The resting membrane potential is largely determined by which ion?

Study for the Paramedic Aandamp;P Exam. Engage with flashcards and multiple choice questions, complete with hints and explanations. Prepare effectively for your exam!

Multiple Choice

The resting membrane potential is largely determined by which ion?

Potassium sets the resting membrane potential because the membrane is most permeable to K+ when a cell is at rest. Potassium leaks out through open channels along its concentration gradient, making the inside of the cell more negative. The equilibrium potential for K+ is very negative, so the resting potential moves toward that value. Sodium and chloride contribute less at rest because their permeability is lower in the resting state, so their opposing effects are weaker. Calcium has minimal permeability then, so it doesn’t significantly influence the resting potential. The Na+/K+ pump maintains the gradients that allow this leak to occur, but the resting potential is mainly defined by the leak of potassium.

Potassium sets the resting membrane potential because the membrane is most permeable to K+ when a cell is at rest. Potassium leaks out through open channels along its concentration gradient, making the inside of the cell more negative. The equilibrium potential for K+ is very negative, so the resting potential moves toward that value. Sodium and chloride contribute less at rest because their permeability is lower in the resting state, so their opposing effects are weaker. Calcium has minimal permeability then, so it doesn’t significantly influence the resting potential. The Na+/K+ pump maintains the gradients that allow this leak to occur, but the resting potential is mainly defined by the leak of potassium.

More practice questions