inner ear Flashcards
the inner ear is filled with
fluid
vestibular division
responsible for balance
hearing division
contains cochlea (cochlea is narrower at apex and wider at the base), info related to sound
osseous spiral lamina
inside bony cochlea, structure that is series of shlves where the membranous structure sits and provides support
modiolus
central core (pillar) of spiral lamina, houses auditory nerve fibers in cochlea
heilocortema
scala vestibuli and the scala tympani meet at the apex of the cochlea
endolymph
boney shell of cochlea filled with an interior membranous labyrinth sac of fluid
has high K+ concentration
perilymph
seperates bony and membranous cochlea, has high Na+ concentration
Reissner’s membrane
in cochlea, membrane between the scala vestibuli and the scala media
basilar membrane
in cochlea, membrane between the scala tympani and the scala media
Narrow at the base and Wider at the apex
moves like a wave when sound pressure enters the cochlea and displaces the perilymph
the base is more responsive to high frequencies
location of organ of corti
in cochlea and sits on top of basilar membrane.
inner hair cells organ of corti
one row
outer hair cells organ of corti
3 rows
tectorial membrane
in organ of corti, gel like and capable of bonding hair cells
stereocilia
3 rows, arranged from tallest to shortest, On the top of each hair cell is a set of mechanoreceptors
tip link
stereocilia between rows are connected by tip links, which are important for converting pressure waves into an electrical signal
can regenerate in humans, but if you repeatedly damage them they might not
Von Betsky basilar membrane discovery
basilar membrane moves like a wave when stimulated by sound
electrically stimulating the basilar membrane of a cadaver that the basilar membrane would move
tonotopy
the mapping of place to frequency
traveling wave
wave reaches a peak amplitude that then rapidly falls. The amplitude of the wave is therefore greatest at a particular location on the membrane.
Wave amplitude decreases and becomes extinct at a particular distance along the basilar membrane.
frequency analysis
Complex sound is decomposed into its constituent frequency by the cochlea
mechanotransduction
When stereocilia are bent, K+ enters the channel and depolarizes the cell, leading to an influx of Ca+ resulting in the release of neurotransmitters and the excitation of the afferent nerve fiber at the base of the hair cell.
prestin
protein in outer hair cells that causes the outer hair cells to grow in length , responsible for dancing hair cell, provides a spring action! Adds energy into the system.
responsible for the active amplification that occurs in the inner ear
Otoacoustic Emissions
measure cochlear health
tuning curve
A narrower range of the cochlea is activated , suggestive of sharper tuning (i.e., better sensitivity to frequencies).
another name for ear wax
cerumen
