What happens during an action potential?

Question

What will be an ideal response?

Answer 1

An action potential is a neuron's way of signaling. A neuron is stimulated when its membrane potential is increased. If a neuron's membrane potential reaches a certain threshold value—typically around -55 mV—sodium channels in the neuron's cell membrane open, allowing positively charged sodium ions to flow into the neuron. (Sodium ions flow into the neuron because there are more sodium ions outside the cell than inside.) This influx of positively charged ions causes the membrane potential to spike and become positive. This spike is called an action potential. Once the spike occurs, the sodium channels quickly close, and potassium channels open. Positively charged potassium ions flow out of the neuron (they flow out because there are more potassium ions inside the cell than outside), causing the membrane potential to return to its resting value.