Venous blood of liver is drained by
**Core Concept**
The liver receives venous blood from two main sources: the hepatic portal vein and the hepatic artery. The hepatic portal vein carries deoxygenated blood rich in nutrients and waste products from the gastrointestinal tract, spleen, and pancreas to the liver for detoxification, metabolism, and storage. The hepatic artery, on the other hand, supplies oxygenated blood to the liver.
**Why the Correct Answer is Right**
The hepatic veins are responsible for draining the liver's sinusoidal blood into the inferior vena cava. This process is crucial for the liver's detoxification and metabolic functions. The hepatic veins are formed by the union of smaller hepatic venules that collect blood from the liver sinusoids. The blood then flows into the inferior vena cava, which carries it to the right atrium of the heart.
**Why Each Wrong Option is Incorrect**
**Option A:** The hepatic portal vein is responsible for carrying blood from the gastrointestinal tract, spleen, and pancreas to the liver, but it does not drain the liver's blood.
**Option B:** The hepatic artery supplies oxygenated blood to the liver, but it does not drain the liver's blood.
**Option C:** The hepatic veins are responsible for draining the liver's blood, but this option is incomplete as it does not specify the destination of the blood.
**Clinical Pearl / High-Yield Fact**
The liver's unique dual blood supply, via the hepatic portal vein and hepatic artery, allows it to perform its critical detoxification and metabolic functions.
**Correct Answer: C. Hepatic veins.