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What Is the Autonomic Nervous System?


Updated December 09, 2013

Definition: The autonomic nervous system is the part of the body that regulates involuntary action such as the activity of the heart, smooth muscles such as the intestines, and glands. The autonomic nervous system consists of both the sympathetic nervous system (increases heart rate, raises blood pressure, etc.) and parasympathetic nervous system (slows the heart rate, increases intestinal and glandular activity, etc.)

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