Final answer:
An action potential is a rapid and brief change in the membrane potential along the axon of a neuron. It consists of depolarization, repolarization, and hyperpolarization stages. The action potential occurs at the nodes of Ranvier along a myelinated axon.
Step-by-step explanation:
An action potential is an electrical event that occurs along the axon of a neuron. It is a rapid and brief change in the membrane potential, which is caused by the movement of ions across the cell membrane.
The action potential consists of several stages, including depolarization, repolarization, and hyperpolarization. During depolarization, the membrane becomes permeable to sodium ions (Na+), causing an influx of Na+ into the cell. This leads to a positive shift in the membrane potential.
The action potential occurs along a myelinated axon at the nodes of Ranvier. The presence of myelin sheath allows for saltatory conduction, where the action potential jumps from one node to the next. This increases the speed of conduction along the axon.