Muscular Flashcards
Orbicularis Oculi
blinking, squinting, draws eyebrows inferiorly
Frontalis
raises the eyebrows; wrinkles forehead skin horizontally
Zygomaticus
raises lateral corners of mouth upward (smiling
Orbicularis oris
closes lips; purses and protrudes lips; kissing and whistling
Buccinator
draws corner of mouth laterally; compresses cheek (as in whistling and sucking)
Platysma
helps depress mandible; pulls lower lip back down, i.e., produces downward sag of mouth; tenses skin of neck (e.g. during shaving)
Masseter
prime mover of jaw closure; elevates mandible
Temporalis
closes jaw; elevates and retracts mandible (synergist of masseter)
Sternocleidomastoid
prime mover of head flexion (simultaneous contraction of both); acting alone each rotates head toward opposite shoulder
Erector spinae
prime mover of back extension; acting on one side bend vertebral column to same side
External intercoastal
elevates ribs during inspiration (breathing in)
Internal intercoastal
draws ribs together during expiration (breathing out)
Rectus abdominus
flex and rotate lumbar region of vertebral column; fix and depress ribs, stabilize pelvis during walking, increase intra-abdominal pressure
External oblique
pair flexes vertebral column and compresses abdominal wall increasing intra-abdominal pressure; individually rotate trunk and lateral flexion
Internal oblique
pair flexes vertebral column and compresses abdominal wall increasing intra-abdominal pressure; individually rotate trunk and lateral flexion
Transverse abdominus
compresses abdominal contents
Trapezius
stabilizes, raises, retracts, and rotates scapula; adducts scapula and elevates /depresses scapula
Pectoral major
prime mover of arm flexion; rotates arm medially; adducts arm against resistance
Latissimus doris
prime mover of arm extension; powerful arm adductor; medially rotates arm at shoulder; depresses scapula; e.g. striking a blow, hammering, swimming, rowing; also pulls body upward and forward
Deltoid
prime mover of arm abduction; antagonist of pectoralis major and latissimus dorsi; can flex and medially rotate humerus (syn. of pectoralis major) or extend and laterally rotate arm; active during rhythmic arm swinging movements during walking
Triceps brachii
prime mover of forearm extension; may help stabilize shoulder and assist in arm adduction
Bicep brachii
flexes elbow joint and supinates forearm; turns the corkscrew and pulls the cork
Flexors
powerful flexors of wrist
Extensors
Extends wrist