Inner Ear

Question 1

The inner ear sits in the _____ portion of the temporal bone

Answer 1

Petrous

Question 2

The pathway for the VII and VIII nerves within the skull is called the

Answer 2

Internal auditory meatus

Question 3

The _________ is the conjoining of the scala vestibuli and the scala tympani at the apex of the cochlea.

Answer 3

Helicotrema

Question 4

The modiolus and osseous spiral lamina create the structure of the cochlea

Answer 4

True

Question 5

The point of attachment for the tectorial membrane is known as the _____

Answer 5

Spiral Limbus

Question 6

The oval window is located ________ in the middle ear and is covered by ______.

Answer 6

Superiorly
The stapedial footplate

Question 7

The round window is located ________ in the middle ear and is covered by ______.

Answer 7

Inferiorly
A membrane

Question 8

The central, perforated, bony core that the cochlea wraps around is called the…

Answer 8

Modiolus

Question 9

Coiled canal throughout the bony labyrinth around the modiolus
tha houses the spiral ganglion

Answer 9

Rosenthal’s Canal

Question 10

Small openings within the cochlea that allow neural fibers to pass into or out of the Organ of Corti through the Basilar Membrane

Answer 10

Habenula perforata

Question 11

Name the three ducts of the membranous labyrinth of the cochlea

Answer 11

Scala vestibuli
Scala media
Scala tympani

Question 12

The ionic composition of perilymph and CSF are _____ dominant, whereas endolymph is ______ dominant.

Answer 12

Sodium
Potassium

Question 13

In comparison to the apical end, the basal end of the basilar membrane is _______, ______, and ______.

Answer 13

Thicker
Narrower
Stiffer

Question 14

Describe the concept of an asymmetrical envelope and how it pertains to the traveling wave

Answer 14

When a traveling wave approaches it point of maximum displacement along the basilar membrane, that displacement dies down faster than it initially grew

Question 15

The stereocilia of the outer hair cells are _____ whereas the stereocilia of the inner hair cells are ______

Answer 15

Embedded in the tectorial membrane
Suspended in the scala media

Question 16

The barrier that separates the endolymph from all internal structures of the organ of corti is known as the ______.

Answer 16

Reticular Lamnia

Question 17

Reissner’s membrane separates which two ducts?

Answer 17

Sacala vestibuli and scala media

Question 18

What part of the organ of corti supplies the blood and nutrients to the cochlea, and likely manufactures endolymph?

Answer 18

Stria Vascularis

Question 19

________ separates outer hair cells and inner hair cells within the organ of corti.

Answer 19

Tunnel of Corti

Question 20

Inner hair cells are organized in _____ row(s). There are approximately ______ of them. Their stereocilia are ___-shaped and are ________ to the tectorial membrane.

Answer 20

One
3,500
U
Not attached

Question 21

Outer hair cells are organized in _____ row(s). There are approximately ______ of them. Their stereocilia are ___-shaped and are ________ to the tectorial membrane.

Answer 21

Three to Five
12,000
W or V
Attached

Question 22

Each inner hair cell synapses with _____ Type ___ fibers

Answer 22

10-20
I

Question 23

Each outer hair cell synapses with _____ Type ___ fibers

Answer 23

Multiple
II

Question 24

Efferent fibers communicate largely with _____ and there are much _____ of them compared to afferent fibers.

Answer 24

OHCs
Less

Question 25

Afferent fibers communicate largely with _____ and there are much _____ of them compared to efferent fibers.

Answer 25

Both OHCs and IHCs More

Question 26

The majority of afferent fibers are type I radial fibers

Answer 26

True

Question 27

The supporting cells directly inferior to outer hair cells are called ___________

Answer 27

Deiters Cells

Question 28

When a traveling wave along the basilar membrane compresses, it deflects the basilar membrane ______, pushes the stererocillia towards the _________ fiber, pushes the stapes ______, pushes the round window ________, and results in ________.

