The pancreas is a combination exocrine and endocrine organ. Exocrine tubuloacinar glands are responsible for secreting the digestive juices into the pancreatic ducts and, subsequently, the gastrointestinal tract. Approximately 1 million islets of Langerhans responsible for the endocrine function of the pancreas are distributed throughout the exocrine pancreas. Beta and alpha cells of the endocrine islets are responsible for secreting insulin and glucagon, respectively, while delta cells secrete somatostatin and PP cells secrete pancreatic polypeptide.
