The Heart Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The major Arteries to head and arms external and Right pulmonary veins Left pulmonary internal parts Superior vena cava Left pulmonary of the heart are Interatrial septum Pulmonary trunk shown in this diagram Right atrium Aortic semilunar The black arrows (tricuspid)valve Left ventricle indicate the route Inferior vena cava taken by the Myocardium blood as it is Right ventricle Epicardium pumped along. milunar vaiveThe major external and internal parts of the heart are shown in this diagram. The black arrows indicate the route taken by the blood as it is pumped along. The Heart