middle ear

Question 1

What are the three interconnected air-filled spaces

Answer 1

tympanic cavity, epitympanic recess, mastoid air cells

Question 1

What does the lateral wall of the tympanic cavity inhabit

Answer 1

tympanic membrane (pars tensa and pars flaccida)

Question 2

what is the difference between the pars tensa and pars flaccida

Answer 2

pars tensa = 3 layers
- skin, dense fibers, mucous lining

pars flacida = no middle layer
only 3% of area in humans

Question 3

What does the medial wall of the tympanic membrane inhabit

Answer 3

oval and round window

Question 4

What does the anterior wall of the tympanic membrane inhabit

Answer 4

tubal opening

Question 5

What does the posterior wall of the tympanic membrane inhabit

Answer 5

aditus, pyramid, chorda, tympani, fenestra, and cochleae

Question 6

What is the job/function of the ossicles

Answer 6

transmit sound from the TM to the cochlea
apply force to only the oval window (allows for cochlear fluids to be compressed)

Question 7

What is the functional significance of the middle ear

Answer 7

converts acoustic energy to mechanical energy
impedance matching transformer

Question 8

What are the three principles used to overcome the Z mismatch (impedance)

Answer 8

area ratio (the most important)
- force focused on a small area results in a high pressure

curvature of the TM

lever action

Question 9

What is the input of the middle ear

Answer 9

microphone at the eardrum (the output of the outer ear)

Question 10

What is the output of the middle ear

Answer 10

how the stapes moves or how the pressure in the cochlea is affected

Question 11

What is the correct transfer function for the middle ear
(what is the middle ear transfer function like?)

Answer 11

band-pass filter

the shearing of hair sensory cells in the inner ear is directly proportional to pressure differences within the cochlea
pressure in the partition is determined by pressure at the oval window

Question 12

Is the middle ear linear?

Answer 12

Yes