Explanation

The endocrine part of pancreas is represented by about a million of islets of Langerhans with 5 types of endocrine cells secreting different hormones-α- cells (glucagon), β- cells (insulin), γ- cells (gastrin), δ- cells (somatostatin) and F- cells (pancreatic polypeptide). Insulin, glucagon and somatostain all are polypeptides.