what is ans

The autonomic nervous system (ANS) is a component of the peripheral nervous system that regulates involuntary physiological processes such as heart rate, blood pressure, respiration, digestion, and sexual arousal. It is responsible for controlling unconscious processes that happen without conscious thought, such as breathing and heart rate. The ANS is divided into three anatomically distinct divisions: sympathetic, parasympathetic, and enteric. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS) contain both afferent and efferent fibers that provide sensory input and motor output, respectively, to the central nervous system (CNS) . The SNS and PNS work together to maintain the bodys internal balance or homeostasis. The ANS is always active, even when a person is asleep, and it is key to their continued survival.