Alpha cells in the pancreatic islets secrete which hormone?

• A. Insulin
• B. Somatostatin
• C. Amylin
• D. Glucagon

Answer: (D)

Pancreatic islets have distinct cell types that secrete different hormones to regulate glucose. Alpha cells specifically produce glucagon. When blood sugar drops, glucagon travels to the liver and triggers glycogen breakdown and new glucose production (gluconeogenesis), raising blood glucose back toward normal. This action counterbalances insulin, which lowers blood glucose. Delta cells secrete somatostatin to modulate insulin and glucagon release, beta cells secrete insulin to lower glucose, and amylin (from beta cells) helps regulate post-meal glucose by slowing gastric emptying. So the hormone released by alpha cells is glucagon.