One gland is ninety-nine percent digestive, one percent hormonal
The pancreas is a mixed gland behind the stomach: about ninety-nine percent exocrine for digestion, one percent endocrine for blood sugar. Pancreatitis often tracks alcohol or gallstones; diabetes and hard-to-catch cancers keep the organ in grim headlines despite its quiet daily chemistry.
The pancreas sits in the abdomen behind the stomach and belongs to two body systems at once. It is a mixed gland: about 99 percent of it is exocrine, feeding digestion, and only 1 percent is endocrine, managing blood sugar. The digestive part pours pancreatic juice into the duodenum. That juice carries bicarbonate to neutralise acid arriving from the stomach, plus enzymes that break down carbohydrates, proteins and fats. The hormonal part releases insulin, glucagon, somatostatin and pancreatic polypeptide.
In adults it is a lobulated, salmon-coloured organ some 12 to 15 cm long, reaching from the curve of the duodenum across to the upper left abdomen near the spleen. Anatomists divide it into head, neck, body and tail. The head wraps around the superior mesenteric artery and vein; the neck, about 2 cm wide, lies in front of the spot where the portal vein forms; the body, its longest section, crosses behind the stomach; and the tail finishes beside the spleen.
Two ducts drain it. The main pancreatic duct merges with the common bile duct to form a small chamber, the ampulla of Vater, ringed by a muscle called the sphincter of Oddi and opening into the descending duodenum. A smaller accessory duct has its own opening slightly higher up.
Its Greek name joins pan, all, and kreas, flesh. Its link to diabetes has been recognised since at least 1889, and its role in producing insulin was pinned down in 1921. Inflammation of the organ, pancreatitis, commonly follows long-term alcohol use or gallstones. Pancreatic cancer can develop after chronic pancreatitis or for other reasons, and its outlook is very poor because it is often found only after it has already spread.
Source: Pancreas
