After absorption, glucose enters the portal vein and goes to which tissues?

• A. Adipose tissue
• B. Liver
• C. Muscle and brain
• D. Bone marrow

Answer: (C)

Glucose absorbed from the intestine goes into the hepatic portal vein and goes to the liver first. The liver acts as the first stop for dietary glucose, taking up a large portion after a meal and either storing it as glycogen or converting excess glucose into fat. Only after the liver processes it does glucose enter the general bloodstream to reach other tissues, with muscle and brain being major consumers once circulating glucose is available. The brain requires a steady glucose supply, and muscles take up glucose in response to insulin or contraction, but neither is the initial destination—the liver is.