inner ear

Question 1

What does the inner ear consist of

Answer 1

Vestibule and cochlea

Question 2

How is sound passed from the middle ear to the inner ear

Answer 2

Stapes vibrates against the membrane of the oval window which transmits the sounds to the inner ear

Question 3

What is a conductive hearing issue

Answer 3

Hearing issue with the outer or middle ear

Question 4

How does otosclerosis cause conductive hearing loss

Answer 4

Deposition of new bone where the footplate of the stapes fits onto the oval window which reduces vibration

Question 6

What happens at the cochlea

Answer 6

A Footplate of stapes moves in and out of oval window creating a travelling wave in the scala vestibuli and scala tympani of the cochlea
This causes movement of the basilar membrane and movement of the inner and outer hair cells in the Organ of Corti in relation to the tectorial membrane
The cilia of the hair cells are deflected and ion channels open
Cations flow from the endolymph into the hair cells
Depolarisation takes place and an impulse is sent up the cochlear nerve
Inner hair cells activate the afferent nerves
Outer hair cells modify the response of the inner hair cells

Question 7

Whatis a tonotopic arrangement

Answer 7

For every frequency, there is a specific plate on the basilar membrane where the hair cells are specifically sensitive to that frequency

Question 8

Describe Webers test and what the results means

Answer 8

Move tuning fork on middle of forehead - should hear the same in both ears

Question 9

Describe Rinnes test and what a positive test is

Answer 9

Place tuning fork infront of ear and then on the mastoid process to see if there is conductive hearing loss

Rinnes positive - heard better infront of ear - no conductive hearing loss

If heard better on mastoid process, then conductive hearing loss

Question 10

What is presbycusis

Answer 10

Age related hearing loss

Question 11

What are otoacoustic emissions

Answer 11

Sounds given off by the inner ear when the cochlea is stimulated with sound - the outer hair cells vibrate which produces an almost inaudible sound which can be measured in the middle ear

Hearing loss greater then 25-30 decibels do not produce these

Question 12

What does tympanometry measure

Answer 12

The pressure within the middle ear and the mobility of the ear drum

Question 13

What part of the ear controls balance

Answer 13

The vestibule

Question 14

what are ampullae in the ear

Answer 14

expanded areas at the end of the semicircular canals which contain the sensory organ - the crista
Movement of the crista is the stimulus for the vestibulo-ocular reflex which tells you where your head is in space and allows for your eye to compensate

Question 15

What is the vestibulo-ocular reflex

Answer 15

Stabilises gaze by moving eyes in order to compensate for head and body movement

Question 16

Describe what happens when otoliths (calcium carbonate crystals) break off

Answer 16

When the otoliths break, they float in the semicircular canal and give extra movement to the cilia which causes the eye to move , vertigo and nystagmus - the direction the eye moves in shows which canal the otolith is in

Question 18

What is the test for Benign paroxysmal positional vertigo(BPPV)

Answer 18

Dix-Hallpike manouvre

Question 19

What is the treatment for BPPV - Benign paroxysmal positional vertigo

Answer 19

Epley manouvre

Question 20

What is the presentation of vestibular neuritis

Answer 20

• Acute onset of vertigo
• Nystagmus
• Nausea and vomiting
• if hearing loss present then probably labrynthitis

Question 21

What is the classic presentation of Meniere’s disease

Answer 21

• vertigo - lasts up to a day
• Hearing loss - unilateral and sensorineural
• tinnitus
• Episodic