What are the four major consumers of glucose in our bodies?

• A. Brain
• B. Brain, liver, muscle, and adipose
• C. Heart and kidneys
• D. Stomach and intestines

Answer: (B)

Glucose is the body's main immediate fuel, and several tissues pull from the blood to meet their energy needs, with four tissues standing out as the major consumers. The brain uses a large, constant amount of glucose for its high-energy demands and relies on it largely independent of insulin for uptake. Skeletal muscle uses glucose during activity to fuel contractions and to replenish its glycogen stores, serving as a major sink during the fed state. Adipose tissue takes up glucose to form glycerol phosphate, which is then used to build triglycerides for fat storage. The liver also takes up glucose after meals to store it as glycogen and to convert excess glucose into fatty acids for storage or transport, while helping maintain blood glucose levels during fasting. Together, these four tissues—brain, liver, muscle, and adipose—account for the largest glucose uptake in the body.