Vestibular System Pathways (2)

Question 1

Where does the cochlear portion of CN 8 come from?

Answer 1

Cochlea (hearing)

Question 2

Where does the vestibular portion from CN 8 come from?

Answer 2

Semi circular canals and vestibular apparatus (head movement, postural control, and eye movement in response to head movement)

Question 3

Where do portions of CN 8 travel to?

Answer 3

Nuclei in the pons and medulla

Question 4

Where do vestibular nuclei reside?

Answer 4

Brainstem at pontomedullary junction

Question 5

What does the vestibular system contribute to?

Answer 5

Head movement

Head position relative to gravity

Eye movement control when head moves (gaze stabilization)

Postural adjustments

Autonomic functions

Question 6

What are the 4 vestibular nuclei?

Answer 6

Lateral vestibular nucleus

Medial vestibular nucleus

Inferior vestibular nucleus

Superior vestibular nucleus

Question 7

What is the function of the lateral vestibular nucleus?

Answer 7

Lateral vestibulospinal tract (postural muscles in limbs and trunk)

Question 8

What is the function of the medial vestibular nucleus + inferior vestibular nucleus?

Answer 8

Medial vestibulospinal tract (head and upper back posture)

Question 9

What is the function of the medial vestibular nucleus + superior vestibular nucleus?

Answer 9

CN 3,4 and 6

Superior colliculus and CN 11

Mediates VOR (gaze stabilization)

Question 10

What does the VOR do?

Answer 10

Stabilizes images during head movement

Question 11

What happens in the VOR when the head is turned to the right?

Answer 11

Increase signal from right horizontal canal and decreased signal from left horizontal canal