It needs its own nutrient and oxygen supply so it can keep beating every day, all day long. A complex system of veins and arteries keep the heart supplied with blood and allow the blood to circulate through the body. Coronary arteries supply the heart with oxygenated blood. The right coronary artery starts from the right aortic sinus and travels through the coronary sulcus located between the right atrium and ventricle. It has four branches: Sinoatrial nodal artery: Supplies the sinoatrial node.