EAR Flashcards

1
Q

In the inner ear we find…

A

Sensory organs for hearing and equilibrium

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

The source of sound causes movements of the … in its immediate neighbourhood; these movements cause disturbances in the air a little farther away from the source; these air particles in their turn affect their neighbours which are still farther away from the source; and so the disturbance spreads outward.”

A

air particles

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

Depending on the sound, one part of the cochlea or the other activates.

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

Sound reception and sound transmission is done by…

A
  • The tympanic membrane
  • The auditory or bony ossicles
  • Oval Window
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The bony ossicles:
- Modulate the movement of the …
- Apply force to the …– amplifying the incoming sound wave

A
  • tympanic membrane
    -oval window
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The oval window transforms air pressure variations into…

A

Mechanical movements

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

A sound is any … of air that could cause a displacement of the … which, after transmission by the bone chain, could affect the … in the inner ear in such a way that the auditory … are stimulated.

A

disturbance, eardrum, liquid, nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What can we appreciate?

A

Scanning electron micrograph of the Organ of Corti. The hair- cell cell bodies are pseudo- colored blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Hair cells in the cochlea can regenerate (T/F)

A

False: they cannot regenerate

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

Sterocilia are connected through one another with …

A

TIPS. They are important so as to help other sterocilia to bend, touching the tectorial membrane and amplifying the sound.

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

Hearing is initiated when … in air pressure are converted into fluid pressure that travel down the …

Variations in fluid pressure induce vibrations in the … that are transferred onto … cells

The … extends outward over the hair cells

When the basilar membrane and organ of Corti are displaced, … hit the tectorial membrane opening …. channels and depolarization of the hair cells occurs (opening Ca2+ channels). Then … occurs and K+ enters again.

A

oscillations, cochlear duct

basilar membrane, hair

tectorial membrane

sterocilia, potassium, repolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Action potentials in the VIII nerve keep a phase relationship with the sound stimuli,… for low frequencies and 1:n up to… KHz

A

1:1, 5
(100 vibrations/second=100 action potentials per second)

  • IMPORTANT: Musicality is given by low frequencies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Type I cells connect with…

A

1 Inner cell
(THEY ARE THE MOST IMPORTANT ONES)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Type II cells connect with …

A

Several outer hair cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

General characteristics of the auditory pathway

A
  • Tonotopic organization: frequencies will be represented at different points in the pathway.
  • Multiple comissures: we have comissures in the brain connecting several nuclei, the pathway is very bilateral. Although we also have contralateral connections.
  • Parallel processing: it is done in the brainstem and not in the ear. Frequency, time, location, intensity… all these characteristics are also processed in the brainstem (there is a subpathway for each type of info)
  • Descending projections: help to reduce the input of some sources of info and to increase the input of others (centramos la atención en una conversación aunque haya otras personas hablando).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

In the cochlear nuclei we find just one type of cell (T/F)

A

False: there are different types of cells. The same axon will connect with different cells and create parallel pathways.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

… is common to any type of neuron

A

PERISTIMULUS HISTOGRAM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Tuning curve is measured for…

A

Soft sounds: if we increase the sound, we lose specificity.

  • Frequency selective= small tuning curve
  • Non-frequency selective= wide tuning curve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

To measure how a neuron responds to a specific intensity we use the…

A

Rate-intensity curve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Superior olivary complex mainly … sound (function)
Also the … are responsible for the descending olivocochlear path (descending pathway)

A

Localises.
We can find: Medial olivary nucleus, Lateral olivary nucleus, Medial nucleus of the trapezoid body

Preolivary regions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Which nucleus identifies?
Intensity differences between ears (level detector) Useful for high pitch sounds
Best developed in humans

A

Lateral superior olive and medial n. of the trapezoid body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Which nucleus identifies?

Phase (time) differences between ears (coincidence) Useful for low pitch sounds
Less developed in humans

A

Medial superior olive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

With low pitch sound we can differentiate the …, and with high pitched the …

A

time, where it arrived first (right and left ear can be within the same cycle of the wave), intensities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q
A
33
Q

Hearing: Turning Sound into Voltage
- Changes in … induce fluid motions that travel along the cochlear duct and induce … at the … in the organ of Corti
- Gradual changes in the physical properties of the cochlea from the base to the apex, each segment of the… in response to a specific frequency

A

-air pressure, mechanical vibrations, sensory epithelium
-sensory epithelium vibrates

34
Q

Organ of Corti
- …. element in the inner ear
- Situated on the …

A
  • Sensitive
  • basilar membrane
35
Q

ORGAN OF CORTI
Sensory epithelia of the inner ear contain two major cell types:…

A

hair cells and supporting cells

36
Q
A
37
Q

Organ of Corti
At the hair-cell basal pole are synaptic contacts with …

A

spiral ganglion neurons

38
Q

Name the structure

A

Organ of Corti

39
Q

SUPPORTING CELLS ORGAN OF CORTI

  • … cells that reside between hair cells
  • Span the entire depth of the …: from the basal lamina to the lumen
  • Linked to each other and to hair cells by … junctions
  • They communicate directly with other supporting cells by …
A
  • Non-sensory
  • epithelium
  • tight and adherens
  • gap junctions
40
Q

Membranous Labyrinth
- Filled with …
- Various … – specializations of the epithelium

A
  • endolymph
  • sensory structures
41
Q

Membranous labyrinth

A
42
Q
A
43
Q

Semicircular Ducts
- Continuous with and arise from the …
- … semicircular ducts: perpendicular to each other so that they can detect angular acceleration of the head in three-dimensional space

A
  • utricle
  • Three
44
Q

What can we appreciate in this image?

A

Semicircular ducts

45
Q

An 18-year-old man experiences seasickness while on a deep-sea fishing excursion.
What does he have? What structure is involved?

