What hormone is released from the pancreas when blood glucose levels are low?

• A. Insulin
• B. Glucagon
• C. Cortisol
• D. Adrenaline

Answer: (B)

When blood glucose levels are low, the pancreas releases glucagon. This hormone plays a crucial role in maintaining blood glucose homeostasis. Glucagon is produced by the alpha cells in the islets of Langerhans in the pancreas. Its primary function is to signal the liver to convert stored glycogen into glucose, which is then released into the bloodstream, raising blood glucose levels.

In contrast, insulin is released when blood glucose levels are high and facilitates the uptake of glucose by cells, effectively lowering blood sugar levels. Cortisol, a steroid hormone, increases blood glucose levels but is not directly involved in the immediate response to low blood glucose. Adrenaline, also known as epinephrine, can elevate blood glucose levels by promoting glycogen breakdown, but it acts primarily in response to stress rather than specifically regulating blood glucose like glucagon does.

Thus, glucagon is the key hormone that responds specifically to low blood glucose by mobilizing glucose from liver stores, making it the correct answer to the question.