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
Poal vein is formed ? 
Select and explain. 
A. Behind the spleen, B. Behind the tail of pancreas, C. Behind the neck of pancreas, D. Behind the second pa of duodenum
C: Behind the neck of pancreas
Answer: C: Behind the neck of pancreas 
Explanation: The poal vein is about 8 cm long.It is formed by union of superior mesenteric vein and splenic vein behind the neck of pancreas at the level of L2 veebrae in front of inferior vena cava (IVC).