Question

what is the role of valves in veins ??​

Answer 1

it is not known by myself sorry

Answer 2

Answer:

The valves function to keep blood moving in one direction. ... When the muscles contract the blood within the veins is squeezed up the vein and the valves open. When the muscle is at rest, the valves close helping to prevent the backward flow of blood. This is referred to as the muscle pump.