Which of the following mechanisms is most likely involved?

Degeneration of the axon distal to the lesion-the correct answer is d. after transection of a nerve fiber, degeneration of nerve terminals begins almost immediately. wallerian degeneration (also called orthograde degeneration) refers specifically to the process whereby peripheral nerve fibers (generally the axon) distal to the site of transection are lost as they are cut off from the soma, the source of metabolic nourishment. after the nerve fibers die, calcium is liberated, which activates enzymes that destroy the axon. wallerian degeneration becomes apparent about 1 week after the injury to the axon and continues over the next 12 monthsanswer a is incorrect. while it is possible that changes to the dendrites of a neuron with a transected axon may occur, the most likely mechanism remains degeneration of the distal axonanswer b is incorrect. following a transection the cell body is spared from degeneration, but it may be altered due to loss of neurotrophic factors from the axon to the somaanswer c is incorrect. the most likely consequence of peripheral nerve transaction is de-generation of the axon distal to the lesion. target cells are cells that receive postsynaptic stimuli (i.e., neurotransmitters) from the damaged axons. the target cells (i.e., neurons, endocrine cells, muscle cells) may be spared, although in some cases transneuronal or transynaptic changes may occur. transneuronal degeneration is referred to as anterograde if the targets of the damaged cell are affected. although anterograde degeneration is a possibility, the most likely mechanism remains degeneration of the distal axon as that will definitely occuranswer e is incorrect. in wallerian degeneration the proximal fibers are spared since they maintain communication with the soma.