Anatomy of Ear Flashcards
pinna
visible part of ear; series of ridges and valleys
what does the pinna do?
funnel in sound into the auditory canal
how does the pinna shape the sound?
by accentuating and attentuating some frequencies; helps w localizing sounds in environ
what is the auditory canal?
passageway
what does the auditory canal do?
provides distance between outer world and the tympanic membrane
how does auditory canal shape sound?
attenuates//accentuates some frequencies
what is the tympanic mebrane?
v fragile
what does the typanic membrane do?
separate outer world from middle and inner ear AND transmit sound vibrations into the middle ear
what are ossicles?
tiny bones that take the sound vibrations and amplify them; incus, malleus, and stapes
what do the ossicles do?
transit vibrations further into the middle ear
what is the oval window
separate middle from inner ear
impedance matching
sound amplification; inner ear is filled w fluid– sound has to be amplified to match the impedance (resistance) in the fluid; OSSICLES
acoustic reflex
tensor tympani and stapedius muscles; contract and restrict movement of ossicles through contraction of muscles (restricting amplification); defensive to protect hearing
what is the caveat w acoustic reflex?
only works for sustained sounds b/c it takes time to kick in
eustachian tube
connects middle ear to sinus cavaties; equalize pressure so the transfer of sound can occur properly
how is sound amplified from the tympanic membrane to the oval window?
tympanic membrane – large to oval window – small; ossicles work together as a lever that helps amplify sound
transduction occurs in the ____ ear
inner
what is the cochlea
snail-like bony labyrinth
vestibular canal
top chamber; connected to the oval window
tympanic canal
bottom chamber
cochlear duct
hold structures involved in transduction; central chamber
Reissner’s membrane
separates vestibular canal from cochlear duct
basilar membrane
separates the cochlear duct from the tympanic canal
auditory nerve
output
