This is our superior and inferior vena cava, the right atrium, the right ventricle, the left atrium, the left ventricle. We have the pulmonary arteries that extend into the lungs. And we have our order that splits into the ascending and descending a order. Now let's zoom in. Let's take a look at the right atrium of the heart. So this is the right atrium and the upper wall of the right atrium of the heart.