Vestibular System

Question 1

What are the 3 main contributors to orientation

Answer 1

1.vision (visual space)
2.vestibular system (inertial space)
3.proprioception (internal space)

Question 2

Pull push action of left right signals:

Answer 2

1. Rotation/acceleration is signalled by difference in firing rate between the two ears
2. Lose one ear strong sense of rotation causes vertigo and dizziness

Question 3

Otolith organs: utricle and saccule what do they detect

Answer 3

Detective tilt/linear acceleration. Cells oriented in all directions to pick up movement

Question 4

Structure of utricle and saccule

Answer 4

Utricle approx verticals
Saccule approx verticle

Respond to acceleration and have a slow adaption. Main role is postural stabilisation

Question 5

What are semicircular canals

Answer 5

Canals that are perpendicular to each other therefore detect rotation in any direction

Question 6

What happens to the capula after alcohol

Answer 6

The cuplula becomes lighter than the surrounding fluid. Therefore rises when lying down

Question 7

What happens to the cupula after heavy water

Answer 7

The cupula becomes heavier than the surrounding fluid thus sinks when lying down

Question 8

What is caloric vestibular stimulation

Answer 8

Method of modulating the firing rate of the primary vestibular afferents by irrigation of the ear canal w warm or cold water

Question 9

Comatose patients:

Answer 9

Reflex eye movement evoked by Caloric vestibular stimulation indicate if the patient will die or have a good recovery

Question 10

What is vestibular ocular reflex important for

Answer 10

Stabilising vision

Question 11

How can vestibular function be tested

Answer 11

By real rotation, caloric stimulation of GVS