Which hormone helps move glucose out of the bloodstream and into cells?

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

Answer: (C)

Insulin is the hormone that moves glucose out of the bloodstream and into cells. After a meal, insulin is released and binds to receptors on muscle and fat cells, triggering GLUT4 transporters to move to the cell surface. This openings allows glucose to enter the cells for energy or storage, lowering blood glucose levels. Insulin also promotes glycogen synthesis in the liver and muscles and inhibits glucose production. The other hormones—epinephrine, cortisol, and glucagon—tend to increase blood glucose by signaling liver glucose release or production, not by driving uptake into cells. So insulin best fits the idea of moving glucose from blood into cells.