Chapter 9: Hearing, Vestibular, Taste and Smell Flashcards
(98 cards)
1
Q
Sound
A
Oscillation of increases and decreases in air pressure.
2
Q
How is sound typically discussed?
A
As waves
3
Q
Amplitude
A
Distance between the resting position and maximum height of the wave.
4
Q
What is amplitude measured in?
A
Decibles (dB)
5
Q
Frequency
A
The number of waves passing by a specific point per second.
6
Q
What is frequency measured in?
A
Hertz (Hz)
7
Q
Pure Tone
A
A single frequency
8
Q
Most sounds are not…
A
pure tones
9
Q
Fourier Analysis
A
Decomposes sound into its separate sine waves.
10
Q
What type of force is sound?
A
Mechanical
11
Q
What is used to detect sound?
A
Mechanoreceptors
12
Q
Middle Ear
A
Controlled by stapedius and tensor tympani muscles.
13
Q
How does the middle ear reduce effectiveness of sound?
A
Stiffening links of bone.
14
Q
What is the middle ear important for?
A
Decreasing self-made sounds
15
Q
Inner Hair Cell
A
Transduces the physical force into the neural signal.
16
Q
Basilar Membrane
A
Has different sensitivities to different frequencies.
17
Q
What does the stiff base of the basilar membrane respond better to?
A
High frequencies
18
Q
What does the floppy apex of the basilar membrane respond better to?
A
Low frequencies
19
Q
Inner Hair Cells (IHCs)
A
Responsible for perception of sound.
20
Q
What % of the auditory fibers are from IHCs?
A
90-95%
21
Q
Outer Hair Cells (OHC)
A
Help to fine-tune organ of Corti in response to messages from the brain.
22
Q
Cochlear Amplifier
A
Amplify movements of basilar membrane in some areas while dampening in others.
23
Q
Neurons Tuning Curve
A
Auditory neurons have a precise frequency they are most sensitive to, but also respond to nearby frequencies.
24
Q
Where do binaural interactions occur?
A
The brainstem and superiors olivary nucleus
25
Tonotopic Organization
Organization of the auditory system.
26
What do the auditory systems try to analyze?
1. Pitch
2. Source of the sound
27
Place Theory
Encoded by area of basilar membrane with maximal excitation.
28
Volley Theory
Frequency encoded by firing frequency.
29
What type of frequency is the volley theory mainly used for?
Lower frequencies
30
Binaural Neurons
Serve as “coincidence detectors”
31
Lateral Superior Olive
Processes latency differences in mammals.
32
Medial Superior Olive
Processes latency differences but compares ENTIRE activity of MSO on left vs right.
33
External Ear
Provides spectral filtering and amplifies certain frequencies.
34
What are the 3 ossicles in the ear?
1. Malleus
2. Incus
3. Stapes
35
Auditory Cortex
Processes Complex Sounds
36
The auditory cortex is not involved in...
basic auditory discrimination (can be accomplished at lower levels)
37
Dorsal Stream
Focuses on localization
38
Ventral Stream
Analyzes components of sound.
39
What causes cells to shift their tuning curve?
Experience
40
What type of neurons have tuning curves?
Auditory cortical neurons
41
What are the 3 kinds of deafness?
1. Conduction
2. Sensorineural
3. Central
42
Conduction Deafness
Problem in the outer/middle ear prevents the transmission of vibrations.
43
Conduction deafness is not a _________ problem.
Nervous system
44
Sensorineural Deafness
The auditory nerve is unable to become excited and conduct signals.
45
What can cause sensorineural deafness?
1. Genetic mutation
2. Toxic drug
3. Loud sounds (chronic exposure)
46
What is damaged to cause sensorineural deafness?
Hair cells
47
How can sensorineural deafness by treated?
cochlear implants (auditory nerve is still functional)
48
Central Deafness
Something is wrong in the brain, causing deafness.
49
What is an example of something that can cause central deafness?
