Which hormone is secreted when the blood glucose level is low and works to increase the blood glucose level?

Glucagon is the hormone that is secreted by the pancreas when blood glucose levels are low. Its primary role is to increase blood glucose levels by promoting the conversion of glycogen (stored in the liver) back into glucose, which is then released into the bloodstream. This process is crucial for maintaining energy levels, especially during periods of fasting or between meals when glucose availability is low. By facilitating this conversion, glucagon helps ensure that the body's cells have a sufficient supply of glucose to function properly.

In contrast, glucose itself is not a hormone but a simple sugar that circulates in the blood. Adrenalin (also known as epinephrine) is involved in the body's fight-or-flight response and can also stimulate glucose release, but its primary roles are different from those of glucagon. Insulin, on the other hand, is the hormone responsible for lowering blood glucose levels by facilitating the uptake of glucose into cells. Understanding the distinct roles of these hormones is essential for grasping how the body regulates blood sugar levels.