Write the names and functions of three parts of human nervous system in which it is divided.
The human nervous system has three components—central nervous system, peripheral nervous system and autonomic nervous system.
(i) Central nervous system (CNS): CNS consists of the brain and spinal cord. It controls and regulates all the activities of the body.
(ii) Peripheral nervous system (PNS): PNS consists of all the nerves and the nerve network which is present in the body. It is formed by the cranial and spinal nerves which connect the body parts to CNS.
(iii) Autonomic nervous system (ANS): ANS is an involuntary nervous system. It controls involuntary actions and coordinates the organs such as the heart, stomach and lungs, which do not function according to our will.