where is superior vena cava
Vena cava: The superior vena cava is the large vein which returns blood to the heart from the head, neck and both upper limbs. The inferior vena cava returns blood to the heart from the lower part of the body. The return of blood via the vena cava can be compromised and cause disease. For example, in the superior vena cava syndrome, the symptoms that result from compression of the large vein that carries blood down to the heart.