08.03 Divisions of the nervous system

The nervous system is divided into the central nervous system (CNS), comprising the brain and spinal cord, and the peripheral nervous system (PNS) of peripheral nerves that link the CNS to all parts of the body(Figure 8.3). The PNS is made up of sensory or afferent nerves that transmit information towards the CNS and motor (efferent) nerves that conduct information away from the CNS to muscles and glands. Themotor division of the PNS is further divided into the somatic or voluntary nervous system that allows conscious control of skeletal muscle and the autonomic or involuntary division that regulates the activity ofsmooth and cardiac muscle and glands; we have no conscious control of these nerves. The autonomic nervous system is further divided into the sympathetic division that mobilises the body during activity andthe parasympathetic division that promotes housekeeping functions during rest.

Figure 8.3 Divisions of the nervous system