<prompt> Posterior relations of head of pancreas are all EXCEPT:Common bile ductInferior vena cavaFirst pa of duodenumAoa  <response>: First pa of duodenum is anterior and superior to the head of pancreas.Aoa is posterior to the uncinate process of pancreas not the head. Right and left renal veins drain into IVC behind the head of pancreas 3 veins lie posterior. Bile duct passes behind the head of pancreas and is joined by pancreatic duct, before opening into second pa of duodenum. 