Peripheral nervous system (PNS)

Is the part of the nervous system consisting of the nerves and ganglion outside of the brain and spinal cord.

The main function of the PNS is to connect the central nervous system (CNS) to the limbs and organs, essentially serving as a communication relay going back and forth between the brain and the extremities.

Unlike the CNS, the PNS is not protected by the bone of spine and skull, or by the blood brain barrier, leaving it exposed to toxins and mechanical injuries.

The peripheral nervous system is divided into the somatic nervous system and the autonomic nervous system; some textbooks also include sensory systems.

see Peripheral nerve