AEMCA Practice Exam

Which hormone is secreted by alpha cells in the pancreas?

1. Insulin

2. Glucagon

3. Somatostatin

4. Thyroxine

The correct answer is: Glucagon

Alpha cells in the pancreas are responsible for the secretion of glucagon. This hormone plays a critical role in glucose metabolism by increasing blood glucose levels when they fall below normal. It stimulates the liver to convert stored glycogen into glucose and release it into the bloodstream, ensuring that the body has a sufficient supply of energy. This action is essential, especially during fasting or when the body is in need of immediate energy. Glucagon acts in contrast to insulin, which is secreted by beta cells and lowers blood sugar levels. The roles of the other hormones listed are distinct: somatostatin, produced by delta cells, regulates other hormones and inhibits insulin and glucagon release, while thyroxine, produced by the thyroid gland, regulates metabolism but is unrelated to pancreatic function. Understanding the specific functions and secretions of different pancreatic cells is crucial for grasping how the body maintains glucose homeostasis.