Definition of "autonomic nervous system" []

• The part of the vertebrate nervous system that regulates involuntary action, as of the intestines, heart, and glands, and that is divided into the sympathetic nervous system and the parasympathetic nervous system. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "It has been shown by Cannon6 that such major emotions as fear, rage, or pain acting upon the adrenal glands through the autonomic nervous system are accompanied by an increased discharge of adrenalin into the blood, and by a passing of stored glycogen from the liver for circulation through the body as dextrose, the object of which is the increasing and liberation of muscular energy for the animal's successful flight or fight."