Histology - Auditory and Vestibular Systems Flashcards Preview

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Flashcards in Histology - Auditory and Vestibular Systems Deck (73):
0

what are the tree parts of the ear

external ear
middle ear
internal ear

1

The outer ear contains (2)

pinna (auricle)
external auditory meatus (canal)

2

another name for auricle is

pinna

3

Middle ear contents (5)

tympanic membrane
malleus
incus
stapes
Eustachian tube

4

inner ear contents (5)

oval window
semicircular ducts
cochelea
vestibulochoclear N
round window

5

function of the external ear

collect and conduct sound

6

skin of the outer 1/3 of the ear contains________ and ______ glands that produce what

humerous sebaceous and ceruminous glands
produce cerumen "ear wax"

7

The auricle is supplied by what arteries

superficial temporal
posterior auricular

8

Auricular hematoma

caused by trauma -->damages blood supply to auricle-->hematoma
if blood is not drained=> cauliflower ear and/ or risk of infection

9

middle ear function

transfer sound waves in air into flud waves in the inner ear via vibration of the ossicles

10

ossicle attached to the tympanic membrane

malleus

11

ossicle between the malleus and the stapes

incus

12

footplate of this ossicle articuates with the fenestra vesibuli

stapes

13

another name for the oval window

fenestra vestibuli

14

what does the tensor tympani m do

tenses the tympanic membrane to decrease sound produced by chewing

15

what nerve innervates tensor tympani m

V3 of the trigeminal nerve (mandibular)

16

what does the stapedius muscle do

pulls the stapes away from the fenestra vestibuli to protect excess movement of the stapes due to loud sound

17

inn of stapedius muscle

facial n

18

function of eustachian tube

equalize pressure, connects nasopharynx to ear. decreases pressure of inner ear.

19

function of the inner ear

take fulid waves and transmit them into signals sent via the vestibulocochlear nerve to the cortex for hearing and balance

20

two main parts of the inner ear

membranous labrynth
osseous labrynth

21

Membranous labrynth

ducts tubes sacs filled with endolymph
suspended in the osseous labrynth

22

fluid in the membranous labrynth

endolymph

23

Osseous labrynth

bony portion, forms several canals and cavities
surrounds the membranous labrynth
perilymph(?)

24

perilymph is found where

between the walls of the osseous and membranous labrynths

25

contents of the membranous labyrinth (4) involved in balance and hearing

semicircular ducts
utricle
saccule
cochlea

26

semicircular ducts

tubes suspended in the osseous semicircular canal

27

each semicircular duct ends in an

ampulla

28

each ampulla of the semicircular duct contains ______

a receptor organ = crista ampullaris

29

crista ampularis detects

angular acceleration

30

what structure is attached to the end of the semicircular ducts

utricile

31

receptor organ of the utricle

macula utricle

32

macula utricle detects

linear acceleration

33

What is conneced directly to the cochlear duct

saccule

34

the receptor organ of the saccule

macula saccule

35

macula saccule detects

linear accleratino

36

the components in the membranous labrynth specific to the vestibular system

semicircular ducts
utricle
saccule

37

components in the membranous labyrinth specific to hearing

cochlea

38

crista ampullaris detects

angular acceleration - rotation of the head

39

crista ampullaris - big picture

conains hair cells with sterocilia that detect the movement --> depolarization --> signal sent to brainstem via the vestibular nerve

40

crista ampullaris - how it works

when the head turns, endolymph in the semicircular ducts pushes against the CUPULA --> bends the stereocilia of the hair cells --> the bending stimulates afferent activity through CN8 to the brainstem

41

what is the cupula and its function

???

42

Macula utricle and macula saccule detect what

linear accleration (horizontal movement)
linear acceleration (vertical movement)

43

macula utricle and macula saccule - big pictue

the utricle and saccule contain hair cells topped with otoliths (Ca carbonate crystals) that detect the movement -->depolarization --> signal sent to brainstem via vestibular nerve

44

macula utricle and macula saccule - how it works

the saccule and utricle lie 90degrees to each other --> head moves in any direction--> the sterocilia of the hair cells will bend due to the weight of the otoliths --> the bending stimulates afferent activity through CN8 to the brainstem

45

otoliths are

Ca carbonate crystals

46

endolymphatic duct is a duct formed by the joining of

ducts from the utricle and saccule

47

the endolymphatic duct ends in the ____ space

subdural

48

THe _______ drains the perilymph

perilymphatic duct

49

the perilymphatic duct extends through the ______ and ends in the ______ space. Why do we care

dura
subarachnoid
can be a possible cause of meningitis

50

most common cause of the symptoms of vertigo

benign paroxysmal positional vertigo

51

Benign paroxysmal positional vertigo is charachterised by

breif recurrent episodes of vertigo triggered by change in head position with respect to gravity

52

what is the cause of benign paroxysmal positional vertigo

debris floating in the endolymph of one or more of the semicircular canals

53

how do you diagnose bppv?

Dix-Halpike maneuver

54

Scala vestibuli aka

vestibular duct

55

scala vestibuli is located inside the _____, filled with ____ and extends from ______ to ______

cochlea
perilymph
oval window
the helicotrema

56

scala tympani aka

tympanic duct

57

scala tympan is located in side the _____, filled with _______ and extends from _____ to ________

cochlea
perilymph
helicotrema to round window

58

Vestibular membrane separates what

the vestibular duct from the cochlear duct

59

the basilar membrane separates what

the cochlear duct from the tympanic duct

60

The helicotrema is where? It is a connection point for what

at the apex of the cochlea
connection point for the vestibular and tympanic ducts

61

The cochlear duct is located____, filled with _____ and houses ____

inside the cochlea,
endolymph
organ of corti

62

The organ of corti contains _____. it is composed of _____

the cochlear nerve
hair cells

63

what is the purpose of the hair cells in the organ of corti

detect movement --> stimulate depolarization --> sends signal to brain via cochlear nerve--> sound

64

The purpose of the vestibular and tympanic ducts

to conduct sound vibrations in the air into fluid sound waves that are transmitted to the organ of corti inside the cochlear duct.

65

how we hear sound

1. sound waves in air hit external ear
2. they go to tympanic membrane, cause ossicles in middle ear to vibrate
3. vibration of ossicles (stapes) transmits movement to oval window of inner ear
4. stapes hitting oval window causes movement of fluid within the inner ear
5. fluid waves move up and down from the oval window to the round window (via the vestibular and tympanic ducts)
6. movement of the fluid waves causes bibration of the basilar membrand and hence the organ of corti inside the cochlear duct to move
7. movement of the hair cells inside the organ of corti trigger depolarization
8. depolarization allows signals to be sent to the brain via the cochlear nerve
9. interpretation of sound

66

why is otitis external more common in children

their external auditory meatus is more horizontal

67

Otitis externa

pain with manipulation of ear
aka swimmers ear

68

otitis external infection caused by

pseuomonas aeruginosa or staph aureus

69

otitis media
infection caused by

bulging tympanic membrane, erythema, middle ear effusion
strep pneumoniae
haemophilus influenza
morexella catarrhalis

70

Meniere's Disease and triad of Sx's

excessive endolymphatic fluid within the inner ear
intermittant vertigo, tinnitus, and hearing loss

71

Vestibular neuritis

inflammation of vestibular nerve
spontaneously begins and spontaneously resolves - lasts about 2wks
nausea, vomitting, vertigo without hearing loss or tinnitus

72

tinnitus

?????