Anatomy of Ear

Question 1

pinna

Answer 1

visible part of ear; series of ridges and valleys

Question 2

what does the pinna do?

Answer 2

funnel in sound into the auditory canal

Question 3

how does the pinna shape the sound?

Answer 3

by accentuating and attentuating some frequencies; helps w localizing sounds in environ

Question 4

what is the auditory canal?

Answer 4

passageway

Question 5

what does the auditory canal do?

Answer 5

provides distance between outer world and the tympanic membrane

Question 6

how does auditory canal shape sound?

Answer 6

attenuates//accentuates some frequencies

Question 7

what is the tympanic mebrane?

Answer 7

v fragile

Question 8

what does the typanic membrane do?

Answer 8

separate outer world from middle and inner ear AND transmit sound vibrations into the middle ear

Question 9

what are ossicles?

Answer 9

tiny bones that take the sound vibrations and amplify them; incus, malleus, and stapes

Question 10

what do the ossicles do?

Answer 10

transit vibrations further into the middle ear

Question 11

what is the oval window

Answer 11

separate middle from inner ear

Question 12

impedance matching

Answer 12

sound amplification; inner ear is filled w fluid– sound has to be amplified to match the impedance (resistance) in the fluid; OSSICLES

Question 13

acoustic reflex

Answer 13

tensor tympani and stapedius muscles; contract and restrict movement of ossicles through contraction of muscles (restricting amplification); defensive to protect hearing

Question 14

what is the caveat w acoustic reflex?

Answer 14

only works for sustained sounds b/c it takes time to kick in

Question 15

eustachian tube

Answer 15

connects middle ear to sinus cavaties; equalize pressure so the transfer of sound can occur properly

Question 16

how is sound amplified from the tympanic membrane to the oval window?

Answer 16

tympanic membrane – large to oval window – small; ossicles work together as a lever that helps amplify sound

Question 17

transduction occurs in the ____ ear

Answer 17

inner

Question 18

what is the cochlea

Answer 18

snail-like bony labyrinth

Question 19

vestibular canal

Answer 19

top chamber; connected to the oval window

Question 20

tympanic canal

Answer 20

bottom chamber

Question 21

cochlear duct

Answer 21

hold structures involved in transduction; central chamber

Question 22

Reissner’s membrane

Answer 22

separates vestibular canal from cochlear duct

Question 23

basilar membrane

Answer 23

separates the cochlear duct from the tympanic canal

Question 24

auditory nerve

Answer 24

output

Question 25

helicotrema

Answer 25

at the apex (end of cochlea); connects vestibular canal to the tympanic canal

Question 26

organ of corti

Answer 26

sits on top of basilar membrane; contains specialized cells where transduction will occur

Question 27

perilymph

Answer 27

fluid in inner ear

Question 28

organ of corti vibrates w traveling wave of _______ _______

Answer 28

basilar membrane

Question 29

inner hair cells

Answer 29

where transduction actually occurs

Question 30

outer hair cells

Answer 30

3 rows; refines the sensitivity and frequency selectivity of the mechanical vibrations of the cochlea

Question 31

stereocilia

Answer 31

hair like protusions that come off the top of the hair cells; bends back and forth

Question 32

tectorial membrane

Answer 32

over top of organ of corti; lays on top of the hair cells

Question 33

endolymph

Answer 33

dense fluid that fills cochlear duct; more resistant to starting and stopping vibrations; shearing force on stereocilia