A neuron consists of three parts : cell body, dendrites and axon (see Figure on next page). The cell body of a neuron is like a typical animal cell which contains cytoplasm and a nucleus. A number of long and thin fibers stretch out from the cell body of a neuron. They are celled nerve fibres. The shorter fibres on the cell body of a neuron are called dendrites. The longest fibre on cell body of a neuron is called axon. The axon
has an insulating and protective sheath (or cover) of myelin around it. The function of neurons is to carry messages over long distances in the body of a person quickly. The messages which neurons transmit in mervous system are in the form of electrical impulses (also called nerve impulses). Actually, neurons make the whole nervous system work efficiently. For example, the sensory neurons transmit impulses from the sensory cells or receptors (present in sense organs) towards the central nervous system (spinal cord and brain). And the motor neurons transmit impulses from the central nervous system towards the muscle cells (or effectors) for taking appropriate action.
