Ear Physiology

Question 1

What is the process called where sound energy is converted into action potentials in the auditory nerve fiber?

Answer 1

Sensory transduction in the hair cells of the organ of Corti

This process is crucial for hearing, as it allows sound waves to be interpreted by the brain.

Question 2

What happens to the receptor potential when sound waves reach the inner ear?

Answer 2

Causing mild depolarization

This depolarization is essential for the conversion of sound energy into electrical signals.

Question 3

What is the effect of the movement of stereocilia towards the kinocilium?

Answer 3

Results in hair cell depolarization

This movement opens K+ channels and increases action potentials.

Question 4

What occurs when stereocilia move away from the kinocilium?

Answer 4

Leads to hyperpolarization

This movement decreases the likelihood of action potentials being generated.

Question 5

What does the endocochlear potential relate to?

Answer 5

The electrical potential of cochlear fluids

This potential is vital for the functioning of hair cells in the cochlea.

Question 6

What governs the action potential in the auditory nerve fiber?

Answer 6

The all-or-none law, with a definite threshold and refractory period

This ensures that action potentials are generated reliably in response to sufficient stimuli.

Question 7

What is the resting state of hair cells regarding K+ ions?

Answer 7

K+ leaks into cells due to negative membrane potential and high apical [K+]

This contributes to the maintenance of the resting membrane potential.

Question 8

What happens during mechanical deformation of stereovilli towards the kinocilium?

Answer 8

Opens cation channels, allowing K+ influx and cell depolarization

This process is essential for the mechanotransduction in hair cells.

Question 9

What is the consequence of depolarization in hair cells, except for auditory outer hair cells?

Answer 9

Activates Ca2+ channels, triggering synaptic vesicle release

This neurotransmitter release is vital for transmitting auditory information to the brain.

Question 10

What occurs when stereovilli deform away from the longer stereovilli?

Answer 10

Closes cation channels, leading to hyperpolarization

This hyperpolarization decreases the likelihood of neurotransmitter release.

Question 11

Fill in the blank: The _______ is the fluid within the cochlea that has a high concentration of potassium ions.

Answer 11

Endolymph

Endolymph is crucial for the function of hair cells in the cochlea.

Question 12

True or False: The movement of stereocilia towards the kinocilium causes K+ channels to close.

Answer 12

False

This movement actually opens K+ channels, allowing K+ to enter the cell.

Question 13

What is the role of tip links in hair cells?

Answer 13

They connect stereocilia and facilitate mechanotransduction

Tip links are essential for the opening and closing of ion channels in response to mechanical stimuli.

Question 15

What is the Rinne test?

Answer 15

A tuning fork test where a vibrating fork is placed on the mastoid process until no vibration or sound is felt/heard.

Used to evaluate hearing loss by comparing air and bone conduction.

Question 16

What indicates normal hearing in the Rinne test?

Answer 16

Vibration still heard in air after bone conduction ceases.

This means air conduction is better than bone conduction.

Question 17

What does a positive Rinne test indicate?

Answer 17

AC > BC = Normal hearing.

This means air conduction is better than bone conduction.

Question 18

What does a negative Rinne test indicate?

Answer 18

BC > AC = Conductive loss.

This suggests that bone conduction is better than air conduction.

Question 19

What is conduction deafness?

Answer 19

Air vibration not heard after bone conduction stops.

This indicates an issue with the outer or middle ear.

Question 20

What is nerve deafness?

Answer 20

Both air and bone conduction diminished or lost.

This indicates a problem with the inner ear or auditory nerve.

Question 21

What does the Weber test assess?

Answer 21

It assesses hearing loss by placing a tuning fork on the vertex of the skull or forehead.

It helps to determine the type of hearing loss.

Question 22

What indicates normal hearing in the Weber test?

Answer 22

Sound heard equally on both sides.

This shows no significant hearing loss in either ear.

Question 23

What does unilateral conduction deafness indicate in the Weber test?

Answer 23

Sound heard louder in the diseased ear.

This occurs due to the absence of masking effect of environmental noise.

Question 24

What does unilateral nerve deafness indicate in the Weber test?

Answer 24

Sound heard louder in the normal ear.

This suggests a problem in the auditory nerve or inner ear.

Question 25

Define sensorineural hearing loss.

Answer 25

Involving the inner ear, cochlea, or the auditory nerve. ## Footnote This type of loss is often permanent.

Question 26

Define conductive hearing loss.

Answer 26

Involving any cause that limits external sound from accessing the inner ear. ## Footnote Common causes include cerumen impaction.

Question 27

What is mixed hearing loss?

