BIOLOGY 3XL3 Chapter 2: Muscle I - General
4 Feb 2017
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Toadfish sound producing organ + modified swim bladder (allows fish to maintain neutral buoyancy vs rattlesnake rattle. Electric eel muscles that multiply electric charge to communicate/stun prey. Fish swimming with unique architecture of muscles to ensure max. power output when they bend bodies also mutually separated muscles for sprinting/long distance (red vs white) Skeletal muscle: connected to at least 2 bones: e. g. some exceptions= facial muscles, larynx, external urethral sphincter. Smooth: no striations: e. g. blood vessels, gi tract, uterus. Cardiac muscle: characteristics of both skeletal + smooth. Muscles made up of bundles (fascicles) of muscle fibers. Theory: nucleus can only service a given volume of cytosol muscle fibers are multinucleated: fibers can be quiet large satellite cells donate their nuclei to that fiber: allows for constant volume of nucleus to ccytosol. Fibers have mitochondria regionally distributed: subsarcolemmal mitochondia (right under membrane; sarcolemma = muscle cell membrane) Myofibrils have a striated appearance due to sarcomeres.
