Motor systems III

Question 1

which cranial nerves receive inputs from corticonuclear fibers?

Answer 1

5, 7, 9, 10, 11, 12

Question 2

what is the course of the corticonuclear tract in the internal capsule? corticospinal tract?

Answer 2

1. corticonuclear - genu - posterior limb 2. corticospinal - genu - posterior half

Question 3

what is the course of the cortical projections to the trigeminal (V) nucleus?

Answer 3

at pontine level, corticonuclear fibers terminate bilaterally on interneurons in the reticular formation next to the V motor nucleus

Question 4

what is the course of the cortical projections to the facial nucleus?

Answer 4

1 .bilateral UMNs to superior half of nucleus 2. contralateral UMNs to inferior half of nucleus

Question 5

the facial nucleus receives blood supply from which arteries?

Answer 5

AICA and basilar

Question 6

what is the course of the cortical projections to the nucleus ambiguus?

Answer 6

bilateral (primarily contralateral)

Question 7

how would a right UMN lesion affect the uvula?

Answer 7

uvula deviates to side of lesion

Question 8

cortical projections to the accessory nucleus of the spinal portion of the accessory nerve are ipsilateral or contralateral? where do they go?

Answer 8

1. ipsilateral 2. trapezius and SCM

Question 9

what is the course of the cortical projections to the hypoglossal nucleus?

Answer 9

1. bilateral (mostly contralateral) 2. exception - genioglossus - contralateral

Question 10

how would a right UMN lesion affect protrusion of the tongue?

Answer 10

protrudes to weak side (left side)

Question 11

the motor cortex influences eye movement through which pathways?

Answer 11

frontal an parietal motor eye fields - midbrain reticular formation and paramedian pontine reticular formation (bilaterally) - motor nuclei of CN 3, 4, 6- movement contralateral to side of origin of cortical input