What percentage of the liver's blood supply is contributed by the portal vein?

• A. 25% to 30%
• B. 50% to 60%
• C. 70% to 75%
• D. 80% to 90%

Answer: (C)

The correct response indicates that the portal vein contributes approximately 70% to 75% of the liver's blood supply. The liver has a unique dual blood supply, receiving blood from both the hepatic artery and the portal vein. The hepatic artery provides the remaining percentage of the blood supply.

The portal vein is responsible for delivering nutrient-rich blood from the gastrointestinal tract and spleen to the liver, which is crucial for processing these nutrients and toxins. This significant contribution highlights the importance of the portal vein in liver function and overall metabolism.

In contrast, the hepatic artery contributes a smaller portion of the blood supply, which is primarily oxygenated blood. Understanding this dual supply is vital, as it reflects the liver’s role in digestion and metabolism, emphasizing the predominance of the portal vein in supplying blood necessary for the liver to perform its many functions effectively.