sympathetic nervous system
The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.
DEFINITION:
- sympathetic nervous system
-
1. The portion of the autonomic nervous system that receives its fibers of connection with the central nervous system through the thoracolumbar outflow of visceral efferent fibers. These fibers (preganglionic) arise from cells in the thoracic and upper lumbar levels of the spinal cord, leave by way of ventral roots, and, by way of rami communicantes, enter sympathetic trunks, where some synapse with ganglion cells. The fibers (postganglionic) of these ganglion cells return to spinal nerves by way of rami communicantes to supply the blood vessels, smooth muscle, and glands of the trunk and limbs, or go as visceral branches to the blood vessels, smooth muscles, and glands of the head and neck, and the viscera of the thorax, abdomen, and pelvis. Some preganglionic fibers pass through the sympathetic trunks and synapse in the prevertebral ganglia; postglanglionic fibers from those ganglia supply adjacent viscera.
2. Former name for the autonomic nervous system.
Used in 5 Term definitions
Used in 5 Term definitions