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oxygen, e call venous blood, is pumped

through the leg s to the

heart

"The veins of the legs have valves which are

similar to those of the heart They allow blood to pass

through towards the heart while they prevent the

blood flowing backwards towards the foot In this way

they only allow blood flow in one direction: toward

the heart

"During the pu phase or muscle

contraction, the pressure within the veins is increased,

pu phase or muscle relaxation,

the pressure within the veins is reduced and the veins

fill themselves with blood in preparation for the next

pu phase This prevents thrombosis, blood