Vestibular systems

Question 1

What is the vestibular apparatus responsible for?

Answer 1

Dizziness and orientation in space

Question 2

What is the only other system in the body that can be used to determine direction?

Answer 2

Blood volume distribution

Question 3

What is angular/rotatory motion of the head detected by?

Answer 3

Semicircular canals

Question 4

What is acceleration of the head and strength and direction of gravity detected by?

Answer 4

Otolith organs

Question 5

What are the 5 main functions of the vestibular system?

Answer 5

Subserve perception of movement and tilt in response to gravity
Provide reflex balance reactions to sudden instability of gait or posture- vestibulo-spinal reflexes
Stabilise the eyes on fixed targets preserving visual acuity during head movement- vestibulo-ocular reflexes
Assist control of respiration, blood pressure and heart rate during rapid up-down tilts
Provokes motion sickness when stimulated in unusual motion environments

Question 6

What is vertigo?

Answer 6

False perception of movement in space

Question 7

What is vestibular ataxia?

Answer 7

Instability of gait and posture

Question 8

What is vestibular nystagamus?

Answer 8

Inability to stabilise the eyes so rapid, involuntary movements in any direction

Question 9

What is oscillopia?

Answer 9

Objects in the visual field appear to oscillate

Question 10

What is a saccule?

Answer 10

Bed of sensory cells situated in the inner ear- it translates head movements into neural impulses which the brain can interpret. The saccule detects linear accelerations and head tilts in the vertical plane