Question
A patient presents with hearing loss specifically affecting high-frequency sounds, attributed to damage of the basilar membrane. Which of the following regions of the cochlea is most likely the site of damage to the hair cells?
| A. |
Modiolus
|
| B. |
Stria vascularis
|
| C. |
Helicotrema
|
| D. |
Oval window
|
Show Answer
|
Correct Answer » D
Explanation
|
|
– The cochlea is tonotopically organized; different sound frequencies are detected at various basilar membrane locations.
– High-frequency sounds are detected at the cochlea’s base near the oval window, where the basilar membrane is narrow & stiff.
– Sound vibrations enter through the oval window via the stapes footplate.
– Basal hair cells convert high-frequency vibrations → electrical signals.
– Damage here → high-frequency hearing loss, matching the clinical case.
Incorrect Options:
A. Modiolus – Central cochlear core; relays signals but doesn’t detect frequencies.
B. Stria vascularis – Maintains environment for hair cells; damage → general hearing loss.
C. Helicotrema – Apex of cochlea; sensitive to low frequencies, not high.
