Which hemorrhoidal veins provide rapid absorption routes bypassing hepatic metabolism, and which path is slower and directs blood to the liver?

• A. Upper hemorrhoidal veins provide rapid absorption bypassing liver; middle and inferior go to liver.
• B. Middle and inferior hemorrhoidal veins provide rapid absorption bypassing liver; upper goes to liver.
• C. All hemorrhoidal veins bypass the liver.
• D. No hemorrhoidal veins bypass the liver; all go to portal circulation.

Answer: (B)

The key idea is how rectal veins drain into either the portal (liver) system or the systemic (body-wide) circulation, and how that affects first-pass metabolism. The middle and inferior hemorrhoidal veins drain into the internal iliac veins and then into the inferior vena cava, so blood from these routes goes directly into systemic circulation without first passing through the liver. That makes absorption via these pathways rapid and largely bypasses hepatic metabolism. In contrast, the upper hemorrhoidal veins drain into the superior rectal vein, which feeds the portal system via the inferior mesenteric vein to the liver, so substances absorbed this way encounter hepatic first-pass metabolism and reach systemic circulation more slowly.