Vestibular system

Question 1

what is the vestibular system?

Answer 1

provides the sense of balance and the information about body position that allows rapid compensatory movements in response to both self-induced and externally generated forces

Question 2

what are the sensory organs of the vestibular system?

Answer 2

utricle, saccule, and the three semicircular canals (posterior, superior, and horizontal)

Question 3

what is the vestibular organ?

Answer 3

labyrinth = vestibular organ + cochlea

Question 4

transduction

Answer 4

similar to cochlea.

Question 5

describe the semi-circular channels

Answer 5

function: detect head movements via rotary acceleration.
structure:
- 3 fluid filled canals, right angles to each other, 1 for each major plane.
- crista: sheet of cells are clustered.
- ampulla: bulge along canal, contains crista.
- cilia: project into gelatinous cupula.
- kinocilia orientated in same direction so all excited or inhibited together.
- semi-circular canals: filled with endolymph
- movement causes fluid to circulate and displace cupula.

Question 6

how are the three semi-circular canals arranged?

Answer 6

• lie in 3 orthogonal planes located on both sides of the head forming push-pull pairs with their contralateral counterparts.
• posterior canal shares plane with contralateral anterior canal.
• horizontal canals share plane.

Question 7

what are the otolith organs?

Answer 7

• two: saccule and utricle.

Question 8

what do the otolith organs do?

Answer 8

• sense linear acceleration and gravity.
• saccule has iportant role in movement in vertical/sagittal plane
• utricle has important role in the horizontal plane.