CAMRT Radiography Practice Exam

Which two vessels join to form the main portal vein?

1. Inferior mesenteric vein and splenic vein

2. Superior mesenteric vein and splenic vein

3. Renal vein and inferior vena cava

4. Hepatic artery and aorta

The correct answer is: Superior mesenteric vein and splenic vein

The main portal vein is formed by the convergence of the superior mesenteric vein and the splenic vein. This combination is crucial in the human circulatory system as it plays a vital role in transporting nutrient-rich blood from the intestines and spleen to the liver. The superior mesenteric vein is responsible for draining blood from the small intestine and part of the large intestine, while the splenic vein collects blood from the spleen, pancreas, and part of the stomach. The formation of the main portal vein at the level of the second lumbar vertebra facilitates the delivery of these nutrients to the liver, where they can be metabolized and detoxified. This anatomical configuration is essential for maintaining proper digestive and metabolic processes. In contrast, the other combinations of vessels mentioned do not contribute to the formation of the main portal vein. The inferior mesenteric vein drains blood from the lower part of the colon and typically joins the splenic vein before it merges with the superior mesenteric vein. The renal vein and inferior vena cava are associated with the kidney's venous drainage system, while the hepatic artery and aorta involve the supply of oxygenated blood to the liver, not venous drainage. Thus, the specific joining of the superior mes