Lecture 11: Smell and Hearing Flashcards

1
Q

olfaction

A

specialized for identifying special molecules called odorants

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

what kind of receptors detects smell?

A

metabotropic g protein-coupled receptors

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

how do receptors detect smell?

A

Metabotropic g protein-coupled receptors transduce ions into a change in membrane potential

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

how many odorant receptors are there per odorant molecule?

A

1

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

are odorant molecules lipid soluble?

A

yes

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

are odorant molecules organic (made from life)?

A

yes

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

Olfactory epithelium

A

the tissue of the nasal sinus that sits underneath the skull (the cribriform plate) and contains olfactory receptor cells

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

how many types of receptor proteins does each olfactory cell express?

A

1

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

Glomeruli

A

located in the olfactory bulb. Where olfactory receptor cells synapse, which in turn sends axons to the brain

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

each glomerulus processes information about ____ types of olfactory receptor cells

A

1

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

what process allows us to recognize smells?

A

combinational processing

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

how many smells can humans recognize

A

tens of thousands

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

how is smell perception developed?

A

through learned assocaitions

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

is smell innate?

A

no

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

where does olfactory information go?

A

to the primary olfactory cortex in the temporal lobe, then to the amygdala

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

sound waves

A

fluctuations in air pressure that are caused by the molecules of air surrounding a vibrating object condensing and rarefying (pulling apart)

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

how fast do sound waves travel?

A

~700 MPH

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

what length of soundwaves can humans detect?

A

1.7 cm-17 m

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

what sound wave frequencies can humans detect?

A

20-20,000 times per second

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

3 dimensions of sound

A

loudness, pitch, and timbre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

loudness

A

corresponds to the amplitude or intensity of the molecular vibrations

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

how is loudness determined?

A

by the total number of hair cells that are active and their overall activity levels

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

pitch

A

corresponds to the frequency of the molecular vibrations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how is pitch measured?

A

in hertz (Hz) or cycles per second

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

what is another word for pitch

A

tone

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

how is pitch determined?

A

place coding for moderate to high frequencies
rate coding for low frequencies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

timbre

A

corresponds to the complexity of the sound

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

why do we use timbre

A

to determine the source of sound waves

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

how is timbre determined

A

Perceived by assessing the precise mixture of hair cells that are active throughout the entire cochlea

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

pinna

A

outer ear; receives sound from the external environment

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

typanic membrane

A

vibrates in response to sound waves and transfers them to the middle ear

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

middle ear

A

composed of three ossicles (small bones)

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

three ossicles

A

malleus, incus, stapes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

oval windows

A

receives the vibrations from the ossicles and transmits them to the cochlea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

cochlea

A

inner ear; a long, fluid-filled, coiled tube-like structure that contains sensory neurons. divided into three longitudinal divisions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

three longitudinal divisions of the cochlea

A

Scala vestibuli
Scala media
Scala tympani

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

basilar membrane

A

encodes high notes on the end closest to the oval window. Like a xylophone, the low notes correspond to the longest (widest) section.

38
Q

effect of sound waves on the basilar membrane

A

Sound waves cause the basilar membrane to move relative to the tectorial membrane, which causes hair cell cilia to stretch and bend`

39
Q

organ of corti

A

Receptive organ that consists of the Basilar membrane on the bottom, the tectorial membrane on the top, and auditory hair cells in the middle

40
Q

cilia

A

hair-like extension cells that transduce sound

41
Q

outer hair cells

A

have cilia that are physically attached to the rigid tectorial membrane

42
Q

inner hair cells

A

are not attached to anything. They sway back and forth with the movement of the solution

43
Q

what does the movement of cilia do?

A

pulls open ion channels, which changes the membrane potential of hair cells.

44
Q

there are ____ outer hair cells than inner hair cells

A

3 times

45
Q

what type of hair cells transmit auditory information to the brain?

A

inner hair cells

46
Q

people without _____ hair cells are deaf but people without _______ hair cells aren’t

A

inner; outer

47
Q

how do outer hair cells adjust the sensitivity of the tectorial membrane

A

they contract like muscles to adjust the sensitivity of the tectorial membrane to vibrations

48
Q

how do outer hair cells affect inner hair cells

A

they influence the sensitivity of inner hair cells to specific frequencies of sound

49
Q

tip links

A

elastic filaments that attach the tip of one cilium to the side of the adjacent cilium

50
Q

intersertional plaque

A

the point of attachment of a tip link to a cilium

51
Q

what kind of protein do interserional plaques contain?

A

Each intersertional plaque has a single ion channel in it that opens and closes according to the amount of stretch exerted by the tip link

52
Q

how do hair cells release neurotransmitters

A

they don’t have axons or action potentials so they continuously release neurotransmitters based on the amount of the stimulus

53
Q

what is the effect of loud noises on the ear?

