Approach to Hearing Loss

Question 1

Where do sound waves enter?

Answer 1

External auditory canal

Question 2

After entering the external auditory canal the sound wave does what?

Answer 2

Bounces off the tympanic membrane

Question 3

What does the tympanic membrane move?

Answer 3

Malleus, incus, stapes

Question 4

What does movement of the stapes footplate cause?

Answer 4

Changes in pressure in the fluid-filled inner ear that triggers a traveling wave in the basilar membrane of the cochlea

Question 5

How does hearing occur through bone conduction?

Answer 5

Vibration of bones in the skull

Question 6

How does the traveling wave in the basilar membrane move?

Answer 6

From the base to the apex of the cochlea

Question 7

Where is the Organ of Corti found? What is found inside?

Answer 7

Inside the cochlea on the basilar membrane

Hair cells with stereocilia

Question 8

What are the hair cells in contact with?

Answer 8

Tectorial membrane

Question 9

What deforms the hair cells?

Answer 9

Traveling wave of sound

Question 10

Where do high frequency tones maximally displace the basilar membrane?

Answer 10

Near the base of the cochlea

Question 11

As frequency of sound decreases, the point of maximal displacement moves where?

Answer 11

Toward the apex of the cochlea

Question 12

Distortion of the stereocilia causes?

Answer 12

Depolarization of the cell and results in increased electrical activity along the auditory nerve

Question 13

Category of hearing loss?

Answer 13

Conductive

Sensorineural hearing loss

Question 14

Conductive hearing loss?

Answer 14

Transmission of sound through air is blocked

Question 15

Otosclerosis?

Answer 15

Bony overgrowth of the stapes at its point of attachment to the cochlea that causes the ossicles to stiffen and fail to transmit sound vibrations from the tympanic membrane

Question 16

Sensorineural hearing loss?

Answer 16

Arises primarily from damage to hair cells in the organ of Corti

Question 17

Presbyacusis?

Answer 17

Age related hearing loss that is gradually progressive and involves mostly high frequency sounds

Question 18

What does Meniere’s disease produce?

Answer 18

Vertigo, fluctuating sensorineural hearing loss, and tinnitus

Question 19

Pathogenesis of Meniere’s disease?

Answer 19

Decreased resorption of endolymphatic fluid causes fluid buildup or hydrops with high pressure, bowing, and subsequent rupture in the membrane separating the endolymph from the perilymph

Question 20

What happens when the two fluids mix in Meniere’s disease?

Answer 20

Bc they have two different compositions the mixture produces a sudden change in vestibular cochlear pressure and in their electrical firing properties

Question 21

Most common cause of tympanic membrane perforation?

Answer 21

Infection

Question 22

In TM perforation what does the degree of hearing loss depend on?

Answer 22

Size of the hole

Question 23

Otosclerosis Onset? Which ears? FHx?

Answer 23

20-30
Bilateral
Positive