Chapter 6 - Audition & Mechanical Sense Flashcards
(145 cards)
1
Q
What is amplitude of a sound wave?
A
It’s intensity. The greater the amplitude, the louder the sound.
2
Q
What is frequency?
A
The number of compressions per second (Hertz)
3
Q
What is pitch?
A
Perception - sounds higher in frequency are higher in pitch.
4
Q
What is timbre?
A
The tone quality or complexity.
5
Q
What is pinna and where is it?
A
The out ear includes the pinna - flesh and cartilage attached to each side of the head.
6
Q
What is the tympanic membrane?
A
The ear drum. It vibrates at the same frequency as the sound waves.
7
Q
What does the tympanic membrane connect to?
A
Three tiny bones that transmit the vibrations to the oval window, a membrane of the inner ear.
8
Q
What are the three tiny bones in the ear?
A
Hammer / malleus
Anvil / incus
Stirrup / stapes
9
Q
How big is the tympanic membrane?
A
About 20 times bigger than the footplate of the stirrup that connects to the oval window.
10
Q
What does the inner ear contain?
A
Cochlea.
11
Q
What is the cochlea?
A
A snail-shaped structure that contains three long fluid filled tunnels (scala vestibuli, scala media, scala tympani).
12
Q
What are the three fluid tunnels in the cochlea
A
Scala vestibuli
Scala media
Scala tympani
13
Q
How does the stirrup impact on the cochlea?
A
The stirrup makes the oval window vibrate at the entrace to the scala vestibuli, setting in motion the fluid in the cochlea.
14
Q
What are auditory receptors?
A
Hair cells. They lie between the basilar membrane of the cochlea on one side and the tectorial membrane on the other side. Vibrations displace the hair cells, opening ion channels in its membrane. The hair cells excite the cells of the auditory nerve - part of the eighth cranial nerve.
15
Q
How do auditory receptors work?
A
Vibrations displace the hair cells, opening ion channels in its membrane. The hair cells excite the cells of the auditory nerve - part of the eighth cranial nerve.
16
Q
What is place theory?
A
Basilar membrane resembles strings of a piano with each areas tuned to a specific frequency.
17
Q
What is frequency theory?
A
Basilar membrane vibrates in synchrony with a sound, causing auditory nerve axons to produce an axon potential at the same frequency.
18
Q
What is current theory?
A
Low-frequency sounds (up to 100 Hz) - frequency theory. For higher-frequency sounds - the neruon might fire every 2nd, 3rd or 4th or higher wave. It’s action potentials are phase-locked to the peaks of the sound waves. Other auditory neurons fire action potentials at different peaks to create a summed effect of the frequency of the sound wave.
19
Q
What is the volley principle?
A
Auditory nerve produces volleys of impulses for sound up to about 4000/second even though no individual axon can approach that frequency.
20
Q
How does the basilar membrane vary?
A
Stiff at the base to floppy at the apex. Hair cells respond to different frequencies along it.
21
Q
What is amusia?
A
Tone deaf - can have difficulty recognising people being happy or sad in their voice.
22
Q
What is absolute pitch?
A
Perfect pitch - early musical training is important
23
Q
How does auditory information pass through the brain?
A
Information from the auditory system passes through subcortical areas, axons cross over in the midbrain so each hemisphere of the forebrain gets its information mostly from the opposite ear.
24
Q
How are the auditory system and visual systems similar?
A
Organisation of the auditory cortex is strongly parallel to the visual cortex. “what” pathway - sensitive to patterns of sound in the anterior temporal cortex. “where” pathway - sensitive to sound location in the posterior temporal cortex and the parietal cortex.
25
What is the auditory what pathway?
sensitive to patterns of sound in the anterior temporal cortex.
26
What is the auditory where pathway?
sensitive to sound location in the posterior temporal cortex and the parietal cortex.
27
What does damage to the superior temporal cortex cause?
Patients are not able to tell the source of a sound is moving.
28
Where is the primary auditory cortex located?
Superior temporal cortex (area A1).
29
What does area A1 do?
Responds to imagined sounds as well as real ones. Damage to area A1 does not leave someone deaf but they have trouble with speech and music but they can identify and localise single sounds well.
