The pancreas in humans is a solid, elongated, flattened gland about 10 in. (25 cm) long, lying behind the stomach and attached to the back of the abdominal cavity. Its "head" is just to the right of the mid-line and its "body" and "tail" point slightly upwards and lie just beneath the extreme edge of the left side of the ribs. The head is closely attached to the first part of the small intestine, into which the stomach empties partially digested solid and liquid food. It is to this that the pancreas adds its digestive juices, containing enzymes. The tube draining the liver of its bile (the bile duct) lies just behind the head of the pancreas and usually joins the bowel at the same place where the fluids from the pancreas enter the bowel.

The pancreas is composed of two major types of tissues: exocrine tissue, the acini, which...