The active cell of the nervous system is the neuron, generally described as the nerve or nerve cell. The function and role of this cell is greatly tied to its morphological structure.
Describe the major structures of the neuron and the role of each region.
Each neuron has a cell body, called the neurocyton, 4 to 25 microns in diameter, containing a nucleus and cytoplasm much like that of other cells, and from this radiate out one or more highly elongated processes. One type, called an axon, usually extends for some distance. Thus, an axon is the process of a nerve cell that carries impulses away from it. In addition to axon the cell body of a neuron gives off many smaller processes, which are called dendrites because they are usually highly branched like trees. Thus, a dendrite or dendron is the process that carries impulses towards the cell body.
Cell bodies and dendrites are usually aggregated into ganglia, and an animal's main assemblage of ganglia is called its central nervous system.