A

He has VERTIGO. The structure involved is the MACULA.
It is an overstimulation of STEROCILIA.

46
Q

Which cells of the cochlea are responsible for converting vibration into a nerve signal?

A

Inner cells

47
Q

Which cells in the cochlea are responsible for acting as an amplifier? Regulating the vibration of the tectorial membrane and helping to detect the signal correctly.

A

OUTER HAIR CELLS

48
Q

From certain frequencies onwards (…), the action potential in the ear gets sent every 2/3 vibrations.

A

5kHz

49
Q

Auditory neurons have their some located at…

A

Spiral ganglion in cochlea.

50
Q

Type 1 auditory neurons synapse with…

A

1 single inner cell

51
Q

Type II auditory neurons synapse with…

A

Many outer hair cells

52
Q

Input from the auditory nerve will reach the cochlear nuclei:
They are located in…

A
  • VENTRAL COCHLEAR NUCLEI (VCN)
  • DORSAL COCHLEAR NUCLEI (DCN)

junction between medulla and pons, near the pontocerebellar angle (where VII and VIII enter or exit the brainstem)

53
Q

AUDITORY PATHWAY
The … is the 1st relay pathway. The auditory nerve synapses in it with different cellular types, which initiate parallel processing of different characteristics. Each type of info will go to relay centers and all converge back in the … .

A

cochlear nucleus, inferior colliculi

54
Q

LATERAL LOCALIZATION FOR LOW-PITCHED SOUNS
The neurons located in the superior olive receive … of different length: it depends on the LENGTH

MSO neurons fire when the input from both ears is… (coincidence detectors). There are different “delays” in the conduction time through the axons of the spherical cells to each MSO cell.
Each MSO neuron represents therefore a different point in space in the lateral plane.

A

R and L axons

simultaneous

55
Q

LATERAL LOCALIZATION OF HIGH-PITCHED SOUNDS

When the intensity of the sound is higher in one ear compared to the other, the excitatory input from the ear with the louder sound … the inhibitory input from the ear with the softer sound, causing the firing of the ipsilateral LSO (lateral superior olive).

A

overcome

56
Q

DESCENDING AUDITORY PATHWAYS

A
  • OLIVOCOCHLEAR BUNDLE: both medial and lateral olivocochlear efferences
  • CORTICO-THALAMIC PROJECTIONS.
  • CORTICO-COLLICULAR PROJECTIONS: filter system.
  • DESCENDING PROJECTIONS FROM THE INFERIOR COLLICULUS.
57
Q

OLIVOCOCHLEAR BUNDLE
Medial efferences connect with… hair cells
Lateral efferences connect with … and inner hair cells

A

Outer
Type I olivocochlear neurons

58
Q

Lateral lemniscus-auditory system
Which nucleus is responsible for temporal processing and ONLY receives input from the contralateral ear?

A

VENTRAL NUCLEUS OF THE LATERAL LEMNISCUS

59
Q

NUCLEI OF THE LATERAL LEMNISCUS IN THE AUDITORY PATHWAY

A

VENTRAL AND DORSAL NUCLEUS OF THE LATERAL LEMNISCUS

60
Q

Point where all the auditory pathway converges

A

INFERIOR COLLICULUS

61
Q

Which nucleus of the inferior colliculus carries out frequency processing (in a tonotopic manner) and has narrower tuning curves?

A

CENTRAL NUCLEUS

62
Q

Which part of the inferior colliculus participates in integrative processes?

A

CORTICES

63
Q

Which motor structure integrates sensory inputs from different pathways orienting responses towards images or sounds?

A

SUPERIOR COLLICULUS

64
Q

BRAINSTEM AUDITORY EVOKED POTENTIALS is…

A

A test that helps us explore auditory pathways

65
Q
A
66
Q

MEDIAL GENICULATE BODY- THALAMUS. WHICH DIVISION?
Glomerular organization
Tonotopic distribution
Narrow (even “closed”) tuning curves Projects to primary auditory cortex

A

VENTRAL DIVISION

67
Q

MEDIAL GENICULATE BODY- THALAMUS. WHICH DIVISION?

Polimodal integration areas
Auditory afferences (IC cortex), but also afferences from other modalities
Projects to secondary auditory cortex and associative areas

A

Dorsal and medial divisions

68
Q

Primary auditory cortex corresponds to area…

A

41

69
Q

Secondary auditory cortex corresponds to area…

A

42

70
Q

Which auditory cortex has:

Tonotopic organization
Binaural responses
Contralateral connections through corpus callosum
Cortical, thalamic and collicular projections
And is EXCLUSIVE

A

Primary auditory cortex

71
Q

Which auditory cortex is an association cortex and is not exclusive?

A

Secondary auditory cortex

72
Q

Cortical plasticity is only present until the ages of…

A

3 and 4. If a child has a problem in the primary cortex which recovers after this age, it will not be able to connect to secondary cortex.
If a blind child recovers vision, even though he knew braille, he would not be able to read because 1ary cortex has not developed.

73
Q

The organ of Corti allows

A

frequency coding

74
Q

Auditory parallel processing begins in the…

A

cochlear nuclei

75
Q

The superior olivary complex mediates…

  • Low pitched sounds: … (MSO)
  • High pitched sounds: … (LSO)
A

Lateral localization
- phase
- intensity

76
Q

…. Participates in temporal pattern recognition

A

Ventral nucleus of the lateral lemniscus

77
Q

The … has a central nucleus and peripheral cortices

A

Inferior colliculus

78
Q

The … has functionally relevant subdivisions

A

medial geniculate body

79
Q

There are primary (BA …) and secondary (BA…) auditory cortices

A

41, 42