The Nervous system of the body consists of all the nerve cells. It is the body's "speedy" electrochemical communication system.
every neuron (nerve cell) has a long process known as 'axon' which is used to contact the next cell in the circuit. The receiving cell (another neuron) has small processes called 'dendrites' which are contacted by the axon. Now the neurons, like all other cells in the body, are enclosed by a selectively permeable cell membrane - which means it allows certain chemicals to pass through, while others are prevented from entering or leaving the cell