Islets of Langerhans are endocrine clusters in the pancreas that secrete which hormones?

• A. Insulin and Glucagon
• B. Adrenaline and Cortisol
• C. Thyroxine and Calcitonin
• D. Orexin and Leptin

Answer: (A)

The main idea is how the pancreas uses its endocrine cells to control blood glucose. The islets of Langerhans are clusters of hormone-secreting cells in the pancreas. The primary hormones they release are insulin and glucagon. Insulin, made by beta cells, lowers blood glucose by helping cells take in sugar and by promoting storage of glucose as glycogen in the liver and muscles. Glucagon, made by alpha cells, raises blood glucose by signaling the liver to break down glycogen and create new glucose. These two hormones work in opposition to keep blood sugar balanced across fasting and fed states.

The other hormones listed come from different organs: adrenaline and cortisol come from the adrenal glands; thyroxine and calcitonin come from the thyroid; orexin and leptin originate in the brain and adipose tissue, respectively. So insulin and glucagon are the hormones produced by the islets of Langerhans.