Hello everyone! It’s Matt from Kenhub, and in this tutorial, we will discuss the superior vena cava. The superior vena cava, also known as the cava, is a short but large-diameter vein located in the anterior right superior mediastinum. In this tutorial, we will refer to it as the SVC. You can see now, on this image of the anterior view opened thorax, the SVC highlighted in green. Embryologically, the SVC is formed by the left and right brachiocephalic veins, sometimes called the innominate veins, which also received blood from the upper limbs, eyes, and neck.
There is no valve that divides the SVC from the right atrium. This atrium conducts blood from right atrial and right ventricular contractions upwards into the internal jugular vein which is measured as the jugular venous pressure and into the sternocleidomastoid muscle. Positionally, the SVC begins behind the lower border of the 1st right costal cartilage and descends vertically behind the 2nd and 3rd intercostal spaces to drain into the right atrium at the level of the 3rd costal cartilage. Its lower half is covered by the fibrous pericardium which is pierced by the SVC at the level of the 2nd costal cartilage.
The SVC is one of the 2 large veins by which blood is returned from the body to the right side of the heart. After circulating through the body systematically, deoxygenated blood returns to the right atrium of the heart through either the SVC which drains the upper body or the inferior vena cava (IVC) that drains everything below the diaphragm.