Fibers of muscles whose motor neurons are severed
A)hypertrophy.
B)may be replaced by fat or fibrous connective tissue.
C)cannot ever be reinnervated.
D)die as their sarcomeres are progressively eliminateD.

Question

Quizplus · Accepted Answer

When the motor neurons of a muscle fiber are severed, the muscle fiber can no longer receive signals to contract and will eventually atrophy. Over time, the fibers may be replaced by fat or fibrous connective tissue. They cannot be reinnervated, as the motor neurons that originally innervated the muscle fibers are permanently damaged. However, the fibers do not die as their sarcomeres are progressively eliminated, they simply become smaller and may be replaced by other tissues. Therefore, option B is the best choice.

Fibers of Muscles Whose Motor Neurons Are Severed