Answer 28

Downward Shortest Inward Outward Hyperpolarization/Inhibition

Question 29

When a traveling wave along the basilar membrane rarefacts, it deflects the basilar membrane ______, pushes the stererocillia towards the _________ fiber, pushes the stapes ______, pushes the round window ________, and results in ________.

Answer 29

Upward Longest Outward Inward Depolarization/Excitation

Question 30

The direction of the travelling wave is due to the _____, _____, _____ and _____ of the basilar membrane.

Answer 30

Shape Thickness Stiffness Mobility

Question 31

The idea that frequency encoding is dependent on its place of maximum vibration along the basilar membrane is called....

Answer 31

Place Theory

Question 32

The idea that frequency is encoded based on the timing and rate of neuronal firing patterns (i.e. if neurons fire 500 times a second, then the frequency you’re hearing is 500 Hz) is called....

Answer 32

Temporal Theory

Question 33

The idea that frequency encoding is dependent on a population of neurons firing action potentials at a particular phase of the input frequency is called....

Answer 33

Volley Theory

Question 34

Low frequencies have _____ tuning curves and ______ frequency specificity than high frequencies.

Answer 34

Broader Less

Question 35

Viscous drag is when ____

Answer 35

Fluid in the subtectorial space is pushed away or towards the inner hair cells' stereocilia

Question 36

Name two limitations of von Bekesy’s travelling wave theory

Answer 36

Tuning is too broad at lower frequencies Doesn't take into account active processes such as the cochlear amplifier

Question 37

The cochlear amplifier increases the ______ level in the outer hair cells as a response to sound. This increases the ______ of the outer hair cells, which changes the motion of the _______, increasing ______ along the basilar membrane, which increases _______ to the inner hair cells, amplifying the sound.

Answer 37

Voltage Motility Traveling Wave Displacement Mechanical Input

Question 38

As the travelling wave moves towards the apex, its amplitude ______ and its velocity ______.

Answer 38

Increases Decreases

Question 39

Define the travelling wave paradox

Answer 39

The traveling wave always moves from base to apex due to the biophysical characteristics of the basilar membrane

Question 40

How is a complex signal encoded via the travelling wave?

Answer 40

The basilar membrane peaks at several places, each correlating to the frequency components of the signal, similar to an FFT

Question 41

In regards to excitation and inhibition, _________ is a result of compression and _____________ is a result of rarefaction.

Answer 41

Inhibition Excitation

Question 42

What is the key anatomical difference of shearing action and viscous drag?

Answer 42

IHCs are not embedded in the tectorial membrane and thus cannot take advantage of shearing action to open ion channels, instead fluid dynamics cause the streocillia on the IHCs to move parallel with the fluid (endolymph).

Question 43

Define OAEs and describe how they are evidence of nonlinearity of the cochlea

Answer 43

Sounds generated in the inner ear at a low intensity that are detected in the EAM Are only present in cochleas with a healthy/functioning cochear amplifier

Question 44

Name 3 anatomical factors that make shearing action possible

Answer 44

The tectorial membrane can pivot up and down The basilar membrane can pivot up and down Sterocillia can deflect towards or away from the tectorial membrane

Question 45

Inner hair cells are innervated primarily by ______, transduce sensory information via _____ and are ______.

Answer 45

Type I Spiral Ganglion Cells Viscous Drag Not Motile

Question 46

Outer hair cells are innervated primarily by ______, transduce sensory information via _____ and are ______.

Answer 46

Type II Spiral Ganglion Cells Shearing Action Motile

Question 47

The cochlear amplifier results in _____ tuning

Answer 47

Sharper

Question 48

Two pieces of evidence of the nonlinearity of the cochlea include _____ and ____.

Answer 48

Frequency Encoding being sharper at higher frequencies Intensity Encoding being broader at higher intensities

Question 49

Label the inner ear

Answer 49

Question 50

Label the cochlear ducts

Answer 50

Question 51

Label the bony labyrinth

Answer 51

Question 52

Label the organ of corti

Answer 52

Question 53

Label the scala media

Answer 53

Question 54

Label the cross-section of the cochlea

Answer 54