PHYL 141 Lecture Notes - Lecture 11: Flexor Digitorum Profundus Muscle, Extensor Pollicis Longus Muscle, Levator Scapulae Muscle

• School: UH, UH Manoa, UHM
• Department: Physiology
• Course: PHYL 141
• Professor: Rachel Lindsey

Document Summary

How skeletal muscles produce movements: skeletal muscles produce movement by exerting force on tendons, tendons attach to & pull on bones movement occurs (e. g. flexion, extension, rotation) If load is closer to fulcrum & effort applied farther from fulcrum, then only small effort required to move large load over small distance = mechanical advantage. Arrangement of fascicles (1) parallel fascicles parallel to longitudinal axis of muscle; terminate at either end in flat tendons. Fewer fascicles than pennate muscle, but have long fibers that extend length of muscle greater rom, but less power. Ex: sartorius muscle (longest muscle in body, runs from hip to knee) (2) fusiform fascicles nearly parallel to longitudinal axis of muscle. Muscle tapers toward tendons where diameter is less than at belly. Ex: digastric muscle (3) circular fascicles in concentric circular arrangements form sphincter muscles that enclose an orifice (opening) Ex: orbicularis oculi muscle (4) triangular fascicles spread over broad area converge at thick central tendon.