Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
the part of the nervous system that controls automatic processes such as breathing, digestion, and the beating of the heart
Share your knowledge with the community
Browse our collection of 300,000+ community-written definitions
