Anatomy - Hearing
endolymph is composed of ______
potassium
_ in ____ children born with profound hearing impairment; _ in _____ will acquire deafness in early childhood
1 in 1000 2 in 1000
what decibels is a mild hearing loss
16 to 40
what decibels is a moderate hearing loss
41 to 55
what decibels is a moderate/severe hearing loss
56 to 70
what decibels is a severe hearing loss
71 to 90
The nerve impulses are passed on to the ________ and then transmitted to the ______ area of the brain
8th cranial nerve auditory
what decibels is normal hearing
< 15 dB
what decibels is a profound hearing loss
> 91 dB
Tonotopicity- outer bands of this nerve carry high frequency information; inner bands, low freq
Auditory Nerve (VIII)
this membrane is narrow and stiff at the base (high freq) and wider and less stiff at the apex (low freq)
Basilar Membrane
what type of hearing loss has problems in the outer or middle ear with the inner ear being normal?
Conductive Loss
acts like our body's spectrograoh - info about freq, intensity, and time. different parts of lobe respond to different freq
Heschyl's Gyrus (Temporal Lobe)
What kind of sounds stimulate the base of the Organ of Corti?
High frequency sounds
caused by excess fluid in the inner ear
Meniere's Disease
Essentially, the tensor tympani and stapedius muscle do what?
Not allow the tympanic membrane and ossicular chain to move as much
bathed in endolymph in the basilar membrane most important structure of hearing
Organ of Corti
What is the physiology of hearing? *definitely going to be an essay*
Sound waves are directed by the pinna into the external auditory meatus Waves strike the eardrum, causing it to vibrate The eardrum is connected to the malleus, moves the ossicles back and forth As the stapes moves, it pushes the oval window in and out The movement of the oval window makes waves in fluid in cochlea Pressure of the waves causes movement in the hair cells in the Organ of Corti The movement of the hair cells generates nerve impulses The nerve impulses are passed on to the 8th CN, and transmitted to the auditory area of the brain
Origin: posterior wall of the middle ear Insertion: Neck of stapes Stiffens the ossicular chain to reduce its vibrations
Stapedius Muscle
external auditory canal is narrow
Stenosis
Names of the three semicircular canals
Superior Horizontal Posterior
Origin: cartilaginous and bony margins of auditory tube Insertion: Handle of Malleus Tenses the eardrum to reduce its vibrations
Tensor Tympani
What is the tonotopic of the acoustic nerve?
The nerve's outer bands carry high frequencies. The nerve's inner bands carry low frequencies.
what is atresia? not important but helps me understand aural atresia
a closure where there shouldn't be one
the outer ear collects ____ energy
acoustic
carries electrical impulses from the cochlea to the brain
acoustic nerve
cranial nerve VIII
acoustic nerve
quick buildup of fluid/pus results in pain and possible rupturing of ear drum causes fever and vertigo
acute otitis media
Meniere's disease generally occurs in ______ and is ______
adults unilateral
sound waves travel through the air to the outer ear and are transmitted through the middle ear to the cochlea
air conduction
Air is conducted into the inner ear by: (2)
air conduction bone conduction
the middle ear is an ____ ____ cavity
air filled
We normally hear our own voice through a combination of...
air-bone conduction sounds
bone is less effected
air-bone gap
discrepancy between air conduction and bone conduction
air-bone gap
Profound SHL may have a severe effect on the acquisition of speech and language; ____________ may be affected
articulation
an expert in hearing and its disorders
audiologist
The study of hearing, its disorders, and the measurement and management of those disorders
audiology
instruments that are used to measure hearing loss - electronic devices that generates and amplifies pure tones at various frequencies
audiometer
external ear canal is completely closed
aural atresia
with central auditory hearing loss, ______________________ may make it difficult to understand speech
background noise
the three semicircular canals help to maintain _______, ____ , and ____-
balance posture and movement
floor of scala
basilar membrane
With mixed loss, bone conduction is ______ than air conduction threshold, but both indicate loss
better
a _____________ creates an airtight middle ear; soon the air is thinned out and the pressure is reduced
blocked Eustachian Tube
With a conductive hearing loss, there is always some hearing left because of the ___ _____ Therefore, a person with conductive hearing loss can hear his/her own speech well.
bone conduction
because the inner ear is damaged with sensorineural loss, _______________ also may be impaired
bone conduction
bone oscillator on skull; to assess the sensorineural portion of the auditory mechanism when the sound strikes the bones of the skull, the bones vibrate and stimulate the fluids in the inner ear
bone conduction
vibrations of bone cause movement int he fluids of the inner ear
bone conduction
2 kinds of labyrinths in the middle ear
bony (temporal bone) membranous
includes the brainstem where the auditory nerve terminates or areas of cortex responsible for filtering and interpreting sound
central auditory hearing loss
with central auditory hearing loss, it's caused by lesions to the _________________________
central auditory system
ear wax
cerumen
what 2 things found in the outer ear that helps to protect?
cerumen cilia
long term infection painless but foul smelling discharge from ear treatment : drugs and surgery expect speech and language delays
chronic otitis media
small hairs
cilia
the _________ is a primary inner ear structure of hearing
cochlea
tonotopicity - different parts of the cochlea respond to different frequencies
cochlea
what are the things called you can get when you have sensorineural hearing loss to possibly hear again
cochlear implants
so with central auditory hearing loss, generally the person hears but does not understand speech under certain conditions, such as _________________________
competing stimuli
absent external canal occurs in some syndromes like Down Syndrome, Treacher Collins
congenital atresia
cannot hear or understand conversational speech under normal circumstances
deaf
treatment of otitis media?
