So the ductus arteriosis connects the pulmonary trunk directly to our order. And so as that blood fills the pulmonary trunk, some of it actually leaves or most of it leaves this section, the pulmonary artery and enters our aorter. Now, of course, a small amount of that oxygenated and nutrient filled blood will actually leave and enter the left and right pulmonary artery. And so they will carry the oxygen to the lungs. And that's okay because the lungs do need a small amount of oxygen to actually develop further. So once our partially oxygenated blood travels into our order, what happens is it begins to move into the tissues and organs found in the upper portion of that fetus and the lower portion of that fetus.