the deep muscles of the back, originating from the sacrum, spines of the lumbar and the eleventh and twelfth thoracic vertebrae, and the iliac crest, which split and insert as the iliocostal, longissimus, and spinal muscles.

muscles of expression  a group of cutaneous muscles of the facial structures, including the muscles of the scalp, ear, eyelids, nose, and mouth, and the platysma.

extensor muscle of fingers  origin, lateral epicondyle of humerus; insertion, common extensor tendon of each finger; innervation, posterior interosseus; action, extends wrist joint and phalanges.

extensor muscle of great toe, long  origin, front of fibula and interosseous membrane; insertion, dorsal surface of base of distal phalanx of great toe; innervation, deep peroneal; action, dorsiflexes ankle joint, extends great toe.

extensor muscle of great toe, short  a name given the portion of the short extensor muscle of toes that goes to the great toe.

extensor muscle of index finger  origin, dorsal surface of body of ulna, interosseous membrane; insertion, common extensor tendon of index finger; innervation, posterior interosseous; action, extends index finger.

extensor muscle of little finger  origin, common extensor tendon; insertion, tendon of extensor muscle of fingers to little finger; innervation, deep radial; action, extends little finger.

extensor muscle of thumb, long  origin, dorsal surface of ulna and interosseous membrane; insertion, dorsal surface of distal phalanx of thumb; innervation, posterior interosseous; action, extends, abducts thumb.

extensor muscle of thumb, short  origin, dorsal surface of radius and interosseous membrane; insertion, dorsal surface of proximal phalanx of thumb; innervation, posterior interosseous; action, extends thumb.

extensor muscle of toes, long  origin, anterior surface of fibula, lateral condyle of tibia, interosseous membrane; insertion, common extensor tendon of four lateral toes: innervation, deep peroneal; action, extends toes.

extensor muscle of toes, short  origin, dorsal surface of calcaneus; insertion, extensor tendons of first, second, third, fourth toes; innervation, deep peroneal; action, extends toes.

extensor muscle of wrist, radial, long  origin, lateral supracondylar ridge of humerus; insertion, base of second metacarpal bone; innervation, radial; action, extends and abducts wrist joint.

extensor muscle of wrist, radial, short  short radial extensor muscle of wrist: origin, lateral epicondyle of humerus, insertion, base of third metacarpal bone; innervation, radial; action, extends and abducts wrist joint.

extensor muscle of wrist, ulnar  origin, humeral head—lateral epicondyle of humerus, ulnar head—dorsal border of ulna; insertion, base of fifth metacarpal bone; innervation, deep radial; action, extends and adducts wrist joint.

extraocular muscles  the six voluntary muscles that move the eyeball: superior, inferior, middle, and lateral recti, and superior and inferior oblique muscles.

extrinsic muscle  one not originating in the limb or part in which it is inserted.

facial muscles  m's of expression.

fibular muscle, long  origin, lateral condyle of tibia, head and lateral surface of fibula; insertion, medial cuneiform, first metatarsal; innervation, superficial peroneal; action, abducts, everts, plantar flexes foot.

fibular muscle, short  origin, lateral surface of fibula; insertion, base of fifth metatarsal bone; innervation, superficial peroneal; action, abducts, plantar flexes foot.

fibular muscle, third  origin, anterior surface of fibula, interosseous membrane; insertion, fifth metatarsal; innervation, deep peroneal; action, everts, dorsiflexes foot.

fixation muscles , fixator muscles accessory muscles that serve to steady a part.

flexor muscle of fingers, deep  origin, shaft of ulna, coronoid process; insertion, distal phalanges of fingers; innervation, ulnar and anterior interosseous; action, flexes distal phalanges.

flexor muscle of fingers, superficial  origin, humeroulnar head—medial epicondyle of humerus, coronoid process of ulna, radial head— oblique line of radius, anterior border; insertion, middle phalanges of fingers; innervation, median; action, flexes middle phalanges.

flexor muscle of great toe, long  origin, posterior surface of fibula; insertion, base of distal phalanx of great toe; innervation, tibial; action, flexes great toe.

flexor muscle of great toe, short  origin, undersurface of cuboid, lateral cuneiform; insertion, base of proximal phalanx of great toe; innervation, medial plantar; action, flexes great toe.

flexor muscle of little finger, short  origin, hook of hamate bone, transverse carpal ligament; insertion, medial side of proximal phalanx of little finger; innervation, ulnar; action, flexes little finger.

flexor muscle of little toe, short  origin, base of fifth metatarsal, sheath of long peroneal muscle; insertion, lateral surface of base of proximal phalanx of little toe; innervation, lateral plantar; action, flexes little toe.

flexor muscle of thumb, long  origin, anterior surface of radius and coronoid process of ulna; insertion, base of distal phalanx of thumb; innervation, anterior interosseous; action, flexes thumb.

flexor muscle of thumb, short  origin, flexor retinaculum, ridge of trapezium; insertion, base of proximal phalanx of thumb; innervation, median, ulnar; action, flexes and adducts thumb.

flexor muscle of toes, long  origin, posterior surface of shaft of tibia; insertion, distal phalanges of four lateral toes; innervation, posterior tibial; action, flexes toes and extends foot.

flexor muscle of toes, short  origin, medial tuberosity of calcaneus, plantar fascia; insertion, middle phalanges of four lateral toes; innervation, medial plantar; action, flexes toes.

flexor muscle of wrist, radial  origin, medial epicondyle of humerus; insertion, base of second metacarpal; innervation, median; action, flexes and abducts wrist joint.

flexor muscle of wrist, ulnar  origin, humeral head—medial epicondyle of humerus, ulnar head—olecranon, ulna, intermuscular septum; insertion, pisiform, hook of hamate, proximal end of fifth metacarpal; innervation, ulnar; action, flexes and adducts wrist joint.

gastrocnemius muscle  origin, medial head—popliteal surface of femur, upper part of medial condyle, and capsule of knee, lateral head—lateral condyle and capsule of knee; insertion, aponeurosis unites with tendon of soleus to form calcaneal tendon (Achilles tendon); innervation, tibial; action, plantar flexes ankle joint, flexes knee joint.

gemellus muscle, inferior  origin, tuberosity of ischium; insertion, greater trochanter of femur; innervation, nerve to quadrate muscle of thigh; action, rotates thigh laterally.

gemellus muscle, superior  origin, spine of ischium; insertion, greater trochanter of femur; innervation, nerve to internal obturator; action, rotates thigh laterally.

genioglossus muscle  origin, mental spine of mandible; insertion, hyoid bone and inferior surface of tongue; innervation, hypoglossal; action, protrudes and depresses tongue.

geniohyoid muscle  origin, mental spine of mandible; insertion, body of hyoid bone; innervation, a branch of first cervical nerve through hypoglossal; action, elevates, draws hyoid forward.

glossopalatine muscle  palatoglossus m.

gluteal muscle, greatest  gluteus maximus m.

gluteal muscle, middle  gluteus medius m.

