pancreas
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:
- pancreas
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An elongated, tapered gland that lies across the back of the abdomen, behind the stomach. Its right-hand end (called the head) is the broadest part and lies in the loop of the duodenum. Tapering from the head, the main part of the gland (the body) extends left and slightly upward; the left-hand, narrower end (the tail) terminates near the spleen.
Structure
Most of the pancreas consists of exocrine tissue, embedded in which are "nests" of endocrine cells (the islets of Langerhans). The exocrine cells secrete digestive enzymes into a network of ducts that meet to form the main pancreatic duct. This duct joins the common bile duct (which carries bile from the gallbladder) to form a small chamber, called the ampulla of Vater, that opens into the duodenum. The islets of Langerhans are surrounded by many blood vessels into which they secrete hormones.Function
The pancreas has two functions: digestive and hormonal. The exocrine tissue secretes various digestive enzymes that break down carbohydrates, fats, proteins, and nucleic acids. Most of these enzymes are secreted in inactive form and are activated in the duodenum by other enzymes. Also secreted by the exocrine tissue is bicarbonate, which neutralizes stomach acid entering the duodenum. The endocrine cells in the islets of Langerhans secrete the hormones insulin and glucagon, which regulate the level of glucose in the blood.
Used in 28 Term definitions
Used in 28 Term definitions