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26 Cards in this Set
- Front
- Back
What is the name of the first first membrane an air pressure wave will see in the ear?
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Tympanic membrane
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What are the names of the bones? Start with the one touching the tympanic membrane.
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Malleus bone -> incus -> staples
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What does the footplate of the stapes cover?
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A hole in the temporal bone called the oval window.
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What structure is found on the other side of the oval window?
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Bony laybrinth
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What is fluid is contained within the vetibule of the bony labyrinth?
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perilymph
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Regarding hearing, to what structure does the vetibule lead?
What hearing structure is found in this area? |
cochlea
organ of Corti |
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What liquid surrounds the hair cells?
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endolymph
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What are the three cavities within the organ of Corti?
In which of these are the hair cells located? |
Scala vestibuli, Chochlear duct,
Scala tmpani Chochlear duct |
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The hair cells are attached to this structure: ______.
What structure touches the top of the outer hair cells and may touch the top of the inner hair cells? |
Baslar membrane
Tectorial membrane |
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Name the structures found in the organ of Corti.
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Tectorial membrane
Outer and inner hair cells Basliar membrane Fibers of choclear nerve |
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What happens after the pressure wave results in the movement of the oval window?
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The stapes goes in-out-in, the secondary tympanic membrane (round window) goes out-in-out, and the basilar membrane goes down-up-down. The result is vibration of hair cells and the generation of an electrical signal.
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What is the name of the structures attached to a hair cell which result in electrical activity when moved?
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Stereocillum
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What happens as the sterecillum of hair cells are moved?
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Each stereocillum is mechanically linked to its neighbor by a tip link. When the stereocillum is bent, the tip link will open a gated K+ channel on a neighboring stereocillum. The inflow of K+ leads to depolarization of the hair cell which results in an influx of Ca++. This in turn releases glutamate on the basilar side of the cell and this leadds to stimulation of the postynaptic cochlear nerve.
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What special effect is exhibited by outer hair cells?
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They are contractle. Vibration of their basilar membrane results in a change of their membrane potential. This in turn increases the stimulation of inner cells, i.e. amplifies their signal.
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How is a tonotopic distribution obtained in the cochlear duct?
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The basilar membrane increases in thickness versus distance along the chochlear duct. Higher frequencies will tend to resonate at the thinner regions of the membranes.
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What is the pathway followed by the vestibulocochlear nerve as it leaves the Cochlea?
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Synapse in Cochlear nuclei in the pons -> synapse in the inferior colliculus of midbrain -> synapse in the medial geniculate nucleus of the thalamus -> synape in primary auditory cortex.
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What is the pathway which leads to cochlear tuning?
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vestibulocochlear nerve -> synapse coclearn nuclei -> synapse superior olivary nucleus of pons -> synapse in cochlea.
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What is the pathway for the tympanic reflex?
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Vestibulocochlear nerve -> syanpse superior olivary nucleus of pons -> CN V3 and VII -> synapse tensor tympani and stapedus muscles.
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What is the pathway for the auditory reflex (head turning)?
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Vestibulocochlear nerve -> synapse inferior colliculus of midbrain -> synapse neck muscles.
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What is conduction deafness?
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There is some type of blockage or mechanical problem in delivering the sound to the labyrinth.
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What type of deafness has damage to the hair cells, cochlear nerve firbers or cochlear nuclei?
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Sensorineural deafness
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What two mechanisms does the brain use to perform sound localization?
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1) Shadowing (head attenuates signal from one side)
2) Distance (time of arrival differences) |
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What structure in the brainstem compares signals fromt eh right and left ears to identify the direction from which a sound is coming?
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Superior olive
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What is the major ascending auditory pathway of the brainstem? Where does it mostly terminate?
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lateral lemniscus
inferior colliculus |
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What structure carries fibers fromt eh inferior colliculus to the medial geniculate nucleus?
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brachium of inferior colliculus
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What three things are done by the superior olive?
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1) Involved in cochlear tuning
2) Controls tensor tympani and stapedius mm 3) Compares signals from teh right and left ears to identify the direction from which sound is coming. |