The question is slightly misleading. Hormones do not produce glucagon. Rather, specific cells within the pancreas produce and secrete glucagon in response to hormonal and other signals. Therefore, a more accurate question would be "What cells produce glucagon?" The answer is:
Alpha cells of the pancreas produce glucagon.
Here's a more detailed explanation:
- The Pancreas: The pancreas is an organ located in the abdomen that has both endocrine and exocrine functions. The endocrine function involves the production and secretion of hormones directly into the bloodstream.
- Islets of Langerhans: Within the pancreas are clusters of endocrine cells called the islets of Langerhans. These islets contain several types of cells, including alpha cells, beta cells, delta cells, PP cells, and epsilon cells.
- Alpha Cells: Alpha cells are responsible for synthesizing and secreting glucagon. When blood glucose levels are low (hypoglycemia), alpha cells release glucagon.
- Glucagon's Function: Glucagon acts primarily on the liver, stimulating it to break down glycogen (stored glucose) into glucose and release it into the bloodstream, thereby raising blood glucose levels.
- Other Factors Influencing Glucagon Secretion: While low blood glucose is the primary trigger, glucagon secretion can also be influenced by:
- Amino acids (especially alanine and arginine)
- The sympathetic nervous system (via catecholamines like epinephrine)
- Gastrointestinal hormones
In summary, alpha cells within the pancreatic islets are the specific cells that produce and release glucagon in response to various signals, most notably low blood glucose levels. While hormones don't directly produce glucagon, they can influence the secretion of glucagon from the alpha cells.
