Top view of the heart.
Observe the right atrium (RA) and ventricle (RV) with the right coronary artery (1), the ascending aorta (Ao) and the pulmonary trunk (PT).
The sinoatrial node (3) artery is observed.
On the left , observe the anterior descending artery (2) with its branches. And the circumflex artery (Cx)-

Image #34