Lecture 25- Vestibular System 2

Question 1

What is the juxtarestiform body?

Answer 1

a subdivision of the inferior cerebellar peduncle that contains projections from the vestibular ganglion neurons

Question 2

What are the major projects from the vestibular nuclei?

Answer 2

1. cerebellum
2. spinal cord
3. oculomotor nuclei

Question 3

What is the role of the lateral vestibule-spinal tract?

Answer 3

projects down the spinal cord to antigravity muscles

controls posture and mediates vestibulo-spinal reflexes

Question 4

What does the lateral vestibulospinal tract trigger when the head and trunk tilt to the right?

Answer 4

triggers ipsilateral extensor muscles to prevent falling

Question 5

What would a unilateral lesion of the lateral vestibulospinal tract result in?

Answer 5

stumbling and falling to the ipslateral side due to lost tone in extensor muscles that maintain posture

Question 6

What is another name for the medial vestibulospinal tract?

Answer 6

MLF- medial longitudinal fasiculus

Question 7

How do neurons from the vestibular nucleus reach the nuclei of CN III, IV and VI?

Answer 7

via the MLF- medial longitudinal fasiculus

Question 8

Because of the vestibule-ocular reflex, if the head moves to the left the eyes move to the_______?

Answer 8

right

Question 9

If the head moves to the left, which semicircular canal is stimulated? Which is inhibited?

Answer 9

the Left horizontal semicircular canal is activated and the Right horizontal semicircular canal is inhibited

Question 10

What will disruption of the medial longitudinal fasiculus (MLF) result in?

Answer 10

failure to coordinate eye movements in response to vestibular stimulation or other stimuli