Answer 27

A combination of conductive and sensorineural hearing loss. ## Footnote This indicates issues in both the outer/middle ear and inner ear.

Question 28

What does dynamic equilibrium refer to?

Answer 28

Acceleration of the head in rotation, horizontal, and vertical movements. ## Footnote It involves the vestibular system of the inner ear.

Question 30

What is the Rinne test?

Answer 30

A tuning fork test where a vibrating fork is placed on the mastoid process until no vibration or sound is felt/heard. ## Footnote Used to evaluate hearing loss.

Question 31

What indicates normal hearing in the Rinne test?

Answer 31

Vibration still heard in air after bone conduction ceases. ## Footnote This suggests that air conduction is functioning properly.

Question 32

What indicates conduction deafness in the Rinne test?

Answer 32

Air vibration not heard after bone conduction stops. ## Footnote This means that there is an issue in the conductive pathway.

Question 33

What indicates nerve deafness in the Rinne test?

Answer 33

Both air and bone conduction diminished or lost. ## Footnote This suggests a problem with the auditory nerve or inner ear.

Question 34

What is the Weber test used for?

Answer 34

To evaluate hearing loss by assessing sound lateralization. ## Footnote It helps differentiate between conductive and sensorineural hearing loss.

Question 35

What does normal centralization in the Weber test indicate?

Answer 35

Sound heard equally on both sides. ## Footnote This suggests normal hearing function.

Question 36

In the Weber test, what does lateralization to the same ear indicate?

Answer 36

Conductive loss in that ear. ## Footnote This occurs due to the absence of masking effect of environmental noise.

Question 37

In the Weber test, what does lateralization to the opposite ear indicate?

Answer 37

Sensorineural loss in the tested ear. ## Footnote This suggests that the normal ear is hearing better.

Question 38

What is the difference between air conduction (AC) and bone conduction (BC)?

Answer 38

AC refers to sound traveling through the ear canal and eardrum, while BC refers to sound transmitted through the bones of the skull. ## Footnote These are assessed in hearing tests.

Question 39

What are the classifications of hearing loss?

Answer 39

* Conductive * Sensorineural * Mixed ## Footnote Each type has different underlying causes and implications for treatment.

Question 40

What does 'AC > BC' indicate?

Answer 40

Normal hearing. ## Footnote This is a standard finding in healthy ears.

Question 41

What does 'BC > AC' indicate?

Answer 41

Conductive loss. ## Footnote This means that bone conduction is better than air conduction.

Question 42

What is dynamic equilibrium?

Answer 42

The ability to maintain balance during head movements, including rotation and acceleration. ## Footnote It involves structures like the ampulla and utricle in the inner ear.

Question 43

What role do hair cells play in hearing?

Answer 43

They are involved in the detection of sound vibrations in the cochlea. ## Footnote Their function is crucial for converting sound waves into neural signals.

Question 45

What indicates a unilateral nerve deafness?

Answer 45

Sound heard louder in normal ear

Question 46

What is dynamic equilibrium?

Answer 46

Acceleration of the head in rotation, horizontal, and vertical movements

Question 47

What are the semicircular ducts involved in dynamic equilibrium?

Answer 47

* Anterior * Lateral * Posterior

Question 48

What is the function of the cupula?

Answer 48

Stimulates hair cells and sends an impulse via vestibular nerve to cerebellum

Question 49

What happens to endolymph during head rotation?

Answer 49

Endolymph lags behind due to inertia

Question 50

What is the effect of head movement to the left on vestibular afferent fibers?

Answer 50

* Increase in firing on the right * Decrease in firing on the left

Question 51

What is mixed hearing loss?

Answer 51

A combination of conductive and sensorineural hearing loss

Question 52

What does bending of stereocilia towards the kinocilium result in?

Answer 52

Depolarization and increase in impulses

Question 53

What does bending of stereocilia away from the kinocilium result in?

Answer 53

Hyperpolarization and decrease in impulses

Question 54

Fill in the blank: The _____ is pushed over and stimulates hair cells.

Answer 54

Cupula

Question 55

What is the role of hair cells in the crista ampullaris?

Answer 55

Respond to fluid motion in the duct

Question 56

What direction does the endolymph move during head rotation from left to right?

Answer 56

Opposite direction by inertia from right to left

Question 57

What is the response of hair cells when the head rotates to the right?

Answer 57

Cilia of the right side bent towards the kinocilium, leading to depolarization

Question 58

What are the supporting cells in the crista ampullaris?

Answer 58

Cells that support hair cells

Question 59

True or False: All rights reserved indicates a legal notice.

Answer 59

True