Lecture 14: Vestibular System

Question 1

The semicircular canals and what organs make up the vestibular labyrinth?

Answer 1

The otolith organs

Question 2

What are the otolith organs?

Answer 2

The saccule and utricle

Question 3

What are the two types of vestibular hair cells?

Answer 3

Stereocilia and kinocilium

Question 4

Are the macula of the utricle and saccule horizontal or vertical?

Answer 4

Utricle - horizontal

Saccule - vertical

Question 5

What is the midline of the macula called?

Answer 5

Striola

Question 6

What does the striola do?

Answer 6

Divide hair cells into two subpopulations of opposite polarities.

Question 7

What is the direction of depolarisation in the utriclar and saccular macula with regard to the striola?

Answer 7

Utricular macula - depolarisation towards striola

Saccular macula - depolarisation away from striola

Question 8

Does the utricle or saccule respond to up and down movements of the head?

Answer 8

Saccule

Question 9

What is the gelatinous cap containing many hair cells in each semi-circular canal called?

Answer 9

Cupula

Question 10

Displacement of the cupula occurs in which direction in relation to the rotational movement occurring?

Answer 10

In the opposite direction to the rotational movement

Question 11

What pairs are the semi-circular canals arranged in?

Answer 11

• left and right horizontal canals
• right anterior and left posterior canals
• left anterior and right posterior canals

Question 12

In a pair, how are the cells aligned?

Answer 12

Oppositely.

Question 13

Where are the vestibular nuclei located?

Answer 13

In the pons and medulla

Question 14

Do the left and right vestibular nuclei receive input just from the ear on their side or from both ears?

Answer 14

Both ears!