3) The liver produces urea andother waste materials andthen it pours it all in the rightventricle of the heart for oxygenation.The heart then distributesthe blood to variousparts of the body. So the impureblood brought by the HepaticVein and other blood vesselsgets distributed throughthe aorta. This clearly indicatesthat hepatic vein carries thelargest amount of urea, whilethe renal vein carries the least.