Which pancreatic cells secrete glucagon?

• A. Alpha cells
• B. Beta cells
• C. Delta cells
• D. Acinar cells

Answer: (A)

Glucagon is produced by alpha cells in the pancreatic islets. These cells respond to low blood glucose by releasing glucagon, which signals the liver to convert stored glycogen into glucose and to produce new glucose (glycogenolysis and gluconeogenesis), helping raise and stabilize blood sugar between meals or during fasting.

The other pancreatic cell types have different roles: beta cells secrete insulin, which lowers blood glucose; delta cells secrete somatostatin, which modulates the activity of other islet cells and slows digestive processes; acinar cells are part of the exocrine pancreas and release digestive enzymes into the gut, not hormones.

So, alpha cells are the ones that secrete glucagon, making them the best answer.