30
What is the tonotopic map of sounds?
Cells in area A1 respond to a preferred tone.
31
What is conductive or middle-ear deafness?
Diseases, infections or tumorous bone growth can prevent the middle ear from transmitting sound waves properly to the cochlea. Can be corrected by surgery or hearing aides.
32
What is nerve deafness or inner-ear deafness?
Damage to part of the cochlea, hair cells or auditory nerve. Can be contained to part of the cochlea impairing certain frequencies. Nerve deafness can produce tinnitus - frequent or constant ringing in the ears.
33
What is tinnitus?
Frequent or constant ringing in the ears.
34
What causes hearning loss in old age?
Brain areas responsible for language comprehension have become less active. Can have a decrease in inhibitory neurotransmitters, making it more difficult to suppress the irrelevant sounds and attending to relevant ones.
35
What is sound localisation?
High frequencies - time of arrival differences - intensity between ears (loudness) low frequencies - phase differences.
36
What is the vestibular organ?
Located next to the cochlea, it monitors movement and directs compensatory movement of your eyes. It detects the direction of tilt and amount of acceleration of your head.
37
What does the vestibular organ consist of?
The saccule, utricle and 3 semicircular canals. They are modified touch receptors. Calcium carbonate particles called otoliths lie next to the hair cells. They push against the and excite them.
38
How does the vestibular organ work?
The semicircular canals are filled with a jellylike substance and lined with hair cells. Acceleration causes the jelly to push against the hair cells. Action potentials travel through the 8th cranial nerve to the brainstem and cerebellum.
39
What happens when a touch receptor is stimulated?
It opens sodium channels in the axon, starting an action potential.
40
What is the Pacinian corpuscle?
It detects sudden displacements or high-frequency vibrations on the skin. The onion-like outer structure provides mechanical support that resists gradual or constant pressure. A sudden or vibrating stimulus bends the membrane allowing sodium ions to enter.
41
What are Merkel disks?
They respond to light touch i.e. stroking of the skin.
42
How does information go from touch receptors to the brain?
Info from the touch receptors in the head enters the CNS via the cranial nerves. From below the head, it enters through the 31 spinal nerves to the brain.
43
What spinal nerves are there?
8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal nerve pairs.
44
What does a spinal nerve consist of?
A sensory and motor component. Each spinal nerve innervates a limited area of the body called a dermatome.
45
What is a dermatome?
An area of the body that a spinal nerve innervates.
46
How does sensory information travel through the brain?
The various areas of the somatosensory thalamus send their impulses to different areas of the primary somatosensory cortex, located in the parietal lobe. Various aspects of body sensation remain separated though to the cortex.
47
What does pain do?
It directs attention towards a danger. The PFC typically responds only briefly to new light, touch, or sound. With pain, it continues to respond as long as the pain lasts.
48
How does pain flow from the skin to the brain?
Pain sensations begin with bare nerve endings. Axons carrying pain information have no myelination and are therefore slow. Thicker and faster axons convey sharp pain, whereas thinner ones convey dull pain. The brain processes pain more rapidly.
49
What does the brain do when it receives a pain signal?
Mild pain releases the neurotransmitter glutamate. Stronger pain releases several neuropeptides including substance P and CGRP (calcitonin gene-related peptide).
50
What brain pathways are activated?
Painful stimuli activates a path that goes through the reticular formation of the medulla and then to several central nuclei of the thalamus, amygdala, hippocampus, PFC and cingulate cortex. These also respond to emotional associations. The path extends to the ventral posterior nucleus of the thalamus and then to the somatosensory cortex, which responds to painful stimuli, memories of pain and signals warning of impending pain.
51
Where do pain sensations cross sides?
Pain sensations cross the spinal cord immediately before travelling to the brain.
52
What does damage to the cingulate gyrus do to pain responses?
People with damage to the cingulate gyrus still feel pain but it doesn't distress them.
53
How are emotional and physical pain similar?
Hurt feelings are similar to physical pain. Emotional pain causes increased activity in both the cingulate gyrus and sensory areas. Emotional pain can also be relieved by pain medication.
