Brainscape's Knowledge GenomeTM

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


See full index

NSB > Physiology of Hearing > Flashcards

Physiology of Hearing Flashcards

1
Q

What range of Hz can humans hear within?

A
  • between 20Hz and 20,000Hz
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Over 140dB is the

A

threshold of pain

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

What receptors convert sound pressure waves to receptor potential and ultimately neuronal signalling events

A

Mechanoreceptors are sensory receptors whose membrane contains cation channels that convert a mechanical signal to a graded receptor potential for the release of neurotransmitters or the generation of an action potential

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

The Ear:

A

insert slide

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

What are the auditory ossicles?

A
  • three small bones located in the middle
    ear
  • malleus = hammer
  • incus = anvil
  • stapes = stirrup

the malleus is attached to the tympanic membrane

the stapes is attached to the oval window

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

Purpose of the auditory ossicles?

A

to convert sound waves received through the outer ear to fluid waves in the inner ear

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

Middle Ear:

A

insert diagram

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

Inner Ear:

A

insert slide

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

The Cochlear Canal:

A

insert diagram

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

The Upper Cochlear Canal:

A

scala vestibuli contains perilymph

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

The Middle Cochlear Canal:

A

scala media (cochlear duct) contains endolymph and the organ of corti

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

The Lower Cochlear Canal:

A

scala tympani contains perilymph which ends in the narrow window

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

Oscillation of the Stapes causes

A

pressure waves to the perilymph in the scala vestibuli and scala tympani

which causes the vibration of the basilar membrane

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

What is the organ of corti?
Where is it located?
Contains?

A
  • the primary sensory receptor of the
    auditory system?
  • sits on the basilar membrane
  • contains the inner and outer hair cells
    which are sensory mechanoreceptors
  • the hair cells are supported by epithelial
    cells

vibrations of the basilar membrane are received by the hair cells

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

Organ of Corti:

A

Peri, endo, peri

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

Hair Cells:

A
  • contain stereocilia
  • sits on the basilar membrane in scala
    media
  • the hair cells are sensory
    mechanoreceptors
  • supported by epithelial cells
  • inner = inner side of organ of corti
  • outer = outside of organ corti = embedded
    in the tectorial membrane

stereocilia are projections of the hair cell membrane; structure is achieved through actin filaments

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

Sound pressure is

A

localised deviation of pressure caused by a sound wave from the atmospheric pressure

18
Q

Hearing loss can be caused by a high sound pressure levels or low sound pressure levels?

A

High sound pressure levels

19
Q

The bony labyrinth is filled with

A

perilymph (high Na+, low K+)

20
Q

The membranous labyrinth is filled with

A

endolymph (low Na+, high K+)

21
Q

Stereocilia:

A

insert diagrams

22
Q

Journey of vibration through the ear

A
  • vibration of the tympanic membrane
  • vibration of the ossicles
  • waves travel through perilymph
  • basilar membrane vibrates
  • results in outer hair cells bending
  • as they bend membrane depolarisation
    begins
  • the inner hair cells move in response to
    endolymph movement
  • oscillation of outer hair cells and vibration
    of membranes influence the sensitivity of
    inner hair cells
  • both inner and outer hair cells depolarise
  • opening of K+ channels on stereocilia so
    influx of K+ from endolymph into
    perilymph
  • depolarisation of perilymph
  • which opens Ca2+ voltage gated channels
  • influx of Ca2+ and efflux of K+ causes
    repolarisation
  • neurotransmitter released
23
Q

What does medial displacement of stereocilia cause?

A
  • hyperpolarisation
  • K+ influx does not open Ca2+ channel
  • no neurotransmitter released
24
Q

How can the CNS modulate the auditory system at the receptor level?

A
  • outer hair cells are directly innervated by
    afferent and efferent nerves
  • inner hair cells are directly innervated by
    afferent nerves
  • CNS can modulate the auditory system at
    the receptor level
25
Q

Tonotopic Organisation:

A

Hair cells respond to different sound frequencies depending on their location along the basilar membrane of the cochlear canal

26
Q

The Central Auditory Pathway:

A
  • spiral ganglion bipolar sensory neurons
    innervate the stereocillia
  • travels to the cochlear part of CNVIII
  • CNVIII projects to the ventral and dorsal
    cochlear nuclei
  • The nerve from the dorsal cochlear
    nucleus will travel to the superior olivary
    complex and then to the inferior colliculus
    from where the signal will be directed to
    the relevant cortical area

the path travelled from the superior olivary complex to the inferior colliculus is referred to as the lateral lemniscus

27
Q

The Central Auditory Pathway:

A

insert diagram

28
Q

Summary of Auditory Nuclei:
- superior olivary complex
- lateral leminscus
- inferior colliculus
- medial geniculate nucleus
- auditory cortex

A
  • superior olivary complex = receives
    bilateral signal from the cochlear nuclei,
    can distinguish sounds based on the time
    of arrival and the perceived intensity in
    each year
  • lateral leminscus = projects to the inferior
    colliculus
  • inferior colliculus = tonotopically organised
  • medial geniculate nucleus (thalamus) =
    tonotopically organised
  • auditory cortex = receives all input and is
    tonotopically organised
29
Q

What areas of the brain are involved in auditory signal processing?

A
  • the auditory cortex is located in the
    transverse temporal gyrus of Heschl (area
    41)
  • 42 is the auditory association area
  • Wernicke’s area is a secondary auditory
    area and is important for the
    interpretation of the spoken word
  • Broca’s area in the frontal cortex is
    involved in speech
  • 41 and 42 send descending projections to
    the auditory system, involving efferent
    nerves
30
Q

Auditory Signal Processing:

A

insert diagram

31
Q

Conductive Hearing Loss:

A

disease in the outer ear canal or in the middle ear

32
Q

Sensorineural Hearing Loss:

A

disease in the cochlea or in the neural pathway from the cochlea to the brain

33
Q

Occupational Hearing Loss:

A

a noisy work environment can use the deterioration of the organ of corti

34
Q

Ototoxic Hearing Loss:

A

noisy work environment can cause deterioration of the organ of corti streptomycin, quinine)

35
Q

Infectious Hearing Loss:

A

drug induced (mumps or rubella)

36
Q

Tinnitus

A

hearing a sound that has no external source

37
Q

Conductive Hearing Loss Examples and Causes:

A
  • earwax
  • outer ear infection
  • otitis media (middle ear inflammation)
  • perforated eardrum
  • tumour in the ear canal or middle ear
  • otosclerosis
38
Q

Ototsclerosis: Causes:

A
  • genetic or external factors like viral
    infection
  • temporal bone sclerosis affects the stapes
    that becomes fixed to the oval window
    leading to impaired vibration
  • treatment: involves external hearing aids
    to amplify sounds or stapedectomy
39
Q

Stapedectomy: Risk:

A

can damage a branch of the facial nerve called corda tympani which passes through the inner ear

lose sense of taste

40
Q

Sensorineural Hearing Loss:

A
  • GJB2 encodes for protein connexin 26
    involved in innner ear K+ homestasis so
    struggle to depolarise sterocillia
    membrane
  • SLC26A4 encodes for anion transporter
41
Q

Cochlear Implants:

A
  • electronic device that provides a sense of
    sound to someone with severe hearing
    loss
  • surgically implanted
  • contains microphone, speech processor,
    transmitter and receiver, electrode array
  • electrodes transform sounds to nerve
    stimulations that bypass the damage part
    of the inner ear
  • does not completely restore hearing
42
Q

Cochlear Implants:

A

insert diagram

NSB (50 decks)

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