Expansion
Runs obliquely from the duodenojejunal flexure to the right sacroiliac joint, about 15 cm long
Expansion
- Runs from the duodenojejunal flexure (upper left, at L2) to the right sacroiliac joint (lower right)
- About 15 cm long at its root, but fans out to support around 6 metres of small bowel
- Crosses the third part of the duodenum, the aorta, the inferior vena cava, the right ureter and the right psoas
Contents include the superior mesenteric vessels and their branches, autonomic nerves, lymphatics and mesenteric nodes, and a variable amount of fat.
The obliquity matters clinically. It divides the inframesocolic compartment into right and left spaces, and the broad base normally prevents rotation. In malrotation the root is narrow and vertical, allowing the entire midgut to twist around the superior mesenteric artery, a surgical emergency in the neonate.