Now, inside the pulmonary trunk, we also have another type of duct known as the ductus arteriosis. Remember the other type of duct that's known as the ductus venosis, but we're not going to focus on it in this lecture. So we have the ductus arteriosis that connects the pulmonary trunk to the aorter. And remember, inside that developing fetal heart, there's a higher pressure inside the pulmonary trunk than inside the order. And so what happens is most of that oxygenated blood will once again bypass the lungs, will be redirected away from the lungs and directly into the systemic circulatory system into the order. Now, a tiny bit of that blood will still make its way into the lungs.