Auditory Anatomy and Physiology Flashcards
(142 cards)
1
Q
The concha has a resonance of _____ Hz.
A
5000 Hz
2
Q
The acoustic property of the concha ___________________________.
A
Adds a peak of energy to the incoming message.
3
Q
The external auditory canal has a resonance of _____ Hz.
A
2500
4
Q
The acoustic property of the external auditory canal ______________________.
A
Adds a second boost of energy to the incoming message.
5
Q
The acoustic properties of the outer ear _______ from person to person. (Stay the same/change)
A
Change from person to person
6
Q
The first half to two-thirds of the canal is ___________.
A
cartilaginous - lined with glands that produce cerumen; lined with cilia
7
Q
The second 1/3 of the canal is _______.
A
bone - it forms the first layer of skin that comprises the TM
8
Q
The length of the external canal in adults is:
A
29-30 mm; 2.9-3.0 cm
9
Q
The length of the external canal in infants is:
A
~14mm (grows to 21 mm by age 2)
10
Q
The outer ear (pinna and ear canal) assists us in ________________
A
sound localization
11
Q
The pinna and ear canal serve as a _________
A
resonator
12
Q
The pinna and ear canal act as a ________ for the temporal bone (the hardest bone in the body)
A
cushion
13
Q
What are the three ossicular bones?
A
malleus, incus, stapes
14
Q
The tympanic membrane sits in a groove called the ______________
A
tympanic sulcus
15
Q
What are the three layers of the tympanic membrane?
A
- Cutaneous: outer layer (skin)
- Fibrous: provides most of the structure and compliance. Density is greatest at center. Gives integrity to the very thin structure.
- Internal: mucous membrane; helps keep membrane healthy
16
Q
Which layer of the tympanic membrane provides most of the structure and compliance?
A
The Fibrous layer
17
Q
In the fibrous layer, density is greatest at the _______ and gives _______ to the very thin structure.
A
center; integrity
18
Q
Which layer of the tympanic membrane is the outer layer (the skin)?
A
The Cutaneous layer
19
Q
Which layer of the tympanic membrane is the mucous membrane that helps to keep the membrane healthy?
A
The Internal layer
20
Q
The ossicular chain is held in place by what four things?
A
- TM
- 4 ligaments attached to the malleus and 1 ligament attached to the incus
- Tendon of the Tensor Tympani muscle and tendon of the Stapedius muscle.
- Annular ligament around Stapes footplate in the oval window.
21
Q
Which two tendons help hold the ossicular chain in place?
A
The Tensor Tympani and Stapedius muscle
22
Q
Which tendon contracts when presented with a loud sound?
A
Stapedius muscle
23
Q
Which tendon protects the inner ear from damage?
A
Stapedius
24
Q
The tendon of the Tensor Tympani and the Stapedius muscle are ________ elastic than in other places in the body.
A
much more elastic
25
The tendon of the Tensor Tympani and the Stapedius muscle make muscle contractions occur ________
more slowly - no sudden contractions
26
The Tensor Tympani muscle is a _____ muscle with a ____ effect.
large muscle; small effect
27
The Stapedius muscle is a _____ muscle with a _____ effect.
Small muscle; large effect on the transmission of sound through the ear
28
Middle ear muscles (2):
Tensor Tympani
| Stapedius
29
The stapedius and tensor tympani contract in _______ directions to prevent primary rotation of the ossicular chain
opposite directions
30
Why do the stapedius and tensor tympani contract in opposite directions?
keeps them in their correct plane
31
The stapedius is completed encased in ____, only ___ enter the tympanic activity.
bone; tendons
32
(T/F) The stapedius is a protective mechanism.
True
33
The function of the middle ear muscles are to _____________________________.
Modify the vibration of the ossicular chain
34
The _______ contracts with loud sounds and just before speaking.
Stapedius
35
The _______ contracts during swallowing, chewing and some other facial movements.
Tensor Tympani
36
What are the two muscles of the eustachian tube?
Tensor veli palatine (TVP)
| Levator veli palatin (LVP)
37
Can the ear drums repair themselves?
If they are healthy, they can repair minor issues
38
What is the function of the Eustachian tube?
To equalize the air pressure in the middle ear
| To allow fluids trapped in the middle ear to be drained
39
Whose function is to modify the vibration of the ossicular chain?
The middle ear muscles: the tensor tympani and stapedius
40
What is the function of the middle ear?
To create an impedance match
41
There is an impedance mismatch between the ____ and the ____
outer ear; inner ear
42
Impedance
the sum of all the energy that opposes the transmission of sound
43
Equalizes the air pressure in the middle ear; allows fluid trapped in the middle ear to be drained
Eustachian Tube
44
(T/F) It takes an equal amount of energy to produce a wave in the fluid of the inner ear than in the atmosphere where sounds are generated.
