Which term describes the rapid change in membrane potential when Na+ rushes into the cell during an impulse?

Which term describes the rapid change in membrane potential when Na+ rushes into the cell during an impulse?

• A. Depolarization
• B. Hyperpolarization
• C. Repolarization
• D. Resting Potential

Answer: (A)

Depolarization is the rapid change in membrane potential when Na+ rushes into the cell during an impulse. The influx of positively charged sodium ions makes the inside of the cell less negative (moving toward zero and often above it), triggering the action potential to propagate. Hyperpolarization would be a movement to a more negative value than the resting potential, usually after the spike due to continued K+ efflux. Repolarization is the process of returning toward the resting potential after depolarization, and resting potential is the stable, negative baseline when the neuron is not firing.

Depolarization is the rapid change in membrane potential when Na+ rushes into the cell during an impulse. The influx of positively charged sodium ions makes the inside of the cell less negative (moving toward zero and often above it), triggering the action potential to propagate.

Hyperpolarization would be a movement to a more negative value than the resting potential, usually after the spike due to continued K+ efflux. Repolarization is the process of returning toward the resting potential after depolarization, and resting potential is the stable, negative baseline when the neuron is not firing.