Action Potential

Description

An action potential is a rapid, temporary electrical signal that travels along neurons and muscle cells. It begins when a stimulus causes depolarization, reaching a threshold that opens voltage-gated sodium channels, allowing Na⁺ influx. This is followed by repolarization as potassium channels open, allowing K⁺ efflux. A brief hyperpolarization phase occurs before the membrane returns to resting potential. Action potentials are all-or-none, unidirectional, and essential for nerve signal transmission, muscle contraction, and communication within the nervous system.