A 4-month-old male infant is brought to the clinic because of excessive noisy respiration. On examination, the infant is within the normal range of growth, appears healthy, and does not show respiratory distress. Pronation is normal, along with head and neck examination findings. However, the child displays stridor (high pitched breathing sound) on inspiration, accentuated in the supine position. The parents report that the same stridor is heard during feeding or when the child is agitated. The attending physician places the child in the prone position and the stridor is relieved. To confirm, she holds the child in a neck extended position, which also relieves the stridor. An endoscopic laryngeal examination reveals bulky arytenoids cartilages and the diagnosis of laryngo-malacia is established. During development, the arytenoids cartilages arise from which of the following? (A) first pharyngeal arch (B) second pharyngeal arch (C) third pharyngeal arch (D) fifth pharyngeal arch (E) sixth pharyngeal arch
Posted on: Sat, 25 Jan 2014 03:02:20 +0000