Gross Anatomy USMLE Step 1 Practice Question
A 6-hour-old male newborn presents with bilious vomiting and abdominal distension. Vital signs show HR 145 bpm, RR 42/min, BP 65/40 mmHg, and temp 37.2°C. Prenatal ultrasound documented polyhydramnios. Current abdominal radiography reveals the classic double-bubble sign with air-fluid levels; notably, distal bowel gas is absent. The infant has not passed meconium. Failure of which developmental process most likely caused this condition?
Answer choices
- AAbnormal migration of ventral pancreatic bud
- BLateral palatine shelves
- CFailure of recanalizationCorrect answer
- DFailure of fusion of pancreatic buds
- EFirst pharyngeal arch
- FFailure of rotation of the midgut
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