Autonomic nervous system

The autonomic nervous system is a division of the peripheral nervous system that supplies smooth muscle and glands, and thus influences the function of internal organs.[1] The autonomic nervous system is a control system that acts largely unconsciously and regulates bodily functions such as the heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal.[2] This system is the primary mechanism in control of the fight-or-flight response.