background, pattern, brain @ Pixabay

The nerve impulse is a signal that travels down the axon of a neuron to another neuron or muscle cell.

This process can be broken down into three parts:

depolarization, propagation and repolarization.

In order for this process to occur.

It must have an initial stimulus such as when a neurotransmitter binds with a receptor on the presynaptic membrane.

The binding of the neurotransmitter creates a conformational change in voltage-gated ion channels.

That leads to an influx of sodium and chloride ions.

biology, brain, cell @ Pixabay

The depolarization reaches threshold, causing an action potential that can travel down the axon at speeds up to 120 meters per second (m/s).

Thereby triggering contraction of muscle cells or signals traveling across synapses.

Finally, there needs to be a repolarization before another signal can occur.

Which happens through potassium ion currents flowing out of the cell .

Along with changes in sodium and chloride fluxes facilitated by altered interactions between proteins embedded within cellular membranes. 

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