Lecture 25 - Ear Flashcards Preview

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Flashcards in Lecture 25 - Ear Deck (42):
1

Where is the inner ear?

within the petrous part of the temporal bone

2

The outer ear is supported by ...

cartilage - except for the lobule which has some fat in it

3

What carries the sound into the ear

external auditory meatus - through to the tympanic membrane

4

tragus is which part of the outer ear?

the bit that hair grows off, in front

5

The external auditory meatus is cartilaginous in which parts?.

lateral 1/3

medial 2/3 is embedded in the temporal bone

6

what releases wax in the ear?

cerumen glands - coats are prevents maceration of skin with water

7

what is sensory to the posteroinferior part of the outer ear?

vagus

8

what is sensory to the anterosuperior part and external surface of tympanic membrane?

Auroculotemporal nerve V3

good example of referred pain, can go to other branches of V3 - e.g to the tongue, inferior teeth

9

tympanic membrane has __ junctions all around it

tight jnctions - no holes, no mechanical energy lost

10

What is the cone of light?

antero-inferior quadrant - reflection is created if normal

if not normal the reflection will be somewhere else to to change in curvature

11

Where is the tympanic cavity proper?

directly medial to the membrane

12

Epitympanic recess is where? what does it communicate with?

superior to the cavity proper

communicates with sinuses in the mastoid

13

where does the auditory tube (pharyngotympanic tube) open in the middle ear

antero-inferior wall - project antero-medially towards to nasopharynx

14

auditory tube is largely..

cartilagenous

15

auditory tube allows equalisation of ..

pressure, only opening to the atmostphere for the middle ear

16

The ossicles from lateral to medial are

malleus
incus
stapes

17

The gradient of the auditory tube is higher in ____

adults - less likely to cause infection compared to kids

18

Tensor tympani hangs off the ____wall

what CN innervates it

anterior - attach to malleus

CN5 - trigeminal

T for tensor, T for trigeminal

19

Stapedius hangs off the ____ wall

what CN innervates it

posterior wall

CN7

20

what is the function of Stapedius and Tensor tympani

dampen really loud sounds

21

Chorda tympani is a branch of the ___ nerve, what does it supply

taste to ant. 2/3 of tongue

runs through middle ear


goes with lingual nerve towards the tongue

very complicated course

22

What is the promontary?

formed by the basal (first) turn of the cochlea

good marker for the two opening to the inner ear: Oval and round window

23

oval window is where energy comes __ to the inner ear

in

24

The internal carotid artery is very close to the

middle ear - can feel pulsations

25

The bony labyrinth is..

the space inside the petrous part of the temporal bone, filled with perilymph

26

The membranous labyrinth..

is one continuous sac which sits suspended in the bony labyrinth itself (within the perilymph).

has its own fluid inside - the endolymph

27

Round window acts a means to allow energy to escape the...

bony labyrinth - energy is transmitted by the mebrane back into the middle ear

28

There are semicirclar canals in the bony labyrinth which provide us with...

information regarding dynamic equilibrium

anterior
horizontal
posterior

29

What is between the cochlea and the semicirclar canals?

the vestibule

30

What are the receptors of the vestibule associated with..

static equilibrium

31

The membranous labyrinth is a ___ __ filled with endolymph

The membranous labyrinth is a closed sac filled with endolymph

32

The ampulla (swellings) at the base of the semiciruclar dcts are responseible for..

dynamic equilibrium - head movements

33

What are the to swellings of the vestibule?

utricle and saccule

34

The vestibular nerve and cochlear nerve come together to form..

CN8

35

the cochlea, if you were to unroll it, projects...

antero-medially

36

frequencies deflect different hair cells in the cochlea duct (within the membranous labyrinth)

This mostly happens at a spot called the ...

organ of corti - the strucutre of stuff that transmits the vibrations

37

High frequency sounds stimulate hair cells at the __ of the cochlea

base

38

Low frequency sounds stimulate hair cells at the __ of the cochlea

apex

39

Vibration of ____membrane results in movement of hair cells against _____membrane

Vibration of bascilar membrane results in movement of hair cells against tectorial membrane

40

The auditory/cochlea nerve is part of which canial nerve?

CN8

41

What is the mechanism for dynamic equilibrium?

movement of the endolymph through semicircular ducts into ampulla deflecting cupula and acivating hair cells (sensory receptors)

42

what is the mechanism of static equilibrium?

sesnsory receptors inn th utricle and saccule

movement of otolithic membrane due to gravity activates hair cells in utricle and saccule