Gastrointestinal embryology

Card Set Information

Gastrointestinal embryology
2013-03-20 16:11:37

GI embryology
Show Answers:

  1. GI embryology
    embryological structures
    • Foregut: pharynx to duodenum
    • Midgut: duodenum to transverse colon
    • Hindgut: distal transverse colon to rectum
  2. Anterior abdominal wall defects
    Failure of ...
    • Rostral fold closure: sternal defect
    • Lateral fold closure: omphalocele, gastroschisis
    • Caudal fold closure: bladder exstrophy
  3. Gastroschisis
    • Extrusion of abdominal content through abdominal folds
    • NOT covered by peritoneum
  4. Omphalocele
    • Persistence of herniation of abdominal contents into umbilical cord
    • Covered by peritoneum
  5. Omphalocele: covered by peritoneum
  6. Atresia
    Duodenal, jejunal, ileal, colonic
    • Duadenal atresia: failure to recanalize (trisomy 21)
    • Jejunal, ileal, colonic atresia: due to vascular accident (apple peel atresia)
  7. Midgut development
    • 6th week: midgut herniates through umbilical ring
    • 10th week: returns to abdominal cavity + rotates around SMA
  8. Pathology
    • Malrotation of midgut
    • Omphalocele
    • Intestinal atresia or stenosis
    • Volvulus
  9. Tracheoesophageal anomalies
    Esophageal atresia (EA) with distal tracheoesophageal fistula (TEF) is most common  (85%)

    • Sx:
    • -drooling, choking, vomiting with first feeding
    • -TEF allows air into the stomach (visible on CXR)
    • -Cyanosis secondary to laryngospasm (to avoid reflux-related aspiration)

    • Clinical test:
    • -Filure to pass NG tube into stomach

    • Types:
  10. Congenital pyloric stenosis
    Hypertrophy of the pylorus causes obstruction

    • Presentation:
    • -Palpable "olive" mass in epigastric region
    • -nonbilious projectile vomiting at ~ 2 wks of age
    • -1/600 live births; more common in firstborn males

    Tx: Surgical incision
  11. Pancreas embryology
    • Derived from foregut:
    • -Ventral pancreatic bud → pancreatic head, main pancreatic duct; uncinate process
    • -Dorsal pancreatic bud → everything else (body, tail, isthmus, accessory pancreatic duct)
  12. Annular pancreas
    • Ventral pancreatic bud abnormally encircles 2nd part of duodenum
    • Forms ring of pancreatic tissue → duodenal narrowing
  13. Pancreas divisum
    Ventral and dorsal parts fail to fuse at 8 weeks
  14. Spleen embryology
    • Arises in mesentery of stomach (hence is mesodermal)
    • Supplied by foregut (celiac artery)