vena cava

a large vein carrying deoxygenated blood into the heart

There are two venae cavae in humans, the inferior vena cava (carrying blood from the lower body) and the superior vena cava (carrying blood from the head, arms, and upper body).

Venae Cavae

Either of two large veins that drain blood from the upper & lower body and empty into the right atrium of the heart.

"Hey Doc, when you cut me open, could you show me my venae cavae?"
"...F*ck that, just put this mask on."