Most of the major muscle groups used or movement and communication are voluntary. Involuntary muscles would be things like your heart and the muscles around your intestines, which you generally cannot consciously control. The skeletal is called voluntary muscle because it is usually subject to conscious control.
Medical Definition of Autonomic nervous system. Autonomic nervous system: A part of the nervous system that regulates key involuntary functions of the body, including the activity of the heart muscle; the smooth muscles, including the muscles of the intestinal tract; and the glands.
The Autonomic Nervous System (ANS) is the involuntary division of the nervous system. It consists of autonomic neurons that conduct impulses from the central nervous system (brain and/or spinal cord) to glands, smooth muscle and cardiac muscle.he nucleus of the first neuron is located in the central nervous system. (SNS neurons begin at the thoracic and lumbar areas of the spinal cord, PNS neurons begin at the cranial nerves and sacral spinal cord). The first neuron's axons are located in the autonomic ganglia.