54
How brain does the brain stop pain?
The brain stops pain by opioid mechanisms. Opiates bind to receptors found in the spinal cord and periaqueductal grey area of the midbrain. The transmitters that attach to the same receptors as morphine are endorphins.
55
What is gate theory?
Spinal cord neurons that receive messages from pain receptors also receive input from touch receptors and from axons descending from the brain. These other inputs can close the "gates" for pain messages through releasing endorphins. Morphine does not affect large-diameter axons that convey sharp pain but does block thinner axons that convey dull pain.
56
How do placebos impact on pain?
Placebos can relieve pain or depression. Placebos produce a large effect on the emotional response to pain in the cingulate cortex. Distraction plus placebo relieves more pain.
57
Where do cannabinoids act?
In the periphery of the body rather than the CNS.
58
How does capsaicin impact on pain?
Capsaicin stimulates receptors for heat. When rubbed on a sore shoulder etc it produces a temporary burning sensation followed by a longer period of decreased pain. Capsaicin applied in high doses causes a build up of calcium in heat receptors and damages the mitochondria in those receptors.
59
What role do histamines play?
Damaged or inflamed tissue releases histamine, nerve growth factor that helps repair the damage but also magnify the responses of nearby heat and pain receptors.
60
How do non-steroidal anti-inflammatory drugs relieve pain?
By reducing the release of chemicals from damaged tissues.
61
What does chronic pain do?
Chronic pain leads to clinical depression and to decreased activity in the PFC. A barrage of stimulation to pain receptors potentiates them so they respond more vigorously in the future.
62
What do opiates do to pain?
They decrease pain but increase itch.
63
What does the nociceptive system do?
Responds to tissue damage or threat of it.
64
What is analgesia?
Attempts to alleviate pain.
65
What is the anti-nociceptive system?
Ignorance of pain or wounds to aid with fighting or fleeing.
66
What are neurons activated by tissue damage called?
Nociceptive neurons. They come in different forms corresponding to the types of stimuli that activate them.
67
What are the neurons in the spinal cord that nociceptive neurons form synapses with called?
Transmission cells (T cells). T cells convey information to the brain in the spino-thalamic tract (STT).
68
What parts of the brain are closely involved with affective aspects of pain?
Anterior cingulate cortex and insula cortex. The somatosensory cortex is where the location of pain is determined.
69
What does rubbing a sore area do?
It reduces pain. It stimulates that large diameter neurons.
70
What chemicals are released from damaged cells?
Prostaglandins and other substances. They sensitise nociceptros. This increases the chances that tissue damage will initiate action potentials.
71
What is aspirin?
A peripherally acting analgesic that blocks the synthesis of prostaglandins.
72
What does lignocaine do?
Blocks sodium channels in the membrane of neurons. When sodium is blocked the action potential can't continue.
73
What do opiates do?
They act on the CNS. Opioid receptors in the brain are occupied and this activates descending inhibitory pathways. Opioid receptors are also at T cells and nociceptive neurons. Opioids prevent action potentials from releasing enough neurotransmitters to stimulate activity in the T cells.
74
What is neuropathic pain?
Pain that arises intrinsically as a result of damage to, or malfunction within, the nervous system.
75
After damage to the somatosensory cortex, a person would have the most difficulty with:
pointing to their own body parts.
76
A mild degree of pain releases the neurotransmitter ____. A more intense pain also releases ____.
glutamate, substance P
77
A distinctive feature of itch is that it relies on:
Unusually slow axons
78
After hurting your elbow in a biking accident, the gate-control theory of pain suggests that to reduce the pain, you could:
Rub it gently
79
Loudness is to ____ as pitch is to ____.
amplitude; frequency
80
Along each strip of somatosensory cortex, different sub-areas respond to:
different areas of the body.
81
One peculiarity of itch sensations is that:
they depend on action potentials transmitted at very slow speeds.
