And as soon as the pressure drops, now, the blood inside the right atrium can begin moving easily into the right ventricle, then into the pulmonary trunk and into the lungs. And so what that means is the pressure inside the right side of the heart will drop. And because we have more blood rushing into the lungs, the lungs will pump more blood into the left side of the heart, into the left atrium, and so the pressure on the left side will increase. And so what happens at birth is we have a reversal in pressure taking place. Before birth, the right side of the heart was at a higher pressure than the left side. And what that means is the pulmonary system was at a higher pressure than the systemic circulatory system.