Question

Put the following action potential events in order. i) Regenerative Na+ influx occurs at the threshold potential ii) Weak Na+ influx and strong K+ efflux iii) Continuous K+ efflux causes the membrane potential to become more negative than resting potential iv) Strong Na+ influx and weak K+ efflux.

Answer 1

Answer:

i) iv) ii) iii)

Explanation:

The excitable cell begins being in a resting state, with a negative charge, -70 mV. First (i) there is a stimulus of influx of sodio into the cell, if the stimulus is strong enough and exceeds -55 mV, the threshold potential, then an action potential will occur. (iv) A strong influx of sodium that deporalizes the cells causes a change to a positive charge in the cell. (ii) Then potassium efflux from the cell in large quantities, which repolarizes the cell. (iii) With a continuous efflux of potassium the cell can become more negative than the resting potential, this is called hyperpolarization.