Anatomy of the inferior mesenteric blood vessels and their branches. The transverse colon is reflected upwards to reveal the inferior mesenteric vein and the splenic vein draining into the superior mesenteric vein (blue). Veins of part of the transverse colon and all of the descending colon unite to form the inferior mesenteric vein. From Sobotta, J. (1906) Atlas der deskriptiven Anatomie des Menschen. Vol 3, Das Nerven- und Gefasssystem des Menschen. J. F. Lehmann, Munchen, Fig 518.