Motor Systems (Lecture #7) Flashcards Preview

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Flashcards in Motor Systems (Lecture #7) Deck (30):
1

what is the only pathway we possess to move our extremities voluntarily

lateral corticospinal tract

2

what does the lateral corticospinal tract pathway do

voluntary movement of extremities
voluntary unilateral movement of trunk
(nothing with head or neck)

3

how many neurons does the lateral corticospinal tract consist of?

2
upper motor neuron and lower motor neuron

4

where is the cell body of the upper motor neuron of the corticospinal tract?

primary motor cortex

5

where is the cell body of the lower motor neuron of the corticospinal tract?

ventral horn of the spinal cord

6

Pathway of axon of the upper motor neuron of the corticospinal tract

corona radiata
internal capsule (posterior limb)
basis of midbrain
basis of pons
basis of medulla
crosses midline at pyramidal decussation (caudal medulla)
lateral aspect of spinal cord

7

where does the axon of the lower motor neuron of the corticospinal tract travel?

travels out ventral horn via ventral root
spinal nerve
plexus
peripheral nerve
synapses with muscle

8

corona radiata

axons heading to or from the cerebral cortex superior fo the thalamus

9

area IX of the spinal cord

location of lower motor neuron
occupies medial and lateral portion of each ventral horn
LMN for UE and LE are in lateral portion of area IX

10

what parts of the spinal cord is the lateral part of area IX the largest

cervical
lumbosacral

11

what part of the cervical enlargement provides axons for proximal part of UE

rostral part
C5-6

12

what part of the cervical enlargement provides axons for the distal part of UE

caudal part
C8-T1

13

what part of the lumbosacral enlargement provides axons for the proximal part of LE

rostral part
L2-4

14

what part of the lumbosacral enlargement provides axons for the distal part of LE

caudal part
L5-S2

15

Where does the cell body of the LMN always come from for muscles of the right side of the body

right ventral horn
(L ventral horn --> muscles on L side)

16

function of anterior corticospinal tract

voluntary control of proximal extremities and trunk muscles
-especially when you move both sides simultaneously

17

decussate

cross midline

18

if pt damages left motor cortex, will he/she still be able to move his/her right trunk/proximal extremities

yes, but only bilaterally simultaneously

19

where does UMN of lateral corticospinal tract decussate

caudal medulla

20

where does UMN of anterior corticospinal tract bifurcate?

at spinal level of LMN in spinal cord

21

where does axon of anterior corticospinal tract travel in spinal cord

anterior (ventral) column

22

where does axon of lateral corticospinal tract travel in spinal cord

lateral column

23

function of corticobulbar tract

voluntary movements of head and neck

24

which CNs motor nuclei are on the midbrain

III
IV

25

which CNs motor nuclei are on the pons

V
VI (eye mvmt)
VII (rostral/caudal halves = upper/lower face)

26

which CNs motor nuclei are on the medulla

IX (swallowing)
X (vocalization)
XII (tongue)

27

which CNs motor nuclei are on the spinal cord

XI (shoulders, turn head)

28

do the UMNs for the upper part of the face bifurcate?

yes

29

do teh UMNs for the lower part of the face bifurcate?

no, they cross the midline and innervate contralaterally

30

what is the most notable clinical sign when a person has damage to UMN in lateral corticobulbar tract supplying the lower part of face

paralysis of lower part of face on opposite side