Question

During the action potential of a neuron, which ion is primarily crossing the membrane during the depolarization phase, and in which direction is the ion moving? View Available Hint(s) During the action potential of a neuron, which ion is primarily crossing the membrane during the depolarization phase, and in which direction is the ion moving?

A. K+ is entering the cell.
B. Na+ is exiting the cell.
C. Na+ is entering the cell.
D. K+ is exiting the cell.

Answer 1

Answer:

C. Na⁺ is entering the cell.

Explanation:

In the depolarization phase, the permeability of sodium ions (Na⁺) increases, allowing a large flow of sodium ions to enter the cell through the membrane by simple diffusion.

This process causes intracellular liquids to be positively charged due to the large amount of cations.