The system of the superior vena cava, the superior vena cava, is a thick (about 2.5 cm) but short (5–6 cm) trunk, located on the right and somewhat behind the ascending aorta.
The superior vena cava is formed from the confluence vv. brachiocephalicae dextra et sinistra behind the junction I of the right rib to the sternum. From here it goes down along the right edge of the sternum behind the first and second intercostal spaces and at the level of the upper edge of the third rib, hiding behind the right ear of the heart, flows into the right atrium.
Its back wall is in contact with a. pulmonalis dextra, which separates it from the right bronchus, and for a very short distance, at the site of the confluence with the atrium, with the upper right pulmonary vein; both of these vessels cross it transversely.
At the level of the upper edge of the right pulmonary artery, v. Flows into the superior vena cava. azygos, bending over the root of the right lung (the aorta bends over the root of the left lung). The anterior wall of the superior vena cava is separated from the anterior wall of the chest by a rather thick layer of the right lung.