gluteal muscle, least  gluteus minimus m.

gluteus maximus muscle  origin, lateral surface of ilium, dorsal surface of sacrum and coccyx, sacrotuberous ligament; insertion, iliotibial tract of fascia lata, gluteal tuberosity of femur; innervation, inferior gluteal; action, extends, abducts, and rotates thigh laterally.

gluteus medius muscle  origin, lateral surface of ilium between anterior and posterior gluteal lines; insertion, greater trochanter of femur; innervation, superior gluteal; action, abducts and rotates thigh medially.

gluteus minimus muscle  origin, lateral surface of ilium between anterior and inferior gluteal lines; insertion, greater trochanter of femur; innervation, superior gluteal; action, abducts, rotates thigh medially.

gracilis muscle  origin, lower half of body and entire inferior ramus of pubis; insertion, medial surface of shaft of tibia; innervation, obturator; action, adducts thigh, flexes knee joint.

hamstring muscles  the muscles of the back of the thigh: biceps femoris, semitendinous, and semimembranous muscles.

muscle of helix, greater  origin, spine of helix; insertion, anterior border of helix; innervation, auriculotemporal and posterior auricular (branches of facial); action, tenses skin of auditory canal.

muscle of helix, lesser  origin, anterior rim of helix; insertion, concha; innervation, temporal, posterior auricular.

Horner's muscle  the lacrimal part of the orbicular muscle of eye.

Houston's muscle  fibers of the bulbocavernosus muscle compressing the dorsal vein of the penis.

intrinsic muscle  one whose origin and insertion are in the same part or organ.

hyoglossus muscle  origin, body and greater cornu of hyoid bone; insertion, side of tongue; innervation, hypoglossal; action, depresses and retracts tongue.

iliac muscle  origin, iliac fossa and base of sacrum; insertion, greater psoas tendon and lesser trochanter of femur; innervation, femoral; action, flexes thigh, trunk on limb.

iliococcygeus muscle  the posterior portion of the levator ani which originates as far anteriorly as the obturator canal and inserts on the side of the coccyx and the anococcygeal body; innervation, third and fourth sacral; action, helps to support pelvic viscera and resist increases in intra-abdominal pressure.

iliocostal muscle  the lateral division of the erector muscle of spine.

iliocostal muscle of loins  origin, iliac crest; insertion, angles of lower six or seven ribs; innervation, branches of thoracic and lumbar; action, extends lumbar spine.

iliocostal muscle of neck  origin, angles of third, fourth, fifth, and sixth ribs; insertion, transverse processes of fourth, fifth, and sixth cervical vertebrae; innervation, branches of cervical; action, extends cervical spine.

iliocostal muscle of thorax  origin, upper borders of angles of six lower ribs; insertion, angles of six upper ribs and transverse process of seventh cervical vertebra; innervation, branches of thoracic; action, keeps thoracic spine erect.

iliopsoas muscle  a compound muscle consisting of the iliac and psoas major muscles.

incisive muscles of inferior lip  small bundles of muscle fibers, one arising from the incisive fossa of the mandible on each side and passing laterally to the angle of the mouth.

incisive muscles of superior lip  small bundles of muscle fibers, one arising from the incisive fossa of the maxilla on each side and passing laterally to the angle of the mouth.

infraspinous muscle  origin, infraspinous fossa of scapula; insertion, greater tubercle of humerus; innervation, suprascapular; action, rotates humerus laterally.

intercostal muscles, external 

1. musculi intercostales externi.

2. origin, inferior border of rib; insertion, superior border of rib below; innervation, intercostal; action, draw ribs together in respiration and expulsive movements.

intercostal muscles, innermost  the layer of muscle fibers separated from the internal intercostal muscles by the intercostal nerves.

intercostal muscles, internal  origin, inferior border of rib and costal cartilage; insertion, superior border of rib and costal cartilage below; innervation, intercostal; action, draw ribs together in respiration and expulsive movements.

interosseous muscles, palmar  origin, sides of second, fourth, and fifth metacarpal bones; insertion, extensor tendons of second, fourth, and fifth fingers; innervation, ulnar; action, adduct, flex proximal phalanges, extend middle and distal phalanges.

interosseous muscles, plantar  origin, medial surface of third, fourth, and fifth metatarsal bones; insertion, medial side of base of proximal phalanges of third, fourth, and fifth toes; innervation, lateral plantar; action, adduct, flex toes.

interosseous muscles of foot, dorsal  origin, adjacent surfaces of metatarsal bones; insertion, base of proximal phalanges of second, third, and fourth toes; innervation, lateral plantar; action, abduct, flex toes.

interosseous muscles of hand, dorsal  origin, by two heads from adjacent sides of metacarpal bones; insertion, extensor tendons of second, third, and fourth fingers; innervation, ulnar; action, abduct, flex proximal phalanges.

interspinal muscles  short bands of muscle fibers between spinous processes of contiguous vertebrae; innervation, spinal; action, extend vertebral column.

interspinal muscles of loins  paired bands of muscle fibers extending between spinous processes of contiguous lumbar vertebrae, innervated by spinal nerves, and acting to extend the vertebral column.

interspinal muscles of neck  paired bands of muscle fibers extending between spinous processes of contiguous cervical vertebrae, innervated by spinal nerves, and acting to extend the vertebral column.

interspinal muscles of thorax  paired bands of muscle fibers extending between spinous processes of contiguous thoracic vertebrae, innervated by spinal nerves, and acting to extend the vertebral column.

intertransverse muscles  small muscles passing between the transverse processes of contiguous vertebrae, including the lateral and medial intertransverse muscles of the loins, the intertransverse muscles of the thorax, and the anterior and posterior intertransverse muscles of the neck.

involuntary muscle  one that is not under the control of the will.

ischiocavernous muscle  origin, ramus of ischium; insertion, crus of penis (crus of clitoris); innervation, perineal; action, maintains erection of penis (clitoris).

Landström's muscle  minute muscle fibers in the fascia around and behind the eyeball, attached in front to the anterior orbital fascia and eyelids.

latissimus dorsi muscle  origin, spines of lower thoracic vertebrae, lumbar and sacral vertebrae through thoracolumbar fascia, iliac crest, lower ribs, inferior angle of scapula; insertion, floor of intertubercular sulcus of humerus; innervation, thoracodorsal; action, adducts, extends, and rotates humerus medially.

levator muscle of angle of mouth  origin, canine fossa of maxilla; insertion, orbicularis oris and skin at angle of mouth; innervation, facial; action, raises angle of mouth.

levator ani muscle  a name applied collectively to important muscular components of the pelvic diaphragm, arising mainly from the back of the body of pubis and running backward toward the coccyx, including the pubococcygeus (levator muscle of prostate in male and pubovaginal in female), puborectal, and iliococcygeus muscles.

levator muscle of prostate  a part of the anterior portion of the pubococcygeus muscle, inserted in the prostate and the tendinous center of the perineum; innervated by sacral and pudendal nerves, it supports and compresses the prostate and is involved in control of micturition.

