Brainscape's Knowledge GenomeTM

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


See full index

CNS > Motor systems > Flashcards

Motor systems Flashcards

1
Q

What is the role of the motor cortex?

A

Fine, voluntary movements

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

What is the role of the basal nuclei?

A

Used in planning and deciding movements

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

What is able to generate motor output?

A

Red nucleus and substantia nigra in midbrain

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

Where do UMNs take information?

A

From the brain to lower motor neurons

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

Where do LMNs take information?

A

They synapse with muscles via a neuromuscular junction

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

What is the role of UMNs, what are they required for?

A

Initiate, regulate, modify and terminate LMN activity

Required for voluntary movement of skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Are UMNs excitatory or inhibitory on LMNs?

A

Most are inhibitory

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

Where do UMNs supplying
1) flexor muscles
2) extensor muscles
travel in the spinal cord?

A

1) lateral funiculi

2) ventral funiculi

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

Where do LMNs have their cell bosy and axon?

A

Cell body in CNS

Axons in PNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where do LMNs for forelimb and hindlimb come from?

A 
Forelimb = cervical intumescence (C6-T2) 
Hindlimb = lumbar intumescence (L4-S3)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do LMNs cause a reflex action?

A

They can fire an AP without UMN input

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

What is atrophy?

A

loss of muscle tone

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

What is the result of LMNs having a constant sub-threshold depolarisation?

A

ACh release

Muscle tone and trophic support

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

What makes up a motor unit?

A

LMN + NMJ + skeletal muscle fibres

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

Which group of muscles are dominant in the body as they maintain posture against gravity?

A

Extensor muscles

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

What would occur if UMNs weren’t inhibitory on the LMNs that supply extensor muscles?

A

Spasticity of extensors

17
Q

What causes a reflex to be exaggerated?

A

Removal of UMN input, as the temporing effect they possess is lost

18
Q

What is the result of a LMN injury?

A

Muscle will lose tone, rapidly lose bulk (atrophy) and have reduced/absent reflexes

19
Q

What is the result of a UMN injury?

A

Reflexes will be normal or increased as will tone, and any atrophy will be relatively mild and due to disuse. Coordination will be reduced, but strength will be normal

20
Q

What is a reflex?

A

It is an innate reaction to a stimulus and is present from birth
Sensory input leads to motor output without input from higher centres – doesn’t require UMN input

21
Q

How is a response different to a reflex?

A

It is learned behaviour

22
Q

Describe the patella reflex

A
  • Monosynaptic reflex

- Intersegmental reflex, it enables the lower limb to be extended

23
Q

Describe the flexor withdrawal reflex

A
  • Polysynaptic reflex
  • Has a painful sensory input - reflex occurs before this is felt
  • Inhibition of extensor muscles, stimulation of flexor muscles to draw limb away
24
Q

What is the function of the spindle?

A

Arranged in parallel with the muscle fibres and are stretch receptors.
Body uses them to tell you the position of muscles e.g. how flexed or extended

25
Q

What is the function of the golgi tendon organ?

A

Arranged in series with the muscle so when the muscle contracts the receptor is stretched, so it is detecting contraction
- they prevent over-contraction

26
Q

What allows constant information about the degree of stretch on our muscles to be relayed?

A

Intrafusal muscle fibres

27
Q

What is the role of “γ – 1a – α activation” ?

A
  • leads to amplification of a signal
28
Q

What is the role of UMN tracts located in the motor cortex?

A

Fine, learned, complex movements

29
Q

What are the 5 UMN tracts?

A
  1. corticospinal
  2. rubrospinal
  3. tectospinal
  4. vestibulospinal
  5. reticulospinal
30
Q

Which of the 5 UMN tracts are pyramidal?

A

Corticospinal

31
Q

What is the role of extrapyramidal tracts?

A

Mainly control posture and subconscious, rhythmic movements

32
Q

What occurs as a result of cerebellar dysfunction?

A

Loss of coordination = ataxia

CNS (12 decks)

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