SBI171 Lecture Notes - Lecture 11: Biceps, Rectus Femoris Muscle, Peroneus Longus
Document Summary
Shortening: insertion moves towards origin (reduction in angle) What one muscle group does, another undoes eg: using flexors to bend arm, extensors undo that movement. Prime mover (agonist - major responsibility for specific movement) Any muscles that cross anterior of joint will produce flexion, Muscles crossing posterior side of joint will cause extension. Muscles crossing lateral side of joint produces abduction. Muscles crossing medial side of joint produces adduction. Eg: sternocleidomastoid - sternum, clavicula - mastoid process. 7. muscle action: named for the action they produce (eg flexor, extensor, adductor) Most common patters: circular, convergent, parallel, fusiform, pennate (3) More than 600 in the body; grouped by function and location. Origin and insertion - usually a joint between origin and insertion. Innervation (name of major nerve that supplies muscle) Muscles that extend trunk and maintain posture. Suprahypoid and infrahyoid (synergists to head flexion) Sternocleidomastoid and scalenes - lateral head movements.