levator muscles of ribs  originating from the transverse processes of the seventh cervical and first to eleventh thoracic vertebrae and inserting medial to the angle of a lower rib; innervated by intercostal nerves and aiding in elevation of the ribs in respiration.

levator muscle of scapula  origin, transverse processes of four upper cervical vertebrae; insertion, medial border of scapula; innervation, third and fourth cervical; action, raises scapula.

levator muscle of thyroid gland  an inconstant muscle originating on the isthmus or pyramid of the thyroid gland and inserting on the body of the hyoid bone.

levator muscle of upper eyelid  origin, upper border of optic foramen; insertion, tarsal plate and skin of upper eyelid; innervation, oculomotor; action, raises upper lid.

levator muscle of upper lip  origin, lower orbital margin; insertion, muscle of upper lip; innervation, facial nerve; action, raises upper lip.

levator muscle of upper lip and ala of nose  origin, nasal process of maxilla; insertion, cartilage and skin of ala nasi, and upper lip; innervation, infraorbital branch of facial; action, raises upper lip and dilates nostril.

levator muscle of velum palatinum  origin, apex of petrous portion of temporal bone and cartilaginous part of auditory tube; insertion, aponeurosis of soft palate; innervation, pharyngeal plexus of vagus; action, raises soft palate.

lingual muscles  the extrinsic and intrinsic muscles that move the tongue.

long muscle of head  origin, transverse processes of third to sixth cervical vertebrae; insertion, basal portion of occipital bone; innervation, branches from first, second, and third cervical; action, flexes head.

long muscle of neck  origin, superior oblique portion—transverse processes of third to fifth cervical vertebrae; inferior oblique portion—bodies of first to third thoracic vertebrae; vertical portion—bodies of three upper thoracic and three lower cervical vertebrae; insertion, superior oblique portion—tubercle of anterior arch of atlas; inferior oblique portion—transverse processes of fifth and sixth cervical vertebrae; vertical portion— bodies of second to fourth cervical vertebrae; innervation, anterior cervical. action, flexes and supports cervical vertebrae.

longissimus muscle of head  origin, transverse processes of four or five upper thoracic vertebrae, articular processes of three or four lower cervical vertebrae; insertion, mastoid process of temporal bone; innervation, branches of cervical; action, draws head backward, rotates head.

longissimus muscle of neck  origin, transverse processes of four or five upper thoracic vertebrae; insertion, transverse processes of second to sixth cervical vertebrae; innervation, lower cervical and upper thoracic; action, extends cervical vertebrae.

longissimus muscle of thorax  origin, transverse and articular processes of lumbar vertebrae and thoracolumbar fascia; insertion, transverse processes of all thoracic vertebrae, nine or ten lower ribs; innervation, lumbar and thoracic; action, extends thoracic vertebrae.

longitudinal muscle of tongue, inferior  origin, inferior surface of tongue at base; insertion, tip of tongue; innervation, hypoglossal; action, changes shape of tongue in mastication and deglutition.

longitudinal muscle of tongue, superior  origin, submucosa and septum of tongue; insertion, margins of tongue; innervation, hypoglossal; action, changes shape of tongue in mastication and deglutition.

lumbrical muscles of foot  origin, tendons of long flexor muscles of toes; insertion, extensor tendons of four lateral toes; innervation, medial and lateral plantar; action, flex metatarsophalangeal joints, extend distal phalanges.

lumbrical muscles of hand  origin, tendons of deep flexor muscles of fingers; insertion, extensor tendons of four lateral fingers; innervation, median and ulnar; action, flex metacarpophalangeal joint and extend middle and distal phalanges.

masseter muscle  origin, superficial part—zygomatic process of maxilla and inferior border of zygomatic arch, deep part—inferior border and medial surface of zygomatic arch; insertion, superficial part—angle and ramus of mandible, deep part—superior half of ramus and lateral surface of coronoid process of mandible; innervation, mandibular division of trigeminal; action, raises mandible, closes jaws.

masticatory muscles  a group of muscles responsible for the movement of the jaws during mastication, including the masseter. temporal, and medial and lateral pterygoid muscles.

Müller's muscle 

1. the circular fibers of the ciliary muscle.

2. orbital muscle.

multifidus muscles  origin, sacrum, sacroiliac ligament, mammillary processes of lumbar, transverse processes of thoracic, and articular processes of cervical vertebrae; insertion, spines of contiguous vertebrae above; innervation, dorsal branches of spinal nerves; action, extend, rotate vertebral column.

mylohyoid muscle  origin, mylohyoid line of mandible; insertion, body of hyoid bone and median raphe; innervation, mylohyoid branch of inferior alveolar; action, elevates hyoid bone, supports floor of mouth.

nasal muscle  origin, maxilla; insertion, alar part—ala of nose, transverse part—by aponeurotic expansion with fellow of opposite side; innervation, facial; action, alar part—aids in widening nostril, transverse part—depresses cartilage of nose.

oblique muscle of abdomen, external  origin, lower eight ribs at costal cartilages; insertion, crest of ilium, linea alba through rectus sheath; innervation, lower intercostal; action, flexes and rotates vertebral column, compresses abdominal viscera.

oblique muscle of abdomen, internal  origin, inguinal ligament, iliac crest, thoracolumbar fascia; insertion, inferior three or four costal cartilages, linea alba, conjoined tendon to pubis; innervation, lower intercostal; action, flexes and rotates vertebral column, compresses abdominal viscera.

oblique muscle of auricle  origin, cranial surface of concha; insertion, cranial surface of auricle above concha; innervation, temporal and posterior auricular (branches of facial).

oblique muscle of eyeball, inferior  origin, orbital plate of maxilla; insertion, sclera; innervation, oculomotor; action, rotates eyeball upward and outward.

oblique muscle of eyeball, superior  origin, lesser wing of sphenoid above optic foramen; insertion, sclera; innervation, trochlear; action, rotates eyeball downward and outward.

oblique muscle of head, inferior  origin, spinous process of axis; insertion, transverse process of atlas; innervation, dorsal branches of spinal nerves; action, rotates atlas and head.

oblique muscle of head, superior  origin, transverse process of atlas; insertion, occipital bone; innervation, dorsal branches of spinal nerves; action, extends and moves head laterally.

obturator muscle, external  origin, pubis, ischium, and superficial surface of obturator membrane; insertion, trochanteric fossa of femur; innervation, obturator; action, rotates thigh laterally.

obturator muscle, internal  origin, pelvic surface of hip bone, margin of obturator foramen, ramus of ischium, inferior ramus of pubis, internal surface of obturator membrane; insertion, greater trochanter of femur; innervation, fifth lumbar, first and second sacral; action, rotates thigh laterally.

occipitofrontal muscle  origin, frontal belly—galea aponeurotica, occipital belly— highest nuchal line of occipital bone; insertion, frontal belly—skin of eyebrows and root of nose, occipital belly—galea aponeurotica; innervation, frontal belly—temporal branch of facial, occipital belly—posterior auricular branch of facial; action, frontal belly—raises eyebrows, occipital belly—draws scalp posteriorly.

