Skeletal Muscle Actions

Frontalis
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Terms in this set (59)
Frontalis
Elevates eyebrows
Temporalis
Elevation, retraction, lateral, and medial excursion of the mandible
Occipitalis
retracts scalp
Orbicularis oculi
sphincter of the eyelids
Orbicularis oris
encircles mouth, closes lips, protrudes lips as in kissing
zygomaticus major
draws angle of mouth upward and laterally in laughing
masseter
elevation of the mandible
Sternocleidomastoid
unilateral action tilts head slightly upward and toward the opposite side
Splenius capitis
acting unilaterally produce ipsilateral flexion and slight rotation of the head
Levator scapulae
elevates scapula if cervical vertebrae are fixed
trapeziusstabilizes scapula and shoulder during arm movementsPlatysmadraws lower lip and angle of mouth downward in expressions of horror or surpriseLatissimus dorsiadducts and medially rotates humerusRhomboideus major/ Rhomboideus minorretracts scapula and braces shoulderSerratus Posterior Inferioracts to counteract the pull of the diaphragm on the ribs to which it is attachedteres minormodulates action of deltoidteres majorextends & medially rotates humerusinfraspinatusmodulates action of deltoidexternal intercostalwhen scalenes fix rib 1; elevate & protract ribs 2-12Pectoralis majorflexes, adducts, medially rotates humerus (climbing/hugging)Serratus anteriorwith pectoralis minor, draws scapula laterally & forward around chest wallPectoralis minorwith serratus anterior, draws scapula laterally & forward around chest wallInternal intercostalsin inspiration, the intercartilaginous part aids in elevating the ribs & expanding the thoracic cavityExternal abdominal obliquesupports abdominal viscera against pull of gravityRectus abdominisflexes lumbar region of vertebral columnInternal abdominal obliquesupports abdominal viscera against pull of gravity & aids in unilateral contraction causing ipsilateral rotation of waisttransversus abdominalcompresses abdominal contentssupraspinatusaids in abduction of armDeltoidanterior fibers flex & medially rotate armbicep brachiirapid or forceful supination of forearmbrachialisprime mover of elbow flexiontriceps brachiiextends elbowbrachioradialisflexes elbowextensor carpi radialis longusextends wristextensor carpi radialis brevisextends wristflexor carpi radialisflexes wrist anteriorlyGluteus mediusabduct & medially rotate thighflexor carpi ulnarisflexes wrist anteriorlyextensor digitorumextends wristgluteus maximusextends thigh at hip as in stair climbingsartoriusaids in knee and hip flexionvastus medialisextends kneevastus lateralisextends kneerectus femorisextends kneegracilisflexes & medially rotates tibia at kneeadductor longusadducts & medially rotates thighadductor magnusadducts & medially rotates thighsemitendinosusflexes kneesemimembranosusflexes kneebiceps femorisflexes kneetibialis anteriordorsiflexes & inverts footextensor digitorum longusextends toesfibularis (peroneus) longusdorsiflexes & everts foot during walkinggastrocnemicusplantar flexes footsoleusplantar flexes footflexor digitorum longusflexes phalanges of digits II-V as foot is raised from groundtensor fasciae lataeextends kneediaphragmprime mover of inspirationgluteus minimusabduct & medially rotate thigh