- Junction of foregut and midgut
- Duodenum is initially convex ventrally (with a ventral and dorsal mesoduodenum)
- 90 degree rotation leads to stomachs right wall becoming posterior, liver in ventral mesogastrium goes to the RUQ and the duodenum which is elongating becomes retroperitoneal after settling to the right in a C formation
- The walls grow at a differential rate leading to the BP ducts draining onto the medial aspect of the duodenal C
- 3 key steps - rotation, fixation, axial rotation (panc buds)
- Subsequent cell proliferation leading to luminal obliteration (week 10) and recanalization
- Week 4 - commences development from distal foregut and proximal midgut
- Cell proliferation, luminal obliteration (week 10) and recanalization
Key points of embryology
- Junction at ampulla
- Ventral c shape rotates → retro
- Dual blood supply
- Proliferation, obliteration, recanalization
Duodenal Anomalies
- Duodenal atresia
- Luminal obliteration with failure to recanalise
- Projectile vomiting and failure to thrive
- Associated with downs
- Mx - duodenojejunostomy or gastrojejunostomy