FALSE. It takes MORE energy to produce a wave in the fluid of the inner ear than in the atmosphere where sounds are generated.
45
How does the middle ear help to resolve the mismatch between the outer and inner ears?
There is a difference in the surface area of the TM relative to the area of the stapes footplate
This difference contributes about 25 dB of improved sound transmission by focusing the vibratory area onto the smaller footplate.
There is a leverage created by the geometric configuration of the ossicles contributing approximately another 12-13dB of amplification
46
The impedance mismatch between the outer and inner ears contributes about _______ of improved sound transmission by focusing on the vibratory area onto the smaller footplate.
25 dB
47
The sum of all the energy that opposes the transmission of sound
Impedance
48
The leverage created by the geometric configuration of the ossicles contributing approximately another ______ of amplification in the impedance mismatch between the outer and inner ears.
12-13 dB
49
The three semicircular canals are also called _______ canals
balance
50
What are the two windows of the inner ear?
Oval Window
| Round Window
51
The oval window is located at the ______________
stapes footplate
52
The oval window is:
flexible (moveable)
53
The oval window opens into the ______________
scala vestibuli
54
The round window is at the base of the ___________
Scala Tympani
55
The round window equalizes:
pressure when the stapes moves in and out
56
When the stapes moves ___ at the ___ window, the ___ window moves ____.
moves in at the oval window, the round window moves out
57
The oval and round windows always move in _______.
opposition
58
The vibrations created by the oval and round windows are _____ for high frequency sounds and ____ for low frequency sounds.
faster; slower
59
What are the three ducts?
Endolymphatic duct
Scala vestibuli
Scala tympani
60
The boney labyrinth is made up of: (2 things)
scala tympani
| scala media
61
The boney labyrinth is filled with the fluid called ______.
perilymph
62
Perilymph is similar to _________
...cerebrospinal fluid
| ...the ionic composition of extracellular fluid
63
Perilymph fills the:
scala vestibuli, scala tympani, vestibule, vestibular system
64
The vestibule is:
the connection between the cochlea and the semi-circular canals)
(a duct within a duct)
65
The vestibule contains:
the utricle and saccule of the membranous labyrinth
66
The membranous labyrinth houses:
sensory cells
67
What are the three parts of the membranous labyrinth?
```
Vestibular (2 parts): semicircular canals; utricle and saccule
Cochlear duct (1 part): scala media
```
68
What are the three layers of the cochlea?
```
Scala vestibuli (top)
Scala media (middle)
Scala tympani (bottom)
```
69
Where do neurons go after they leave the cochlea?
The auditory pathway extends from the cochlea to the cerebral cortex via five orders of neurons
70
The _____ set of neurons extends from the inner ear cells to the cochlear nucleus.
first-order neurons
71
The utricle and saccule provide information about the movement of the ______
head
71
How many ampulla are there?
3: present at the end of each semicircular canal
71
The cochlea is where the actual transduction of _________ to ________ energy takes place
mechanical --> electrical
71
The movement of the fluid causes a deflection of the tiny hair cells (mechanical) of the inner ear which in turn sets off what?
An electrical signal that is then transferred to the brain for interpretation
71
Higher frequencies cause the ________ to move more than the _____.
base; apex
71
When the OHC's are pushed by the basilar membrane into the tectorial membrane, the stereocilia are bent ______ the _____
towards; kinocilium
71
Shearing opens ______________ near the tips of the sterocolia allowing electrically charged ions to flow into the hair cell.
Ion channels
71
Which hair cells die/damage first?
High frequencies probably due to the scrubbing or shearing motion.
For noise induced hearing loss, the continual 'pounding' of the stapes into the basal ed of the cochlea
71
The stapes is embedded in the:
base of the cochlea
71
Action potential
Electrical Transduction
71
The endolymphatic sac is involved in ____________
fluid exchange
71
What are the boundaries of the membranous labyrinth (3)
Reissner's Membrane
Spiral Ligament
Basilar Membrane
71
Separates the scala vestibuli from the scala media
Reissner's membrane
71
Separates the scala tympani from the scala media as well as houses the sensory cells
Basilar membrane
71
holds the membranes in place
Spiral ligament
71
The membraneous labyrinth is suspended within the bony canal by:
The spiral ligament (stretches to the outside wall; suspends the Basilar membrane)
Osseous Spiral Lamina (thin shelf of bone)
71
What fluid is within the membranous labyrinth (scala media)
Endolymph
71
The ________ energy at the stapes footplate transmits its vibration into the fluids of the cochlea
Mechanical energy
71
The basilar membrane is located at the _____________.
base of the cochlear duct (scala media)
71
The (base/apex) of the basilar membrane is wider, has more mass, and is more flaccid.
