Q. What is the mechanism by which the neural impulse is transmitted along the axon?

The neural impulse is transmitted along the neuronal membrane through depolarization of consecutive neighboring regions when a region in the internal surface of the membrane is depolarized it becomes more positive in relation to the neighboring internal region so positive electrical charges (ions) move towards this more negative region and voltage-gated sodium channels are activated and open. The action potential then linearly propagates along the membrane waiting near the presynaptic region of the axon.