Vagus Nerves (X)

The "vagus nerves" originate in the area between the pons at the base of the brain stem and the spinal column, and extend down through the neck into the chest and abdomen. These are both sensory and motor nerves and, although they contain both voluntary and involuntary branches, the involuntary members predominate. The voluntary components are motor fibers that carry impulses to muscles in the larynx to aid in speech and swallowing. Other sensory fibers carry impulses from the lining of the larynx, pharynx, esophagus, thorax and abdomen to the brain. The involuntary motor fibers supply the heart and several of the smooth muscles and glands in the organs of the thorax and abdomen. Since these nerves are the tenth pair of cranial nerves, the are numbered "X".