How does the body control blood glucose levels?

The pancreas is the main organ involved with controlling blood glucose levels. It is situated in the abdomen just below the stomach. It consists of alpha and beta cells which are arranged into clusters known as islets of Langerhans. When the blood glucose is too high, the beta cells secrete insulin into the blood. Insulin acts on liver and muscle cells to remove glucose from the blood and glucose is stored in these cells as glycogen. When the blood glucose level is too low, the alpha cells of the pancreas secrete glucagon. Glucagon causes the stored glycogen to be converted back to glucose so the blood glucose level returns to normal.