If a nerve cell has a greater concentration of Na⁺ on the outside the cell membrane, compared to inside, then the movement of Na⁺ outside is by diffusion.

Question

Quizplus · Accepted Answer

Diffusion is the movement of solutes from an area of higher concentration to an area of lower concentration. In this scenario, the concentration of Na⁺ is already higher on the outside of the cell membrane, so the movement of Na⁺ would be against the concentration gradient, which is not diffusion. Instead, the movement of Na⁺ would be facilitated by ion channels or pumps.

If a Nerve Cell Has a Greater Concentration of Na⁺