drugs, surgery
area of eardrum vs. area of oval window - increases sound pressure significantly
eardrum/oval window
Mechanical impulses from the middle ear are converted to _______ impulses in the inner ear
electrical
positively charged fluid
endolymph
What is the job of the eustachian tube?
equalize pressure and aerate the middle ear
what connects the middle ear to the nasopharynx?
eustachian tube
leads to the eardrum
external auditory canal
tube resonator - enhances high frequencies
external auditory meatus
infections that result in swelling of the ear canal (swimmer's ear)
external otitis
sensorineural hearing loss is not the same for all _______
frequencies
hearing loss between 16-75 dB
hearing impairment
the lowest intensity of a sound that will stimulate the auditory system
hearing level
Symptoms of meniere's disease
hearing loss vertigo tinnitus
The acoustic nerves outer bands carry ____ frequencies.
high
SHL is greater for ________ frequencies than the ________ frequencies
higher, lower
Sound waves are directed by the _____ into the ____ _____ ____
pinna external auditory meatus
prenatal causes of SHL
inheritance maternal illness drug use
otosclerosis is usually ___________
inherited
presbycusis is loss in the ____ ear, involving the _th nerve, and it is _______ _______
inner 8 cortical degeneration
Whats one specific thing a doctor will do for a blocked Eustachian tube?
insert tubes through the tympanic membrane to ventilate it
Speaking problem is one of _______: person tends to speak too softly, especially in background noise.
intensity
the inner ear is a system of interconnecting tunnels called ______
labyrinths
the acoustic nerves inner bands carry ___ frequencies
low
What kind of sounds stimulate the apex of the Organ of Corti?
low frequency sounds
what are the names of the three bones that make up the ossicular chain?
malleus incus stapes
With central auditory hearing loss, there might be no significant peripheral hearing loss so routine tests...
may not reveal a problem
the middle ear changes acoustic energy to ______ energy
mechanical
The Organ of Corti is responsible for transduction of ____ energy into ____ energy since it contains thousands of hair cells that respond to sound
mechanical energy electric energy
How do you treat a blocked Eustachian tube?
medical or surgical means
impedance matching devices - prevents loss of intensity as sound travels from air to fluid
middle ear
combination of both conductive and sensorineural loss - middle and inner ear are not functioning properly
mixed loss
collects high frequencies, increases sound pressure to EAM, contributes to localization and binaural stim
pinna (auricle)
The movement of the hair cells generates ____ ___
nerve impulses
permanent damage to cochlear hair cells is caused by prolonged exposure to loud ______ or short exposure to extreme _____
noise
pressure of the waves causes movement in the hair cells in the _______________
organ of corti
The eardrum is connected to the malleus, which moves the ____ back and forth
ossicles
ratio of malleus to incus length increase sound pressure slightly
ossicles
funnels sound to the ear canal and helps localize sound
pinna (auricle)
2 parts of the outer ear
pinna (auricle) and external auditory canal
three small bones in the middle ears
ossicular chain
middle ear infection
otitis media
formation of spongy bone that fixates the footplate of the stapes on the oval window
otosclerosis
postnatal causes of SHL
ototoxic drugs that damage the ear mycin family infectious disease
three main parts of the ear
outer ear middle ear inner ear
As the Stapes moves, it pushes the ____ _______ in and out
oval window
part where the inner ear begins the oval window allows communication between scala vestibuli and middle ear spaces
oval window
negatively charged fluid
perilymph
2 types of inner ear fluids
perilymph endolymph
stapes is surgically removed and replaced with a prosthesis
stapendectomy
with otosclerosis, the stapes is often aggravated during ____, making them think it might be linked to hormones
pregnancy
hearing loss associated with normal aging progression from high to low frequencies
presbycusis
function of the outer ear
protection
use selected frequencies air conduction determine a hearing threshold
pure tone audiometry
allows communication between scala tympani and middle ear
round window
bone conduction and air conduction thresholds are essentially the ____
same
noise can cause what kind of hearing loss?
sensorineural
problem with the inner ear, auditory nerves, or brainstem damaged hair cells cannot be repaired - hearing loss is permanent
sensorineural loss
2 types of otitis media
serous and acute
fluid buildup; middle ear is inflamed and filled with thick or watery fluid
serous otitis media
whats the surgery for otitis media like
small incision in the tympanic membrane is made to relieve pressure
perilymph is composed of _____
sodium
Assists in localization ability and makes a contribution to frequency and intensity analysis
superior olivary complex
With sensorineural loss, they have difficulty hearing oneself and others so they tend to... and speech sounds are often...
talk louder difficult to understand
the primary auditory area in the brain is in what lobe?
temporal lobe
the Organ of Corti is ____ at the apex than at the base
thicker
the Organ of Corti is _____ at the base than at the apex
thinner
What makes up the vestibular system?
three semicircular canal
Two primary structures of the inner ear
three semicircular canals cochlea
intensity level at which a person hears the stimuli 50% of the time (Q)
threshold
various types of noise in the ear
tinnitus
people with central auditory hearing loss often complain about....
tinnitus trouble localizing sounds following complex instructions
With a blocked eustachian tube, the greater atmospheric pressure pushes the ________________ inward, reducing the mobility of the __________________, the _________________ does not vibrate properly and results in a conductive loss
tympanic membrane
eardrum thin, tough, elastic cone shaped membrane
tympanic membrane
the outer and middle ear are separated by the what?
tympanic membrane
SHL often goes _____ or ____ for months/years
undetected or misdiagnosed
what are the two branches of the acoustic nerve?
vestibular branch and acoustic branch
waves strike the eardrum causing it to _______
vibrate
The movement of the oval window makes ____ in the fluid in the cochlea
waves
Does Otosclerosis occur more frequently in men or women?
women
the eustachian tube can be opened by ___ and _____ (this lets fresh air into the middle ear)
yawning and swallowing
