What is autonomous nervous system ?

Explanation

Autonomous nervous system:
The Autonomous Nervous System (ANS) is a division of the peripheral nervous system that acts largely unconsciously and regulates the functions of internal organs.
Ex : Heart beat, digestion, respiratory rate. The autonomous nervous system has two branches.
They are
1. Sympathetic nervous system : It is a quick response mobilizing system. It increases the matabolic activity. The system acts as 'excretory'.
2. Parasymphathetic nervous system : It is a more slowly activated dampening system. The system acts as 'inhibitory' and decreases the rate of metabolic activities.
In many cases both systems have 'opposite' actions where one system activates a physiological response and the other inhibits it.