L06 Motor Pathways Flashcards Preview

Brain and Behaviour > L06 Motor Pathways > Flashcards

Flashcards in L06 Motor Pathways Deck (38):
1

is the lower motor neuron body in the CNS or PNS?

CNS

2

is the axon of the LMN in the CNS or PNS?

PNS

3

name 4 major inputs from the CNS that a LMN receives input from?

vestibular nuclei
reticular formation
cerebral cortex (major)
red nucleus

4

which side do LMNs innervate?

ipsilateral

5

where are the LMNs in the spinal cord?

ventral horns

6

where are the LMNs in the brainstem?

discrete nuclei that form the bodies of the cranial nerves

7

a patient presents with hyporeflexia. where is the lesion?

LMN

8

a patient presents with hyperreflexia. where is the lesion?

UMN

9

biceps tendon spinal segment innervation?

C6

10

triceps tendon spinal segment innervation?

C7

11

patellar tendon spinal segment innervation?

L4

12

achilles tendon spinal segment innervation?

S1

13

name symptoms of LMN lesions

ipsilateral weakness
hyporeflexia
flaccid paralysis
atrophy (lack of tropins from nerves)
fasciculations (early onset)

14

role of the vestibulospinal tract?

balance/equilibrium

15

role of the reticulospinal tract?

gait

16

role of the rubrospinal tract?

upper limb flexors

17

role of the corticospinal tract?

voluntary control of skeletal muscle

18

UMNs are modulated by which parts of the brain?

basal nuclei and cerebellum, via thalamus.

19

function of the lateral corticospinal tract?

skilled asymmetric limb movement

20

where do axons of the UMNs in the corticospinal tract synapse?

in the lower cervical and lumbosacral enlargements. innervate distal limb musculature for fine motor skills.

21

name the path of an UMN from cortex to spinal cord

cortex
corona radiata
internal capsule
cerebral peduncles
pyramids
decussation of the pyramids
lateral corticospinal tract in lateral column

22

name symptoms of UMN lesions

contralateral hemiplegia if in brain, ipsilateral if in spinal cord.
hyperreflexia
atrophy (disuse)
no fasciculations
positive babinski's sign

23

lesion in CN IV nucleus affects which side?

contralateral

24

lesion in CN IV nerve affects which side?

ipsilateral

25

lesion in cranial nerve nuclei affects which side?

ipsilateral (except IV)

26

babinski's sign tests for what?

UMN lesion

27

the corticobulbar tract includes motor for which cranial nerves?

V, VII, IX, X, XI, XII

28

which cranial nerves in the corticobulbar tract are controlled bilaterally?

V, IX, X

29

effect of unilateral LMN lesion in the masticator nucleus (V3)?

ipsilateral defect
weakness in muscles of mastication

30

effect of unilateral UMN lesion in the masticator nucleus (V3)?

little to none. (bilateral control)

31

effect of unilateral LMN lesion in the nucleus ambiguus (IX, X)?

paresis of vocal cords, soft palate, larynx, pharynx

32

effect of unilateral UMN lesion in the nucleus ambiguus (IX, X)?

little to none. (bilateral control)

33

effect of unilateral LMN lesion in the hypoglossal nucleus (XII)?

paralysis of ipsilateral tongue (points in direction of lesion)

34

effect of unilateral UMN lesion in the hypoglossal nucleus (XII)?

paralysis of contralateral tongue (points away from side of lesion)

35

effect of unilateral LMN lesion in the accessory nucleus (XI)?

ipsilateral weakness (shoulder shrug and head turn away)

36

effect of unilateral UMN lesion in the accessory nucleus (XI)?

contralateral shoulder weakness.
ipsilateral SCM weakness.

37

effect of unilateral LMN lesion in the facial nucleus (VII)?

ipsilateral facial weakness

38

effect of unilateral UMN lesion of the facial nucleus (VII)?

eyebrows unaffected. (rostral nucleus controls frontalis and is bilaterally innervated)
contralateral caudal paralysis. (caudal nucleus is contralaterally innervated)