The nervous system coordinates all body functions and activities. The nervous
system comprises the brain, spinal cord, and a complex network of nerves that
course through the body. The brain and spinal cord are collectively referred to as
the central nervous system (CNS). Nerves originating in the brain and spinal cord
and traveling to peripheral parts of the body form the peripheral nervous system
(PNS). The peripheral nervous system consists of the cranial nerves, the spinal
nerves, and the sympathetic nervous system. The peripheral nervous system is
involved in regulating cardiovascular, respiratory, and other automatic body functions.
These nerve trunks also transmit nerve impulses associated with sight,
hearing, balance, taste, touch, pain, and temperature between peripheral sensors
and the spinal cord and brain.