A stroke - damages auditory cortex / MGN projections to the cortex
50
Is central deafness complete or selective deafness?
Both
51
Auditory Brainstem Implants (ABIs)
Bypass auditory nerve and directly stimulate the brainstem nuclei
52
Vestibular Perception
Informs you about forces acting on the body (especially the head)
53
What are the two major forces in the vestibular system?
Gravity and acceleration
54
What is the vestibular system important for?
Balance and body/head position awareness
55
What are the 3 components for awareness in space?
1. Vestibular system
2. Visual system
3. Proprioceptive System
56
What are the Semicircular Canals important for?
Detecting rotational forces
57
What are the utricle and saccule important for?
Detecting linear forces (horizontal and vertical)
58
Each canal is located along a different ___.
Axis
59
Ampulla
Enlarged region of EACH semicircular canal
60
Where is the ampulla located?
The junction of canal and utricle
61
What do the hair cells in the ampulla respond to?
Precise kinds of mechanical rotational force (depends on orientation of hair cells)
62
Utricle
Saclike structure at the ends of canals
63
Saccule
Saclike structure below the utricle
64
What do the utricle and saccule contain?
Otoliths that enhance sensitivity of receptors
65
Lateral Line System
Array of receptors along the side of the body.
66
What is the importance of the movements of water stimulate receptors?
Tells animals about current and nearby animals.
67
What did the auditory system develop from?
Vestibular system
68
What does the vestibular nucleus send signals to?
1. Motor nuclei of eye
2. Thalamus
3. Cortex
69
Vestibular Ocular Reflex
Enables you to precisely control the muscles of the eye even as you move your head. (keeps eyes focused on one thing).
70
What happens after too much spinning of your body occurs?
Conflict between vestibular system and visual system feedback.
71
Taste and smell is a form of...
chemo detection
72
Flavors
taste and smell combined
73
What is taste processed by?
The gustatory system
74
How many taste receptor cells are on a taste bud?
50-100
75
What are the 5 tastes?
1. salty
2. sweet
3. sour
4. bitter
5. umami
76
Salty
Sodium transported across the cell membrane via channels - leads to depolarization
77
Sour
Dependent on the acidity of a substance
- Hydrogen ions enter through channels and depolarize
78
Sweet
Detected by the combination of two members of the T1R family (GPCRs)
79
Bitter
Often evoked by toxic substances that want to be highly sensitive
80
What kind of taste is poorly discriminated?
Bitter
81
Umami
meaty and savory flavor
82
What are the two receptor types of taste?
1. Responds to glutamate (amino acids)
2. Responds to most amino acids
83
What are amino acids highly present in?
meat
84
How many functional genes do humans have for odor receptors?
350
85
What does sensitivity reflect?
Evolutionary needs
86
What is the path of smell?
1. Olfactory receptor cells
to
2. The axons
to
3. The mitral cell
to
4. The brain
87
Mitral Cells
Cells in the olfactory bulb
88
Where do mitral cells send their axons?
Further into the brain
89
What does olfactory information have to pass through to reach the cortex?
The thalamus
90
How does olfactory transduction work?
1. Odorant binds to GPCR, leading to G protein activation.
2. The G protein activities cyclase, which produces cAMP
3. cAMP binds to channels, opening them, leading to depolarization
91
How many odors can humans discriminate?
5000 odors
92
Vomeronasal System
Pheromone detection system in the nose of some animals
93
What are the receptors in the vomeornasal system important for?
Organizing reproductive behavior
94
Histocompatibility Complexes (MHCs)
Important for detecting degree of relatedness to other animals.
95
Where is MHC information sent?
To the accessory olfactory bulb, medial amygdala, and to the hypothalamus
96
What do humans not appear to have?
A functional VNO (both receptor genes are nonfunctional)
97
What does behavioral evidence suggest humans are sensitive to?
pheromones
98
Pheromones and ___ ____ may not be so independent.
Olfactory systems
