1. The three divisions of nervous system are central nervous system, peripheral nervous system and autonomous nervous system.
2. The central nervous system (CNS) consists of brain and spinal cord. The brain and spinal cord are the coordinators for all nervous functions.
3. The peripheral nervous system (PNS) is constituted by several nerves given by the central nervous system to all the body parts. All these nerves carry impulses to the CNS and bring back the responses from them. They are divided into cranial nerves and spinal nerves.
4. The autonomous nervous system controls all the internal organs and is not under voluntary control.
