Muscle Actions Flashcards
Epicranius frontalis
Raise eyebrows
Epicranius occipitalis
Pull scalp posteriorly or fix aponeurosis
Orbicularis oculi
Close eye and pull eyebrow downward
Orbicularis oris
Close and protrude lips
Masseter
Elevate mandible (close jaw)
Temporalis
Elevate mandible (close jaw)
Sternocleidomastoid
Flexion of neck or rotate head toward opposite shoulder
Digastric
Elevate hyoid bone or depress mandible (open jaw)
Mylohyoid
Elevate hyoid bone & base of tongue
Sternohyoid
Depress larynx and hyoid bone
Pectoralis major
Adduct and medially rotate arm or pull chest upward to inhale
Serratus anterior
Pull scapula anterior/inferior; raise ribs to inhale
Deltoid
Abduct arm or flexion, extension or rotation of humerus
Pectoralis minor
Move scapula anterior/inferior; raise ribs to inhale
Rectus abdominis
Flex vertebral column, depress ribs, compress abdomen causing increased abdominal pressure to exhale
External oblique
Flex vertebral column, depress ribs, constrict & compress abdomen causing increased abdominal pressure to exhale, rotate trunk to opposite side
Internal oblique
Same actions as external oblique (flex vertebral column, depress ribs, constrict & compress abdomen causing increased abdominal pressure to exhale) but in perpendicular direction and rotate trunk to same side
Transverse abdominis
Compress abdomen to exhale
Trapezius
Extend head; adduct or abduct scapula and elevate or depress scapula
Latissimus dorsi
Extend, adduct and medially rotate arm
Infraspinatus
Stabilizes the shoulder joint & laterally rotates the arm