Physiology and clinical aspects of hearing and balance

Question 1

Does the middle ear transform acoustic energy from the medium of fluid –>air or air–>fluid?

Answer 1

air –> fluid
middle ear should be air - atmospheric pressure
inner ear (cochlear) - fluid filled

Question 2

How does the middle ear act as a sound amplifier?

Answer 2

area effect of tympanic membrane

lever action of ossicular chain

Question 3

What type of hearing loss do otitis media, perforation of ear drum, eroded incus and otosclerosis cause?

Answer 3

conductive hearing loss

Question 4

otitis media with effusion - what is the problem with this?

Answer 4

middle ear filled with fluid

middle ear works optimally with being air filled to facilitate better pushing of ear drum

Question 5

What is a hole in the ear drum called?

Answer 5

perforation

Question 6

What can cause an eroded incus?

Answer 6

chronic infection eg vasculitis

Question 7

What part of the middle ear does otosclerosis most commonly affect?

Answer 7

stapes footplate

Question 8

What is otosclerosis?

Answer 8

bony deposition in the annular ligament

Question 9

2 parts of the cochlea

Answer 9

scala vestibule

scala tympani

Question 10

The part of the basilar membrane which vibrates more is in relation to what?

Answer 10

frequency

Question 11

What do assessments of hearing loss determine?

Answer 11

degree of hearing loss

Question 12

describe the 2 tuning fork tests

Answer 12

webers - test of lateralisation, midline and assess hearing comparison on both sides which should be equal
rinne’s - compares loudness of perceived air conduction to bone conduction in one ear at a time

Question 13

puretone audiometry

Answer 13

air conduction to determine faintest sounds heard at different frequencies
earphones worn

Question 14

What is presbyacusis?

Answer 14

age related hearing loss

Question 15

tympanometry - what does it measure, detect and how?

Answer 15

measures mobility of the ear drum
pushes air pressure into ear canal causing the drum to move
detect wax, fluid and perforation

Question 16

What are autoacoustic emissions?

Answer 16

sounds given off by the inner ear when the cochlea are stimulated by a sound
the hair cells vibrate and measured with a probe

Question 17

Auditory brainstem response

Answer 17

cochlea and brain pathways used with disabled/young

electrodes on the head record brain wave activity in response to sound

Question 18

Hearing aid - parts, what frequencies used for and how is it operated?

Answer 18

speaker, microphone, amplifier, ear hook and mould
low and mid frequencies
battery operated

Question 19

What type of hearing aid is used for high frequencies?

Answer 19

open fit

Question 20

Bone anchored hearing aid

Answer 20

through the bone and into the inner ear to bypass the external and middle ear in conductive hearing loss

Question 21

name the 2 hearing implants

Answer 21

middle ear and cochlear

Question 22

name the 3 parts of the inner ear concerned with balance

Answer 22

utricle, saccule and semi circular canals

Question 23

What do utricle and saccule detect?

Answer 23

utricle - horizontal

saccule - vertical

Question 24

how are the cilia arranged in the otolith organ?

Answer 24

sensory epithelium with cilia in a gel matrix with calcium carbonate crystals on top

Question 25

What is the vestibule-ocular reflex?

Answer 25

stabilises gaze by moving eyes in order to compensate for head and body movements
fixes image on retina for clear sight

Question 26

What are the 3 body balancing regulating inputs?

Answer 26

peripheral vestibular apparatus
visual
pressure

Question 27

Ear conditions affecting balance (3)

Answer 27

benign paroxysmal positional vertigo
vestibular neuritis
Meniere’s disease

Question 28

BPPV - what causes it, diagnosis and treatment

Answer 28

utricle crystals float into semicircular canal

dix hallpike test and Epley manoeuvre

Question 29

Vestibular neuritis cause

Answer 29

reactivation of latent virus eg HSV causing neuritis of vestibular nerve

Question 30

Meniere’s disease cause

Answer 30

increase in endolymph

Question 31

Non ear common condition causing balance problems

Answer 31

migraine