<prompt> In a patient with liver cirrhosis, where does poal vein obstruction occur?Poal veinSplenic veinSinusoidsHepatic vein  <response>: In cirrhosis of the liver, poal vein obstruction occur at the level of sinusoids. In cirrhosis there is fibrosis of the liver resulting in architectural distoion with the formation of regenerative nodules. This results in a decrease in hepatocellular mass, its function, and an alteration of blood flow. Complications of cirrhosis includes poal hypeension and its consequences such as gastroesophageal variceal hemorrhage, splenomegaly, ascites, hepatic encephalopathy, spontaneous bacterial peritonitis SBP, hepatorenal syndrome, and hepatocellular carcinoma. Ref: Harrisons Internal Medicine, 18th Edition, Page 2598, Chapter 308 