Superior mesenteric artery
The superior mesenteric artery is the second of the three major anterior branches of the abdominal aorta (the other two are the coeliac trunk and inferior mesenteric artery). It arises anteriorly from the abdominal aorta at the level of the L1 vertebrae, immediately inferior to the origin of the coeliac trunk.
After arising from the abdominal aorta, the superior mesenteric artery descends the posterior aspect of the abdomen. At this point, it has several important anatomical relations:
- Anterior to the SMA – pyloric part of the stomach, splenic vein, and neck of the pancreas.
- Posterior to the SMA – left renal vein, the uncinate process of the pancreas, and inferior part of the duodenum.
- The uncinate process is the only part of the pancreas that hooks around the back of the SMA.
- The superior mesenteric artery then gives rise to various branches that supply the small intestines, cecum, ascending, and part of the transverse colon (fig).