Which vessel receives blood from the gallbladder, pancreas, spleen, and gastrointestinal tract?

• A. Main portal vein
• B. Superior mesenteric vein
• C. Inferior vena cava
• D. Hepatic artery

Answer: (A)

The blood from the gallbladder, pancreas, spleen, and gastrointestinal tract is collected by the portal venous system and delivered to the liver. The main portal vein is the central trunk that receives tributaries from these organs: the splenic vein brings blood from the spleen (and parts of the pancreas), the superior mesenteric vein drains much of the GI tract (and also receives pancreatic venous blood), and cystic veins drain the gallbladder into the portal system. All these streams converge into the main portal vein, which then carries nutrient-rich venous blood to the liver for processing. After passing through the liver, blood exits via the hepatic veins into the inferior vena cava. The other vessels don’t serve as the direct collection point for blood from all these organs: the inferior vena cava handles systemic return, the hepatic artery supplies arterial blood to the liver, and the superior mesenteric vein is a major tributary feeding the portal system but does not alone receive blood from the gallbladder and spleen.