Vestibular System

Question 1

What are the parts to the peripheral vestibular system?

Answer 1

1. Superior/anterior canals
2. Middle/horizontal canals
3. Posterior Canals
4. Utricle
5. Saccule

Question 2

What structures make up the inner ear?

Answer 2

Cochlea, vestibule, semicircular canals

Question 3

What are the names of the vestibular nuclei?

Answer 3

superior, inferior, lateral, and medial

Question 4

What are the functions of the vestibular system?

Answer 4

motion detection

generating compensatory movement

needs to maintain the stability of the body, head, and eyes in space

Question 5

The horizontal canal is pitched ___ degrees above true horizontal. What is this called?

Answer 5

30

Reed’s line

Question 6

The semicircular canals are at ___ degrees angles to one another.

Answer 6

90

Question 7

The cochlear apparatus is at a ___ degree angle to midline.

Answer 7

45

Question 8

What motion is pitch?

Answer 8

“yes”

Cervical flexion

Question 9

What motion is yaw?

Answer 9

“no”

cervical rotation L and R

Question 10

What motion is roll?

Answer 10

cervical extension and rotation

Question 11

Where is perilymph fluid located?

Answer 11

between boney and membranous labyrinth

Question 12

Where is endolymph fluid located?

Answer 12

Within membranous labyrinth

Question 13

____ are hair cells that detect motion via movement of ____.

Answer 13

stereocilia

endolymph

Question 14

Large hair like projection that detects motion

Answer 14

Kinocilium

Question 15

What factor (excitation/inhibition) is detected when steriocilium bend toward kinocilium?

Answer 15

excitation

Question 16

What factor (excitation/inhibition) is detected when stereocilium bend away from kinocilium?

Answer 16

inhibition

Question 17

Name the pairs of canals that maximize fluid flow?

Answer 17

horizontal

Left anterior, Right posterior

R anterior, L posterior

Question 18

If you turn your head to the L, you will maximally excite which canal? What is this called?

Answer 18

L horizontal

Yaw

Question 19

If you turn head to R and pitch, what are you exciting?

Answer 19

L anterior canal

Question 20

If you turn head to the R and roll, what are you exciting?

Answer 20

R posterior canal

Question 21

During acceleration, endolymph flows in the same or opposite direction of head movement?

Answer 21

opposite

Question 22

During deceleration prior to stopping, endolymph flows in the same or opposite direction of head movement?

Answer 22

same

Question 23

True or False.

Otoliths are sensitive to rotation.

Answer 23

False

Question 24

What structures are otoliths?

Answer 24

saccule and utricle

Question 25

You decide to go bungy jumping. What otolith is engaged?

Answer 25

saccule (think dropping a sac)

Question 26

You are taking a train ride when suddenly the train comes to a screeching halt, what otolith is involved?

Answer 26

utricle

Question 27

What structures unite with the Vestibular Nuclei complex?

Answer 27

Lateral= LVST Medial= MVST Superior= MLF Inferior= fibers of MVST traverse (no pathway)

Question 28

This tract extends the length of the spinal cord; responsible for maintaining balance and extensor tone. Does its fibers runs ipsilateral, contralateral, or both?

Answer 28

LVST ipsilateral

Question 29

This tract extends through cervical spine; controls neck and head position. Does its fibers runs ipsilateral, contralateral, or both?

Answer 29

MVST Bilateral

Question 30

Connects the nuclei involved in eye movements to each other and to the vestibular nuclei

Answer 30

MLF

Question 31

What pathway mediates VOR?

Answer 31

MLF

Question 32

The vestibulocerebellar pathways have links to what part of the cerebellum?

Answer 32

flocculonodular lobes and cerebellar vermis

Question 33

If you turn head to the L and pitch, what canal is maximally excited?

Answer 33

R anterior canal

Question 34

If you turn your head to the L and roll, what canal is maximally excited?

Answer 34

L posterior canal

Question 35

When you turn your head to the L, this is excitatory or inhibitory to the R horizontal canal?

Answer 35

inhibitory

Question 36

What are the two components of VOR?

Answer 36

Angular: mediated by SCC Linear: mediated by otoliths

Question 37

Stabilizes visual images during head movements.

Answer 37

vestibulo-ocular reflex (VOR)

Question 38

When you turn your head to the R, which eyes muscles do you engage?

Answer 38

L lateral rectus, R medial rectus

Question 39

When you turn your head to the R, the MLF on the ___ ascends ipsilateral to CN 3, MLF on the ___ ascends contralateral to CN 6.

Answer 39

Right Left

Question 40

In vertical VOR, when extend your neck, the eyes move ___. When you flex your neck, the eyes move ___.

Answer 40

down up

Question 41

When eyes and head go in the same direction.

Answer 41

VOR cancellation

Question 42

The ratio of eye velocity and head velocity

Answer 42

VOR gain

Question 43

Generates compensatory body movement in order to stabilize the body for postural control.

Answer 43

Vestibulo-spinal reflex (VSR)

Question 44

____ activity is induced on the side of the head movement, via the ___.

Answer 44

extensor LVST

Question 45

____ activity is induced on the opposite side of the head movement.

Answer 45

flexor

Question 46

This structure adjusts and maintains VOR gain

Answer 46

flocculus

Question 47

This structure responds to vestibular stimulation

Answer 47

vermis

Question 48

This structure adjusts duration of VOR responses and processes otolith input

Answer 48

Nodulus

Question 49

A person's eyes move slowly to the R and rapidly moves to the L. This is considered a ___ (R or L) beating nystagmus?

Answer 49

Left beating

Question 50

No matter which direction you look, the nystagmus is always in same direction due to one side being stronger. This is indicative a peripheral or central nystagmus?

Answer 50

Peripheral

Question 51

This type of nystagmus can be suppressed with fixation.

Answer 51

Peripheral

Question 52

This nystagmus is seen in darkness but not in light.

Answer 52

Peripheral

Question 53

Pure vertical nystagmus is always indicative of central or peripheral?

Answer 53

central