Billions of nerve cells working in our bodies
The nervous system can be considered as a network via which information as for example a pain stimulus is conveyed within the body. It consists of billions of nerve cells and is classified according to the anatomy and function.
Anatomy: Central nervous system (CNS) and Peripheral nervous system (PNS)
The nerve cells that convey sensory impulses from the periphery of the body to the CNS are described as afferent (ascending to the CNS).
The nerve cells that transmit signals from the CNS to the muscles, glands and organs are referred to as efferent neurons (descending from the CNS). The central nervous system consists of the brain and the spinal cord.
The structures of the CNS significant in pain perception are the cerebral cortex, brain stem and the dorsal horn of the spinal cord.
Function: Autonomic nervous system and Somatic nervous system
The peripheral nervous system contains the nerves which link the CNS with the organs, muscles and other peripheral tissues. It consists of the somatic nervous system and the autonomic nervous system.
The autonomic nervous system influences involuntary organ functions, e.g. blood pressure, heart beat and digestion. The somatic nervous system on the other hand controls voluntary movements or processes and the signals of the sensory organs.