The nervous system is the information highway of the body. It consists of the central and peripheral nervous systems. The central nervous system is composed of the brain and the spinal cord. The peripheral nervous system is made up of neurons and nerve endings. The neuron is the basic unit and messenger of the peripheral nervous system. It is composed of dendrites, a cell body, an axon and axon terminals. When a nerve signal is sent by the nervous system, the dendrites receive the signal. The axon then transmits the nerve signal to the axon terminals which synapse with dendrites or other tissues such as a muscle. (Refer to the Figure below) 
There are two types of axons, myelinated and unmyelinated. Unlike unmyelinated axons, myelinated axons have a sheath of fatty tissue called myelin wrapped around them. There are breaks in the myelin called Nodes of Ranviers which allow the nerve signal to jump from node to node. This causes the nerve signal to be transmitted faster.

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