Ear Physiology

Question 1

What role does the external ear play in hearing?

Answer 1

Collects sound

Question 2

What role does the middle ear play in hearing?

Answer 2

Amplifies sound

Question 3

What role does the inner ear play in hearing?

Answer 3

Transduces sounds

Question 4

What is the speed of sound in air?

Answer 4

330m/s

Question 5

Does sound travel faster or slower in water than air?

Answer 5

Faster

Question 6

What frequencies should humans hear ?

Answer 6

20 - 20K Hz

Question 7

What range of frequencies are tested on an audiogram?

Answer 7

250Hz to 6000Hz

Question 8

What does the frequency of a sound wave do?

Answer 8

Dictates how high or low

Question 9

What does the amplitude of a sound wave do?

Answer 9

Dictates loudness

Question 10

In the middle ear, how is sound amplified?

Answer 10

Stapes hits against the oval window with greater force when vibrations are higher

Question 11

What ligament suspends the stapes bone?

Answer 11

Annular ligament

Question 12

What muscles are related to the stapes bone?

Answer 12

Stapedius Tensor tympani

Question 13

What muscles open the Eustachian tube?

Answer 13

Tensor veli palatini Levator palatine

Question 14

What manoeuvre can be done to equalise the ears?

Answer 14

Valsalva manoeuvre

Question 15

What can cause glue ear to be more common?

Answer 15

Cleft palate which causes the muscles which open the eustachian tube to be dysfunctional

Question 16

Through which window is sound waves transmitted?

Answer 16

Oval

Question 17

What is the round window for?

Answer 17

Allows pressure to leave

Question 18

Where is the sound actually perceived?

Answer 18

The fine hairs on the cochlea

Question 19

What nerve transmits the sound vibrations to the brain?

Answer 19

Cochlear nerve

Question 20

What bone is the inner ear located in?

Answer 20

Petrous part of the temporal bone

Question 21

Where is perilymph?

Answer 21

Within the bony labyrinth

Question 22

Where is the endolymph?

Answer 22

Within the membranous labyrinth

Question 23

What makes up the membranous labyrinth?

Answer 23

3 semicircular ducts- anterior, posterior and lateral

Question 24

What connects each semicircular duct to its base- the utricle?

Answer 24

The ampulla

Question 25

What sensory organ is contained within the ampulla?

Answer 25

Cristae ampullaris

Question 26

What happens when endolymph moves against the cristae ampullaris?

Answer 26

Hair cells become depolarised which sets up an action potential

Question 27

What separates the endolymph and perilymph?

Answer 27

Basilar membrane

Question 28

How does gentamicin cause tinnitus?

Answer 28

It causes damage to the outer hair cells

Question 29

What is another name for stereo cilia?

Answer 29

Inner hair cells

Question 30

What is meant by tonotopic organisation of the cochlea?

Answer 30

Different areas of the basilar membrane are responsible for different frequencies of sound

Question 31

Where it the apex of the cochlea?

Answer 31

Furthest from the round window i.e. centre of spiral

Question 32

What are the two otolith organs called?

Answer 32

Utricle Saccule

Question 33

What structure is responsible for vertigo and what are they made of?

Answer 33

Otoconia Calcium carbonate crystals

Question 34

What is special about the orientation of the semicircular canals?

Answer 34

They are orientated at 90 degrees to each other and are paired.

Question 35

What causes deflection?

Answer 35

Movement of endolymph by bodily movement causes the stereocilia to deflect

Question 36

What is spontaneous nystagmus?

Answer 36

Movement of the eye without a stimulus