A level Biology Nervous System Doubts

 refractory period

Following the passage of one Action Potential, there is a time delay before the next one can pass. This time delay is known as refractory period and it lasts for a few milliseconds. During this time, the sodium channels in the membrane are closed, preventing the inward movement of Sodium ions. This is known as the absolute refractory period. Another impulse cannot be conducted no matter how large the stimulus is.

or


When an action potential has just occurred at a section of the axon, there is a short period of time when a second action potential can be generated at the same point. This is called the refractory period.