What is the process called when the cell recharges back to its resting state?

What is the process called when the cell recharges back to its resting state?

• A. Repolarization
• B. Depolarization
• C. Hyperpolarization
• D. Threshold

Answer: (A)

Repolarization is the process of returning the cell to its resting membrane potential after depolarization. During depolarization, the cell’s interior becomes more positive as Na+ ions rush in. After the peak, Na+ channels inactivate and K+ channels open, allowing potassium to exit the cell. This outward flow of positive charge brings the membrane potential back toward the negative resting level. In cardiac cells there’s a brief plateau from Ca2+ influx, but the ongoing K+ outflow finishes repolarization, restoring the resting state. Hyperpolarization would push the membrane potential even more negative than resting, which is a separate phase that can follow repolarization. Threshold is the level needed to trigger an action potential, not the return to rest.

Repolarization is the process of returning the cell to its resting membrane potential after depolarization. During depolarization, the cell’s interior becomes more positive as Na+ ions rush in. After the peak, Na+ channels inactivate and K+ channels open, allowing potassium to exit the cell. This outward flow of positive charge brings the membrane potential back toward the negative resting level. In cardiac cells there’s a brief plateau from Ca2+ influx, but the ongoing K+ outflow finishes repolarization, restoring the resting state. Hyperpolarization would push the membrane potential even more negative than resting, which is a separate phase that can follow repolarization. Threshold is the level needed to trigger an action potential, not the return to rest.