Duodenojejunal flexure

Dr Henry Knipe and Dr Yair Glick et al.

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

Abdominal and pelvic anatomy
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Article information

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

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Cases and figures

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    The normal positi...
    Case 1: Normal position of the DJ flexure
    Drag here to reorder.
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