Pancreas has both a duct and a ductless gland. The exocrine secretion (pancreatic juice) of the pancreas is poured into the deuodenum to aid digestion of food. The endocrine part of the pancreas, has a special group of hormone secreting cells called the Islets of Langerhans. They have three different kinds of cells : alpha, beta and delta cells : they produce glucagon, insulin and somatostatin respectively.