Question

In excitable cells, repolarization is closely associated with one of the following events

• A. $N{a}^{+}$efflux
• B. $N{a}^{+}$influx
• C. $K^{+}$efflux
• D. $K^{+}$influx

Answer 1

The correct option is C $K^{+}$efflux

A nerve impulse causes $N{a}^{+}$ to enter the cell, resulting in depolarization. At the peak action potential, $K^{+}$ channels open and the cell becomes hyperpolarized.
Repolarization is a stage of an action potential in which the cell experience a decrease of voltage due to efflux of potassium ions along its electrochemical gradient. Thus, efflux of potassium ions causes repolarization.