Hearing Practical

Question 1

What do you use otitis media

Answer 1

Grommits used to treat inner ear infection

Question 2

What is conductive hearing loss

Answer 2

Loss of stereocilia (hair cells)

Question 3

What is sensoineural hearing loss

Answer 3

Issue with spinal ganglia (nerves)

Question 4

Describe Rinne’s test method

Answer 4

Strike the tuning fork to get it vibrating. Place the end of the stem on the mastoid bone until the sound becomes inaudible. Bring the fork close to the hear canal and listen

Question 5

Describe Rinne’s test results

Answer 5

If the sound appears louder on the bone than the air it indicates conductive hearing loss. You would get a positive result in sensorineural hearing loss

Question 6

Describe Weber’s test method

Answer 6

Strike the tuning fork so that it is vibrating and place the stem against the vertex of the skull

Question 7

Describe Weber’s test results

Answer 7

In normal hearing you can hear the sounds equally in both ears. In sensorineural hearing loss the sound is louder in the ear that isn’t affected (normal ear). In conductive hearing loss the sound is louder in the ear that has conductive hearing loss (quieter in the normal ear)

Question 8

What do you need to determine if someone has sensorineural or conductive hearing loss

Answer 8

A combination of results from both Weber’s and Rinne’s tests

Question 9

What is presbycusis

Answer 9

Age related deafness

Question 10

What are the features of presbycusis

Answer 10

Lose higher frequencies, range is now more to do with consonants

Question 11

What natural mechanism protects the ear from loud noise

Answer 11

Stapedius contracts

Question 12

Why is stapedius contracting not effective for a gun shot

Answer 12

It is for continuous and loud noise, not sudden

Question 13

Which frequency is the stapedius contraction most effective for

Answer 13

Low frequencies

Question 14

How long can a person spend in an environment of 85 dB

Answer 14

8 hours

Question 15

How do you work out how long someone can spend in an environment

Answer 15

8 divided by 2 to the power of (ndB-81)/3. ndB is the number of dB

Question 16

Which bone contains inner ear

Answer 16

Pectous part of temporal bone

Question 17

What effects does severing the corda tympani have

Answer 17

Bell’s palsy and loss of taste

Question 18

What is the role of the ear ossicles

Answer 18

Reduces amplitude, increases pressure, allows for impedence matching i.e. transduction of sound from air filled middle ear to fluid filled inner ear

Question 19

What is the role of the round window

Answer 19

Fluid in the inner ear is compressible. Vibrations of the scapes pushes into the tympanic membrane which pushes into the round window which acts as a pressure release valve so that waves can propagate to the organ of corti

Question 20

How does the fluid composition in the scala vestibuli and scala tympani differ from the scala media

Answer 20

Scala vestibuli and scala tympani contain perilymph which has more sodium and less potassium. Scala media contains endolymph which has more potassium and less sodium

Question 21

Describe the endocochlear potential

Answer 21

Endolymph secreted fluid high in potassium so that potassium concentration is higher outside the hair cells than inside so that when potassium channels open in response to sound potassium is released into the cell resulting in an action potential

Question 22

What secretes potassium into the endolymph

Answer 22

Stria vascularis

Question 23

What is the role of the inner hair cells

Answer 23

Transfer sound waves in the fluid of the cochlear into electrical signals. Detect waves as sound and send this information to the CNS via electrical signals

Question 24

What is the role of the outer hair cells

Answer 24

Amplifier

Question 25

What is ototsclerosis and what type of patient is most likely to be susceptible

Answer 25

Calcification of the ossciles. Women 15-35 most vulnerable, can be brought on by pregnancy

Question 26

Under what circumstances are cochlear implants an appropriate treatment

Answer 26

When hair cells are damaged but the nerves (spinal ganglia) are still intact

Question 27

Why can cochlear implant use in young children raise ethical issues

Answer 27

They can be cut off from the silent community

Question 28

What ability do Wernicke’s and Broca’s areas support

Answer 28

Linguistics

Question 29

What artery supplies Wernicke’s and Broca’s area

Answer 29

Middle cerebral artery

Question 30

How would the consequence of stroke damage to the middle cerebral artery on the left side differ from the same lesion on the right

Answer 30

No linguistic problems caused by a lesion on the right

Question 31

Why is gentamicin prescribed in endocarditis

Answer 31

It is an antibacterial which can be used to treat the bacterial infection endocarditis