The blood returns to the heart through the veins under low pressure.

The blood returns to the heart through the veins under low pressure. What feature of the structure of the veins ensures the movement of blood through them?

It’s not really about the structure of the veins. These are normal blood vessels that travel to the heart and lungs. The blood flows through the veins really slower. This is due to the fact that the veins are located much further relative to the heart. In any closed water supply or heating system, we will notice the same effect. The water from the pump moves faster because there is a short distance from the pump. Also, capillaries are affected. In capillaries, blood moves much slower due to their number. The blood accelerates a little through the veins.