In patients with cirrhosis of the liver the site of obstruction in the poal system is in the?
**Core Concept**
Liver cirrhosis is a condition characterized by scarring and fibrosis of the liver, leading to portal hypertension. The portal system is a network of veins that carry blood from the gastrointestinal tract, spleen, and pancreas to the liver. In cirrhosis, the increased pressure in the portal system causes obstruction at a specific site.
**Why the Correct Answer is Right**
The site of obstruction in the portal system in patients with cirrhosis of the liver is typically at the hepatic veins or at the level of the hepatic sinusoids, where the liver receives blood from the portal vein. However, the most common site of obstruction is at the level of the hepatic sinusoids, where the liver's sinusoidal architecture is disrupted due to fibrosis and scarring. This leads to increased resistance to blood flow and portal hypertension.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the hepatic artery is a branch of the aorta that supplies oxygenated blood to the liver, and its obstruction would not lead to portal hypertension.
* **Option B:** This option is incorrect because the splenic vein is a part of the portal system, but its obstruction would lead to splenic vein thrombosis, not portal hypertension due to cirrhosis.
* **Option C:** This option is incorrect because the inferior vena cava is a large vein that carries blood from the lower body to the heart, and its obstruction would lead to inferior vena cava syndrome, not portal hypertension due to cirrhosis.
**Clinical Pearl / High-Yield Fact**
In patients with cirrhosis, the increased resistance to blood flow in the portal system can lead to the development of portal hypertension, which is a major risk factor for variceal bleeding and ascites.
**Correct Answer: C.**