Ans. The autonomic nervous system (ANS) is responsible for the involuntary control of internal organs and glands. It has two main divisions: the sympathetic nervous system and the parasympathetic nervous system. The sympathetic division activates the 'fight-or-flight' response, preparing the body for action in response to stress or danger. The parasympathetic division promotes 'rest and digest' activities, conserving energy and promoting relaxation. Together, these divisions maintain homeostasis and regulate various bodily functions such as heart rate, digestion, and respiration.