The pancreas, located in the upper abdomen behind the stomach, is both an endocrine and exocrine gland. As an exocrine gland it secretes pancreatic juice - an alkaline fluid containing digestive enzymes - into the pancreatic duct which leads to the small intestine (duodenum). Pancreatic enzymes are amylases, proteases such as trypsin and lipases.The endocrine role of the pancreas is in controlling blood sugar levels by producing the hormones glucagon and insulin from the alpha and beta cells of the islets of Langerhans respectively.Within an islet of Langerhans the alpha cells are larger but less numerous than the beta cells, which make up most of the islet.