Pancreatic Hormones and Glucose Regulation

Blood glucose must stay available to the brain and other tissues without remaining high enough to damage blood vessels, nerves, and kidneys. The pancreas helps maintain that balance through insulin and glucagon. Pancreatic beta cells release insulin when blood glucose rises, especially after eating. Insulin helps glucose move from the bloodstream into insulin-responsive cells and tells the liver to stop releasing so much stored and newly made glucose. Its overall effect is to lower blood glucose. Alpha cells release glucagon when glucose falls. Glucagon directs the liver to break down glycogen and produce glucose, placing fuel back into circulation. The liver functions like a glucose warehouse: insulin signals, “Store fuel and stop shipping,” while glucagon signals, “Release fuel now.” Diabetes develops when insulin action is inadequate. - Type 1 diabetes involves absolute insulin deficiency. Without replacement insulin, glucose cannot be managed normally and ketone production can become dangerous. - Type 2 diabetes involves relative insulin deficiency and impaired response to insulin. The liver may continue releasing glucose despite an already elevated blood glucose level. Inappropriately high glucagon contributes to this...