Which ion's exit from the cell leads to hyperpolarization?

The exit of potassium ions from the cell results in hyperpolarization. Hyperpolarization refers to an increase in the negative charge inside the cell membrane, making it more negative than the resting membrane potential. When potassium ions, which carry a positive charge, leave the cell, they reduce the overall positive charge within the cell, thus increasing the negative charge inside.

This process is crucial in various physiological functions, including neurons and cardiac myocytes, wherein hyperpolarization can inhibit action potentials or alter pacemaker activity. As a result, understanding the role of potassium in hyperpolarization is fundamental in physiology, especially regarding excitable tissues like nerves and muscles.