An action potential begins at a special place, the axon hillock, adjacent to the soma of a motor neuron. You record an action potential 30 cm away on an efferent nerve. The action potential measured far away from the soma
A) Is much smaller than the action potential near the soma because it decays with distance.
B) Is smaller, but not much, because the decay with distance is prevented by myelination
C) Is larger than the one at the soma because it is amplified at each new area of membrane
D) Is the same size as the action potential near the soma because it is regenerated anew along the axon
E) Is the same size as the action potential near the soma because there is no decay of potentials in axons

Question

Quizplus · Accepted Answer

Action potentials are regenerated anew at each segment of the axon, maintaining their size over distance. This is due to the ion channels in the axon membrane that open in response to the action potential, allowing ions to flow in or out and regenerate the action potential at each segment. This process ensures that the signal does not degrade as it travels along the axon, regardless of the distance.

An Action Potential Begins at a Special Place, the Axon