NEU211 Chapter 11 EXAM 3 NOTES

audition

sound

vestibular system

balance

sound range = ____ hz

20-20k

amplitude

loudness

louder = ___ amplitude

higher

outer ear has

pinna, auditory canal

pinna

fleshy part of ear

auditory canal

1 in, tube carries info from pinna to head

mid ear has

tympanic membrane, ossicles

tympanic membrane

vibrates at same rate as sound wave that struck it

ossicles

increase intensity of soundwaves to get thru fluid fillec cochlea

inner ear has

oval window, cochlea, auditory vestibular nerve

ovwal window

passes vibration to fluid of inner ear

cochlea

fluid filled, converts vibrations to electrical nerve signals

auditory vestibular nerve

carries info from inner ear to brain

how sound waves travel in ear

sound hits tympanic membrane, membrane moves ossicles, ossicles convert waves to stronger vibrations, hair cells in basilar membrane in cochlea fluid moved, neurons respond

nuclei in bs processes sound to

nerve signals

mid ear is

air filled, has 1st elements moving in response to sound, turns sound to neural signal

diff in air pressure causes ___ mvt

ossicle

footplate of stapes

pushes sound vibrations into inner ear thru oval window

w tiny muscles attaching to ossicles

ctrl mvt of ossicles

eustachian tube

connects air in mid ear to nose, usually closed, opens when swallow/yawn/chew

attenutation reflex

protects innear ear from loud sounds, allows us to understand speech better

attenutation reflex 2 muscles

tensor tympani, stapedius

tensor tympani muscle

1 end attached to mid ear bone, other to malleus

stapedius muscle

1 end attached to bone, other to stapes

how attenuation reflex works

loud sound, muscle contraction, rigid ossicles, less sound passed to inner ear

inner hear has ___ and ____

cochlea, labyrinth

cochlea

snail shaped auditory system

labyrinth

vestibular system/balance

3 fluid tunnels in cochlea

scala vestibuli, media, tympani

scala media is always ____

closed off

oval window

where stapes push vibrations to inner ear fluid

round window

lets fluid move, release pressure from inner ear

reissners membrane

separates fluid dilled chambers in cochlea

basilar membrane

vibrates 2 diff pitch

tectorial membrane

moves hair cells when sound vib

organ of corti

where auditory receptors are

hair cells are between ___ membrane and ___ membrane in cochlea

basilar, tectorial

heliicotrema

connects scala tympani and vestibuli at top

at base/bottom, scala vestibuli connects to ____, while scala tympani connects to ______

oval window, round window

2 fluids in cochlea

perilymph, endolymph

peilymph

fluid in scala vestibuli and tympani, low k/high na

endolymph

fluid in scala media, high k/low na

endocochlear potential

endolymph potential is 80mv ore than perilymph

stria vascularis

uses active transport to keep ion diff

mvt at oval window causes the ____ to push into scala vestibuli, which causes the ____ membrane to bulge

perilymph, round window

basilar membrane apex is more ___/___

wide/flp[[y

basilar membrane base is more ___

stiff

how basilar membrane responses to sound

endolymph mvt, basilar membrane bent, wave moves 2 apex

high freq sounds =

stiff base vibrates, energy used quick, wave doesnt travel far

low freq sounds =

travel to apex, energy used slowly

tonotopy

diff pitches have diff locations in brain

auditory receptor cells convert ___ energy to ___

mech, membrane polarization change

hair cell is composed of ___ stereocilia

10-300

flex basilar membrane = stereocilia ____

bending

basilar membrane = ___ of corti base

organ

tectorial membrane = ___ over structure

rodd

reticular lamina = ___, holds hair cells

middle

rods of corti provide

structural support

inner hair cells

detect sound, 4.5k, 1 row

outer hair cells

amplify sound, 12-20k, 3 rows

sprial ganglion

collect signals from hair cells

auditory vestibular nerve

send signals to cochlear nuclei in medulla

how transduction by hair cells work

sound, stapes move, basilar membrane moves, structure supporting hair cells moves towards/away from tectorial membrane

tip of hair stereocilium has

ion channel

bent tip link =

more tension, k goes in, depolarization, ca channels open, ca goes in, glutamate released, spiral ganglion fibers on

1 inner hair cell sends signals to ___ spiral ganglion fiber w __ contact pts

1, 10

how sound travels in ear

spiral ganglion, auditory nerve, ventral cochlear nucleus, superior olive, lateral lemniscuc, inferior colliculus, mgn, auditory cortex

auditory cortex

processes sound, in superior temporal cortex

acoustic radiation

signals go from mgn thru internal capsule to auditory cortex

primary auditory cortex/a1

processes sounds in detail, imagine sounds, need experience

damaged primary auditory cortex =

trouble w speech/music, not deaf

left hemi gets info from ___ ear

right

right hemi gets info from ___ ear

lefr

high freq sounds = ___ of bundle

peripheral

low freq sounds = __ of bundle

mid

diff cells respond to __ sound freq

diff

around a1 areas respond to

auditory objects/real world sounds

sound localization

find direction/distance of sound

brain uses 2 things to find where sound is coming from

diff in time of arrival, intensity diff

less diff in time of arrical = ___ to midline

closer

sound shadow = sound is ___ for closer ear

louder

amusia

tone deaf, cant tell diff in freq, genetic, normal aud cortex, less connections between auditory/frontal cortex

study w transcranial alternating current stimulation on right prefrontal cortex = ___ ability to remember pitch

increased

absolute/perfect pitch

can hear/identify note, genetic

conductive/mid ear deafness

bones in mid ear cant transmit sound waves to cochlea, disease

nerve/inner ear deafness

damage to cochlea/hair cells/auditory nerves, can hear certain freq, disease/loud

tinnitus

contant ear rining, damaged cochlea

vestibular labyrinth in inner ear has

otolith organs, semicircular canals

otolith organs =

gravity/tilt

saccule and utricle

in otolith, detect changes in head angle, linear acceleration

straight head/utricular macula

straight cilia

tilted head

gravity pulls otoconia, gel cap deformed, cilia bent

linear acceleration

force u feel when car slows down

semicircular canals

3 arching structures, head rotation

vestibular sense

controls head position/mvt

scarpas ganglion

20k nerve acons on each side of head

semicircular canals

detect when head is rotating, angular accel, have endolymph jelly like cupua

angular acceleration

changes in rotation