Hepatic veins ultimately from numerous central veins of the liver lobules. None of the hepatic veins have valves. The hepatic veins are divided into an upper and a lower group. The upper three drain the central veins from the right, middle, and left regions of the liver and are larger than the lower group of veins. The lower group of from six to twenty smaller hepatic veins come from the right lobe and the caudate lobe, are in contact with the hepatic tissue, and are valveless. All the veins empty into the inferior vena cava at the back of the liver. Budd–Chiari
Collateral adjective Collateral adjective A collateral adjective is an adjective that is identified with a particular noun in meaning, but that is not derived from that noun. For example, the word "bovine" is considered the adjectival equivalent of the noun "cow", but it is derived from a different word, which happens to be the Latin word for "cow". Similarly, "lunar" serves as an adjective to describe attributes of the Moon; "moon" comes from Old English "mōna" "moon" and "lunar" from Latin "luna" "moon". The adjective "thermal" and the noun "heat" have a similar semantic relationship. As in these examples, the collateral adjective