Embryology USMLE Step 1 Practice Question
A 3-month-old female presents with nasal regurgitation during feeds and recurrent otitis media. Vital signs show HR 140 bpm, RR 35 breaths/min, and normal temperature. Physical examination reveals an isolated cleft of the secondary palate without cleft lip involvement. Palatal imaging confirms the defect. No associated cardiac anomalies are present. Failure of fusion of which embryologic structure most likely caused this isolated palatal defect?
Answer choices
- AFirst pharyngeal pouch
- BFirst pharyngeal arch
- CFrontonasal prominence
- DLateral palatine shelvesCorrect answer
- ESecond pharyngeal arch
- FNasal septum
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