repolarization

bioelectricity

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 13, 2026

Quick Summary

Repolarization is the restoration of the difference in charge across a cell membrane after it has been depolarized. This process is fundamental to bioelectricity, which refers to the electrical currents and voltages generated in biological systems.12

In electrically excitable cells like neurons, a resting potential exists, where the interior is negatively charged relative to the exterior. When a cell is stimulated, depolarization occurs, making the interior less negative or even positive. This is followed by repolarization, where the membrane returns to its negative resting state. This cycle of depolarization and repolarization is crucial for transmitting nerve impulses and for the rhythmic contractions of muscles, including the heart. The movement of ions, particularly sodium and potassium, across the cell membrane is key to these electrical changes.3145

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

5 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

human cardiovascular system
Electrocardiogram
This repolarization process occurs in the muscle of the ventricles about 0.25 second after depolarization. There are, therefore, both depolarization and repolarization waves represented in the electrocardiogram. The atria repolarize at the same time that the ventricles depolarize; however, the atrial repolarization wave is obscured by…
Read More
This repolarization process occurs in the muscle of the ventricles about 0.25 second after depolarization. There are, therefore, both depolarization and repolarization waves represented in the electrocardiogram. The atria repolarize at the same time that the ventricles depolarize; however, the atrial repolarization wave is obscured by…
Read More

electricity
Bioelectric effects
This sequence, called depolarization and repolarization, is accompanied by a flow of substantial current through the active cell membrane, so that a “dipole-current source” exists for a short period. Small currents flow from this source through the aqueous medium containing the cell and are detectable at considerable distances from it.…
Read More
This sequence, called depolarization and repolarization, is accompanied by a flow of substantial current through the active cell membrane, so that a “dipole-current source” exists for a short period. Small currents flow from this source through the aqueous medium containing the cell and are detectable at considerable distances from it.…
Read More

nervous system
Repolarization
As instantaneous as the opening of sodium channels at threshold potential is their closing at the peak of action potential. This is called sodium inactivation, and it is caused by gates within the channel that are sensitive to depolarization. Following sodium inactivation is the…
Read More
As instantaneous as the opening of sodium channels at threshold potential is their closing at the peak of action potential. This is called sodium inactivation, and it is caused by gates within the channel that are sensitive to depolarization. Following sodium inactivation is the…
Read More