Which statement describes the hepatic portal system?

• A. Blood from the GI tract drains directly into the vena cava without passing through the liver.
• B. The hepatic portal vein returns blood from the liver to the GI tract.
• C. Blood from the GI tract goes to the liver via the hepatic portal system.
• D. The hepatic portal system drains blood from the brain.

Answer: (C)

Blood from the GI tract goes to the liver via the hepatic portal system. This setup delivers nutrient-rich and potentially toxin-containing blood to the liver first, so it can be processed, stored, or detoxified before mixing with the rest of the bloodstream. The hepatic portal vein collects blood from the GI tract (via veins like the splenic and superior mesenteric veins) and delivers it to the liver. After processing, blood exits the liver through hepatic veins into the caudal vena cava, joining systemic circulation.

Bypassing the liver would mean no first-pass processing. If blood moved from the liver back toward the GI tract, that would be the opposite direction of flow for the portal system. Draining from the brain isn’t part of this pathway, which is why those statements don’t describe the hepatic portal system.