So let's begin with the right pump. So once the right ventricle is fully filled with our deoxygenated blood, what happens is there is a build up of pressure. And what that means is this ventricle, the right ventricle, begins to contract and that causes the closure of this tricuspid valve and it causes the opening of the pulmonary valve. And now our de oxygenated blood can flow via the pulmonary arteries and into the left and the right lung. Now, at the same exact moment in time we have our filling of this left ventricle. Because it is now fully filled with oxygenated blood.