The nervous system can be divided up into two sub systems the central nervous system and the peripheral nervous system.
Central nervous system (CNS)
The central nervous system is the bodies think tank! Or you can also call it the control centre. It is comprised of the brain and the spinal cord. All human movement is initiated from a nerve impulse that originated from the CNS.
Peripheral nervous system (PNS)
The peripheral nervous system consists of all the nerves that lie outside the spinal cord. It transmits messages to and from the CNS. The information it gathers via the senses is transmitted to the CNS to analyse. After analysis the CNS will then instruct the PNS what to do with that information. This can be autonomic (voluntary) or somatic (involuntary) as discussed in the function of the skeletal system section.