Name a substance transported to the liver by the blood in the hepatic portal vein.

• A. CO2
• B. Oxygen
• C. Glucose
• D. Hormones

Answer: (C)

The blood in the hepatic portal vein carries nutrients absorbed from the digestive tract directly to the liver, so the liver is the first major metabolic processing site for these substances. After a meal, glucose is a major nutrient absorbed from the small intestine and transported in this portal blood. The liver can take up this glucose and store it as glycogen (glycogenesis) or release it later to maintain blood glucose levels. That makes glucose the best answer because it’s a primary substance delivered to the liver through this specific portal circulation.

CO2 is a waste product carried away from tissues to the lungs, not specifically routed to the liver via the portal vein. Oxygen is delivered to tissues, including the liver, primarily through the hepatic artery, not the portal vein. Hormones travel in the bloodstream, but the defining feature of the hepatic portal vein is delivering nutrients from the gut, especially glucose, to the liver for processing.