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Unformatted text preview: Page 1 of 1 BIOE 322/BIOS 332 Fundamentals of Systems Physiology Spring 2008 Problem Set #3 Solutions 1. A decrease in muscle control occurs when reinnervation of muscle fibers occurs after poliomyelitis because the number of motor units in the muscle is decreased. Reinnervation results in a greater number of muscle fibers per motor unit. Control is reduced because the number of motor units than can be recruited is decreased. The greater the number of motor units in a muscle, the greater the ability to have fine gradations of muscle contraction as motor units are recruited. A smaller number of motor units means that gradations of muscle contraction are not as fine. 2. Start with a subthreshold stimulus and increase the stimulus strength by very small increments. Apply the stimulus to the nerve of muscle A and muscle B. If the number of motor units is the same for both preparations, each time the stimulus strength is increased the degree of tension produced by the muscles will also increase to the same degree in each muscle. If one muscle has more motor units than the other, the muscle with the greater number of motor units will exhibit a greater number of separate increases in tension,...
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- Spring '08