Neuron

The cell body contains nucleus and cell organelles in the cytoplasm. Dendrites (short branching processes) extend out from the cell body. They bring signals (impulses) from the receptor or from the axon endings of another neuron. There may be as many as 200 dendrites in a single neuron allowing as many connections with the axon endings of other neurons.

A long nerve fibre or axon carries the impulse from the cell body towards its terminal branches which may either pass on the impulse to another neuron, or into a muscle or gland to bring about the required action. Synapse is the point of communication between one nerve cell and another or between nerve cell and a muscle.

A sheath of fatty material (myelin) often covers the axon, and such nerve fibres are called medullated or myelinated fibres.

Conduction of Nerve Impulse

The conduction of nerve impulse through the nerve fibre is electrical in nature and the one through the synapse is chemical in nature.