The islets of Langerhans in the pancreas secrete which hormones?

• A. Insulin and glucagon
• B. Digestive enzymes
• C. Gastrin
• D. Somatostatin

Answer: (C)

The islets of Langerhans are the endocrine part of the pancreas and their main job is to regulate blood glucose through hormone secretion. The key hormones are insulin, produced by beta cells, and glucagon, produced by alpha cells. Insulin lowers blood glucose by helping cells take up glucose and promoting storage as glycogen; glucagon raises blood glucose by stimulating the liver to release glucose. The islets also produce somatostatin (which modulates the activity of insulin and glucagon) and pancreatic polypeptide, but the exocrine pancreas—made of acinar cells—secretes digestive enzymes, not islets. Gastrin is produced by stomach glands, not the pancreas. So the best answer is insulin and glucagon.