ABSTRACT
The pancreas is a slender, soft, lobulated gland (ca. 75 g in the adult human), located transversally in the upper abdomen in the space framed by the three portions of the duodenum and the spleen. Most of the pancreas is an exocrine gland which secretes proteolytic and lipolytic enzymes, conveying more than 1 l per day of digestive juices to the gastrointestinal tract. This liquid originates in cell clusters called acini and is collected by a system of microscopic ducts, which coalesce in a channel (the canal of Wirsung) which courses horizontally through the length of the organ and opens into the duodenum next to, or together with, the main hepatic duct (choledocous). Interspersed throughout the exocrine tissue are about 1 million separate, highly vascularized and individually innervated cell clusters known as islets of Langerhans, which together constitute the endocrine pancreas (1 to 2% of the total pancreatic mass). Blood is supplied to the islets by the pancreatic artery and drained into the portal vein. Therefore the entire output of pancreatic hormones is first delivered to the liver.
