How does veins prevent back flow?
The pressure excreted by the heart pushes the blood back
The valve in the veins prevent back flow
The suction in the heart pulls up the blood
None of the above
The valves in the veins are unidirectional. They allow blood flow only in one direction and this way veins do not have back flow.
Due to presence of _______ , back flow of blood is prevented in veins.
Veins have valves to prevent the backflow of blood because the blood in veins flow ________.