Vestibular Function Lec28 Flashcards Preview

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Flashcards in Vestibular Function Lec28 Deck (27)
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1
Q

Vestibulo-Ocular Reflex - maintains

A

steady gaze

2
Q

Vestibulo-Ocular Reflex moves the eyes

A

opposite to head so they stay fixed on a point

3
Q

Vestibulo-Colic Reflex - maintains

A

orientation of head and neck against gravity

4
Q

Vestibulo-Spinal Reflex isn involved in ___ and ___

A

kinesthetic awareness, correction for stumbling.

5
Q

The Vestibular System can detect (3)

A

rotation, translation, and gravity

6
Q

The 3 semicircular canals sense

A

rotational movement/angular acceleration

7
Q

The otoliths (utricle and saccule) detect ___-

A

translational movement/linear acceleration & gravity

8
Q

where are hair cells found in the vestibular system

A

in 3 semiciruclar canals, otoliths

9
Q

Utricle is oriented to sense  ___ acceleration,

A

horizontal

10
Q

Sacculus is oriented  to sense ___ acceleration

A

vertical

11
Q

The utricle and sacculus hair cells project into a gelatinous ___ with otoconia, calcium carbonate crystals which provide mass

A

“otolithic membrane”

12
Q

Inertial forces on the head will displace the otolithic membrane and hair cells in the ___ direction

A

opposite direction

13
Q

if hair bends towards kinocilia then __ occurs

A

cn 8 excitement, depolarization

14
Q

if hair bends away from kinocilia then

A

hyperpolarization, cn 8 inhibitor

15
Q

he 3 pairs of semicircular canals on each side of the head work

A

together Rotation in a particular direction will excite the hair cells of one canal and inhibit the hair cells in its partner.

16
Q

All the hair cells in a canal’s ___ are oriented in the same direction

A

ampulla

17
Q

All the hair cells in a canal’s are opposite of the ____

A

sterocilia in the paired canal

18
Q

The ampulla of each canal has a gelatinous membrane called the ___

A

cupula

19
Q

____ displaces endolymph --> which displaces the cupula.

A

Acceleration

20
Q

Head rotation to face R. ____ the R. horizontal canal

A

excites

21
Q

Head rotation to face R. excites the L. horizontal canal

A

inhbiits

22
Q

VOR Rotation to the L. excites the

A

L. CN 8 & L. vestibular nuclei,

23
Q

VOR The L. vestibular nuclei excite the ____

A

R. abduscens and left medial rectus

24
Q

VOR L. vestibualr n. excites abduscens ---> activates

A

right lateral rectus muscle

25
Q

increased firing in one canal means the head is

A

rotating toward that side

26
Q

Vestibular balance nystagmus – one side has less firing than the other, so the other side compensates

 

eyes move slowly to ___ of the decrease firing and then back to midlin

A

the side

27
Q

he vestibular system is poor at detecting constant ___

A

velocity motion.