Vestibular

Question 1

Role of the Vestibular System

Answer 1

• Estimate body position and movement
• postural control
• control of eye movements

Question 2

Peripheral Vestibular System Functions

Answer 2

• Stabilize visual images on the fovea of the retina during head movement allow for clear vision
• maintain postural stability, especially during movement of head
• provide information for spatial orientation

Question 3

What is in the Bony Labyrinth

Answer 3

Perilymphatic fluid + supportive connective tissue

Question 4

What is in the Membranous Labyrinth

Answer 4

Vestibule, 3 semicircular canals & Cochlea

Question 5

What are the otoliths organs

Answer 5

Utricle and Saccule

Question 6

What are the 3 semicircular Canals

Answer 6

Anterior, Posterior & Horizontal

Question 7

What plane does the Utricle and Saccule detect movement in?

Answer 7

Utricle: Horizontal
Saccule: Vertical

Question 8

What are the stereocilia in the otoliths and what do they do?

Answer 8

Motion receptors - gravity dependent

Move towards kinocilium = excitatory
Move away from Kinocilium = inhibitory

Question 9

What are otoconia

Answer 9

On top of macula

Control directions of macula

Question 10

What position is the Anterior Canal most sensitive in?

Answer 10

Forward Rotation

Question 11

What motion is the Posterior Canal Sensitive to?

Answer 11

Backward rotation

Question 12

What direction is the horizontal canal most sensitive?

Answer 12

“No” motion

Question 13

What is the Ampulla and what does it contain?

Answer 13

Bulbous formation at the start or finish of each canal

-contains cupola, which houses stereocilia

Question 14

What type of movement goes with the semicircular canals?

Answer 14

Angular velocity/Rotation

Question 15

Describe relationship between anterior and posterior canal

Answer 15

When one is excited, the other is inhibited

Question 16

What is the relationship with the horizontal canals?

Answer 16

They work together

When one is excited, the other is inhibitory

Question 17

What plane and degrees correlate with the Anterior, Posterior and Horizontal Plane?

Answer 17

Anterior: 45 degrees off sagittal
Posterior: 45 degrees off sagittal
Horizontal” 30 degrees above horizontal plane

Question 18

What is VOR

Answer 18

Vestibule-Ocular Reflex

• Stable vision during head motion
• Gaze stabilization
• results in eye movements that equally counter head movements

Question 19

In regards to VOR

Explain what is excited and inhibited when you rotate your head to the Left

Answer 19

Excitatory:
L semicircular canal, R Abducens, L Oculomotor

Inhibitory: R semicircular canal, L Abducens, R Oculomotor

Question 20

What is the function of the Vestibular Nu

Answer 20

• Eye movement control for gaze stability during movement (Oculomotor)
• Postural Control and movement (BS)
• Spatial Orientation (Cortex)
• Autonomic Nervous system control

Question 21

What are the 4 sets of subnuclei

Answer 21

Lateral (Dieter’s)
Medial
Superior
Inferior

Question 22

What does the Lateral Nu do

Answer 22

Outputs to the cerebellum (feedback) and to lateral vestibulospinal tract to facilitate extensors

-posture; muscles of trunk and legs

Question 23

What does the Medial Nu do

Answer 23

Provides descending output to muscles of head and neck Mia MLF

-head position

Question 24

What does the Superior Nu do

Answer 24

Provides ascending output via MLF to Oculomotor Nu

Question 25

What does the Inferior Nu do

Answer 25

Outputs to the cerebellum (feedback) to the RF (arousal and ANS) and to the Oculomotor Nu

Question 26

What is the vestibulocerebellum responsible for

Answer 26

Responsible for postural and gaze stabilization

Question 27

What does the Parieto-Insular Vestibular Cortex do and where is it?

Answer 27

Receives input from cerebellum and vestibular nu via thalamus

Junction of parietal and insular lobe

Question 28

What does the Medial Superior Temporal do

Answer 28

Visuo-vestibular integration

Self motion perception

Question 29

What does the Ventral Intraparietal Region

Answer 29

Multi sensory spatial coding

Proprioception, auditory, visual, tactile, vestibular