Chapter 7: Structure of the Inner Ear and Its Mechanical Response

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Chapter 7 Structure of the Inner Ear and Its
Mechanical Response
This Power Point Presentation is to accompany the
textbook FUNDAMENTALS OF HEARING AN
INTRODUCTION (5th Edition) Published by Elsevier
Press and authored by William A. Yost. Please
consult the Power Point Instructions at this Web
Site before using this Presentation.
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Inner Ear The Cochlea
1 Vestibular System 2 Cochlea 3
Apex 4 Base 5 Round
Window 6 Scala Media
7Scala Vestibuli 8Scala
Tympani
3
2
3
Turn 3
7
6
8
7
2
6
8
Turn 2
4
7
6
Turn 1
8
4
5
2
3
1
4
5
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Inner Ear The Cochlea and the unrolled Cochlea
1 Oval Window 2 Round Window 3 Scala
Vestibuli 4 Scala Tympani 5 Scala Media 6
Apex 7 Base-Vestibule
6
5
1
7
3
2
4
4
Scala Media in cross section
1 Reisners Membrane 2 Stria Vascularis 3
Claudius Cells 4. Hensens Cells 5. Outer Hair
Cells (3) 6. Tectorial Membrane 7. Tunnel of
Corti 8. Inner Hair Cell 9. Rods of Corti 10.
Border Cells 11. Inner Spiral Sulcus 12. Spiral
Limbus 13. Osseous Spiral Lamina 14.
Auditory Nerve 15. Habenula Perforata 16, Basilar
Membrane 17. Deiters Cells 18. Spiral
Ligament 19. Inner Hair Cell
Stereocila
1
6
19
2
10
5
10
5
5
8
7
9
9
14
Scala Media
17
14
16
5
4
6
7
8
9
11
10
12
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Scala Vestibuli
18
9
17
13
Scala Tympani
14
14
15
16
Cross Section
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Cochlear Fluids
Perilymph (in red) Fluid in Scalae Vestibuli and
Tympani containing a high concentration of
sodium (Na) and a low concentration of potassium
(K). Endolymph (in blue) Fluid in Scala Media
containing a high concentration of potassium (K)
and a low concentration of sodium (Na).
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Hair Cells
Sc
SM
IHC
Sc
CP
Sc
IP
Sc
Sc
CP
TC
OP
OP
OHC1
PP
N
OHC1
IP
BM
OHC2
IHC
SN
N
OHC3
H
D
AN
AN
TC
D
OHC1-OHC3 Outer Hair Cells Rows 1-3 IHC Inner
Hair Cells N Cell Nucleus CP Cuticular Plate
TCTunnel of Corti IP Inner Pillar OP Outer
Pillar TC Tunnel of Corti ScStereocilia SN
Space of Nuel H Hensen Cells PP Phalangeal
Process BM Basilar Membrane DDeiters Cells
SM Scala Media AN Auditory Nerve
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Stereocilia
Deiter Cells
Row 1
Row 3
Row 2
Inner Pillar Cells
OUTER HAIR CELLS
INNER HAIR CELLS
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Tip Links/Cross Bridges of Inner Hair Cell
Stereocilia
Tip Links
Cuticular Plate
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Cochlear Traveling Wave
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Traveling Wave Simulation
High-Frequency Sound
Low-Frequency Sound
Base Apex
Basilar Membrane
Base
Apex Basilar Membrane
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Envelope of the Traveling Wave
High-Frequency Sound
Low-Frequency Sound
Base Apex
Basilar Membrane
Base
Apex Basilar Membrane
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Travel Time of the Traveling Wave
Maximum Displacement
Footplate of the Stapes
Base Apex
Basilar Membrane
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Traveling Wave for a Two-Tone Complex
Maximal Displacement-1
Maximal Displacement-2
Base Apex
Basilar Membrane
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Temporal Following of Traveling Wave to a
Two-Tone Complex
Traveling Wave
Displacement at one place along basilar membrane
Displacement at any one place along basilar
membrane follows sounds temporal waveform.
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Biomechanical Tuning of the Cochlea
Th
Measurement Probe
Th Threshold displacement
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Basilar Membrane Input-Output Function
Measurement Probe
Measurement at CF
Measurement off of CF