82
Most theorists believe that the first sensory system was:
Chemical
83
Itching appears to be one type of pain message. T or F
False
84
The inner ear contains a snail-shaped structure called the cochlea. T or F
True
85
Strong pain releases both glutamate and substance P. T or F
True
86
A mild pain stimulus is associated with a release of:
Glutamate
87
Somatosensory information travels from the thalamus to which area of the cortex?
parietal lobe
88
In the auditory system, hair cells are specialized receptors that respond to:
mechanical displacement.
89
After sound waves pass through the auditory canal, they strike the tympanic membrane. T or F
True
90
An acceleration of the head at any angle causes:
the jelly-like substance in one of the semicircular canals to push against hair cells.
91
An individual with damage to the primary somatosensory cortex would most have problems with:
ability to locate where someone was touching them.
92
The outer ear includes:
the pinna
93
The amplitude of a sound wave is its intensity. T or F
True
94
The hammer, anvil and stirrup are found in the:
Middle ear
95
Vibrations in the fluid of the cochlea causes?
hair cells to displace
96
Antihistamine drugs tend to ____ itching, and opiates tend to ____ itching.
reduce; increase
97
Pitch is a perception related to which aspect of sound?
Frequency
98
Itching is primarily the result of:
Histamine release
99
Areas bordering the primary auditory cortex are important for:
analyzing the meaning of sounds.
100
The ____ of a sound is the number of compressions per second.
frequency
101
"Every sound causes one location along the basilar membrane to resonate, and thereby excites neurons in that area." This is one way to state which theory about pitch perception?
place theory
102
Most cells in the auditory cortex respond best to pure tones. T or F
false
103
Comparisons between which two responses are helpful in locating the source of a sound?
The left and right ear
104
Pain receptors of the skin are:
simple, bare neuron endings.
105
A person would have the most difficulty locating the sight and sound of an approaching train with damage to the:
parietal cortex
106
The somatosensory system involves sensation of:
the body and its movements.
107
How do sound waves ultimately result in the production of receptor potentials?
Hair cells in the cochlea vibrate, causing ion channels to open in their membrane.
108
The ability to detect motion of sounds depends on the same area of the brain that helps detect motion of objects. T or F
True
109
Someone who has suffered damage to the sensory component of one spinal nerve would lose sensation from:
one dermatome
110
The ability to hear a note and identify it perfectly is called:
Absolute pitch
111
The eardrum vibrates at:
the same frequency as the sound waves that hit it.
112
For what kind of sounds can differences in loudness be used most accurately for localization?
b. high-pitched
113
At low frequencies, our perception of loudness is determined by:
the number of activated hair cells.
114
Damage to the primary auditory cortex results in:
difficulty in responding to sequences of sounds
115
At low frequencies, the intensity of the sound is coded by the:
number of neurons producing action potentials.
116
```
If two voices differ in their frequency, this means that they differ in their:
Select one:
a. loudness.
b. height of each wave.
c. amplitude.
d. number of waves per second.
```
number of waves per second.
117
Conductive deafness is also known as:
middle ear deafness.
118
Suppose you suddenly become deaf in one ear. With practice, you would most likely be able to locate familiar sounds based on differences in:
loudness.
119
A person who "sees" spoken language or music may be experiencing:
synesthesia.
120
According to the frequency theory, the:
basilar membrane vibrates in synchrony with a sound, producing action potentials at the same frequency.
121
Anti-inflammatory drugs, such as ibuprofen, relieve pain by:
reducing the release of chemicals from damaged tissues.
122
What is the relationship between pain and itch?
Pain inhibits itch.
123
Tinnitus is often:
d. due to a phenomenon like the phantom limb.
124
Through which mechanism do we perceive low-frequency sounds (up to about 100HZ)
The basilar membrane vibrates in synchrony with the sound waves, and each responding axon in the auditory nerve sends one action potential per sound wave.
125
How do we perceive middle frequency sounds (100 to 4000Hz)?
No single axon fires an action potential for each sound wave, but different axons fire for different waves and so a volley (group of axons) fires for each wave.
126
How do we perceive high frequency sounds (above 4000Hz)?
The sound causes maximum vibrations for the hair cells at one location along the basilar membrane.
127
What evidence suggests that amuse depends on special experiences?
