The "all-or-none law" refers to the observation that an action potential
A) will diminish to near zero when transmitted down a long axon.
B) fires at the same rate regardless of the inputs to the neuron.
C) is conducted more rapidly down the axon as it reaches the axon terminal.
D) is produced whenever the membrane potential reaches threshold.
E) travels only in one direction.

Question

Quizplus · Accepted Answer

The "all-or-none law" refers to the fact that an action potential is produced only when the membrane potential reaches the threshold level. If the membrane potential does not reach threshold, no action potential is generated. Once the threshold is reached, however, the action potential is produced in a fixed and all-or-none manner, regardless of the magnitude of the stimulus that produced it. Therefore, option D is the correct answer.

The "All-Or-None Law" Refers to the Observation That an Action