Apex
71
The (base/apex) of the basilar membrane is narrower and more stiff (under more tension).
Base
71
The scala media gets ________ base to apex.
Smaller
71
The basilar membrane gets _____ from base to apex.
Wider
71
Low frequencies cause a motion from the ______ to the _____ but more at the _____.
base; apex; apex
71
Are the outer and inner hair cells embedded in the basilar membrane?
Yes
71
Do the stereocilia of the outer hair cells touch the tectorial membrane?
YES
71
Do the outer hair cells touch the tectorial membrane?
NO: They stop just short of the tectorial membrane
71
The basilar membrane displacement causes ______ of the stereocilia.
Shearing
71
The tallest of the hair cells
Kinocilium
71
When the stapes moves ______, it pushes the basilar membrane up. Hair cells move into the tectorial membrane. Bend is ______ the tallest hair cells.
Out; toward
71
When the stapes moves ____, the basilar membrane extends downward, the stereocilia are bent _______ from the kinocilium.
Up; away from
71
The shearing movement of the hair cells is what transmits __________
The electrical energy
71
The shearing motion is due to :
several pivot points in the Organ of Corti - pivot points are attached to the spiral lamina and spiral ligament
71
How fast does the shearing motion occur?
If the tone is 1000 Hz, the BM moves at a rate of 1000 x/sec.
E.g., 4000 Hz = 4000 times/second
71
Does the whole BM move at 1000 x/second during the shearing motion?
No. Just the spot that responds best to 1000 Hz. Higher frequencies at the base, lower toward the apex.
71
What makes the IHC's move back and forth?
Movement of fluid between the TM and the BM. Fluid washing over the stereocilia
71
The ion channels create a change of voltage from ________ to _____ and is what generates the firing of the nerve
Negative to positive
71
Some of the fluids and cells within the cochlea are positively charged and some are negatively charged
Resting potential
71
Has little/no electrical change (0-5mV)
Perilymph
72
Movement of the perilymph within the cochlea
Hydromechanical Transduction
73
traveling wave and shearing of the stereocilia
Mechanical (Step 3) Transduction
74
TM, ossicular, and stapes movement
Mechanical (Step 1) Transduction
75
Order of transduction:
Mechanical, hydromechanical, mechanical, electrochemical, electrical --> auditory nerve
76
change in the ionic composition within the hair cells that produces an action potential
Electrochemical transduction
77
Inner hair cells transduce sound waves into electrical impulses that reach the brain via the ______ nerve.
VIII
78
the signal is transduced a number of times:
Transduction
79
___________ motion of BM causes fluid to be pumped in and out of the internal spiral sulcus which bends ______.
Up and down; stereocilia
80
Current causes the cell to release ____________ which elicits responses in primary auditory neurons
a neurotransmitters
81
Reflects amplification provided by the cochlear amplifier. Low level sounds near center frequency are amplified
Active response
82
Because inner hair cells are not directly attached to the tectorial membrane, shearing occurs via _____________.
fluid movement
83
The cochlear amplifier improves: (2)
The sensitivity of the basilar membrane
| Frequency selection
84
Reflects variation in stiffness of the Basilar Membrane
Passive response
85
Motility increases the ______ of the basilar membrane.
Displacement
86
Increase in input is called the:
Cochlear amplifier
87
OHC change in _________________
shape - they length and shorten
88
Motility generates:
force
(Force changes the motion of the traveling wave
Positive feedback loop
Increases the displacement of the basilar membrane)
89
Outside the cell, there is _________ charge.
Positive
90
Isolates the cell body from the stereocilia
Reticular lamina
91
The battery of the cell; pumps positively charged ions into the hair cell and then pumps them back out again into the endolymph.
Stria vascularis
92
Inside the cell, there is _________ charge.
Negative
93
Where do neurons go after they leave the cochlea?
The auditory pathway extends from the cochlea to the cerebral cortex via five orders of neurons
94
Has a high positive charge (80mV)
Endolymph
94
The intracellular potential (inside the hair cells) is highly ________
negative
94
Energy starts as acoustic energy and then once it hits the ear drum, becomes:
Mechanical energy
94
In the aging ear, we now believe that it is the aging of the __________ that is actually changing more rapidly than actual hair cell loss.
Stria vascularis
94
OHC's are equal to the:
rate of the stimulus frequency
94
Forces changes the motion of the ______________
traveling wave
94
Outer hair cells ________ sound impulses
Amplify
109
at the top of each hair cell
Sterocilium
110
Kinocilium are the tallest of the outer/inner hair cells
Outer
111
forms the overlying portion of the tectorial membrane
internal spiral sulcus
112
pivotal points are found on the:
basilar membrane