omohyoid muscle  a muscle comprising two bellies (superior and inferior) connected by a central tendon that is bound to the clavicle by a fibrous expansion of the cervical fascia; origin, superior border of scapula; insertion, lateral border of hyoid bone; innervation, upper cervical through ansa cervicalis; action, depresses hyoid bone.

opposing muscle of little finger  origin, hook of hamate bone, transverse carpal ligament; insertion W>, medial aspect of fifth metacarpal; innervation, eighth cervical through ulnar; action, rotates, abducts, and flexes fifth metacarpal.

opposing muscle of thumb  origin, ridge of trapezium, flexor retinaculum; insertion, radial side of first metacarpal; innervation, sixth and seventh cervical through median; action, flexes and opposes thumb.

orbicular muscle  one that encircles a body opening, e.g., the eye or mouth.

orbicular muscle of eye , orbicularis oculi muscle the oval sphincter muscle surrounding the eyelids, consisting of three parts: origin, orbital part—medial margin of orbit, including frontal process of maxilla, palpebral part—medial canthus, medial palpebral ligament, lacrimal part—posterior lacrimal crest; insertion, orbital part—near origin after encircling orbit, palpebral part—fibers intertwine to form lateral palpebral raphe, lacrimal part—lateral palpebral raphe, upper and lower tarsi; innervation, facial; action, closes eyelids, wrinkles forehead, compresses lacrimal sac.

orbicular muscle of mouth  a name applied to a complicated sphincter muscle of mouth, comprising a labial part, fibers restricted to the lips, and a marginal part, fibers blending with those of adjacent muscles; innervation, facial; action, closes and protrudes lips.

orbital muscle  a thin layer of nonstriated muscle that bridges the inferior orbital fissure and inserts in the fascia of inferior orbital fissure; innervation, sympathetic branches; action, protrudes eye.

palatoglossus muscle  origin, undersurface of soft palate; insertion, side of tongue; innervation, pharyngeal plexus of vagus; action, elevates tongue, constricts fauces.

palatopharyngeal muscle  one of the intrinsic muscles of the larynx; origin, soft palate; insertion, aponeurosis of pharynx, dorsal border of thyroid cartilage; innervation, pharyngeal plexus of vagus; action, aids in deglutition.

palmar muscle, long  origin, medial epicondyle of humerus; insertion, flexor retinaculum, palmar aponeurosis; innervation, median; action, flexes wrist joint.

palmar muscle, short  origin, palmar aponeurosis; insertion, skin of medial border of hand; innervation, ulnar; action, assists in deepening hollow of palm.

papillary muscles  conical muscular projections from the walls of the cardiac ventricles, attached to the cusps of the atrioventricular valves by the chordae tendineae. There is an anterior and a posterior papillary muscle in each ventricle, as well as a group of small papillary muscles on the septum in the right ventricle.

pectinate muscles  a name applied to small ridges of muscle fibers projecting from the inner walls of the auricles of the heart, and extending in the right atrium from the auricle to the crista terminalis.

pectineal muscle  origin, pectineal line of pubis; insertion, femur distal to lesser trochanter; innervation, obturator and femoral; action, flexes, adducts thigh.

pectoral muscle, greater  origin, clavicle, sternum, six upper ribs, aponeurosis of external oblique muscle of abdomen. These origins are reflected in the subdivision of the muscle into clavicular, sternocostal, and abdominal parts; insertion, crest of greater tubercle of humerus; innervation, medial and lateral pectoral; action, adducts, flexes, rotates arm medially.

pectoral muscle, smaller  origin, third, fourth, and fifth ribs; insertion, coracoid process of scapula; innervation, lateral and medial pectoral; action, draws shoulder forward and downward, raises third, fourth, and fifth ribs in forced inspiration.

peroneal muscle, long  long fibular m.

peroneal muscle, short  short fibular m.

peroneal muscle, third  third fibular m.

pharyngeal muscles  the muscular coat of the pharynx, comprising the three constrictor muscles and the stylopharyngeal, salpingopharyngeal, and palatopharyngeal muscles.

piriform muscle  origin, ilium, second to fourth sacral vertebrae; insertion, upper border of greater trochanter; innervation, first and second sacral; action, rotates thigh laterally.

plantar muscle  origin, oblique popliteal ligament, lateral supracondylar line of femur; insertion, posterior part of calcaneus; innervation, tibial; action, plantar flexes foot.

pleuroesophageal muscle  a bundle of smooth muscle usually connecting the esophagus with the left mediastinal pleura.

popliteal muscle  origin, lateral condyle of femur, lateral meniscus; insertion, posterior surface of tibia; innervation, tibial; action, flexes leg, rotates leg medially.

procerus muscle  origin, fascia over nasal bone; insertion, skin of forehead; innervation, facial; action, draws medial angle of eyebrows down.

pronator muscle, quadrate  pronator quadratus m.

pronator muscle, round  pronator teres m.

pronator quadratus muscle  origin, anterior surface and border of distal third or fourth of ulna; insertion, anterior surface and border of distal fourth of shaft of radius; innervation, anterior interosseous; action, pronates hand.

pronator teres muscle  origin, humeral head—medial epicondyle of humerus, ulnar head— coronoid process of ulna; insertion, lateral surface of radius; innervation, median; action, pronates hand and flexes elbow.

psoas muscle, greater  origin, lumbar vertebrae; insertion, lesser trochanter of femur; innervation, second and third lumbar; action, flexes thigh or trunk.

psoas muscle, smaller  origin, last thoracic and first lumbar vertebrae; insertion, arcuate line, iliopectineal eminence, iliac fascia; innervation, first lumbar; action, flexes trunk.

pterygoid muscle, external  lateral pterygoid m.

pterygoid muscle, internal  medial pterygoid m.

pterygoid muscle, lateral  origin, superior head—lateral surface of greater wing of sphenoid and infratemporal crest; inferior head—lateral surface of lateral pterygoid plate; insertion, neck of condyle of mandible, temporomandibular joint capsule; innervation, mandibular division of trigeminal; action, protrudes mandible, opens jaws, moves mandible from side to side.

pterygoid muscle, medial  origin, lateral pterygoid plate, tuberosity of maxilla; insertion, medial surface of ramus and angle of mandible; innervation, mandibular division of trigeminal; action, closes jaws.

pubococcygeus muscle  the anterior portion of the levator ani muscle, originating anterior to the obturator canal; insertion, anococcygeal ligament and side of coccyx; innervation, third and fourth sacral; action, helps support pelvic viscera and resist increases in intra-abdominal pressure.

puboprostatic muscle  smooth muscle fibers contained within the medial puboprostatic ligament, which pass from the prostate anteriorly to the pubic bone.

puborectal muscle  a portion of the levator ani muscle having a more lateral origin from the pubic bone, and continuous posteriorly with the corresponding muscle of the opposite side; innervation, third and fourth sacral; action, helps support pelvic viscera and resist increases in intra-abdominal pressure.

