Answer:
All of the above are true.
Step-by-step explanation:
The structure and function of components of the nervous system are altered by the process of aging. In late adulthood, there is alteration in the neuromuscular junction and the nerve conduction velocity is also reduced.
The age-related slowed response of the nervous system is a result of the loss of nerve fibers from the peripheral nerves with aging. Both myelinated and non-myelinated nerve fibers of the peripheral nervous system are affected by aging and are lost resulting in slowed conduction of nerve impulse.