What is an action potential?

An action potential is characterized by a rapid rise and fall in the membrane potential of a neuron. This process begins when a neuron is stimulated beyond a certain threshold, leading to the opening of sodium channels. As sodium ions flood into the neuron, the membrane potential quickly becomes more positive. This is followed by a rapid repolarization phase where potassium channels open, allowing potassium ions to exit the cell, which decreases the membrane potential back to its resting state. This explosive change in membrane potential is what enables neurons to transmit signals over long distances, allowing for communication within the nervous system.

The other options do not accurately describe the nature of an action potential. A slow change in membrane potential does not capture the rapid dynamics involved in action potentials, and a steady potential does not reflect the transient nature of action potentials that are vital in signal propagation. Similarly, cellular division processes are unrelated to the electrical activities described in action potentials.