Autonomic nervous system controls the internal maintenance of the body and is the involuntary element of the nervous system. The autonomic nervous system can be divided into parasympathetic and sympathetic divisions. In case of imminent stress or danger sympathetic nervous systems functions to increase the blood pressure, heartbeat and in other physiological changes including excitement because of increasing adrenaline in the body.
Another division of autonomic nervous system that is the parasympathetic nervous system is responsible pupil constriction, dilating the blood vessels slowing down the heart and stimulating genitourinary and digestive system when the person is relaxing and rested. It is used in the system of health Cenegenics.
Both divisions of the autonomic nervous system innervates the systems innervate the identical organs and work in antagonism to keep up homeostasis of the body. Impulses of the autonomic nervous system originates from the central nervous system but most of the functions are performed more o less involuntarily. Autonomous nervous system is the nervous system that coordinates and controls the activity of the body.