So these are the four ways by which there can be an exchange of nutrients and waste products inside the capillary, between the lumen of the capillary and the surrounding cells, tissues and organs of our body. So these are the three different blood vessels found inside our body. Arteries are very elastic. They have a high resistance, and they can recoil as a result of that thick layer of smooth muscle found in a tunica media. And they always carry blood away from the heart. Veins always carry blood to the heart.