After it has been purified, the blood returns to the circulatory system through the renal vein. The kidneys produce urine and this helps maintain water balance. The urine is taken from the kidneys ...

Medically reviewed by Scott Sundick, MD The inferior vena cava (also known as IVC or the posterior vena cava) is a large vein that carries blood from the torso and lower body to the right side of the ...