Which of the Following Statements About Action Potentials is Correct

Question

Which of the following statements about action potentials is correct?
A)Action potentials for a given neuron vary in magnitude.
B)Action potentials for a given neuron vary in duration.
C)Action potentials are propagated down the length of the axon.
D)Movement of ions during the action potential occurs mostly through the Na⁺ pump.
E)Action potentials of all cells are of the same speed.

Accepted Answer

Action potentials are propagated down the length of the axon, from the cell body to the axon terminal. Option A is incorrect because action potentials have a fixed magnitude known as the threshold of excitation. Option B is incorrect because action potentials have a fixed duration of about 1 millisecond. Option D is incorrect because the movement of ions during the action potential occurs through voltage-gated ion channels, not the Na⁺ pump. Option E is incorrect because the speed of action potentials can vary between neurons and types of cells.