Which hormone lowers blood glucose levels by promoting uptake of glucose into cells?

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

Answer: (C)

Insulin lowers blood glucose by promoting uptake of glucose into cells, especially in muscle and fat tissue. It signals cells to insert GLUT4 transporters into the cell membrane, allowing glucose to move from the bloodstream into cells. It also stimulates the liver and muscles to store glucose as glycogen and reduces glucose production. Other hormones in this set raise blood glucose: adrenaline triggers glycogen breakdown and glucose release; cortisol increases gluconeogenesis; glucagon stimulates liver glucose production. So insulin best fits the description of lowering blood glucose by promoting cellular glucose uptake.