Now, when the oxygen is picked up, it is picked up by these blood vessels. And then the blood vessels connect to the umbilical vein and umbilical vein. This blood vessel, shown in red, actually carries the oxygenated and nutrient filled blood to the organs, tissues and structures found within that developing fetus. So this is how gas exchange actually takes place. Now, the question we want to ask in this lecture is what exactly makes the placenta effective and efficient in actually exchanging that oxygen and what allows it to exchange that oxygen, carbon dioxide, in the right direction. So remember, we want the placenta not only to exchange the gases quickly and efficiently, but we also want to exchange the gasses in the right direction.