The pancreas contains clusters of endocrine cells known as Islets of Langerhans, and these islets comprise four distinct types of hormone-secreting cells
1. Alpha (α) cells:
constituting 20%, release glucagon—a hyperglycemic hormone that promotes glucogenolysis in the liver, elevating blood glucose levels.
2. Beta (β) cells:
comprising 70%, produce insulin—a hypoglycemic hormone triggering glycogenesis in the liver and muscles, reducing blood glucose levels.
3. Delta (δ) cells:
accounting for 5%, secrete somatostatin, which inhibits both glucagon and insulin secretion. It also diminishes gastric secretions, motility, and absorption in the digestive tract, acting as a growth inhibiting factor.
4. PP cells or F cells:
making up 5%, release pancreatic polypeptide (PP) that inhibits the release of pancreatic juice.