A

they can easily break tip links that interconnect each cilium. if broken, the tip links cannot transmit auditory information

54
Q

can tip links grow back

A

yes, they grow back within a few hours and hearing comes back to normal

55
Q

why does tip link breakage occur

A

as a protective measure against permanent damage

56
Q

effect of glutamate on the ear

A

too much glutamate can release onto the cochlear nerve causing permanent cell death (excitotoxicity)

57
Q

what percentage of 20 year olds have nose-induced hearing loss?

A

20%

58
Q

place coding

A

The place where the cell is most active in the cochlea indicates the fundamental frequency (the pitch) of the sound wave

59
Q

what types of frequencies are encoded by place coding?

A

moderate and high frequencies

60
Q

rate coding

A

the rate of neurotransmitter release from the hair cells deepest in the cochlea determines the animal’s perception

61
Q

what types of frequencies are encoded by rate coding?

A

very low frequencies

62
Q

basilar membrane and place coding

A

Higher frequencies cause the bending of the basilar membrane, resulting in more hair cell activity in that area

63
Q

tuning cures

A

indicate the sensitivity of individual inner hair cells, as is shown by their response threshold to pure tones of varying frequency. low points of the solid points indicate that the individual cells will respond to a faint sound only if it is a specific frequency. for louder sounds, cells will respond to frequencies above and below their preferred frequencies

64
Q

Fundamental frequency:

A

the lowest frequency in a sound wave

65
Q

overtone

A

sound wave frequencies that occur at integer multiples of the fundamental frequency

66
Q

timbre

A

the specific mixture of frequencies (fundamental frequency + overtones) that different instruments emit when the same note is played

67
Q

cochlear implant

A
  • Typically 20-24 electrodes are positioned along the length of the cochlea
  • By delivering electricity to distinct parts of the cochlea, we can cause actions potentials that correspond to different notes
  • We can’t recreate this entire system, but we can create many different tones
68
Q

fundamental frequency of human speech

A

85-180 Hz for men and 165-355 Hz for women

69
Q

spatial location and phase differences and low-frequency sounds

A

innate method of detecting the source of continuous low-pitches sounds by means of phase differences

70
Q

spatial location and loudness and high-frequency sounds

A

innate method of detecting the source of high-pitched sounds by analyzing the difference in loudness between ears

71
Q

spatial location and timbre

A
  • Sound waves bounce off the folds and ridges of the pinna before entering the ear canal
  • Depending on the angle at which sound waves strike these folds and ridges, different frequencies of sounds can be enhanced or attenuated
72
Q

sound pathway (steps)

A
  1. The organ of Corti sends auditory information to the brain via the cochlear nerve.
  2. These axons synapse in the cochlear nuclei of the medulla, where copies of the signal are made to be analyzed in parallel ascending paths.
  3. Axons from the cochlear nuclei synapse in the superior olivary nuclei in the medulla and the inferior colliculi in the midbrain, both of which help localize the source of sounds.
  4. Axons from the inferior colliculi synapse in the medial geniculate nucleus of the thalamus, which in turn relays the information to the primary auditory cortex in the temporal lobe
73
Q

tonotropic represenation

A

The organization where different frequencies of sound are analyzed in different places of the auditory context

74
Q

primary auditory cortex

A

the upper section of the temporal lobe, mostly hidden in the lateral fissure

75
Q

auditory association cortex

A

the belt and parabelt regions

76
Q

two streams of the auditory cortex

A

posterior and anterior pathways

77
Q

posterior auditory pathway

A

where/ dorsal pathway
involved in spatial localization
meets up with the where vision pathway in the parietal lobe

78
Q

anterior pathway

A

what/ ventral pathway
goes to the frontal lobe where the analysis of complex sounds occurs

79
Q

auditory agnosia

A

various forms of auditory processing issues

80
Q

amusia

A

The inability to perceive or produce melodic music

81
Q

vestibular system

A

Detects gravity and angular acceleration of the head. maintains your upright head position, organizes your balance and corrects eye movements to compensate for head movements

82
Q

Semicircular sacs

A

three ring-like, fluid-filled strictures that detect changes in head rotation (angular acceleration)

83
Q

Cupula

A

gelatinous mass found in the ampulla of the semicircular canals; movies in response to the flow of fluid in canals

84
Q

Vestibular sacs

A

a set of two receptor organs in each inner ear (utricle & saccule) that detect changes in the tilt of the head. Otoconia moves with gravity, depolarizing the hair cells it sits on

85
Q

odorants

A

volatile substances that activate olfactory receptors

86
Q

olfaction receptor cells

A

located in the olfactory epithelium

87
Q

where do olfaction receptor cells synapse

A

in the glomeruli

88
Q

how many types of receptors do olfaction receptor cells activate

A

1

89
Q

loudness

A

the number of hair cells that are active

90
Q

phase difference

A

Timing difference between the ears

91
Q

level difference

A

Loudness difference between ears

92
Q

how is the auditory cortex organized?

A

tonographically (by frequency)