They have different properties. So what happens when blood actually injures our veins? Well, when blood flows through our veins, the blood exerts a pressure on the walls of the veins. But the walls of the veins cannot actually push back the same way that the arteries can. And that's exactly why when the blood flows through the veins, that increases the volume of our vein and the veins can actually push back. They cannot recoil back.