ANP 1106 Lecture Notes - Lecture 5: Myocyte, Skeletal Muscle, Diac

• School: University of Ottawa
• Department: Anatomy and Physiology
• Course: ANP 1106
• Professor: Joanne Savory

Document Summary

Muscle tissues make up nearly half of the body"s mass, and are distinguished by their ability to transform chemical energy (atp) into directed mechanical energy, becoming capable of exerting force. The three types are: skeletal muscle, cardiac muscle, smooth muscle. Branching chains of cells, uni or bi-nucleate, striations. Involuntary, can contract with- out nervous system stimulation. Unitary muscle in walls of hol- low visceral organs. Voluntary (conscious control), requires nervous system stimu- lation. Excitability (responsiveness): ability to perceive and respond to stimuli by changing its membrane potential. Response: action potential along the sarcolemma and a muscle contraction. Contractibility: ability to shorten forcibly when adequately stimulated. Extensibility: ability to extend to stretch (contraction = shorten, relax = stretch) Elasticity: ability of a muscle cell to recoil and resume its resting length after stretching. Muscles also protect organs, form valves and controls pupil size (smooth muscle). Each skeletal muscles is a discrete organ, made up of several kinds of tissues.