Vestibular Function

Question 1

What makes up the vestibular apparatus?

Answer 1

3 semi-circular canals at right angles to each other and have ampulla at base that contain sensory structures
Utricle is continuous with this and also has sensory structures then the saccule is at the base. Saccule is connected to the cochlea via the endolymph.

Question 2

What are the sensory components of the vestibular apparatus?

Answer 2

Maccula of the saccule and utricle.

Ampulla of semi circular canal.

Question 3

What is another name for the saccule and utricle and what is their function?

Answer 3

Otolith organs and they detect linear motion of the head and neck. Back/front tilt of the head is detected by the utricle and vertical movements are detected by the saccule.

Question 4

What movement does the semi circular canal detect?

Answer 4

Rotational movement of the head

Question 5

What structure inside the cristae of the ampulla responds to endolymph?

Answer 5

Cupula that contains hair cells that are directly attached to vestibular nerve cells of the vestibular nerve.

Question 6

What are two types of hair cells?

Answer 6

Larger hair cell is called kinocilium. Distortion of the cilia towards them causes depolarisation of the vestibular nerve, away causes hyperpolarisation.
Smaller hair cells are called stereocilia

Question 7

What do tonic labyrinth reflexes do?

Answer 7

Keep the head axis in line with the rest of the body using macuale and neck proprioreceptors.

Question 8

What do dynamic righting reflexes do?

Answer 8

Rapid postural adjustments made when you trip to stop falling.