So since the fetal lungs are filled with fluid, they contain a high resistance to flow and that creates a high pressure. And as a result, the blood is rerouted and moves to the lower pressure left atrium via the four men ovaly. So there is this tiny one way door that opens as a result of that push, as a result of that difference in pressure. And so as the blood moves from the high pressure into the low pressure, this forayman O'Valley opens up and the blood travels into the left atrium and from the left atrium, it passes into the left ventricle and then it moves into our aorter. Now, of course, a small portion of that blood will leak from the right atrium and into the right ventricle and then will pass into the pulmonary trunk. Now, in the pulmonary trunk, remember, we don't want to waste any of that oxygen and nutrients on the lungs because the lungs inside that fetal individual are not yet developed.