This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Small and Large intestine, Subject name: Anatomy
Which of the following is anteriorly related to third pa of duodenum: 
Select and explain. 
A. Poal vein, B. Head of pancreas, C. Hepatic aery, D. Superior mesenteric vein
D: Superior mesenteric vein
Answer: D: Superior mesenteric vein 
Explanation: Superior mesenteric vein (and aery) cross the anterior to the third pa of the duodenum to enter the mesentery of small intestine. Head of pancreas is in superior relation. Relations : anteriorly: small bowel mesentery root and sup. mesentric aery. :posteriorly: right psoas muscle, right ureter, gonadal vessels, aoa and IVC.