9-2

Question 1

How many semicircular canals

Answer 1

3

Question 2

Names of each semicircular canal

Answer 2

1. Superior/anterior
2. Lateral/horizontal
3. Posterior

Question 3

Superior/anterior plane

Answer 3

Sagittal

Question 4

Superior/anterior movement

Answer 4

Nodding your head

Question 5

Lateral/horizontal plane

Answer 5

Transverse plane

Question 6

Lateral/horizontal movement

Answer 6

Checking both sides of traffic

Question 7

Posterior plane

Answer 7

Coronal

Question 8

Posterior movement

Answer 8

Head touch either shoulder, cartwheel

Question 9

What do the semicircuclar canals detect

Answer 9

Head rotation

Question 10

Where does head rotation arise from

Answer 10

Self-induced head rotation or angular accelerations imparted by external forces (such as merry go round)

Question 11

What is the ampulla filled with

Answer 11

endolymph

Question 12

Gelatinous mass that bridges the canal of the ampulla

Answer 12

Cupula

Question 13

The cuplua blocks ____

Answer 13

flow of endolymph

Question 14

In the cupula, all stereocilia are orientated in the same/different direction

Answer 14

Same

Question 15

Is there striola in the ampulla

Answer 15

No

Question 16

What contains hair cells in the ampulla

Answer 16

Crista (epithelium)

Question 17

The cupula extends from ___ to ___

Answer 17

crista

top of ampulla

Question 18

Hair cells in the ____, stereocilia in the _____

Answer 18

Crista

Cupula

Question 19

Endolymph moves in the same/opposite direction of acceleration

Answer 19

Opposite

Question 20

What happens when the endolymph flows in the opoosite direction of head rotation

Answer 20

Stereocilia move towards kinocilia (depolarize)

Question 21

Movements in relation to head movement for:

1. SCC depolarization
2. Eye movement
3. Endolymph movement

Answer 21

1. Same direction
2. Opposite direction
3. Opposite direction

Question 22

AP at constant velocity

Answer 22

Slightly higher than basal level discharge

Question 23

Major classes of vestibular relfexes

Answer 23

1. Vestibulo-ocular reflex (VOR)
2. vestibulocervical reflex (VCR)
3. vestibulospinal reflex (VSR)

Question 24

VOR

Answer 24

Produces eye movement that counters head movement

Question 25

VCR

Answer 25

Produces postural adjustment of the head

Question 26

VSR

Answer 26

Produces postural adjustment of the body

Question 27

Bilateral loss of VOR leads to ____

Answer 27

oscillopsia (bouncing vision - eyes move along with the head)

Question 28

Most of the time, oscillopsia is due to

Answer 28

Unavailability of vestibular information to the occulomotor nucelus (ex: stroke in this region)

Question 29

Intact ___ is essential for VOR

Answer 29

brainstem

Question 30

Where does most damage in the brainstem happen

Answer 30

Medial longitudinal pascilculus

Question 31

Why does the eye move with the head in oscillopsia

Answer 31

All connections are lost

Question 32

What is not working in oscillopsia

Answer 32

Brainstem

Question 33

What is not working in supernuclear gaze palsy

Answer 33

Cebrebral cortex

Question 34

Presentation of supernuclear gaze palsy

Answer 34

Will still have VOR but cannot voluntarily rotate eyeballs

Question 35

Alexander's law

Answer 35

Refers to spontaneous nystagmus that occurs after an acute unilateral vestibular loss

Question 36

Test of vestibular function

Answer 36

Caloric testing

Question 37

Vestibular problems can arise in:

Answer 37

1. Semicircular canal | 2. Nerve tracts

Question 38

Warm water irrigation effect

Answer 38

- Endolymph moves (mimics head turning) | - Increases firing rate

Question 39

Cold water irrigation effect

Answer 39

- Decreases endolymph movement | - Decreases firing rate

Question 40

Fast eye movement

Answer 40

Saccades

Question 41

Slow eye movement

Answer 41

Physiological nystagmus

Question 42

What happens when the eye moves all the way to one side

Answer 42

We need to make a fast correction to bring it back to the other side

Question 43

Baseline firing on one side and no firing on the other side

Answer 43

There is a difference, so the eye will spontaneously move and correct back again (leads to vertigo)

Question 44

Vertigo

Answer 44

Feeling of moving when you are not (dizziness, motion sickness)

Question 45

Damage to the vestibular system:

Answer 45

1. Menieres disease | 2. Vestibular nerve section

Question 46

Menieres disease

Answer 46

The ear feels full because there is too much endolymph in the sac. Starts unilateral and progresses to the other ear

Question 47

Vestibular nerve section

Answer 47

Does not progress. CNS compensates

Question 48

Eye is always moving towards warm/cold water

Answer 48

Cold

Question 49

Decebrebrate rigidity

Answer 49

Characterized by rigid extension of the limbs

Question 50

When does decrebrate rigidity arise

Answer 50

When the brainstem is transected/cut above the vertebral nuclei

Question 51

___ is importain for maintaining muscle tone

Answer 51

Vestibular system

Question 52

___ suppresses ____ to prevent excessive muscle tone rigidity

Answer 52

Cerebral cortex | Vestibular nuceli

Question 53

What happens when the cerebral cortex is removed

Answer 53

Rigidity

Question 54

What types of stimuli does the vestibular cortex respind to

Answer 54

Vestibular, proprioceptive, and visual

Question 55

Lesion to the vestibular cortex leads to

Answer 55

Altered perception of personal and extrapersonal space (contralateral neglect syndrome)