Embryology USMLE Step 1 Practice Question
A 3-day-old male neonate presents with polyhydramnios noted prenatally and respiratory distress at birth. Examination reveals excessive drooling and inability to pass a nasogastric tube into the stomach. Chest X-ray shows a coiled catheter in the proximal esophagus with air in the stomach. Which of the following embryologic defects best explains this presentation?
Answer choices
- AIncomplete neural crest cell migration to the enteric nervous system
- BFailure of the dorsal pancreatic bud to fuse with the ventral pancreatic bud
- CFailure of foregut lateral plate mesoderm to form the diaphragm
- DAbnormal migration of the vitelline duct remnant
- EFailure of the tracheoesophageal septum to divide the foregutCorrect answer
- FFailure of the esophageal epithelium to recanalize during the 8th to 12th week of development
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