Backflow

... limbs back to heart through the inferior vena cava is aginst gravitational pull. thats why vena cava, veins all have semi lunar valve to prevent backflow of blood.

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Hello, Well all the comments are very true, but if you want to see why we dont want backflow we think about why we have it going one way. Vertebrates such as the mammals have a 4 chambered heart which efficiently keeps the oxegenated blood separate from the oxygenated ...

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Do veins have valves on the inside to prevent backflow?

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... finally the blood ends up in the vena cava where the blood has lost most of its pressure. That's why there are valves in veins - to prevent the backflow of blood!!.. because, among other reasons, the blood has little pressure. Also, the blood from the vena cava ends up in the heart. The heart ...

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