Brainscape's Knowledge GenomeTM

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


See full index

Neuro > Upper motor neurons > Flashcards

Upper motor neurons Flashcards

1
Q

What does the medial group control?

A

Axial and girdle musculature, so:

  • posture
  • locomotion
  • proximal components of reaching movements
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the medial tracts?

A

reticulospinal
tectospinal
vestibulospinal
ventral corticospinal

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

What is the lateral group made up of?

A

rubrospinal

lateral corticospinal

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

What does the lateral group control?

A

limb movement

involved in precision grip and palpation

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

Draw the descending tracts

A

OneNote

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

Mnemonic for descending tracts

A

Cleopatra May Think Provided Vain Monks Riot Calmly.

  • anterior Corticospinal
  • Medial longitudinal fasciculus (includes the medial vestibulospinal)
  • Tectospinal
  • Pontine reticulospinal
  • lateral Vestibulospinal
  • Medullary reticulospinal
  • Rubrospinal
  • lateral Corticospinal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is another name for pyramidal tracts?

A

Corticospinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is another name for extrapyramidal tracts?

A

Extra-corticospinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe briefly the pyramidal tracts

A
  • originate in the cerebral cortex
  • carry motor fibres to the spinal cord and brainstem
  • responsible for the voluntary control of the musculature of the body and face
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe briefly the extrapyramidal tracts

A
  • Originate in the brain stem
  • Carry motor fibres to the spinal cord
  • Responsible for involuntary and automatic control of musculature (such as muscle tone, balance, posture and locomotion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Do the cerebellum and basal ganglia send projections down into the spinal cord?

A

No, they send neurons which modulate the descending information

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

Where do the pontine and medullary reticulospinal tracts originate?

A

In the pontine and medullary reticular formations respectively in the

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

Describe pontine reticulospinal tract

A
  • travels ipsilaterally in the ventral funiculus
  • enhances the antigravity reflexes of the spinal cord, facilitates AXIAL AND PROXIMAL EXTENSORS OF THE LOWER LIMB and maintains a standing posture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the medullary tract

A
  • projects contralaterally in the anterolateral funiculus
  • liberates the anti-gravity muscles from reflex control - inhibits reflexes
  • FLEXOR MUSCLES
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the reticular formation?

A
  • series of interconnected nuclei in brainstem from upper midbrain to lower medulla
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Input to pontoreticulospinal

A

No cerebral cortex

Ascending pathways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Input to medullary reticulospinal

A

Cerebral cortex - corticoreticular fibres

Ascending tracts

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

What does the vestibulospinal tract comprise?

A

Lateral and medial branches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where does the vestibulospinal tract originate?

A

Vestibular nuclei of the medulla

  • the medial tract originates in the medial vestibular nucleus (Schwalbe’s nucleus)
  • the lateral tract originates in the lateral vestibular nucelus (Deiter’s nucleus)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What do the vestibular nuclei receive input from? What do these signal?

A

The semicircular canals and otolith organs of the inner ear

  • Head position and movement via the auditory nerve
  • also receive input from the cerebellum (fastigial nucleus w/proprioceptive information)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do the vestibulospinal tracts travel?

A
  • both ipsilaterally in the ventral funiculus
  • smaller medial tract innervates axial muscles in the cervical region controlling neck movements
  • the larger lateral tract descends as far as the lumbar spinal cord → fascilitates antigravity (EXTENSOR) motor neurones, especially axial ones, and helps to maintain posture by controlling postural muscles (e.g. the hip, back and shoulder muscles)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which tracts do extensor muscles?

A

Vestibulospinal tract

Ponto-reticulospinal tract

23
Q

Which tracts to flexor muscles?

A

Rubrospinal tract

Medullo-reticulospinal tract

24
Q

Where does the superior colliculus receive input from?

A
  • retina

- also somatosensory and auditory inputs

25
Q

Where does the superior colliculus receive input from?

A
  • retina

- also somatosensory and auditory inputs

26
Q

Where does the tectospinal tract end? What does it innervate?

A

At the cervical level

Muscles of the neck, shoulder and upper trunk

27
Q

Main functions of the tectospinal tract

A

Coordinating head and neck movement

Mediating gaze

28
Q

Where does the superior colliculus receive input from?

A
  • retina

- also somatosensory and auditory inputs

29
Q

Where does the tectospinal tract end? What does it innervate?

A

At the cervical level

Muscles of the neck, shoulder and upper trunk

30
Q

Where does the rubrospinal tract terminate? What does it do?

A

Cervical spinal levels
Arm movements
Biased towards flexion movements
End on interneurons

31
Q

Where does the rubrospinal tract originate?

A

Red nucleus of the midbrain, primarily from the caudal magnocellular part

32
Q

Where does the rubrospinal pathway decussate?

A

Midbrain - ventral tegmental decussation

33
Q

What are the two corticospinal tracts?

A

Ventral and lateral

34
Q

Where does the rubrospinal pathway decussate?

A

Midbrain - ventral tegmental decussation

35
Q

Where is the primary motor cortex?

A

In the precentral gyrus

36
Q

What is on either side of the medullary pyramid?

A

Medullary olives

37
Q

Where is the primary motor cortex?

A

In the precentral. gyrus

38
Q

What is on either side of the medullary pyramid?

A

Medullary olives

39
Q

Where do the corticospinal tract decussate? What percentage decussate?

A

At the medullary pyramids - 80%

40
Q

What happens to the corticospinal fibres that decussate at the medullary pyramids?

A

They go into the lateral columns and become the lateral corticospinal tracts

41
Q

What happens to the corticospinal fibres that DON’T decussate at the medullary pyramids?

A

Goes down the anterior white column
Becomes the ventral cortispinal tract
Cross over to the opposite ventral grey horn to stimulate lower motor neurones

42
Q

What is the lateral corticospinal tract associated with?

A

Distal limb musculature

Fine and precise movements

43
Q

What is the anterior corticospinal tract associated with?

A

Axial musculature

Gross/large movements

44
Q

Path of ventral corticospinal tract

A 
Internal capsule
Crus cerebri
Pons 
Pyramid
Ipsilateral ventral funiculus
45
Q

Path of lateral corticospinal tract

A 
Internal capsule 
Crus cerebri
Pons 
Pyramid 
Contralaterally in the lateral funiculus
46
Q

What does the supplementary motor area do?

A

Relays inputs from the basal ganglia via the thalamic ventral anterior nucleus
Also receive input from the prefrontal lobe and is important in internally-generated movements

47
Q

What is Brown Sequard syndrome?

A

lateral hemisection of the spinal cord where there is:

  • loss of pain and temperature contralaterally due to the decussation of nociceptive inputs in the spinal cord
  • sensory loss ipsilaterally due to the lack of decussation
  • motor impairment ipsilaterally due to decussation at higher points of the majority of motor input to the descending tracts
48
Q

What is anterior cord syndrome?

A
  • lesion in anterior portion of the spinal cord
  • dorsal column is left intact (retains proprioception and vibratory sensation)
  • motor and nociceptive function is lost due to entire lesion bilaterally of both anterior segments of the spinal cord
49
Q

Draw a section of the spinal cord - ascending and descending tracts

A

OneNote

50
Q

What is anterior cord syndrome?

A
  • lesion in anterior portion of the spinal cord where the dorsal column is left intact, but complete motor and nociceptive function is lost due to entire lesion bilaterally of both anterior segments of the spinal cord
51
Q

Compare LMN and UMN lesions

A 
LMN - everything is downregulated:
- flaccid - less muscle contraction
- hypotonic - less muscle tone
- hyporeflexic - less muscle reflexes
- denervation atrophy - less muscle innervation
- Babinski negative - toes point down 
UMN - everything upregulated:
- Spastic - more
- Hypertonic - more
- Hyperreflexic - more
- Disuse atrophy - more
- Babinski positive - toes point up
52
Q

What is central cord syndrome?

A
  • loss of nociceptive fibres bilaterally due to effect of decussation
  • impairment of function of nerves that mediated tendon reflexes
  • size of lesion determines subsequent effects
  • greater motor loss in upper limbs than lower limbs
53
Q

Compare LMN and UMN lesions

A 
LMN - everything is downregulated:
- flaccid - less muscle contraction
- hypotonic - less muscle tone
- hyporeflexic - less muscle reflexes
- denervation atrophy - less muscle innervation
- Babinski negative - toes point down 
UMN - everything upregulated:
- Spastic - more
- Hypertonic - more
- Hyperreflexic - more
- Disuse atrophy - more
- Babinski positive - toes point up

Neuro (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions