Nerves that originate in pairs from the central nervous system and extend to the peripheral regions of the body are called the peripheral nervous system. It is mainly divided into 2 parts. namely-
1. Voluntary Nervous System: The nerves that are under the control of the central nervous system and coordinate the functioning of various organs are called voluntary nervous system. It consists of 12 pairs of carotid nerves and 31 pairs of sympathetic nerves
2. Autonomic Nervous System: Those nerves that are not under the control of the central nervous system but coordinate the functioning of various organs are called autonomic nervous system. It is of two types. Sympathetic Nerve and Parasympathetic Nerve. Sympathetic and parasympathetic nerve functions are antagonistic. Sympathetic nerves increase heart rate while parasympathetic nerves decrease heart rate.