When the stereocilia of a hair cell in the inner ear bends, it causes:
a. potassium ions to enter the hair cell
b. you to hear low frequency sounds
c. chloride ions to leave the basilar membrane
d. all of the above
To determine the correct answer, let's break down the options and their implications:
a. Potassium ions enter the hair cell: This is correct. When the stereocilia of a hair cell in the inner ear bend, it opens ion channels on the cell membrane, allowing potassium ions (K+) to enter the hair cell. This influx of potassium ions triggers an electrical signal, which is essential for hearing.
b. You hear low-frequency sounds: This is not directly caused by the bending of stereocilia. The perception of different frequencies of sound is primarily determined by the location on the basilar membrane where the hair cell is located. High-frequency sounds cause the basilar membrane near the base (close to the oval window) to vibrate, while low-frequency sounds cause the basilar membrane near the apex (farthest from the oval window) to vibrate. So, the bending of stereocilia causes the hair cell to send signals to the brain, but it does not directly determine the frequency of the sound being heard.
c. Chloride ions leave the basilar membrane: This is incorrect. The bending of stereocilia in the inner ear hair cells does not cause chloride ions (Cl-) to leave the basilar membrane.
Considering the explanations above, the correct answer is:
a. Potassium ions to enter the hair cell