Neuron: Cells that transmit information.
If a nerve is stimulated by an electrical shock, pH change, mechanical stimulation, a nerve impulse is generated. This is where the sodium potassium pump comes into play. During the beginning of action potential, the sodium potassium pump membrane becomes permeable to Na+ ions, where 3 ions travels into the axon and depolarization occurs. Then, during repolarization, the membrane becomes permeable to K+ ions, where 2 ions travel outside of the axon. This happens continuously until the impulse reaches the axon terminal. The process is sped up by the myelin sheaths created by the shwann cells, creating gaps between gaps called the nodes of ranvier. This allows the impulse to jump across nodes and speed up the impulse, causing it to depolarize and repolarize only at certain points of the axon.
Once the impulse reaches the end of the axon, the nerve impulse travels to the dendrite of the next neuron. The synapse is the region between the two membranes. The action potential causes synaptic vesicles to release neurotransmitters into the synaptic cleft. Then the neurotransmitters bind to the receptors on the post synaptic membrane, which causes the impulse to continue travelling down the next neuron, where depolarization and repolarization continues.