Asthma USMLE Step 1 Practice Question
A male newborn presents 2 hours after birth with cyanosis, choking, and coughing during his first feeding. Maternal history includes polyhydramnios. Vital signs show tachypnea (RR 68/min), tachycardia (HR 162/min), and SpO2 88% on room air. Attempts to pass a nasogastric tube fail at 10-12 cm. Chest X-ray reveals coiling of the tube in the proximal esophagus with no gastric air bubble. No cardiac murmur is auscultated. Which embryologic abnormality most likely explains this presentation?
Answer choices
- AFailure of fusion of pleuroperitoneal membranes
- BAbnormal partitioning of the foregut by the tracheoesophageal septumCorrect answer
- CFailure of recanalization of the laryngeal lumen
- DPersistence of the urachus
- EAbnormal migration of neural crest cells into the conotruncal ridges
- FFailure of separation of the dorsal and ventral pancreatic buds
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