Why do PNS postganglionic motor neurons have short axons?

The correct answer emphasizes that postganglionic motor neurons of the parasympathetic nervous system (PNS) have short axons because they lie close to their target organs. This anatomical feature allows for a more localized and efficient response of the PNS, which is designed to manage bodily functions during restful states, such as digestion and energy conservation.

Because the ganglia of the PNS are typically located in or near the organs they innervate, the axons do not need to extend very far to reach their targets; this proximity reduces transmission time and allows for quick modulation of organ function. This organization contrasts with the sympathetic nervous system, where postganglionic neurons are more distant from their targets, necessitating longer axons to reach distant organs.

The other options do not accurately describe the relationship between the axons and their target organs. For example, if the neurons were positioned far from their targets (as suggested by the first option), longer axons would be necessary, which is not the case for PNS postganglionic fibers. The mention of unmyelinated fibers (in the third option) does not directly relate to their length but rather to their conduction properties. Finally, the connection to sensory neurons (as per