Dictionary > Repolarize

Repolarize

Definition
noun
To return to a polarized condition
Supplement
The term repolarize refers to the returning to an initially polarized condition. In physiology, the plasma membrane of a cell (e.g. nerve cell) can be repolarized; that is from being polarized to depolarized, and then back to being polarized again. At rest, the plasma membrane has a negative membrane potential. But with the process of depolarization, the membrane shifts to a positive membrane potential. However, this occurs rather abruptly and briefly. The membrane returns to a polarized state and the process is called repolarization. This is possible through physiological mechanisms involving the efflux and influx of ions across the plasma membrane. The movement of ions into and outside of the cell is regulated by transport proteins located in the plasma membrane.
In repolarization, the negative membrane potential of the cell is restored through the regulation of the movement of ions via the K+ channels. Examples of K+ channels are A-type channels, delayed rectifiers, and Ca2+-activated K+ channels.1 When there is an efflux of K+ ions from the cell via the K+ channels in the plasma membrane, the electrical charge of the internal environment of the cell is able to return to negative.
Word origin: re- (again) + polarize
Variant(s):

  • repolarise

See also:

  • polarization
  • depolarization
  • membrane potential
  • transport protein
  • positive afterpotential
  • anti-arrhythmia agents
  • mean electrical axis
  • T wave
  • temporal dispersion
  • Related term(s):

    Reference(s):

    1 Purves D, Augustine GJ, Fitzpatrick D, et al., ed. (2001). Neuroscience (2. ed.). Sunderland, Mass: Sinauer Assoc.


    You will also like...

    Growth and Plant Hormones
    Growth and Plant Hormones

    Plants, like animals, produce hormones to regulate plant activities, including growth. They need these hormones to respo..

    Human Neurology
    Human Neurology

    Human Neurology deals essentially with the nervous system of humans. It also features the various theories put forward b..

    Human perception in action
    Human Perception – Neurology

    This tutorial investigates perception as two people can interpret the same thing differently. Know more about human perc..

    Growth Patterns
    Growth Patterns

    This tutorial describes the sigmoid curve, annual plant growth, tree growth, human growth, and insect growth as the grow..

    Wart-like leaf galls on grape leaves
    Plant Cell Defense

    Plants protect themselves by releasing hydrogen peroxide to fight against fungal invasion. Another way is by secreting c..

    Birth of a Human Baby
    Birth of a Human Baby

    Following nine months inside the mother's womb is the birth of the baby. Know the different stages of the birthing proce..