This 3D printed specimen preserves the external anatomy of the heart and the distal trachea, carina, and primary bronchi in the posterior mediastinum relative to the great vessels and left atrium (which demonstrates the pericardial reflections of the transverse and oblique pericardial sinuses). An anterior window has been dissected into the right atrium and base of the auricle, exposing the right atrioventricular (tricuspid) valve and passage into the right ventricle. Both the right and left coronary arteries and named branches are visible (with the posterior interventricular artery arising from the right coronary artery). The left auricle has been sectioned to demonstrate the course of the circumflex artery in the coronary groove. The cardiac veins have been removed, but the coronary sinus has been retained inferior to the left atrium. The pulmonary trunk has been removed to expose the (open) pulmonary semilunar valves, while the arch of the aorta is intact to display the origins of the brachiocephalic trunk, left common carotid, and left subclavian. Adjacent to the aorta, the termination of the left and right brachiocephalic veins and azygos vein into the superior vena cava is preserved.