The nervous system is the set of neurons and support structures that process and organize information from the senses and bodily organs, analyze and coordinate appropriate responses and control the behavioral actions of an organism. All anatomical structures of the nervous system are made up of nervous tissue.
The nervous system is present in some form in all chordates with the simplest system represented in the flatworms, which has two nerve cords running on opposite sides that connect to two simple brains called ganglia.
In the more complex vertebrates the nervous system is divided into two parts: the central nervous system, composed of the brain and the spinal cord; and the peripheral nervous system, which is composed of all the nervous tissue throughout the rest of the body.
- Kandel, ER; Schwartz JH, Jessell TM (2000). Principles of Neural Science, 4th ed., New York: McGraw-Hill. ISBN 0-8385-7701-6.
- Martin, JH (2003). Neuroanatomy text and atlas 3rd ed., New York: McGraw-Hill.
- Sanes, Reh, Harris (2005). Development of the Nervous System, 2nd edition. Academic Press; ISBN 0-12-618621-9