Vestibular

Question 1

Requirements for proper balance

Answer 1

• vestibular
• proprioception
• vision
• only 2 of 3 essential for balance

Question 2

Purpose of SCC, utricle, & saccule

Answer 2

SSC = precise head movement
utricle = horizontal gravity
saccule = vertical gravity

Question 3

Differential displacement

Answer 3

Kinocelium of hair cells move in opposite directions, one leads to increase in firing while other equals decrease
–Greater difference = higher velocity

Question 4

Medial & Superior vestibular nuclei

Answer 4

signals from SCC, interacts with CN 3, 4 , & 6 via MLF (ascending) for coordination of eye and neck movements

Question 5

Inferior vestibular nuclei

Answer 5

projects to the cerebellum for voluntary movements/ learned responses

Question 6

Lateral Vestibular nuclei

Answer 6

signals from utricle and saccule, becomes the lateral vestibulospinal tract responsible for ipsilateral extensors

Question 7

Medial vestibulospinal

Answer 7

descending MLF
bilateral projection through medial ventral funiculus
cervical spine for neck muscles

Question 8

vestibulo - ocular reflex

Answer 8

Eyes and neck moving in opposite direction

Question 9

Optokinetic response

Answer 9

• Nystagmus
• slow one way, then saccade (fast the other way)
• clinical test caloric test COWS (cold, other side/warm, same side)