Passage of an Action Potential

When an action potential is generated by a receptor, it rapidly 'moves' down the neurone, in what is called an nerve impulse. In reality, nothing physically 'moves' down the neurone. what happens is that the reversal of electrical potential is reproduced again and again, and this wave of depolarisation travels down the neurone towards the CNS, effectors or other neurones.

The passage of an action potential can be likened to a Mexican wave, where a wave can pass all around a stadium with no one actually physically moving.

Mechanism of an unmyelinated neurone

• Resting potential. All parts of the neurone maintain a constant potential of negative 60-70 mV. There is a higher concentration of sodium ions outside the cell, and a…