middle ear

Question 1

Eustachian tube

Answer 1

connects with nasopharynx, important for pressure equalization

Question 2

3 ossicles of middle ear

Answer 2

malleus, incus, stapes- suspended by ligaments

Question 3

describe malleus

Answer 3

manubirum, neck, head, lateral process

Question 4

describe incus

Answer 4

short process, long process, lenticular process, incudostapedial joint (connection)

Question 5

describe stapes

Answer 5

head, neck, anterior crux, posterior cross, footplate

Question 6

faces of middle ear (ME)

superior/tegmental

Answer 6

ceiling, separates ME from the cranium

Question 7

faces of ME

Inferior/jugular

Answer 7

floor, formed by the tympanic plate, passage for jugular vein

Question 8

faces of ME

lateral/membraneous

Answer 8

front wall, formed by tympanic membrane

Question 9

faces of ME

medial/labyrntheous

Answer 9

back wall, boundary with inner ear (oval window, footplate, round window, promontory)

Question 10

faces of ME

posterior/mastoid

Answer 10

;eft side wall, partition between ME and mastoid air cells (buffer system).
Aditus: hole connecting to air cells
Pyramidal eminence contains stapedius muscle

Question 11

faces of ME

anterior/carotid

Answer 11

right side wall

interal carotid artery runs behind this wall, Eustachian tube

Question 12

function of muscles of ME (tensor tympani, stapedius)

Answer 12

dampen vibration of ear drum and loud sounds, including our chewing

Question 13

impedence

Answer 13

opposition to the flow of sound within a medium

sounds hits a boundary, difference in impedance, loss of energy transference

Question 14

what is the middle ear filled with

Answer 14

air

Question 15

2 ways ME overcomes impedence mismatch

Answer 15

1. area differential, the tympani membrane is 21x larger than the stapes footplate
2. lever action, incus and stapes act as levers

Question 16

2 ways basilar membrane can be stimulated?

Answer 16

Air conduction: In humans, the basilar membrane is stimulated by sound pressure waves traveling into the middle ear and initiating changes in pressure in the fluid endolymph.
Bone conduction: Pressure changes in the fluid of the inner ear also arise as a consequence of vibrations in the temporal bone. Bone conduction bypasses the middle ear.