Neuron

A neuron or nerve cell contains a cell body with a nucleus. The cell body has a number of fine branches extending from it, called dendrites. The dendrites carry impulses towards the cell body that are known as incoming impulses. The neuron also has a large single branch, the axon, which carries impulses away from the cell body; these are known as outgoing impulses. The axon is covered by a white lipoid (resembling fat) called myelin, which acts as an insulator to prevent short-circuiting of neural impulses. The white matter substance of the brain is made up of bundles of these myelinated axons, called tracts