This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
In which of the following organs are fenestrated endothelial cells common? 
Select and explain. 
A. Hea, B. Liver, C. Lungs, D. Pancreas
B: Liver
Answer: B: Liver 
Explanation: Fenestrated ("windowed") endothelial cells, which permit free flow of serum across the endothelium, are an unusual feature of the hepatic sinusoids. They are not seen in the other organs listed.