pubovaginal muscle  a part of the anterior portion of the pubococcygeus muscle, which is inserted into the urethra and vagina; innervated by the sacral and pudendal nerves, it is involved in control of micturition.

pubovesical muscle  smooth muscle fibers extending from the neck of the urinary bladder to the pubis.

pyloric sphincter muscle  pyloric sphincter.

pyramidal muscle  origin, anterior aspect of pubis, anterior pubic ligament; insertion, linea alba; innervation, last thoracic; action, tenses abdominal wall.

pyramidal muscle of auricle  an inconstant prolongation of the fibers of the muscle of tragus to the spine of helix.

quadrate muscle of loins  origin, crest of ilium, thoracolumbar fascia, lumbar vertebrae; insertion, twelfth rib, transverse processes of four upper lumbar vertebrae; innervation, first and second lumbar and twelfth thoracic; action, flexes lumbar vertebrae laterally.

quadrate muscle of lower lip  depressor m. of lower lip.

quadrate muscle of sole  origin, calcaneus and plantar fascia; insertion, tendons of long flexor muscle of toes; innervation, lateral plantar; action, aids in flexing toes.

quadrate muscle of thigh  origin, upper part of lateral border of tuberosity of ischium; insertion, quadrate tubercle of femur, intertrochanteric crest; innervation, fourth and fifth lumbar and first sacral; action, adducts, rotates thigh laterally.

quadrate muscle of upper lip  levator m. of upper lip.

quadriceps muscle of thigh  a name applied collectively to the rectus muscle of thigh and the intermediate, lateral, and medial vastus muscles, inserting by a common tendon that surrounds the patella and ends on the tuberosity of the tibia, and acting to extend the leg upon the thigh.

rectococcygeus muscle  smooth muscle fibers originating on the anterior surface of the second and third coccygeal vertebrae and inserting on the posterior surface of the rectum, innervated by autonomic nerves, and acting to retract and elevate the rectum.

rectourethral muscles  bands of smooth muscle fibers extending from the perineal flexure of the rectum to the membranous urethra in the male.

rectouterine muscle  a band of fibers running between the cervix of the uterus and the rectum, in the rectouterine fold.

rectovesical muscle  a band of fibers in the male, connecting the longitudinal musculature of the rectum with the external muscular coat of the bladder.

rectus abdominis muscle  origin, pubis; insertion, xiphoid process, cartilages of fifth, sixth, and seventh ribs; innervation, branches of lower thoracic; action, flexes lumbar vertebrae, supports abdomen.

rectus muscle of eyeball, inferior  origin, common tendinous ring; insertion, underside of sclera; innervation, oculomotor; action, adducts, rotates eyeball downward and medially.

rectus muscle of eyeball, lateral  origin, common tendinous ring; insertion, lateral side of sclera; innervation, abducens; action, abducts eyeball.

rectus muscle of eyeball, medial  origin, common tendinous ring; insertion, medial side of sclera; innervation, oculomotor; action, adducts eyeball.

rectus muscle of eyeball, superior  origin, common tendinous ring; insertion, upper aspect of sclera; innervation, oculomotor; action, adducts, rotates eyeball upward and medially.

rectus muscle of head, anterior  origin, lateral mass of atlas; insertion, basilar process of occipital bone; innervation, first and second cervical; action, flexes, supports head.

rectus muscle of head, lateral  origin, upper surface of transverse process of atlas; insertion, jugular process of occipital bone; innervation, first and second cervical; action, flexes, supports head.

rectus muscle of head, posterior, greater  origin, spinous process of axis; insertion, occipital bone; innervation, suboccipital and greater occipital; action, extends head.

rectus muscle of head, posterior, lesser  origin, tubercle on dorsal arch of atlas; insertion, occipital bone; innervation, suboccipital and greater occipital; action, extends head.

rectus muscle of thigh  origin, anterior inferior iliac spine, rim of acetabulum; insertion, patella, tubercle of tibia; innervation, femoral; action, extends leg, flexes thigh.

Reisseisen's muscles  the smooth muscle fibers of the smallest bronchi.

rhomboid muscle, greater  origin, spinous processes of second, third, fourth, and fifth thoracic vertebrae; insertion, medial margin of scapula; innervation, dorsal scapular; action, retracts, elevates scapula.

rhomboid muscle, lesser  origin, spinous processes of seventh cervical to first thoracic vertebrae, lower part of nuchal ligament; insertion, medial margin of scapula at root of the spine; innervation, dorsal scapular; action, adducts, elevates scapula.

risorius muscle  origin, fascia over masseter; insertion, skin at angle of mouth; innervation, buccal branch of facial; action, draws angle of mouth laterally.

rotator muscles  a series of small muscles deep in the groove between the spinous and transverse processes of the vertebrae; innervation, spinal; action, extend and rotate vertebral column toward opposite side.

Ruysch's muscle  the muscular tissue of the fundus uteri.

sacrococcygeal muscle, anterior  a musculotendinous slip passing from the lower sacral vertebrae to the coccyx.

sacrococcygeal muscle, posterior  a muscular slip passing from the posterior aspect of the sacrum to the coccyx.

sacrospinal muscle  erector m. of spine.

salpingopharyngeal muscle  origin, auditory tube near its orifice; insertion, posterior part of palatopharyngeal muscle; innervation, pharyngeal plexus of vagus; action, raises nasopharynx.

sartorius muscle  origin, anterior superior iliac spine; insertion, medial side of proximal end of tibia; innervation, femoral; action, flexes thigh and leg.

scalene muscle, anterior  origin, transverse processes of third to sixth cervical vertebrae; insertion, scalene tubercle of first rib; innervation, second to seventh cervical; action, raises first rib, flexes cervical vertebrae forward and laterally, rotates cervical vertebrae to opposite side.

scalene muscle, middle  origin, transverse processes of second to sixth cervical vertebrae; insertion, upper surface of first rib; innervation, second to seventh cervical; action, raises first rib, flexes cervical vertebrae laterally.

scalene muscle, posterior  origin, posterior tubercles of transverse processes of fourth to sixth cervical vertebrae; insertion, second rib; innervation, second to seventh cervical; action, raises first and second ribs, flexes cervical vertebrae laterally.

scalene muscle, smallest  a band occasionally found between the anterior and middle scalene muscles.

semimembranous muscle  origin, tuberosity of ischium; insertion, medial condyle and border of tibia, lateral condyle of femur; innervation, tibial; action, flexes and rotates leg medially, extends thigh.

semipennate muscle  a muscle in which the fiber bundles approach the tendon of insertion from only one direction and are inserted through only a small segment of its circumference.

semispinal muscle of head  origin, transverse processes of five or six upper thoracic and four lower cervical vertebrae; insertion, occipital bone; innervation, suboccipital, greater occipital, and branches of cervical; action, extends head.

