Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neurology > Mechanisms and Pathologies of Hearing > Flashcards

Mechanisms and Pathologies of Hearing Flashcards

1
Q

What can cause a conductive hearing loss?

A 
Otosclerosis
Otitis media or glue ear 
Blockage in external auditory meatus 
Ruptured tympanic membrane
Eustachian tube dysfunction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a sensorineural hearing loss?

A

When there is damage to the cochlea, cochlear nerve or the central auditory pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What can cause sensorineural hearing loss?

A

Damage to hair cells via ototoxic drugs or excessive noise
Spiral ganglion damage such as acoustic neuroma
Tinnitus
Auditory neuropathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is otosclerosis?

A

A bony outgrowth of the stapes which impedes movement against the oval window

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does otitis media cause a conductive hearing loss?

A

Fluid accumulation and pressure changes in the middle ear, impeding auditory ossicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which is rinne’s test?

A

When you place the tuning fork on the mastoid process then by the ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which test is weber’s test?

A

When you place the tuning fork on the forehead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Rinne’s test: bone > air right ear
Weber’s: lateralises to right ear

What is the diagnosis?

A

Conductive hearing loss in right ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Rinne’s: bone > air (left ear)
Weber’s: lateralises to right ear

What is the diagnosis?

A

Sensorineural deafness in left ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Rinne’s: air > bone both ears
Weber’s: lateralises to left ear

What is the diagnosis?

A

Sensorineural hearing loss in right ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

If Weber’s lateralises to the left ear, what are the two possible diagnoses?

A

Conductive hearing loss in left ear

Sensorineural hearing loss in right ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

If bone is louder than air in a Rinne’s in the left ear, what are the two possible diagnoses?

A

Conductive hearing loss in left ear

Complete sensorineural deafness in left ear (because sound is conducted by bone to the other ear)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is conductive hearing loss?

A

Where there is a problem with the transmission of sound from the outer to the inner ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is sound?

A

A compressed airwave, travels at 343 m/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is frequency measured in?

A

Cycles per second (Hz)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is magnitude measures as?

A

Intensity of the sound in decibels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What attaches the stapes to the oval window?

A

The annular ligament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does the middle ear do?

A

Allows conversion of sound waves in the air to the fluid of the inner ear

19
Q

How is the pressure transmitted to the oval window amplified?

A

Because the area of the tympanic membrane is greater than that of the oval window
Mechanical efficiency of the ossicles acting as levers

20
Q

What does the inner ear consist of?

A

The bony labyrinth
The membranous labyrinth
The organ of Conti

21
Q

In which bone is the bony labyrinth found?

A

The petrous part of the temporal bone

22
Q

Which parts does the bony labyrinth of the inner ear make up?

A

The vestibule
Three semicircular canals
Cochlea

23
Q

Which part of the inner ear is responsible for hearing in response to vibrations?

A

The cochlea

24
Q

What do the cavities of the bony labyrinth contain?

A

Perilymph

25
Q

What is the cochlear canal divided into?

A

Scala vestibule

Scala tympani

26
Q

Where do the vibrations travel in the inner ear?

A

Oval window - scala vestibule - out via the round window

27
Q

What lies within the cochlea which is part of the membranous labyrinth?

A

The scala media/cochlear duct

28
Q

What is the cochlear duct filled with and what is it bound by?

A

Endolymph - high conc of K+ and low conc of Na+

Vestibular/Reissner’s membrane and the basilar membrane

29
Q

Where is the organ of Conti?

A

On the basilar membrane of the cochlear duct

30
Q

Function of the inner hair cells?

A

Sense sound - move in response to endolymph

31
Q

Function of the outer hair cells?

A

Amplify sound

32
Q

Where are the inner and outer hair cells found?

A

Both in the organ of Conti

Outer hair cells are embedded in the tectorial membrane which runs the length of the organ of Conti

33
Q

Where do signals produced by the hair cells travel?

A

To the spiral/cochlear ganglion which are bipolar neurones, forming at the base of the hair cell
Theses nerve endings form the cochlear division of CN VIII

34
Q

How do hair cells move?

A

Compression of perilymph in scala vestibule and tympani, producing oscillatory movements in the basilar membrane

Movement of the membrane causes movement in tips of stereocilia

  • inner hair cells relative to endolymph
  • outer hair cells relative to tectorial membrane
35
Q

How does movement of the stereocilia generate a signal?

A

Mechanical displacement causes influx of K+ through their membrane
This depolarises the hair cell
Causes influx of Ca2+ through VGCC
Intracellular rise in [Ca] causing release of neurotransmitter in the spiral ganglion cells
The action potential then propagates along the nerve fibres of the CN VIII

36
Q

What is the tonotopic distribution of responding receptors?

A

Hair cells located at the base of the basilar membrane respond to hi frequencies
Those at the apical aspect of the membrane respond to low frequencies

37
Q

Where does the central auditory pathway begin?

A

With bipolar neurones in the vestibulocochlear nerve

38
Q

Where does the vestibulocochlear nerve travel?

A

Through the internal acoustic meatus, into the posterior cranial fossa where it divides into the vestibular and cochlear divisions at the level of the brainstem to rostral medulla

39
Q

Where do bipolar neurones synapse onto second order neurones?

A

In the cochlear nuclei of the medulla

Then project in a tonotopic manner

40
Q

Where do the second order neurones travel?

A

Some synapse in the ipsilateral or contralateral superior olivary complex

Others pass contralaterally and synapse directly in the inferior colliculus

41
Q

What does the superior olivary nucleus allow?

A

Localisation of sound in acoustic space

-discriminate differences in time of arrival or intensity of sound to each ear

42
Q

What do neurones passing from the superior olivary nucleus to the inferior colliculus pass through?

A

The lateral lemniscus

43
Q

Where do axons go from the inferior colliculus?

A

Medial geniculate nucleus

Then projected to the auditory cortex (Broadman’s area in the temporal lobe)

44
Q

Summary of the central auditory pathway?

A 
Cochlea
Spiral ganglion cells 
Cochlear nucleus
Superior olivary complex
Inferior folliculus
Medial geniculate nucleus
Auditory complex

Neurology (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions