It is involved in the relay of sensory and motor information to and from the CNS therefore, it consists of motor neurons and sensory neurons. The somatic nervous system is associated with activities traditionally thought of as conscious or voluntary. The PNS has two major subdivisions: the somatic nervous system and the autonomic nervous system. The peripheral nervous system is made up of thick bundles of axons, called nerves, carrying messages back and forth between the CNS and the muscles, organs, and senses in the periphery of the body (i.e., everything outside the CNS).
Figure BB.7 The nervous system is divided into two major parts: (a) the Central Nervous System and (b) the Peripheral Nervous System.