semispinal muscle of neck  origin, transverse processes of five or six upper thoracic vertebrae; insertion, spinous processes of second to fifth cervical vertebrae; innervation, branches of cervical; action, extends, rotates vertebral column.

semispinal muscle of thorax  origin, transverse processes of sixth to tenth thoracic vertebrae; insertion, spinous processes of two lower cervical and four upper thoracic vertebrae; innervation, spinal nerves; action, extends, rotates vertebral column.

semitendinous muscle  origin, tuberosity of ischium; insertion, upper part of medial surface of tibia; innervation, tibial; action, flexes and rotates leg medially, extends thigh.

serratus muscle, anterior  origin, eight or nine upper ribs; insertion, medial border of scapula; innervation, long thoracic; action, draws scapula forward; rotates scapula to raise shoulder in abduction of arm.

serratus muscle, inferior posterior  origin, spines of two lower thoracic and two or three upper lumbar vertebrae; insertion, inferior border of four lower ribs; innervation, ninth to twelfth thoracic; action, lowers ribs in expiration.

serratus muscle, superior posterior  origin, nuchal ligament, spinous processes of upper thoracic vertebrae; insertion, second, third, fourth, and fifth ribs; innervation, first four thoracic; action, raises ribs in inspiration.

skeletal muscles  striated muscles attached to bones, which cross at least one joint.

smooth muscle  nonstriated, involuntary muscle.

soleus muscle  origin, fibula, popliteal fascia, tibia; insertion, calcaneus by Achilles tendon; innervation, tibial; action, plantar flexes foot.

sphincter muscle of anus, external  origin, tip of coccyx, anococcygeal ligament; insertion, tendinous center of perineum; innervation, inferior rectal and fourth sacral; action, closes anus.

sphincter muscle of anus, internal  a thickening of the circular lamina of the muscular tunic at the caudal end of the rectum.

sphincter muscle of bile duct  an annular sheath of muscle that invests the bile duct within the wall of the duodenum.

sphincter muscle of female urethra, external  origin, ramus of pubis; insertion, median raphe behind and in front of urethra; innervation, perineal; action, compresses the central part of the urethra.

sphincter muscle of hepatopancreatic ampulla  sphincter of Oddi.

sphincter muscle of male urethra, external  origin, ramus of pubis; insertion, median raphe behind and in front of urethra; innervation, perineal; action, compresses the membranous part of the urethra.

sphincter muscle of pupil  circular fibers of the iris, innervated by the ciliary nerves (parasympathetic), and acting to contract the pupil.

sphincter muscle of pylorus  pyloric sphincter.

sphincter muscle of urethra, internal , sphincter muscle of urinary bladder a circular layer of smooth muscle fibers surrounding the internal urethral orifice in males, innervated by the vesical nerve, and acting to close the internal orifice of the urethra. No such structure exists in females.

spinal muscle of head  origin, spines of upper thoracic and lower cervical vertebrae; insertion, occipital bone; innervation, spinal nerves; action, extends head.

spinal muscle of neck  origin, spinous processes of seventh cervical and sometimes two upper thoracic vertebrae; insertion, spinous processes of axis and sometimes of second to fourth cervical vertebrae; innervation, branches of cervical; action, extends vertebral column.

spinal muscle of thorax  origin, spinous processes of two upper lumbar and two lower thoracic; insertion, spines of upper thoracic vertebrae; innervation, branches of spinal nerves; action, extends vertebral column.

splenius muscle of head  origin, lower half of nuchal ligament, spines of seventh cervical and three upper thoracic vertebrae; insertion, mastoid process of temporal bone, occipital bone; innervation, middle and lower cervical; action, extends, rotates head.

splenius muscle of neck  origin, spinous processes of third to sixth thoracic vertebrae; insertion, transverse processes of two or three upper cervical vertebrae; innervation, dorsal branches of lower cervical; action, extends, rotates head and neck.

stapedius muscle  origin, interior of pyramid of tympanic cavity; insertion, posterior surface of neck of stapes; innervation, stapedial branch of facial; action, dampens stapedial movement.

sternal muscle  a band occasionally found parallel to the sternum on the sternocostal head of the greater pectoral muscle.

sternocleidomastoid muscle  origin, sternal head—manubrium, clavicular head—clavicle; insertion, mastoid process and superior nuchal line of occipital bone; innervation, accessory nerve and cervical plexus; action, flexes vertebral column, rotates head.

sternocostal muscle  transverse m. of thorax.

sternohyoid muscle  origin, manubrium and clavicle; insertion, body of hyoid bone; innervation, upper ansa cervicalis; action, depresses hyoid bone and larynx.

sternothyroid muscle  origin, manubrium; insertion, lamina of thyroid cartilage; innervation, ansa cervicalis; action, depresses thyroid cartilage.

striated muscle , striped muscle any muscle whose fibers are divided by transverse bands into striations; such muscles are voluntary.

styloglossus muscle  origin, styloid process; insertion, margin of tongue; innervation, hypoglossal; action, raises and retracts tongue.

stylohyoid muscle  origin, styloid process; insertion, body of hyoid bone; innervation, facial; action, draws hyoid and tongue superiorly and posteriorly.

stylopharyngeus muscle  one of the intrinsic muscles of the larynx; origin, styloid process; insertion, thyroid cartilage and pharyngeal constrictors; innervation, pharyngeal plexus, glossopharyngeal; action, raises and dilates pharynx.

subclavius muscle  origin, first rib and its cartilage; insertion, lower surface of clavicle; innervation, fifth and sixth cervical; action, depresses lateral end of clavicle.

subcostal muscles  origin, inner surface of ribs: insertion, inner surface of first, second, third rib below; innervation, intercostal; action, draw adjacent ribs together, depress ribs.

subscapular muscle  origin, subscapular fossa of scapula; insertion, lesser tubercle of humerus; innervation, subscapular; action, rotates humerus medially.

supinator muscle  origin, lateral epicondyle of humerus, ulna, elbow joint fascia; insertion, radius; innervation, deep radial; action, supinates hand.

supraspinous muscle  origin, supraspinous fossa of scapula; insertion, greater tubercle of humerus; innervation, suprascapular; action, abducts humerus.

suspensory muscle of duodenum  a flat band of smooth muscle originating from the left crus of the diaphragm, and continuous with the muscular coat of the duodenum at its junction with the jejunum.

synergic muscles , synergistic muscles those that assist one another in action.

tarsal muscle, inferior  origin, inferior rectus muscle; insertion, tarsal plate of lower eyelid; innervation, sympathetic; action, widens palpebral fissure.

tarsal muscle, superior  origin, levator muscle of upper eyelid; insertion, tarsal plate of upper eyelid; innervation, sympathetic; action, widens palpebral fissure.

temporal muscle  origin, temporal fossa and fascia; insertion, coronoid process of mandible; innervation, mandibular; action, closes jaws.

temporoparietal muscle  origin, temporal fascia above ear; insertion, galea aponeurotica; innervation, temporal branches of facial; action, tightens scalp.

