Tonotopic organization of the basilar membrane follows the principle that:
- A High frequencies are detected near the helicotrema (apex)
- B All frequencies are equally distributed along the basilar membrane
- C High frequencies are detected near the oval window (base), low frequencies near the apex ✓
- D Low frequencies are detected near the round window (basal turn)
Correct answer: C. High frequencies are detected near the oval window (base), low frequencies near the apex
Explanation
The basilar membrane shows tonotopic organization: it is narrow and stiff at the base (near the oval window), responding to high frequencies; wide and flexible at the apex (helicotrema), responding to low frequencies. This is the basis of the travelling wave theory (von Bekesy). Clinical consequence: ototoxicity (aminoglycosides, cisplatin, loud noise) affects high-frequency hearing first because basal hair cells are damaged first. On the audiogram, high-frequency SNHL appears at 4–8 kHz before lower frequencies.
Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.