1 In the control, the amplitudes of the action potentials at R1 and R2 are the same. Which of the following explains this?

Question

There are voltage-gated Na+ channels all along the axon?
• The action potential is an all-or-none event.?
Action potentials propagate or remake themselves at each point along the axon.?

Answer 1

The correct explanation for why the amplitudes of the action potentials at R1 and R2 are the same is:

The action potential is an all-or-none event.

This means that once the threshold for an action potential is reached, the amplitude of the action potential remains consistent along the axon, regardless of the distance traveled. Although there are voltage-gated Na+ channels along the axon and action potentials propagate by remaking themselves at each point, the key factor that ensures the amplitude remains the same is the all-or-none characteristic of action potentials.