Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Nervous System > Vestibular System > Flashcards

Vestibular System Flashcards

1
Q

what does the vestibular apparatus consist of?

A

3 semi-circular canals
the utricle
the saccule

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

which of the ampulla, utricle and saccule contains sensory hair cells?

A

all of them

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

what are the otolith organs?

A

the utricle and saccule

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

what are the functions of the otolith organs?

A

> detect linear acceleration

> encode information about the position of the head in space

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

what does the utricle detect?

A

back and front tilt

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

what does the saccule detect?

A

vertical movement

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

what do the semicircular canals detect?

A

rotational acceleration

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

where are the sensory cells of the semi-circular canals located?

A

in the swellings at the base of the semi circular canals: ampulla

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

what is in the ampulla?

A

sensory receptors called cristae that consist of flexible gelatinous structures called cupula that stretch across the entire width of the ampulla

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

what do the cristae respond to?

A

movement of the endolymph fluid within the canals

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

what are imbedded in the cupula?

A

cilia of hair cells

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

what does the hair cell cilia in the cupula synapse with?

A

directly to the sensory neurons of the vestibular nerve CNVIII

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

name the two types of hair cells

A

> Kinocilium

> stereocilia

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

describe the kinocilium

A

single and very large

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

describe the stereocilia

A

smaller and multiple

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

distortion of cilia away from the kinocilium leads to…..

A

hyperpolarisation and decreased discharge of action potentials in the vestibular nerve

17
Q

distortion of cilia towards the kinocilium causes….

A

depolarisation and increased discharge of action potentials in the vestibular nerve

18
Q

what are maculae?

A

the sensory apparatus of the utricle and saccule

19
Q

are the macula in the utricle in the horizontal and vertical plane?

A

the horizontal

20
Q

are the macula in the saccule in the horizontal and vertical plane?

A

the vertical

21
Q

what do the maculae cilia protrude into?

A

a gelatinous mass, the otolith membrane

22
Q

what are otoliths?

A

CaCO3 crystals embedded in the otolith membrane

23
Q

what has a greater density, otoliths of endolymph?

A

otoliths

24
Q

what do the vestibular nuclei project via?

A

the thalamus to the cerebral cortex

25
Q

what do tonic labyrinthine reflexes do?

A

they keep the axis of the head in a constant relationship with the rest of the body using information from the maculae and neck proprioceptors

26
Q

what are dynamic righting reflexes?

A

rapid postural adjustments made to stop you from falling when you trip, these are long reflexes involving extension of all limbs.

27
Q

why do the semi circular canals have a strong influence on eye movement?

A

because the afferents from the semi-circular canals project and connect, within the vestibular nuclei) to afferent fibres travelling to the extra ocular nuclei.

28
Q

describe the static reflex

A

when you tilt your head the eyes intort/extort to compensate over a certain range, keeping the image the right way up

29
Q

what is dynamic vestibular nystagmus?

A

a series of saccadic eye movements that rotate the eye against the direction of rotation so the original direction of gaze is preserved. when the eyeball comes to the end of its range of movement it rapidly flicks back to the zero position.

30
Q

in post rotatory nystagmus, at the end of left rotation during deceleration what nystagmus will you get?

A

right nystagmus due to endolymph catching up and pushing the cupula in the opposite direction

31
Q

in caloric stimulation does the warm or the cold fluid cause nystagmus towards the affected side?

A

warm

32
Q

what can powerful maintained stimulation of the vestibular system give rise to?

A

kinetosis: motion sickness

33
Q

what is vertigo?

A

perception of movement in the absence of movement

34
Q

what is menieres disease?

A

> vertigo, nausea, nystagmus and tinnitus

> overproduction of endolymph causing increased pressure

35
Q

what is used to compensate in chronic vestibular impairment?

A

visual system

36
Q

what can lead to nystagmus at rest?

A

brain lesions

Nervous System (45 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions