Peripheral and Autonomic Nervous System

Peripheral Nervous System (PNS)

It includes the nerves that arise from the brain and spinal cord. There are twelve pairs of nerves which directly arise from the brain and called cranial nerve. Similarly, there are 31 pairs of nerves that arise from the spinal cord and called spinal nerve. They connect the organ system to the brain.

Autonomic Nervous system (ANS)

It is the system of ganglion and sub-ganglion. The local swelling of nerves in organs are called ganglion and further swelling of nerves to various part of the organ is called sub-ganglia. It is divided into sympathetic and parasympathetic nervous system. The function of ANS is to maintain body steady state rapidly.

Cranial Nerves: They arise from brain and terminate inside it except the Vague. There are 12 pairs of cranial nerves in human beings. They control the activities of eyes ears and tongue etc.

Spinal nerves: They arise from the spinal cord and spread to different parts of the body. There are 31 pairs of spinal nerves in the human beings. Out of them,8 are cervical 12 are thoracic 5 pairs of lumbar 5 pairs of sacral and 1 pair coccygeal nerves.