Which of the following statements on the mammalian circulatory system is NOT true?
-
Blood in the pulimonary artery is richer in oxygen content than blood in the pulmonary vein
- The blood in the hepatic portal vein is the richest in food substance
- Blood flow is controlled by valves in the veins
- Arteries are generally thicker and larger than veins
- Fibrin helps in the formation of blood clot