auditory system Flashcards
sound travels in sine waves and is made up of
compression and rarefaction
sound moves through the ear
outer ear to tympanic membrane to eardrum then to ossicles (malleus, incus, stapes) oval or round window into cochlea to round window
the directional collector and ampifier
outer ear
impedance matching (of sound waves in air vs water) and protection
middle
spectral analysis and transduction
inner ear
outer ear structures
auricle and external auditory canal
middle ear structures
flanked by eardrum (oval window, round window) , ossciles and eustachian tube
the ____ ____ links middle ear with nasopharyngeal cavity- adjust to atmosphere pressure
eustachian tube
major function of middle ear is to transmit sounds in air to sound in ____; the sound is beining concentrated by stapes on oval window
liquid
muscles in middle ear
tensor tampani and stapedius
the oval window connects with liwuid in
scala vestibuli
the scala tympani connects with the ___ ___ and it bulges outward to relieve pressure
round window
within scala media there is the ___ ___
tectoral membrane
the hair cells in the tectoral membrane are apart of the __ ___ __ and innervated by spinal ganglion
orga of corti
all hair cells have ____ which tectoral membrane sits on top of
stereocilia
the vibrations from the stapes on the oval window are conducted through the perilymph, the scala vestibuli ____ perilymph towards helicotrema through scala tympani and displaces ____ ___
displaces; round window
movement of perilymph causes upwards and downwards movements of ___ ___
scala media
_____ frequencies stimulate the basilar membrane to move better at the base
higher
_____ frequencies stimulate the basilar membrane to move better at the apex
lower
at the apex the fibers are ____ and its broad and flaccid
longer
movement of basilar membrane drives _____ force on stereocilia embedded in tectorial membrane
shearing
hair cells do not have ___ ____
action potentials
if the sound moves the tectorial membrane and therefore hair cells to the tallest ones then there is ____ and release of NT
depolarization
the kinocilia is always with the ____ stereocilia
tallest
kinocilia degenerate in cochlea from hair cells during ____
development
transduction of sound occurs through _____ gated ion channels
mechanically
each stereocillium linked to adjacent by ___ ____
tip links
the tip links open lid of ion channel when stretched; closes when relaxed; what happens when stretched towards tallest
channels are not very selective so Ca2+ and K+ caise depolarizatiom and release of NT onto afferent nerve
the scala tympani and vestibuli are perilymph which is low in
K+
scala media has endolymph which has high
K+
hair cells are innervated by two different types of nerve
afferent spiral ganglion and efferent fibers from superior olivary complex
each inner hair cell is innervated by many spiral ___ cells
ganglion
efferent effects on hair cells are typically ____ and ____ target cell
inhibitory and hyperpolarize
outer hair cells respond to different sound volumes by ___ ___
changing length (electromotile response)
outer hair cells help us to focus on particular sounds (attention) and ___ ___ sounds
low level
fibers from specific parts of basilar membrane are active specific frequencies
place code
synchronzied firing (low freq.): phase locking neurons which fire in synchrony to portion of wave form
temporal code
different neurons work together, firing at diff. times- together fire at actual freq.
volley principle of temporal code
areas we receive auditory info in pons
nucleus of lateral leminuscus and superior olivary
difference in arrival times of sound to ears is called
interaural time difference
locations of sound can have same ITDA they will lie in
cone of confusion
difference in sound preference for high freq. sounds; the head will create a barrier that interferes with these sounds reach other ear in front or behind
interaural intensity difference
__ ___ ___ neurons are coincidence detectors- respond only with excitatory signals which arrive simulatanously
medial superior olive
the IID works in _ ___ ___ which gets info from both ears and from ipsilateral side it will be excitatory and from contralateral LSO will make that excitatory signal inhibitory.
Lateral superior olive
sound vibrations can’t be conducted to inner ear (ear wax, ruptured ear drum)
conduction deafness
damaged hair cells or auditory pathway; usually result of age or extremely loud noises
sensorineural deafness
infection of middle ear; eustachian tubes become swollen and occluded
otitis media
