Well, as soon as that fetus is bored and takes their first breath, what happens is the air rushes into the alveoli of the lungs and it displaces the fluid that is within the alveoli of the lungs. And that decreases. It drops the resistance and pressure inside those lungs. 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.