Which hormone lowers blood glucose levels?

• A. Glucagon
• B. Insulin
• C. DKA
• D. Diabetes Mellitus

Answer: (B)

Insulin lowers blood glucose by promoting uptake into tissues and reducing glucose production by the liver. It’s secreted by pancreatic beta cells when blood glucose rises, and it acts on liver, muscle, and fat to bring glucose into cells. In muscle and adipose tissue, insulin triggers signaling that moves GLUT4 transporters to the cell surface, increasing glucose entry. In the liver, insulin stimulates glycogen synthesis and inhibits glycogenolysis and gluconeogenesis, decreasing glucose output. It also promotes fat storage and protein synthesis, shifting energy toward storage. Glucagon, by contrast, raises blood glucose by stimulating hepatic glucose production. DKA and Diabetes Mellitus aren’t hormones—DKA is a dangerous complication of insulin deficiency, and Diabetes Mellitus is a disease characterized by chronic hyperglycemia.