The basic unit of the nervous system is the nerve cell or neurone. There are millions of these in the body.

Neurones vary considerably in size and shape, but they all have certain features in common.

The nucleus of the cell is always contained within the main cell body. (Another name for the cell body is the soma ).

The cell body has a number of short fibres branching from it. These fibres are the dendrites. They conduct impulses to the cell body.

The cell also has a single longer fibre. This is the axon and it conducts impulses from the cell body to neighbouring cells.