The part of the vertebrate peripheral nervous system that supplies stimulation via motor nerves to the smooth and cardiac muscles and to the glands of the body. It is divided into the parasympathetic and the sympathetic nervous systems, which tend to work antagonistically on the same organs (see illustration). The activity of the ANS is controlled principally by the medulla oblongata, midbrain, and pons of the brainstem, which gives rise to the paired cranial nerves, and by the hypothalamus.

The autonomic nervous system (showing one side of each system of the ANS)