Question

Explain the terms hyperpolarization and depolarization

Answer 1

Hyperpolarization is the change in the membrane potential of a cell in which it becomes more negative than the resting membrane potential.The hyperpolarization occurs due to the efflux of K⁺ⁱ ions or influx of Cl^– ions. Meanwhile,the influx of the cations like Na⁺  or Ca²⁺ ions, inhibits hyperpolarization.The hyperpolarization occurs after the action potential and this prevents the action potential from spreading.

Depolarization

In the resting state there is a negative charge of the membrane causes due to the ionic gradient inside the cell.The cytosol has a higher concentration of the K⁺ ions and the negatively charged proteins and anions.The outside of the cell has less K⁺ ions and more Na+ ions.This causes a negative potential in the membrane.When the action potential occurs there is a change in the ionic concentrations and the Na+ ions enter into the cell by the increase in the permeability and opening up of the ion channels.This causes the charge in the cell membrane to reverse its polarity and becomes positive.This is called the depolarization.