Superior vena cava
The superior vena cava (German superior vena cava ) is a short, powerful venous blood vessel in the chest cavity . In animals, it is called the vena cava cranialis ("anterior vena cava").
It arises from the confluence of the right and left brachiocephalic veins retrosternal at the level of the first rib and thus collects the blood from the head, neck and upper extremities. The azygous vein joins the superior vena cava at the level of the third rib . The superior vena cava runs in the mediastinum and opens into the right atrium of the heart from above . As a normal variant, the left superior vena cava can persist .
In adults, the vein does not have a venous valve , which is why tricuspid regurgitation causes blood to flow back into the internal jugular vein , which can be perceived as a so-called venous pulse .