Explain how an action potential is propagated down the axon

Solution

Nerve impulse in the form of an action potential exists only for a few seconds. An action potential moves from the dendrites to cell body to axon along a neuron which get passed on to synaptic terminals. Thus an action potential gets passed on from one neuron to next neuron. The start of action potential in a neuron exists at axon Hillcock, passes through the dendrites and end at the axon terminal. The axon potential propagates as a wave along the axon. During the propagation of action potential, depolarization, repolarization and hyper-polarization of the membrane could be seen. When positively charged Na+ ions rush into a neuron through voltage gated channels, the polarity +40v result in a rising phase to its threshold. During repolarization phase, the gated channels for Na+ ions slowly gets closed, potassium ion channels get open. During hyperpolarization phase, due to presence of high negative ions, results in movement of potassium ions out of membrane. Then the potassium gated channels gets closed.