Motor pathways

Question 1

where is cell body and synape of UMN

Answer 1

body in cortex, synapse on LMN

Question 2

where is body and synapse of LMN

Answer 2

body in brainstem or cord, synapse on striated muscle

Question 3

where are LMN bodies and nerve in brainstem

Answer 3

body in cranial nerve nuclei, travels in cranial nerve

Question 4

where are LMN bodies and nerve in cord

Answer 4

body in ventral horn, travel via ventral root>spinal nerve>peripheral nerve

Question 5

what is only nerve to touch the muscle

Answer 5

LMN – final common pathway

Question 6

where is motor column in brainstem and cord

Answer 6

brainstem - series of motor nuclei

cord - in ventral horn

Question 7

what do medial portions of motor column innervate

Answer 7

ipsilateral axial muscles for posture and balance

Question 8

what do lateral portions of motor column innervate

Answer 8

(only in cervical and lumbar) - ipsilateral limb muscles for skilled voluntary movement

Question 9

what is stretch reflex

Answer 9

stretch causes contraction to maintain muscle length

Question 10

what are 4 levels that can be tested and where

Answer 10

C6 - boceps
C7 - triceps
L4 - patellar
S1 - achilles

Question 11

what happen to reflex in LMN lesion

Answer 11

abolished

Question 12

what happens to reflex in UMN lesion

Answer 12

enhanced via lack of inhibition

Question 13

5 signs of LMN lesions

Answer 13

1. ipsilateral weakness
2. hyporeflexia
3. flaccid paralysis (lower tone)
4. atrophy - loss of trophic substances
5. fasiculations - tiwitching in early onset

Question 14

what are 4 interneuron UMN tracts and what do they control

Answer 14

1. vestubulospinal - balance equilibrium
2. reticulospinal - posture and gait
3. rubrospinal - limb flexors
4. corticospinal - skilled voluntary movement

Question 15

what is lateral corticospinal tract (LCST)

Answer 15

UMNs that allows skilled asymmetic movement

Question 16

where are bodies of LCST

Answer 16

in motor cortex

Question 17

where to LCST fiber decussate

Answer 17

at junction of medulla and cord

Question 18

where to LCST fibers synapse

Answer 18

on LMN in the cervical and lumbosacral enlargments

Question 19

what is axonal path of CST neurons

Answer 19

corona radiata>internal capsule>cerebral peduncles>pyramids>LCST

Question 20

what is babinski sign

Answer 20

normal stroking causes plantarflexion, but in UMN lesions causes dorsiflexion

Question 21

what happens in lesion of LMN in cord

Answer 21

ipsilateral effects

Question 22

what happens in lesion of CN nucleus or CN with LMN in it

Answer 22

ipsilateral effects except for trochlear, which is contralteral for nucleus and ipsi for nerve

Question 23

what is corticobulbar tract

Answer 23

extends from cortex to the bulb, or brainstem

Question 24

which CNs are innervated by tract and which are not

Answer 24

are: V, VII, IX, X, XI, XII
not: III, IV, VI

Question 25

which CN motor are bilateral controlled

Answer 25

V, IX, X

Question 26

what is masticator nucleus

Answer 26

LMN from here control ispilateral muscle of mastication

Question 27

what happens in LMN and UMN lesion in mastication

Answer 27

UMN - nothing

LMN - loss

Question 28

what is nucleas ambigious

Answer 28

LMN leave from here to control ipsilateral larynx and pharynx

Question 29

what is hypoglossal nucleaus

Answer 29

LMN leave from here to hit ipsilateral tongue

Question 30

what does accessory nucleaus hit

Answer 30

LMN hits SCM on ipsilateral side of motor cortex and contralateral side of traps

Question 31

what are 2 subnulei of facial and what do they supply

Answer 31

rostral - ipsilateral upper face

caudal - ipsilateral lower face

Question 32

how are 2 facial nuclei innervates by UMN

Answer 32

rostral - bilateral

caudal - contralateral motor cortex

Question 33

which 2 neurons of corticobulbar tract are not bilaterally inervated

Answer 33

12 and lower 7