Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neurobio Final > Upper motor control - Part II > Flashcards

Upper motor control - Part II Flashcards

1
Q

Where is the lesion for decorticate posturing?

A

above red nucleus (superior colliculus and midbrain)

  • FLEXED (ELBOWS) PATTERN
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where is the lesion for decerebrate posturing?

A

Below the red nucleus (midbrain, at level of cerebral peduncle)

  • EXTENSOR PATTERN
  • MORE “E’s”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What body parts have poor fine motor control recovery due to their less concentrated representation on M1?

A

toes, fingers, and tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How many symmetric concentric topographic representations are there on M1?

A

3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

____ is still strictly represented in homunculus

A

S1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

There is a chimeric distribution of ___

A

M1

  • mixture of columnar units
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the functions of M1 in motor control?

A
  • 1st stimulated, faster response, these UMN can directly control our LMN in the spinal cord
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the delay of M1?

A

5-100 msec delay

  • PM is 1/2 second due to more pathways, each step takes time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What kind of synapse is formed with LMN from M1?

A

direct monosynaptic LMN control

  • directly form a synapse with LMN without interneurons
  • if interneurons are needed (2+) = disynaptic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the roles of M1 for motor control?

A
  • the intention/direction of the movement
  • the preferred direction of movement
  • the force/speed of movement
  • the extent of movement: proprioception mediated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where is the strongest activity of M1?

A

like 360 degrees, 4 oclock to 8 oclock is strongest activity that a motor neuron works

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which cerebral lobe doesn’t have mirror neurons?

A

Occipital lobe, mainly for visual stimuli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When are monosynaptic M1 neurons developed?

A

postnatally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where are monosynaptic neurons located?

A

caudal M1, anterior bank of central sulcus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do monosynaptic M1 neurons directly synapse with? Why?

A

LMN: fine motor control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why do reflexes reappear stroke?

A
  • integrated, disappear as time goes on after we are born, maturation of system caudal M1 axons descend to the spinal cord, will inhibit these reflexes
  • why after stroke, with functions lost, pts will present with spinal reflexes again, such as Babinski and Hoffman
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

When are level 3 and 4 disynaptic UMNs developed?

A

prenatally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do levels 3 and 4 disynaptic UMNs synaps with LMN? Where?

A

through interneurons

  • rostral M1
  • Dorsal and vental PM, SMA: Brodmann area 6
  • two from cingulate gyrus: RCZ, CCZ
  • posterior parietal lobe: Brodmann area 5
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What tracts do levels 3 and 4 UMNs not contribute much to?

A

human corticcobulbar and corticospinal tracts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is unique about cortical descending projection fibers?

A

ROTATE DURING DESCENDING 180 degree until to pons
- at the posterior limb of the internal capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What happens with cortical descending projection fibers below the pons?

A

disperse out, mix together
- NO MORE SOMATOTOPY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is maintained with cortical descending projection fibers above the pons?

A

gross topography maintained above the pons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the cortical desscending projection fibers?

A
  • corticobulbar
  • corticospinal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where are 2/3 of the tracts in the internal capsule from?

A

frontal lobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Where are the target motor nuclei for the corticobulbar tracts?

A

in the brainsetm

26
Q

What cranial nerves DO NOT have motor nuclei?

A

III, IV, VI

27
Q

Which CN is the only one entirely by contralateral control?

28
Q

What can happen with a R MCA stroke?

A

L CN XII compromised, tongue shifts L with tongue protrusions

  • tongue will deviate to weaker side
29
Q

What CN have contralateral control?

A

CN VII ventral nuclei, CN XII

30
Q

Which CN have bilateral control?

A

All other CNs

31
Q

What level has brainstem motor control functions for the corticobulbar tract?

32
Q

What is in the brainstem motor control level 2 of corticobulbar tracts?

A

red/reticular/vestibular nuclei
- inhibition vs activation

33
Q

What percentage of the corticospinal tracts decussate in the pyramid?

A

70-90% for contralateral body control

34
Q

Where do the corticospinal tracts that decussate in the pyramid descend?

A

in the lateral funiculus

35
Q

Where do the corticospinal tracts that do not cross over descend?

A

anterior funiculus and ipsilateral lateral funiculus

36
Q

Why do patients who have the nondecussated tracts stroke recover better?

A
  • more function and fine motor control
37
Q

Where does motor decussation occur?

A

in the caudal medulla

38
Q

What are the 3 tracts in the pons ?

A
  • pontine reticulospinal tract
  • vestibulospinal tract (lateral and medial)
39
Q

What is the tract in the medulla?

A

medullary reticulospinalt ract

40
Q

What tract is in the midbrain?

A

rubrospinal tract

41
Q

What are the functions of the monosynaptic M1 neurons?

A

directly innervate LMN - direction speed and extension of a selected movement

42
Q

What are the functions of the red nucleus for UE fine motor control?

A

Flexors
- decussation in midbrain
- descending in the lateral funiculus of the spinal cord

43
Q

Where does the UE fine motor control of the red nucleus end?

A

Upper thoracic region

44
Q

What is the red nucleus important for?

A

New Skill Learning
- through red nucleus- inferior olivary nucleus
- cerebellum circuitry

45
Q

Where does the pontine reticulospinal tract run? What does it control?

A
  • all spinal levels
  • controls extensors
46
Q

Where does the pontine reticulospinal tract project?

A

bilateral projection, anterior funiculus

47
Q

Where does the medullary reticulospinal tract run? What does it control?

A

all spinal levels/whole spinal cord
- controls flexors

48
Q

Where does the medullary reticulospinal tract project?

A

ipsilateral projection, lateral funiculus

49
Q

Where does the lateral vestibulospinal tract run? What is its function?

A
  • ipsilateral anterior funiculus for proximal extremity extensors
  • WHOLE SPINAL CORD
50
Q

Where does the medial vestibulospinal tract run? What is its function?

A
  • Ends at upper level of thoracic region
  • bilateral anterior funiculus for neck/upper trunk extensors
51
Q

What motor control reflexes help with balance?

A
  • vestibulocular reflex
  • vestibulocervical reflex
  • vestibulospinal reflex
52
Q

What tracts that control extensors run the whole spinal cord?

A
  • Pontine reticulospinal tract (pRST)
  • lateral vestibulospinal tract (lVST)
53
Q

What extensor tract ends in the neck?

A

medial vestibulospinal tract (mVST)

54
Q

What flexor tract ends in the UE?

A

Rubrospinal tract (RuST)

55
Q

What flexor tract runs the whole spinal cord?

A

Medullary reticulospinal tract (mRST)

56
Q

What pathology is BELOW the red nucleus?

A

decerebrate

57
Q

What is unique about decerebrate posturing?

A

NO corticospinal/rubrospinal functions
- extremities in EXT

58
Q

What pathology is above the red nucleus?

A

Decorticate

59
Q

What are the tracts responsible for decorticate posturing?

A
  • Functional rubrospinal tract: UE in FLX
  • Active vestibulospinal tracts: BLE in extension
60
Q

Which level 2 motor contro systems in the brainstem?

A
  • Rubrospinal tract (midbrain)
  • reticular: pontine vs medullary (pons)
  • Vestibular: lateral vs medial (pons)
61
Q

Which level 2 motor control tracts end in the whole spinal cord, and which stop at the upper thoracic region?

A
  • Whole spinal cord: pontine and medullary reticulospinal tracts, lateral vestibulospinal tract
  • Upper thoracic region: rubrospinal tract and medial vestibulospinal tract
62
Q

What controls reflexes?

Neurobio Final (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions