what are the 3 divisions of the cochlear nuclei
the dorsal, posteroventral and anteroventral nuclei.
the whole range of ____ transduced by the cochlea is represented in each of its three nuclei.
one ___ = a sine wave
oval window is smaller than tympanic
20x pressure increase
lever action of ossicular chain -->
___x force increase
- from base to apex there is an increase in
width by a factor of 10
- from base to apex there is a decrease in
3. conduction velocity
how are hair cells at the apex compared to the base?
LESS stiff and LONGER
High frequency = higher amplitude = ___ distance traveled
___ frequencies go farthest on the basilar membrane
Auditory receptor cells at each point along the basilar membrane respond to the amplitude of the traveling wave that ___
Hair cells spontaneously oscillate & are most sensitive to sound frequencies which
match their oscillation frequencies
The ___ membrane is connected to the basilar membrane via the rigid limbus
Pushing up the basilar and tectorial membranes shears the cilia in one direction, which opens __channels and depolarizes the cell
what is the normal potential difference between the sacla media and hair cell interior
(scala media = 80 mV, hair cell interior = -70 mV)
what pushes K+ into hair cells?
The scala media’s high (+) potential electrochemical gradient (150 mv)
what range of frequencies does the 3 cochlear nuclei receive?
each nucleus receives the full
range of frequencies
what type of pitch does the auditory cortex receive?
pitch patterns but necessarily pitch
Cochlear prostheses bypass the hair cells and excite the___
appropriate nerve fibers.
general method of cohclear implants is to pass multiple electrodes into the ___
The auditory system respond to a series of rapid fluctuations in______ brought about by the rarefaction and compression of air molecules.
the greater the magnitude of the amplitude of the sound the greater the
physical magnitude of the sound.
how much of the incident energy is transmitted at the oval window
in decibals how much sound is lost by the time it reaches the oval window
At the oval window, only about 1/1000 of the incident energy is transmitted.
To compensate for this loss requires an approximately ___ increase in pressure
The 32-fold increase is accomplished in the ___ ear,
The effective area of the tympanic membrane is about 60 square millimeters and that of the oval window about 3 square millimeters.
This results in a ___-fold increase in pressure at the oval window.
he force at the oval window is not equal to the force applied at the tympanic membrane but actually exceeds it by a factor of
As a result of forced applied at 1. the oval window 2. at the tympanic membrane
the pressure at the oval window is increased by a factor of ___
In conductive hearing losses more sound is ____ then in the normal middle ear.