tensor muscle of fascia lata  origin, iliac crest; insertion, iliotibial band of fascia lata; innervation, superior gluteal; action, flexes, rotates thigh medially.

tensor tympani muscle , tensor muscle of tympanic membrane origin, cartilaginous portion of auditory tube; insertion, manubrium of malleus; innervation, mandibular; action, tenses tympanic membrane.

tensor veli palatini muscle , tensor muscle of velum palatinum origin, scaphoid fossa of pterygoid process, wall of auditory tube, spine of sphenoid; insertion, aponeurosis of soft palate, horizontal part of palatine bone; innervation, mandibular; action, tenses soft palate, opens auditory tube.

teres major muscle  origin, inferior angle of scapula; insertion, crest of intertubercular sulcus of humerus; innervation, lower subscapular; action, adducts, extends, rotates arm medially.

teres minor muscle  origin, lateral margin of scapula; insertion, greater tuberosity of humerus; innervation, axillary; action, rotates arm laterally.

muscle of terminal notch  an inconstant muscular slip continuing forward from the muscle of tragus to bridge the cartilaginous part of the meatus.

thenar muscles  the abductor and flexor muscles of the thumb.

thyroarytenoid muscle  one of the intrinsic muscles of the larynx; origin, lamina of thyroid cartilage; insertion, muscular process of arytenoid cartilage; innervation, recurrent laryngeal; action, relaxes, shortens vocal folds.

thyroepiglottic muscle  fibers of the thyroarytenoid muscle that continue to the margin of the epiglottis; it closes the inlet to the larynx.

thyrohyoid muscle  origin, lamina of thyroid cartilage; insertion, greater cornu of hyoid bone; innervation, first cervical; action, raises and changes form of larynx.

tibial muscle, anterior  origin, lateral condyle and lateral surface of tibia, interosseous membrane; insertion, medial cuneiform and base of first metatarsal; innervation, deep peroneal; action, dorsiflexes and inverts foot.

tibial muscle, posterior  origin, tibia, fibula, interosseous membrane; insertion, bases of second to fourth metatarsals and tarsals, except talus; innervation, tibial; action, plantar flexes and inverts foot.

tracheal muscle  a transverse layer of smooth fibers in the dorsal portion of the trachea; insertion, tracheal cartilages; innervation, autonomic fibers; action, lessens caliber of trachea.

muscle of tragus  a short, flattened vertical band on the lateral surface of the tragus, innervated by the auriculotemporal and posterior auricular nerves.

transverse abdominal muscle  origin, cartilages of six lower ribs, thoracolumbar fascia, iliac crest, inguinal ligament; insertion, linea alba through rectus sheath, conjoined tendon to pubis; innervation, lower intercostals, iliohypogastric, ilioinguinal; action, compresses abdominal viscera.

transverse muscle of auricle  origin, cranial surface of auricle; insertion, circumference of auricle; innervation, posterior auricular; action, retracts helix.

transverse muscle of chin  superficial fibers of the depressor muscle of the angle of the mouth which turn medially and cross to the opposite side.

transverse muscle of neck  a small muscle often present, passing from the occipital protuberance to the posterior auricular muscle; it may be either superficial or deep to the trapezius muscle.

transverse perineal muscle, deep  origin, ramus of ischium; insertion, tendinous center of perineum; innervation, perineal; action, fixes tendinous center of perineum.

transverse perineal muscle, superficial  origin, ramus of ischium; insertion, tendinous center of perineum; innervation, perineal; action, fixes tendinous center of perineum.

transverse muscle of thorax  origin, mediastinal surface of sternum and of xiphoid process; insertion, cartilages of second to sixth ribs; innervation, intercostal; action, draws ribs downward.

transverse muscle of tongue  origin, median septum of tongue; insertion, dorsum and margins of tongue; innervation, hypoglossal; action, changes shape of tongue in mastication and deglutition.

transversospinal muscles  a name applied collectively to the semispinal, multifidus, and rotator muscles.

trapezius muscle  origin, occipital bone, nuchal ligament, spinous processes of seventh cervical and all thoracic vertebrae; insertion, clavicle, acromion, spine of scapula; innervation, accessory nerve and cervical plexus; action, rotates scapula to raise shoulder in abduction of arm, draws scapula backward.

triangular muscle  a muscle that is triangular in shape.

triceps muscle of arm , triceps brachii muscle origin, long head—infraglenoid tubercle of scapula, lateral head—posterior surface of humerus, lateral border of humerus, lateral intermuscular septum, medial head—posterior surface of humerus below radial groove, medial border of humerus, medial intermuscular septa; insertion, olecranon of ulna; innervation, radial; action, extends forearm, long head adducts and extends arm.

triceps muscle of calf , triceps surae muscle the gastrocnemius and soleus muscles considered together.

muscle of uvula  origin, posterior nasal spine of palatine bone and aponeurosis of soft palate; insertion, uvula; innervation, pharyngeal plexus of vagus; action, raises uvula.

vastus muscle, intermediate  origin, anterior and lateral surfaces of femur; insertion, patella, common tendon of quadriceps muscle of thigh; innervation, femoral; action, extends leg.

vastus muscle, lateral  origin, capsule of hip joint, lateral aspect of femur; insertion, patella, common tendon of quadriceps muscle of thigh; innervation, femoral; action, extends leg.

vastus muscle, medial  origin, medial aspect of femur; insertion, patella, common tendon of quadriceps muscle of thigh; innervation, femoral; action, extends leg.

vertical muscle of tongue  origin, dorsal fascia of tongue; insertion, sides and base of tongue; innervation, hypoglossal; action, changes shape of tongue in mastication and deglutition.

vocal muscle  one of the intrinsic muscles of the larynx; origin, angle between laminae of thyroid cartilage; insertion, vocal process of arytenoid cartilage; innervation, recurrent laryngeal; action, shortens and relaxes vocal folds.

voluntary muscle  any muscle that is normally under the control of the will.

yoked muscles  those that normally act simultaneously and equally, as in moving the eyes.

zygomatic muscle, greater  origin, zygomatic bone in front of temporal process; insertion, angle of mouth; innervation, facial; action, draws angle of mouth backward and upward.

zygomatic muscle, lesser  origin, zygomatic bone near maxillary suture; insertion, orbicular muscle of mouth and levator muscle of upper lip; innervation, facial; action, draws upper lip upward and laterally.

