VESTIBULAR SYSTEM - MODULE Flashcards

1
Q

the sensory organs of the vestibular system are located within the…

A

bony labyrinth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the bony labyrinth

A

an osseous structure found bilaterally in the inner ear within the petrous part of the temporal bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 3 parts that make up the bony labyrinth

A

semicircular canals
vestibule
cochlea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the membranous labyrinth? what does it contain?

A

a series of interconnected ducts and sacs that contain the organs of audition and vestibular sense

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the 3 parts of the membranous labyrinth

A

semicircular ducts
otolith organs
cochlea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the membranous labyrinth filled with

A

a fluid called endolymph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are is the membranous labyrinth surrounded by

A

a fluid called perilymph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Perilymph has HIgh ___ and Low ___

A

Na +

K+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Endolymph has high ___ and low ___

A

K+

Na+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What do hair cells do?

A

transduce mechanical energy into electrical signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does each hair cell project

A

60-100 stereocilia and a single kinocilium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

on what side does the hair cell project the stereocilia and kinocilium

A

on the apical side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

the cilia are linked by…

A

filaments with K+ channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

the depolarizing current in hair cells is triggered by

A

potassium NOT sodium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

why does endolymph have a high [K+]

A

becase the hair cells are triggered by potassium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What triggers cellular effects in the hair cells

A

mechanical forces causing the displacement of cilia

17
Q

what is occuring at the hair cell at rest

A
  • stereocilia parallel to kinocilium
  • some K+ and Ca2+ channels open
  • Baseline K+ and Ca2+ influx
  • baseline glutamate release
  • baseline signal
18
Q

what is the series of events that causes depolarization of the hair cell

A
  • sterocilia move toward kinocilium
  • K+ channels open
  • K+ influx triggers depolarization
  • Depolarization opens voltage-gated Ca2+ channels
  • Ca2+ influx triggers glutamate release
  • Excitatory signal
19
Q

what is the series of events resulting in hyperpolarization of the hair cell

A
  • Kinocilium moves toward stereocilia
  • K+ channels close
  • Very little K+ of Ca2+ influx
  • Very little glutamate release
  • Very little signal
20
Q

Vestibular organs send electrical impulses to branches of what cranial nerve

A

CN VIII the vestibulocochlear nerve

21
Q

What contain the vestibular organs

A

the ampulla

22
Q

Where are the ampulla located

A

at the terminal end of semicircular canals

23
Q

What are the haircells sitting in

A

a gelatinous mass called the cupula

24
Q

How do the cilia get displaced

A

when fluid movements within the semicircular duct displace the cupula

25
The endolymph is displaced ___ relative to the body canal rotating around it
backwards or opposite direction of head and bony canal rotation
26
for semicircular canals in the same place, head rotations that ___ hair cells in one semicircular canal ____ hair cells in the opposite canal
excite | inhibit
27
sagittal rotation is what head movement
yes/nod
28
axial rotation is what head movement
no/shake
29
coronal rotation is what head movement
maybe
30
What are the two endolymph-filled sacs in the body vestibules called
the utricle and saccule - the otolith organs
31
What do the utricle and saccule do
detect linear displacement of the head
32
Specifically what does the utricle detect
horizontal linear movement - forward and backward acceleration/head tilt
33
what is the utricle sensory organ called
the macula of utricle
34
Specifically what does the saccule detect
vertical linear movement - upward and downward acceleration/head tilt
35
What is the sensory organ of the saccule called
macula of saccule
36
Across both maculae, hair cells with opposite orientation line up on either side of a central junction called the _____ and are embedded within a ____
Striola gelatinous otolithic membrane
37
How do linear head movements activate hair cells
by displacing the otoliths that sit atop the membrane
38
what are otoliths
calcium carbonate crystals