Why are action potentials sometimes described as being "all-or-none" in character?
A)The rate of propagation of an action potential down an axon is independent of stimulus strength.
B)They are associated with an absolute refractory period.
C)A supra-threshold stimulus is required to stimulate an action potential during the relative refractory period.
D)An action potential occurs whenever a suprathreshold stimulus occurs,and its amplitude does not vary with the size of a stimulus.
E)Action potentials are always the same size,even when ion gradients vary in size.

Question

Quizplus · Accepted Answer

An action potential occurs whenever a suprathreshold stimulus occurs and its amplitude does not vary with the size of a stimulus, hence the term "all-or-none." This means that once a stimulus reaches a certain threshold value, the action potential will always occur at full strength, regardless of the size of the stimulus.

Why Are Action Potentials Sometimes Described as Being "All-Or-None" in Character