Absolute pitch occurs almost entirely among people who had early musical training and is more common among people who speak tonal languages, which require greater attention to pitch
128
How is the auditory cortex like the visual cortex?
a) Both vision and hearing have "what" and "where" pathways.
b) Areas in the superior temporal cortex analyse movement of both visual and auditory stimuli. Damage there can cause motion blindness or motion deafness.
c) The visual cortex is essential for visual imagery and the primary auditory cortex is essential for auditory imagery.
d) Both the visual and auditory cortices need normal experience early in life to develop normal sensitivities.
129
What is one way in which the auditory and visual cortices differ?
Damage to the primary visual cortex leaves someone blind, but damage to the primary auditory cortex merely impairs perception of complex sounds without leaving the person deaf.
130
What kinds of sounds most strongly activate the auditory cortex?
Most cells respond best to complex sounds that include harmonics. Outside the primary auditory cortex, most cells respond to "auditory objects" that mean something.
131
Which type of hearing loss - conductive deafness or nerve deafness - would be more common among members of rock bands and why?
Nerve deafness is common among rock band members because their frequent exposure to loud noises causes damage to the cells of the ear.
132
Why do many older people have trouble hearing speech in spite of wearing hearing aids?
In some cases the language areas of the cortex have become less responsive. Also, auditory areas of the brain have decreased levels of inhibitory neurotransmitters and the result is decreased ability to focus attention on one speaker in a noisy environment.
133
Which method of sound localisation is more effective for an animal with a small head? which is more effective for an animal with a large head? Why?
An animal with a small head localises sound mainly by differences in loudness because the ears are not far enough apart for differences in onset time to be very large. An animal with a large head localises sound mainly by differences in onset time because its ears are far apart and well suited to noting differences in phase or onset time.
134
People with damage to the vestibular system have trouble reading street signs while walking. Why?
The vestibular system enables the brain to shirt eye movements to compensate for change in head position. Without feedback about head position, a person would not be able to correct eye movements, and the experience would be like watching a jiggling book page.
135
How do japans produce a hot sensation?
Jalapeos and other hot peppers contain capsaicin, which stimulates receptors that are sensitive to heat.
136
In what way is somatosensation several senses instead of one?
We have several types of receptors sensitive to touch, heat and so other, and different parts of the somatosensory cortex respond to different kinds of skin stimulation.
137
What evidence suggests that the somatosensory cortex is essential for the conscious perception of touch?
People are conscious of only those touch stimuli that produce sufficient arousal in the primary somatosensory cortex. Also, cells in the somatosensory cortex respond to what someone experiences, even if it is an illusion.
138
Suppose you suffer a cut through the spinal cord on the right side only. For the part of the body below that cut, will you lose pain sensation on the right side or the left side?? Will you lose touch sensation on the right side or the left side?
You will lose pain sensation on the left side of the body because pain information crosses the spinal cord at once. You will lose touch sensation on the right side of the body because touch pathways remain on the ipsilateral side until they reach the medulla.
139
In what ways are hurt feelings similar to physical pain?
Hurt feelings activate the cingulate cortex, just as physical pain does. Also, acetaminophen relieves hurt feelings.
140
How do opiates relieve dull pain but not sharp pain?
Endorphins block messages form the thinnest pain fibres, conveying dull pain, but not form thicker fibres, carrying sharp pain.
141
How do the pain-relieving effects of cannabinoids differ from those of opiates?
Unlike opiates, cannabinoids eat most of their pain-relieving effects in the peripheral nervous system not the CNS.
142
How do ibuprofen and other non steroidal anti-inflammatory drugs decrease pain?
Anti-inflammatory drugs block the release of chemicals from damaged tissues, which would otherwise magnify the effects of pain receptors.
143
Why is it preferable to start taking morphine before an operation instead of waiting until later?
The morphine will decrease the barrage of pain stimuli that might sensitise pain neurons.
144
Do opiates increase or decrease itch sensations?
Opiates increase itch by blocking pain sensations (pain decreases itch).
145
Suppose someone suffers from constant itching. What kinds of drugs might help relieve it?
Histamines or capsaicin - depending on the source of the itch. Drugs that block gastrin-releasing peptide might help.
