Which organ is primarily responsible for glucose homeostasis by secreting insulin?

• A. Liver
• B. Adipose tissue
• C. Pancreas
• D. Kidney

Answer: (C)

Insulin is the key hormone that lowers blood glucose by signaling tissues to take up sugar and by reducing glucose production by the liver. The pancreas houses insulin-secreting beta cells within the islets of Langerhans, and when blood glucose rises, these cells release insulin into the bloodstream. This direct secretory role is what coordinates glucose homeostasis.

Other organs help regulate glucose in different ways—the liver stores glycogen and produces glucose, adipose tissue stores fat and responds to insulin, and the kidneys can reabsorb or generate glucose—but none of them secrete insulin. Therefore, the pancreas is the organ responsible for secreting the hormone that primarily controls glucose balance.