10. Hearing and the cochlea

Hair cells transduce _ into _ through _.

mechanical vibration, neural signaling, mechanically gated channels.

Pitch is coded by _ along the _.

location, basilar membrane

loudness is coded primarily by _.

action-potential frequency

Sound vibrates the _. The malleus, incus, and stapes _ as it reaches the oval window.

tympanic membrane, preserve the stimulus frequency and amplify the vibration

Movement at the oval window creates _. High-_ surrounds the hair-cell apical surface, and the tectorial and basilar membranes move _.

fluid waves, potassium endolymph, relative to one another

What pulls open mechanically gated ion channels?

Bending the cilia toward the tallest edge of the hair bundle

The hair cell [3 things] the cochlear nerve

depolarizes, releases transmitter, and stimulates

the hair cell itself is not/is an action-potential-generating neuron

is not

A louder sound_, produces _, and _ the firing frequency of the auditory nerve

bends the cilia more, more transmitter release, increases

How does pitch work?

Because the basilar membrane is stiffer and thinker near the oval window, and the opposite is true near the distal cochlea, High frequencies activate hair cells closer to the oval window while lower activate hair closer to the distal regions.

What is the process of which pitch works called?

place/tonotopic coding

How does cochlear implants work?

Noise-damaged hair cells do not regenerate, so the loss can be permanent. A cochlear implant bypasses hair cells and electrically stimulates the cochlear nerve at different locations; electrode stimulation amplitude can encode intensity