Taber’s Cyclopedic Medical Dictionary Online + Mobile powered by Unbound Medicine. Find 65,000 medical and nursing definitions. Download to iPhone, iPad, and Android. Explore these free sample topics:
-- The first section of this topic is shown below --
pl. pancreasespancreata [pan- + Gr. kreas, stem kreat-, flesh, meat]
A compound acinotubular gland located behind the stomach and in front of the first and second lumbar vertebrae. The head lies within the curve of the duodenum, the tail lies near the spleen, and the middle portion constitutes the body. The pancreas is both an exocrine and an endocrine organ. The exocrine glands are acini, each with its own duct; these ducts anastomose to form the main pancreatic duct or duct of Wirsung, which joins the common bile duct and empties into the duodenum at the hepatopancreatic ampulla. An accessory pancreatic duct or duct of Santorini is often present and opens into the duodenum directly. Scattered throughout the exocrine glandular tissue are masses of cells called islets of Langerhans, endocrine glands that secrete hormones.
The exocrine secretion of the pancreas consists of enzymes that digest food in the small intestine, and sodium bicarbonate to neutralize hydrochloric acid from the stomach in the duodenum.
SEE: pancreatic juice
The islets of Langerhans contain alpha, beta, and delta cells. Alpha cells secrete glucagon, which raises blood glucose; beta cells secrete insulin, which lowers blood glucose; delta cells secrete somatostatin, which inhibits the secretion of insulin, glucagon, growth hormone from the anterior pituitary, and gastrin from the stomach.
DISEASES OF THE PANCREAS
Autoimmune damage to the islets of Langerhans results in type 1 diabetes mellitus, a disease in which insulin secretion is insufficient or completely absent. Insulin-secreting tumors of the pancreas, called insulinomas, produce hypoglycemia; they are exceptionally rare. Inflammation of the pancreas, known as pancreatitis, is a common condition that often results from excessive use of alcohol or from obstruction of the exocrine secretions of the pancreas by gallstones. Pancreas divisum is a common congenital anomaly in which the main duct of the exocrine pancreas drains into an accessory pancreatic papilla instead of the duodenal papilla; it has been associated with recurring episodes of pancreatitis.
SEE: diabetes mellitus; SEE: insulin; SEE: pancreatic function tests