Transmit messages from one part of your body to another. They are specialized to carry messages through an electro chemical process.
Millions of messengers. Your nervous system contains millions of nerve cells, called neurons. Neurons are highly specialised to transmit messages from one part of your body to another. All neurons have a cell body and one or more fibres. These fibres vary in length from microscopic to over 1 metre. There are two different kinds of nerve fibres: fibres that carry information towards the cell body, called dendrites, and fibres that carry information away from it, called axons. Your brain is made of approximately 100 billion nerve cells, called neurons. Neurons have the amazing ability to gather and transmit electrochemical signals -- think of them like the gates and wires in a computer. Types of Neurons (Nerve Cells). The human body is made up of trillions of cells. Cells of the nervous system, called nerve cells or neurons, are specialized to carry messages through an electrochemical process. The human brain has approximately 100 billion neurons. To learn how neurons carry messages, read about the action potential. Neurons come in many different shapes and sizes.
http://www.bbc.co.uk/science/humanbody/body/factfiles/nervecellsandnerves/nerve_cells_and_nerves.shtml http://science.howstuffworks.com/life/inside-the-mind/human-brain/brain1.htm https://faculty.washington.edu/chudler/cells.html
what do nerve cells do