A patient presents in the emergency department with a knife wound to the arm. It is noted that some of the muscles of his arm are paralyzed. Which of the following will take place in the neurons whose axons were severed?
A) their soma will shrink
B) their Schwann cells will be unable to undergo mitosis
C) the macrophages surrounding the axons will be unable to function
D) the nucleus of their soma will be displaced
E) the rough ER of their soma will increase in size

Question

Quizplus · Accepted Answer

When the axons are severed, the neurons undergo changes, one of which is the displacement of their nucleus. This happens because the nucleus relies on transport signals from the axons to place it in the proper location in the cell. Without this signal, the nucleus moves to an abnormal position, which can affect the function of the neuron. The other choices are not supported by evidence and do not relate to the known effects of axon severing on neurons.

A Patient Presents in the Emergency Department with a Knife