The pancreas is a structure (an organ) that lies towards the back of the abdomen, the part of the body between the chest and the pelvis (hips). The abdomen contains the stomach, liver, spleen, pancreas, intestines and other structures. The pancreas is near the liver and the spleen (Figure 1) and opens into the small intestine.
The pancreas produces many substances, including the endocrine hormones insulin and glucagon. The cells that produce these hormones are situated in the pancreas within the islets of Langerhans (Figure 2). The islets comprise, amongst others, alpha and beta cells. The beta (β) cells produce insulin. The alpha (α) cells produce glucagon.
If the pancreas is severely damaged or removed for some reason then no insulin is produced in the body and diabetes results.