So the capillaries basically take the de oxygenated blood and dump it out into the small veins known as the Venuels. And then we go into small veins and large veins and finally into our vena CaveA. So once the blood travels through the capillaries it enters the Venuels and the veins. Now let's recall what the structure is of our vein. The vein also contains a three layer system just like the artery but it has a very thin layer called the tunica media. So it has a very thin layer of muscle.