What is the primary hormone produced by the pancreas that regulates blood glucose levels?

The primary hormone produced by the pancreas that regulates blood glucose levels is insulin. Insulin is secreted by the beta cells of the islets of Langerhans within the pancreas and plays a crucial role in glucose metabolism. When blood glucose levels rise, such as after a meal, insulin is released into the bloodstream. It facilitates the uptake of glucose by various tissues, particularly muscle and adipose tissue, and stimulates the liver to store glucose as glycogen. This process effectively lowers blood glucose levels and maintains homeostasis.

In contrast, glucagon, produced by the alpha cells of the pancreas, works to raise blood glucose levels by promoting the conversion of glycogen to glucose in the liver. Somatostatin, produced by delta cells in the pancreas and other parts of the body, regulates the secretion of other hormones, including insulin and glucagon, but does not directly regulate blood glucose levels. Cortisol, a steroid hormone produced by the adrenal glands, influences glucose metabolism as well but is not produced by the pancreas and is more associated with stress responses. Thus, insulin's role as the primary regulator of blood glucose levels highlights its significance in maintaining metabolic balance.