What is the potential difference across a nerve cell membrane when it is at resting state?

The potential difference across a nerve cell membrane during its resting state is typically around -70 millivolts. This value reflects the difference in electrical charge between the inside and outside of the neuron when it is not actively propagating an action potential.

At rest, a nerve cell maintains a negative internal environment compared to its exterior due to the selective permeability of the membrane and the action of ion pumps, particularly the sodium-potassium pump. This pump moves three sodium ions out of the cell and two potassium ions into the cell, contributing to a higher concentration of positive ions outside the cell compared to the inside, leading to a net negative charge within the cell.

This resting membrane potential is crucial for the generation of action potentials, as it establishes the gradients necessary for sodium and potassium ions to flow in and out of the cell in response to stimuli, ultimately triggering nerve impulses. Understanding this resting state is essential for grasping how neurons communicate and respond to signals.