Which organ primarily regulates blood glucose levels through hormonal secretion?

• A. Liver
• B. Pancreas
• C. Adrenal gland
• D. Pituitary

Answer: (B)

Blood glucose is kept in balance by hormones, with the pancreas serving as the primary regulatory organ. The endocrine pancreas contains insulin-secreting beta cells and glucagon-secreting alpha cells. After eating, insulin is released and drives glucose into muscles and fat and promotes storage as glycogen in the liver, lowering blood glucose. During fasting, glucagon is released, signaling the liver to produce and release glucose, raising blood glucose. While the liver acts as the main tissue responding to these signals, the initiating regulator is the pancreas because its hormonal secretion directly sets the level of glucose in the blood. The adrenal gland and pituitary influence metabolism more indirectly, not as the primary hormonal regulator of blood glucose.