Portal Triad
Portal Triad

Portal Triad

Portal triads are composed of three major tubes. Branches of the hepatic artery carry oxygenated blood to the hepatocytes, while branches of the portal vein carry blood with nutrients from the small intestine. The bile duct carries bile products away from the hepatocytes, to the larger ducts and gall bladder. Given that the portal vein carries mostly deoxygenated blood, what do the relative sizes of the portal vein and hepatic artery suggest about oxygen levels in the liver?
Answer: The portal vein is larger, suggesting that the blood in the liver is mostly poorly oxygenated. The blood in this vein has already been through the GI tract. The blood in the smaller hepatic artery is better oxygenated.