21.In order for relaxation to occur, ACh must be removed : 1417092
21.In order for relaxation to occur, ACh must be removed from the muscle cell's receptors.
22.Acetylcholinesterase removes ACh from receptors.
23.A muscle cell’s twitch last longer than the cell’s refractory period.
24.Rigor mortis occurs when Ca2+ links actin and the myosin globular head together in a rigor complex.
25.Muscle cells require ATP in order to relax, following a contraction.
26.More tension is developed during twitch summation than during a single twitch because the duration of elevated cytosolic Ca2+ concentration increases during summation, thus increasing the availability of cross-bridge binding sites.
27.Gradation of muscle contraction can be accomplished by stimulating variable portions of each muscle fiber.
28.Summation events result from increasing amounts of cytoplasmic calcium levels.
29.A motor unit is a single muscle plus all of the motor neurons that innervate it.
30.Muscles that have a fine degree of control have small motor units.