Which hormone mobilizes glucose from body storage when needed?

The hormone that mobilizes glucose from body storage when needed is glucagon. This hormone is produced by the pancreas and plays a crucial role in regulating blood sugar levels, particularly during periods of fasting or low carbohydrate intake.

When blood glucose levels drop, glucagon is secreted into the bloodstream and signals the liver to break down glycogen, a stored form of glucose, into glucose. This process is known as glycogenolysis. The released glucose is then made available to the bloodstream, helping to maintain adequate blood sugar levels for the body's energy needs.

In contrast, insulin is involved in lowering blood sugar levels by promoting the uptake of glucose into cells, adrenaline plays a role in the body's stress response and can increase energy availability, and cortisol helps regulate metabolism but is more associated with longer-term stress responses. Hence, glucagon is specifically responsible for stimulating the release of glucose in response to low blood sugar levels.