4.18 Vestibular Flashcards Preview

7303 Neuroanatomy > 4.18 Vestibular > Flashcards

Flashcards in 4.18 Vestibular Deck (33):
1

2 components of vestibular

- peripheral
- central

2

What is in the peripheral vestibular system?

inner ear receptors that signal position and movement of the head

3

The central vestibular system consists of neurons that: (4)

1. contribute to conscious orientation and acceleration through space
2. mediate reflexive adjustments to maintain visual acuity and equilibrium
3. have both sensory and motor function
4. have extensive cerebellar connections

4

Which system depends heavily on vestibular? Why?

- visual
- eyes move in a compensatory way with the head

5

Where do semicircular canals primarily project?

medial and superior vestibular nuclei

(not as much to lateral and inferior nuclei)

6

semicircular canals are for detection of

rotation

7

What is a major function of the lateral vestibular nucleus?

serves as an important UMN for the lateral vestibulospinal tract

8

What is a major function of the medial vestibular nucleus

important UMN for medial vestibulospinal tract

9

The macula is for

linear acceleration

10

What interacts with the hypothalamus that is important for endocrine autonomics?

RF

11

What does the RF do with respect to vestibular?

controls autonomic responses to vestibular inputs

12

lack of RF input (I think) my cause these vestibular effects

- nausea
- vomiting
- dizziness
- pallor
- sweating

*carsick

13

What are the superior and medial vestibular nuclei for?

eye coordination

14

Which CNs do the superior and medial vestibular nuclei affect? Which reflex is this associated with?

3, 4, 6
VOR

15

components of the bony labyrinth

- 3 semicircular canals
- 2 otolithic organs
- membranous labyrinth

16

How do the semicircular canals detect rotation?

via movement of endolymph

17

position of canals to one another

orthogonal

18

canals open at each end at the

utricle

19

The utrical is an

otolithic organ

20

swelling at the end of the canals

ampulla

21

What does the ampulla contain?

crista

22

What does the crista contain?

- support cells
- hair cells embedded in gelatinous cupula

23

What does the 90˚ orientation of the canals imply?

only 1 set of hair cells affected at a time

24

Hair cells are how this happens

signaling of head acceleration

25

Hair cells are embedded in the

cupula

26

If hair cells bend toward the _____, we get activation

kinocilium

27

If hair cells bend toward the _____, we get inhibition

stereocilia

28

Baseline activity of hair cells

always firing tonically

29

Activation/inhibition causes

speeding up or slowing down of firing rate

30

How do the canals work?

- work in pairs
- get essentially equal and opposite actions

31

What happens when the R side is being activated?

get roughly the same amt of inhibition from the L side

32

What happens to the fluid during spinning?

- fluid speeds up to match rate of turning
- when you stop, the fluid sloshes back

33

With a single plane of rotation, how many pairs of canals are being affected?

ONE