The human nervous system can be divided into the following three parts.
1. Central nervous system (CNS) : It consists of the brain and the spinal cord. It controls and regulates all activities of the body.
2. Peripheral nervous system (PNS) : The peripheral nervous system consists of the nerves originating from the central nervous system which connect the central nervous system with all parts of the body. They are of two types cranial nerves and spinal nerves.
3. Autonomic nervous system (ANS) : The autonomous nervous system consists of the nerves of involuntary organs like the heart, lungs, stomach etc. It is not under the control of our will.
