Ghrelin is best described as

• A. Hunger hormone made in the stomach
• B. Appetite-suppressing hormone produced in fat cells
• C. Hormone that regulates blood sugar produced in the pancreas
• D. Hormone that helps with sleep produced in the pineal gland

Answer: (A)

Ghrelin is the hunger hormone produced in the stomach. It rises before meals to signal hunger and stimulates appetite by acting on hypothalamic neurons, and it also prompts the release of growth hormone. After eating, ghrelin levels fall, helping to suppress further hunger signals. The other hormones described serve different roles—leptin from fat tissue reduces appetite, insulin and glucagon from the pancreas regulate blood sugar, and melatonin from the pineal gland helps regulate sleep. So ghrelin is best described as the hunger signal produced in the stomach.