Question

Describe how an action potential is propagated down the length of an axon and explain the refractory period.

A. Action potential propagates through continuous conduction, and the refractory period ensures unidirectional signal transmission.
B. Action potential propagates through saltatory conduction, and the refractory period prevents backward signal transmission.
C. Action potential propagates through graded conduction, and the refractory period speeds up signal transmission.
D. Action potential propagates through decremental conduction, and the refractory period inhibits signal transmission.

Answer 1

Action potential propagates along an axon through continuous or saltatory conduction, with the refractory period ensuring the unidirectional flow and preventing new action potentials too soon after the first.

Step-by-step explanation:

An action potential propagates down an axon through either continuous conduction in unmyelinated axons or saltatory conduction in myelinated axons. The latter is faster as the action potential 'jumps' from one node of Ranvier to the next.

The refractory period, consisting of absolute and relative phases, ensures that a new action potential is not initiated during a certain time after the first, thus preventing backward signal transmission and promoting unidirectional propagation along the axon.