Superior Duodenal Flexure of the Left Intestine Lateral View

Description

Seen from a left lateral perspective in an adult male, the proximal small intestine is centered on the superior duodenal flexure at the duodenojejunal angle (angulus duodenojejunalis). The horizontal, ascending segment of the duodenum turns abruptly to become the jejunum, with the flexure positioned superior and left of the midline and tucked posterior to the stomach’s pyloric region. Suspensory support by the ligament of Treitz is implied at the cranial margin of the flexure, drawing the junction toward the posterior abdominal wall. A fixed bend. Clinically, the duodenojejunal flexure is a key orientation landmark during upper GI surgery and cross sectional imaging because it marks the transition from the retroperitoneal duodenum to the more mobile intraperitoneal jejunum. Its position relative to the ligament of Treitz matters in malrotation, where an abnormally low or right sided duodenojejunal junction raises concern for midgut volvulus and associated mesenteric vascular compromise. On fluoroscopy and CT enterography, radiologists use this junction to judge the course of the duodenum and to localize pathology near the fourth part of the duodenum, including extrinsic compression or obstructing masses. Use this artwork in gross anatomy and GI teaching modules to clarify the spatial relationship between the pylorus, the ascending duodenum, and the start of the jejunum, and in surgical atlases describing exposure of the ligament of Treitz during procedures such as duodenojejunostomy or reduction of internal hernias near the duodenojejunal region. It also supports radiology publications that reference the duodenojejunal angle as a landmark for normal rotation and fixation. Anatomical accuracy verified by SciePro's Medical Advisory Board.