Morphology/Structure
The superior vena cava is a large valveless vein approximately 7 cm long. It’s formed by the unification of the brachiocephalic veins behind the inferior edge of the first right costal cartilage. The left brachiocephalic vein is the most superficial structure in the superior mediastinum and it travels inferiorly and obliquely to join the right brachiocephalic vein, thus forming the superior vena cava. The superior vena cava descends vertically and opens into the right atrium at the level of the third right costal cartilage.
Related parts of the anatomy
Key Features/Anatomical Relations
The hilum of the right lung sits posterolaterally to the superior vena cava, while the trachea and right vagus nerve sit posteriorly. The phrenic nerve descends laterally, while on its medial side the ascending aorta emerges from the pericardium. Inferiorly, the lower half of the superior vena cava sits within the pericardial sac.
Function
The superior vena cava is responsible for the venous return of deoxygenated blood from regions of the body above the level of the diaphragm. It's formed by the union of the brachiocephalic veins, which contain the deoxygenated blood from the head, neck, and upper limb. It receives the azygos vein which drains the posterior thoracic wall. Additionally, it receives small tributaries from the pericardium and the adjacent mediastinal tissues.
List of Clinical Correlates
- Superior vena cava obstruction
Learn more about this topic from other Elsevier products
Superior Vena Cava
The superior vena cava is a short ∼7-cm valveless vessel that brings blood from the upper half of the body to the heart but has connections to the infracardiac venous structures as well.
