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So the blood does attempt to flow downward from gravity. Low pressure system. ---- Blood flows through veins at a lower pressure and speed than in arteries. For this reason, valves are designed to prevent blood from flowing backwards. Venal blood returning to the heart from the legs, for instance, have the added task of having to fight gravity.
Wiki User
∙ 15y ago
Wiki User
∙ 15y agoto help the blood get back to the heart against gravity
Wiki User
∙ 13y agothey help to keep the bloodfromflowing backwards
Wiki User
∙ 11y agoveins need valves and artieries do not because blood gets stuck but with arteries the blood passes straight through them xxxxxxxx
Wiki User
∙ 13y agoSo that no deoxygenated blood flows backwards through the veins
Wiki User
∙ 12y agoso that the blood cannot flow the wrong way through the vessels
Wiki User
∙ 14y agoto prevent the back flow of the blood
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Do the pulmonary veins have valve?
Vena Cava has valves, if im not wrong, but pulmonary veins definitely do not have valves.
Why is it important for veins to contain valves?
Veins have valves so the blood dosent backflow
Do capilliaries have valves?
Capillaries do not have valves. Veins are the blood vessels with valves.
How is the blood flow controlled in the veins?
The veins have valves in them
Can the valves be replaced in the deep veins with artificial valves?
no
Do veins have valves and arteries don't?
veins have valves because they bring blood from the bottom half of your body and valves stop the back flow of blood since the veins work against gravity.
What do arteries have that veins do not?
valves
What do veins have that arteries do not?
valves
One-way valves are found in which blood vessels?
Veins. Veins are blood vessels that carry blood from tissues and organs back to the heart; they have thin walls and one-way valves.
What prevents blood from flowing backward into the veins?
valves in the veins
Why do veins only have one way valves?
Veins have one way valves because the pressure in veins is lower than that in arteries, and the valves prevent backflow that could be caused by gravity or muscle flexure.
What are flaps of tissue that allow blood to flow in only one direction?
They are called valves, or leaflet valves in the veins, that interlock to prevent backflow of the blood.
