Duodenojejunal flexure

The duodenojejunal (DJ) flexure or junction is the anatomical border between the duodenum and the jejunum.

The DJ flexure is located anterolateral to the aorta at the level of the upper border of the second lumbar vertebra. It makes a sharp turn anteroinferiorly to become the jejunum.

The DJ flexure is suspended from the ligament of Treitz, which serves as its surgical landmark and gives it its unique shape. It also marks the small bowel's transition from the retroperitoneum, which invests the duodenum, into the peritoneal cavity.

  • venous anatomy not well characterised
  • veins accompany arteries of corresponding names and may drain directly into the superior mesenteric vein
  • sympathetic: periarterial plexuses on the branches of the coeliac artery and superior mesenteric artery

  • parasympathetic: vagal fibres from the coeliac plexus synapse on neurones in the duodenal wall

Share article

Article information

rID: 51771
Section: Anatomy
Synonyms or Alternate Spellings:
  • Duodenojejunal junction
  • Duodenal-jejunal flexure
  • Duodenal-jejunal junction
  • DJ flexure
  • DJ junction

Support Radiopaedia and see fewer ads

Updating… Please wait.

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.