Motor System III

Question 1

what are corticonuclear projections

Answer 1

axons that arise from neurons in the sensory and motor cortex to form the corticonuclear tract

Question 2

where do most corticonuclear projections terminate

Answer 2

cranial nerve nuclei

Question 3

where do some corticonuclear projections terminate

Answer 3

cervical spinal cord

Question 4

course of corticonuclear projections

Answer 4

axons descend and enter subcortical white matter
descend through corona radia
descend through internal capsule
descend through genu of internal capsul
enter anterior aspect of poster limb
descend through midbrain

Question 5

what is the first site of termination

Answer 5

trigeminal motor nucleus in pons

Question 6

what is the second site of termination

Answer 6

facial motor nucleus, lower in pons

Question 7

what is the third site of termination

Answer 7

nucleus ambigus in medulla

Question 8

what is the fourth site of termination

Answer 8

cerival spinal cord

Question 9

what happens i fyou have an occlusion of the lenticulostriate arteies

Answer 9

severe sensory and motor deficits on one side of the body

Question 10

what do the lenticulostriate arteries supply

Answer 10

IC and basal nuclei

Question 11

what is the corticonuclear tract doing at the midbrain

Answer 11

no branching or synpasing

Question 12

what is the corticonulcear tract doing midpons

Answer 12

some axons leave to synpase on trigeminal nucleus

Question 13

what is corticonuclear tract doing at caudal pons

Answer 13

some axons leave to synpase on facial nucles

Question 14

upper half of facial nucleus

Answer 14

recieve bilateral projection from corticonuclear tract

Question 15

what does upper half of facial nucleus contain

Answer 15

cell bodies of lower motor neurons that terminate on upper facial muscles

Question 16

what do lower half of facial nucleus receive projections of

Answer 16

contralateral

Question 17

what does lower half of facial nucleus contain

Answer 17

lower motor neurons that terminate on lower facial muscles

Question 18

what happens if you have a lesion on ipsilateral upper motor neuron on facial nucleus

Answer 18

no deficient

Question 19

what happens if you have lesion contralateral upper motor neuron going to just upper half of facial nucleus

Answer 19

no deficient

Question 20

what happens if you have a lesion on contralateral upper motor neuron going to both upper an dlower halves of facial nucleis

Answer 20

motor deficit in lower half of face on the contralateral side

Question 21

corticonuclear projections to nucleus ambiguus are ____

Answer 21

bilateral

Question 22

what happens if you have a lesion of a upper motor nucleus to the nucleus ambiguus

Answer 22

uvular deviation to the same side as the lesion

Question 23

corticonuclear projections to neurons of the hypoglossal nucles that innervate most of the muscles of the tongue are _____

Answer 23

bilateral

Question 24

corticonuclear projections to the neurons of the hypoglassal nucleus that innervate genioglossus muscle are ______

Answer 24

contralateral

Question 25

nucleus ambiguus sends fibers where

Answer 25

to ubula

Question 26

hypoglossal nucleus sends fibers to

Answer 26

genioglossus and other intrinsic muscles of tongue

Question 27

what happens if you have a lesion of upper motor neuron in hypoglossal nucleus

Answer 27

deviation of the tongue to contralateral side as lesion

Question 28

corticonuclear projection to trigemnical are

Answer 28

bilateral

Question 29

which CN do not receive upper motor neuron projections from corticonuclear fibers

Answer 29

III, IV, VI