What is the definition or description of: autonomic nervous system?

Involuntary function: The autonomic nervous system is part of the peripheral nervous system. It is ‘autonomic’ because it does not require voluntary thought to function. The autonomic nervous system is divided into the sympathetic and parasympathetic nervous systems. The sympathetic system manages “fight or flight” responses and the parasympathetic system acts as a counterpart that manages “rest and digest” functions.

Autonomic NS: Is part of peripheral nervous system that acts as a control system functioning largely below the level of consciousness, to control visceral functions. It affects heart rate, respiratory rate, digestion, salivation, perspiration, pupils dilation, urination, & sexual arousal.