39. In experimental preparations, activation of the corticospinal tract can result in excitation of both a- and y-motoneurons. The co-activation of a- and y-motoneurons confers which of the following advantages compared with activation of only a-motoneurons? A) Decreased tension in the intrafusal muscle fibers increases the force of muscle contraction. B) Inhibition of y-motoneurons is overcome by activity in recurrent collaterals of a-motor axons C) y-Motoneuron axon collaterals excite a-motoneurons, increasing their total activity D) Muscle spindles shorten, preventing an unloading effect on muscle spindle sensory endings

39. In experimental preparations, activation of the corticospinal tract can result in excitation of both a- and y-motoneurons. The co-activation of a- and y-motoneurons confers which of the following advantages compared with activation of only a-motoneurons? A) Decreased tension in the intrafusal muscle fibers increases the force of muscle contraction. B) Inhibition of y-motoneurons is overcome by activity in recurrent collaterals of a-motor axons C) y-Motoneuron axon collaterals excite a-motoneurons, increasing their total activity D) Muscle spindles shorten, preventing an unloading effect on muscle spindle sensory endings

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter7: The Peripheral Nervous System: Efferent Division

Section: Chapter Questions

Problem 2TAHL

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