Audition Lec25 Flashcards
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.
frequencies
one ___ = a sine wave
tone
oval window is smaller than tympanic
membrane –>
20x pressure increase
lever action of ossicular chain –>
___x force increase
1.3
- from base to apex there is an increase in
width by a factor of 10
- from base to apex there is a decrease in
- stiffness
- frequency
- conduction velocity
how are hair cells at the apex compared to the base?
LESS stiff and LONGER
High frequency = higher amplitude = ___ distance traveled
shorter
___ frequencies go farthest on the basilar membrane
Low
Auditory receptor cells at each point along the basilar membrane respond to the amplitude of the traveling wave that ___
reaches it.
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
tectorial
Pushing up the basilar and tectorial membranes shears the cilia in one direction, which opens __channels and depolarizes the cell
K
what is the normal potential difference between the sacla media and hair cell interior
150 mV
(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 ___
Scala Tympani.