The pancreas is an organ located in the abdomen that functions as both an exocrine gland and an endocrine gland. It has a head, neck, body, and tail. As an exocrine gland, it produces pancreatic juice containing enzymes to aid digestion. As an endocrine gland, it contains clusters of cells called islets of Langerhans that secrete hormones like insulin and glucagon to regulate blood sugar levels. Diseases of the pancreas include diabetes, pancreatitis, pancreatic cancer, and pancreatic enzyme deficiency. Since the pancreas plays a vital dual role in both digestion and regulating blood sugar, diseases or loss of its function can quickly lead to illness or death.