Unformatted text preview: Fatigue - during periods of intense exercise muscle tension is sometimes unable to be maintained. This can result from muscle fatigue when the muscle cells are 1) unable to synthesize sufficient quantities of ATP to maintain contractile activity, or 2) accumulate too much lactic acid from glycolysis (which may inhibit enzymes involved in the contraction coupling process). It can also result from neuromuscular fatigue when the stores of presynaptic acetylcholine are depleted and neuromuscular synaptic transmission cannot keep pace. Recovery - following periods of intense exercise the oxygen demands of skeletal muscle remain high so that metabolism can replenish the stores of muscle glycogen and creatine phosphate. Skeletal Muscle Types - there exist 3 different types of muscle fibers based on their differences in ATP metabolism and their speed of contraction (i.e. myosin-ATPase activity) (Table 8-1). ...
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- Fall '08