Explain the functioning of the autonomic nervous system. Include in your explanation the functioning of both the sympathetic and parasympathetic branches.

The autonomic nervous system seems to operate almost entirely out of range of conscious control; we have little awareness or direct control of it. The ANS consists of two anatomically distinct parts. The sympathetic branch consists of nerve fibres that emanate from the thoracic and lumbar regions of the spinal cord and make contact with a large number of body organs. These include the: heart, stomach and blood vessels. The parasympathetic branch consists of fibres emanating from the cranial and sacral regions of the spinal cord. The sympathetic system arouses the body for vigorous action. The parasympathetic system returns the body to a more quiescent state.