Simplified schematic of major blood vessels in the mature pancreas. Two sources of splanchnic arteries supply blood to the pancreas. The head of the pancreas, derived from the dorsal bud, receives blood from the superior mesenteric arteries. The rest of the pancreas, namely the neck, body and tail, are supplied by the splenic arteries. Blood is then drained via the splenic vein into the portal vein. Blue, veins; Red, arteries.