MEDICAL PHYSIOLOGY

Detailed explanation-1: -Absolute refractory period: during this time it is absolutely impossible to send another action potential. The inactivation (h) gates of the sodium channels lock shut for a time, and make it so no sodium will pass through. No sodium means no depolarization, which means no action potential.

Detailed explanation-2: -Second, the action potential can only travel in one direction – from the cell body towards the axon terminal – because a patch of membrane that has just undergone one action potential is in a “refractory period” and cannot undergo another.

Detailed explanation-3: -But action potentials move in one direction. This is achieved because the sodium channels have a refractory period following activation, during which they cannot open again. This ensures that the action potential is propagated in a specific direction along the axon.

Detailed explanation-4: -Answer and Explanation: During the absolute refractory period, an action potential cannot be generated no matter what the stimulus strength is because, during this brief period, the voltage-gated sodium channels are inactivated.

Detailed explanation-5: -Moreover, the voltage-gated sodium channels on the dendritic membranes having a higher threshold helps prevent them triggering an action potential from synaptic input.