Question

Which of the following occurs with hypokalemia?

A. Cells are partially depolarized.
B. There is more diffusion of potassium into the cells.
C. Cells are more excitable.
D. The resting membrane potential is more positive.
E. Cells are hyperpolarized.

Answer 1

In the case of hypokalemia, cells are hyperpolarized due to a reduction in extracellular potassium levels that causes the inside of the cell to become more negatively charged, leading to a lower resting membrane potential than normal.

Step-by-step explanation:

The question relates to the effects of hypokalemia, which is a condition characterized by low levels of potassium (K+) in the blood. In the context of cellular membrane potential, hypokalemia would influence the difference in electric potential across the cell membrane, particularly the resting membrane potential which is typically maintained at about -70 mV due to the difference in the concentration of ions such as Na+ and K+ across the membrane.

Given this understanding, the correct answer to the question "Which of the following occurs with hypokalemia?" is E. Cells are hyperpolarized.

A reduction in extracellular potassium (K+) concentration causes fewer K+ ions to leave the cell, which makes the inside of the cell more negatively charged compared to the outside, leading to an even lower membrane potential than the normal resting potential, or hyperpolarization. This increased negative charge inside the cell makes the neurons and muscle cells less likely to reach the threshold needed to initiate an action potential, thereby making them less excitable.