How does hepatic portal circulation differ from the systemic circuit?

• A. Blood from GI tract goes to liver via portal vein for detoxification before entering systemic circulation via hepatic veins to IVC.
• B. Blood from GI tract bypasses the liver completely.
• C. Liver receives blood solely via hepatic artery; portal vein is for oxygen delivery.
• D. Portal circulation delivers oxygenated blood to liver, bypassing detoxification.

Answer: (D)

The main idea is how blood from the digestive organs is processed before it returns to the rest of the body. Blood from the GI tract travels through the portal vein to the liver, bringing nutrients and any absorbed substances to be processed or detoxified by hepatocytes. After the liver does its work, the blood leaves through the hepatic veins into the inferior vena cava and then mixes into the systemic circulation. It’s also important to note that the liver receives oxygenated blood from the hepatic artery as well, and the two sources mix in the liver’s sinusoids. So the portal system specifically delivers material to the liver for detoxification and metabolism, not oxygenated blood bypassing detoxification.