Hearing Flashcards
What is the order of positioning of the hair cells and two membranes
Basilar on the bottom
Hair cells inbetween
Tentorial membrane on top
Antibiotics and aspirin can effect hearing, how?
Damaging the outer hair cells
What is the name of the cilia on the hair cells?
Stereocilia
What must occur to the cilia for K channels to open?
They must move in the direction of the kinocilium
What is the downstream effect of movement towards the kinocilium?
K channels open > K influx > Depolarisation of the cell > Ca channels open > Neurotransmitter is released
What is special about the endolymph in the scala media?
It is high K - means there will be a K influx in response to channel opening
Which hemisphere is speech usually processed?
Left
Where does integration of sound signalling from both ears occur?
In the brainstem - particularly the superior olivary complex
Sclerosis of the ossicles causes what?
Profound effects on hearing
Compare the roles of the outer and inner hair cells?
Inner hair cells do must of the signal transduction for hearing while the outer ones amplify the movement of the membranes
How do you localise low frequency sounds in the horizontal plane?
Measuring the time for sound to arrive at each ear
T/F Must hearing loss has a known cause?
False
Why do you need impedance matching?
Because transferring sound from air to fluid is usually prevented by reflection
How is the auditory cortex organised?
Tonotopically - different areas are organised by the frequency they can process
The amplitude of sound determines its what?
Loudness
Through what do the ossicles transmit the vibrations from the tympani membrane to the inner ear?
Oval window
In which inner ear chamber does most of the important events occur?
Scala media
Which end of the basilar membrane deal with the high frequency sounds?
The base (lateral end)
How do you localise high frequency sounds on the horizontal plane?
Measuring the difference in intensity
Which hemisphere is music usually processed?
Right
What is the function of the outer hair cells?
Amplify the amount of vibration of the basilar membrane in response to efferent signal
What are the membranes of the inner ear?
Basilar
Tentorial
The wavelength of sound determines its what?
Pitch
Which neurotransmitter do the hair cells release?
Glutamate
Which end of the basilar membrane deals with low frequency sounds?
Apex (medial end)
What is the sequence of structures in the auditory pathway?
Hair cells > CNVIII > Cochlear Nucleus > Superior Olive > Lateral lemniscus > Inferior colliculus > Thalamus > Auditory cortex
How are the cilia structured?
Shortest to tallest - the tallest is the most important
Which type of antibiotic is particularly important in causing damage to outer hair cells?
Aminoglycosides
What are the important parts of the superior olivary complex?
Lateral and medial superior olives and the trapezoid body
What is impedance matching?
Translating the info as sound waves in air to waves in fluid
