Vestibular System

Question 1

What is the end organ of sensation for the vestibular system?

Answer 1

-Cristae within the ampulla

Question 2

How many semicircular canals are there?

Answer 2

-3: anterior, posterior, horizontal

Question 3

Which areas are able to determine linear motion? Angular motion?

Answer 3

• Linear motion: saccule, utricle

- Angular motion: semicircular canals

Question 4

What is the typical spontaneous rate of vestibular hair cells?

Answer 4

-75-90 spikes/s

Question 5

What is the cupula? What does it do?

Answer 5

• Gelatinous mass that extends from the surface of the cristae to the roof/lateral walls of each ampulla
• Blocks endolymphatic movement (inertia) during head movement by moving in the opposite direction of head movement (excitation in leading side, inhibition in lagging side)

Question 6

If a head rotates and accelerates to the left, how do the left and right vestibular afferent fibers respond?

Answer 6

• Left afferent fibers: excitatory

- Right afferent fibers: inhibitory