The islets of Langerhans contain four major endocrine cell types that secrete which of the following hormones?

c. Insulin, somatostatin, glucagon, pancreatic polypeptide

Within the pancreas are small nests of cells that are responsible for the secretion of hormones that control glucose homeostasis. These nests are called islets of Langerhans and constitute 2% of the pancreatic mass. The islets contain an average of 3000 cells and range in diameter from 40 to 900 mm. The islets are composed of four major cell types— alpha (A), beta (B), delta (D), and PP or F cells, which secrete glucagon, insulin, somatostatin, and pancreatic polypeptide, respectively. The B cells are centrally located within the islet and constitute 70% of the islet mass, whereas the PP, A, and D cells are located at the periphery of the islet. They constitute roughly 15%, 10%, and 5% of the islet cell mass, respectively.