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mus·cle (msl) n. 1. A tissue consisting predominantly of contractile cells and classified as skeletal, cardiac, or smooth, the last lacking transverse striations characteristic of the first two. 2. Any of the contractile organs of the body by which movements of the various organs and parts are effected, and whose fibers are usually attached at each extremity to a bone or other structure by a tendon.

muscle muscular tissue

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muscle(s),

n an organ that, by cellular contraction, produces the movements of life. The two varieties of muscle structure are striated, which includes all the muscles in which contraction is voluntary and the heart muscle (in which contraction is involuntary), and unstriated, smooth, or organic, which includes all the involuntary muscles (except the heart), such as the muscular layer of the intestines, bladder, and blood vessels. See also each of the individual muscles of the head and neck as they are listed.

muscle, buccinator

(buk´sinātr),
n the muscle consisting of three bands and composing the wall of the cheek between the mandible and the maxilla; it causes the cheek to stay tight to the teeth and the lip corners to pull inward. It is often known as the “cheek muscle.”

muscle, ciliary

(sil´ēer´ē),
n a tiny smooth muscle at the junction of the cornea and sclera, consisting of two groups of fibers: circular fibers, which exert parasympathetic control through the oculomotor nerve and the ciliary ganglion, and radial fibers, which exert sympathetic control. Ciliary muscles are responsible for accommodation for far vision through flattening of the lens.

muscle, concentric, contraction,

n See contraction, muscle, concentric.

muscle contraction,

n See contraction, muscle.

muscle, digastric

n suprahyoid muscle that helps activate the jaw for mastication and swallowing. It has both an anterior and a posterior belly. See also deglutition; mastication; muscle, hyoid.

muscle, eccentric, contraction,

n See contraction, muscle, eccentric.

muscle, elasticity of, physical,

n the physical quality of being elastic, of yielding to passive physical stretch.

muscle, elasticity of, physiologic,

n the biologic quality, unique for muscle, of being able to change and resume size under neuromuscular control.

muscle fatigue,

n the depletion of the metabolites necessary to sustain or repeat a muscle contraction.

muscle fiber,

n the cell of muscle tissue. The three types of muscle fibers are striated (voluntary), cardiac, and smooth (involuntary).

muscle, functional changes of,

n.pl asymmetric modifications in length, diameter, and bulk of muscle fibers as a result of variations in function. Muscle responds to normal function by maintenance of bulk. An increase in bulk is caused by an increase in the number of capillaries and in the mean diameter of individual muscle fibers. The response to function accounts for the asymmetry of the musculature, which is frequently found when the growth patterns have been influenced by a traumatogenic agent such as disease, injury, or surgery, and also by the functional processes of the body itself, such as posture and habit. Asymmetry is not necessarily pathologic; i.e., it may be the result of differences in habits of chewing, incision, speech sounds, and facial gestures.

muscle, genioglossus

(jē´nēōglôs´us),
n an extrinsic tongue muscle that originates from the genial tubercles of the mandible and extends inside the tongue. It aids in tongue extension and prevents respiratory obstruction.

muscle, geniohyoid

(jē´nēōhī´oid),
n suprahyoid muscle attached to the superior surface of the hyoid bone. This muscle, which is used for mastication and swallowing, originates on the genial tubercles of the mandible and extends along the floor of the oral cavity. See also deglutition; mastication; muscle, hyoid.

muscle, hyoglossus

(hī´ōglôs´s),
n an extrinsic tongue muscle that originates from the hyoid bone and extends on the lateral surface of the body of the tongue. It depresses the tongue during mastication and speech.

muscle, hypertenseness,

n an increased muscular tension that is not easily released but that does not prevent normal lengthening of the muscle. Hypertenseness is found in patients with general nervousness.

muscle, innervation of, reciprocal,

n a phenomenon of antagonistic muscles demonstrated during a concentric contraction such as that of the temporal muscle. Innervation of the antagonist, the external pterygoid muscle, is partially inhibited, so that freedom of action in flexing the temporomandibular joint is possible. This phenomenon demonstrates inhibition of antagonistic skeletal muscles in a reflex arc brought about automatically by a reduction of the motor discharges from the central nervous system. One of the two muscles in the reflex arc is activated, and the activity of the other is depressed.

muscle, isometric, contraction,

n See contraction, muscle, isometric.

muscle, isotonic, contraction,

n See contraction, muscle, isotonic.

muscle, lateral pterygoid

(lat´rl ter´igoid),
n the muscle whose superior head attaches to the sphenoid bone and whose inferior head attaches to the pterygoid plate. This muscle moves the jaw from side to side. Also known as the
external pterygoid muscle.

muscle, masseter

(msē´tr),
n one of the four muscles of mastication. The thick rectangular muscle in the cheek that functions to close the jaw. The masseter muscle arises from the zygomatic arch and inserts into the mandible at the corner of the jaw.

Palpation of the masseter muscle.

muscle memory,

n a kinesthetic phenomenon by which a muscle or set of muscles may involuntarily produce movement that follows a pattern that has become established by frequent repetition over a long period.

muscle, mentalis

(mental´s),
n the muscle in the chin that originates in the incisive fossa and is inserted into the skin of the chin; it lifts the lower lip and wrinkles the skin of chin.

muscle, mylohyoid,

n suprahyoid muscle originating from the mandible. It helps to raise the tongue and lower the mandible for mastication and swallowing and also forms the floor of the oral cavity. See also deglutition; mastication; muscles, hyoid.

muscle, omohyoid

n infrahyoid muscle with both inferior and superior bellies. It is used for chewing and swallowing. See also muscles, hyoid.

muscle, orbicularis oris

(orbik´ylar´s or´is),
n the muscle that encircles the oral cavity; it encompasses both fibers proper to the lips as well as the adjacent facial muscles. Also known as the “kissing muscle” for its puckering role, it is intimately involved in the opening and closing of the oral cavity.

muscle, palatoglossal

(pal´tōglos´l),
n the interior palate muscle that serves to raise and lower the posterior part of the tongue.

muscle, palatopharyngeus

(pal´tōferin´jēs),
n the muscle that extends from the soft palate to the walls of the laryngopharynx and the thyroid cartilage to form the posterior facial pillars; it is used during swallowing to cover the opening of the nasopharynx by moving the palate and the posterior pharyngeal wall.

muscle, physical characteristics of primary, elasticity,

n.pl a muscle is an elastic body. Its individual fibers follow Hooke's law of elastic bodies: that is, the amount of elongation is proportional to the stretching force. The muscle organs contain tissue other than muscle fibers and thus deviate slightly from this law. The human muscle fiber can contract to about half its total length.

muscle, platysma

(pltiz´m),
n the muscle that extends from the clavicle and shoulder, along the neck, to the mandible and the muscles surrounding the oral cavity; it allows the corners of the oral cavity to be pulled down in a grimace and the skin of the neck to be raised into ridges and depressions.

muscle, regeneration of reproduction or repair of muscle fiber,

n a sequela to many types of muscle damage. Reparation is always associated with the proliferation of sarcolemmic nuclei. Connective tissue elements do not participate in this process except to bridge the gap and offer support for the regenerative fibers. The regenerative process takes place in two forms: regeneration by budding from the surviving parts of the muscle fibers, which occurs when segments of the muscle fiber and its sheath are destroyed, and regeneration by proliferation of cellular bands, which occurs when the sarcolemmic nuclei are spared and can form a sarcoplasmic band by linkage of the cytoplasmic processes.

muscle relaxation,

n the resting state of a muscle fiber or a group of muscle fibers.

muscle reposition,

n surgical replacement of a muscle attachment into a more acceptable functional position.

muscle, sequence of, develop