Peripheral Nervous System

The Peripheral Nervous System (or PNS) is the name given to the parts of the nervous system not found within the central nervous system (CNS), ie. not found within the brain or spinal cord (see diagram of human CNS and PNS below). It is composed of several bundles of neurons called nerves which connect the various sensors throughout the body to the CNS (afferent neurons) and the CNS to the various effectors throught the body (efferent neurons). As these neurones are not protected by the bone of the skull or spine, or the blood-brain barrier, they are far more suseptible to both physical and chemical damage.