PNS is made up of the autonomic nervous system and the somatic nervous system. The somatic nervous system is composed of 12 pairs of cranial nerves and 31 pairs of spinal nerves. The spinal nerves consist of the motor and sensory nerves of the PNS while the cranial nerves include the memory and motor nerves of the brain stem that serves the eye, tongue, neck, smell, shoulders, mouth, taste, eye muscle and vision.