Pancreas

This organ is located between the greater curvature of the stomach and the duodenum. It is both an endocrine and exocrine gland. It is composed of granular-like epithelial cells forming two masses, 1) the Islets of Langerhans which produce endocrine secretions involved with sugar metabolism and 2) the Acini which secretes digestive enzymes of exocrineorigin. Since the pancreas is not part of the small intestine it must transfer its digestive enzymes through the pancreatic duct (Canal of Wirsung) to the common bile duct. The latter enters the small intestine in a small enlarged area called the ampulla of Vater.

Pancreatic juice is composed of 1) trypsinogen, chymotrypsinogen, and procarboxypepsidase, the inactive forms of trypsin, chymotrypsin, and carboxypeptidase respectively; they are responsible for the total breakdown of complex sugars to disaccharides, 2) lipase which reduces fats to fatty acids and glycerol, and 3) bicarbonate ion (HC03-) which raises the ph of the intestine by neutralizing the HC1 from the stomach. All intestinal enzymes are most active at a ph greater than 7.0.