The internal nasal valve is formed by the angle between the nasal septum and which structure?
- A Lower lateral (alar) cartilage
- B Upper lateral cartilage ✓
- C Nasal bone
- D Piriform aperture margin
Correct answer: B. Upper lateral cartilage
Explanation
The internal nasal valve lies at the junction of the caudal border of the upper lateral cartilage with the dorsal septum, normally measuring 10 to 15 degrees. It is the narrowest segment of the nasal airway and the main site of inspiratory resistance. The angle between the lower lateral cartilage and the septum relates to the external valve, and the piriform aperture margin forms part of the valve area but not the defining angle.
Reference: Dhingra, Diseases of Ear, Nose and Throat, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.