Brainscape's Knowledge GenomeTM

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


See full index

Neuro Physiology > Motor Control > Flashcards

Motor Control Flashcards

1
Q

Levels of the motor system

A

High
Middle
Low

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

Function of the higher level of the motor system

A

Strategy

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

Function of the middle level of the motor system

A

Tactics

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

Function of the low level of the motor system

A

Execution

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

Structures of the higher level of the motor system

A

Association neocortex

Basal ganglion

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

Structures of the middle level of the motor system

A

Motor cortex

Cerebellum

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

Structures of the lower level of the motor system

A

Brain stem

Spinal cord

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

What is the strategy?

A

The goal and the movement strategy best to achieve that goal

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

What are the tactics?

A

The sequence of spatiotemporal muscle contractions to achieve a goal smoothly and accurately

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

What is the execution?

A

Activation of motor neurone and interneuron pools to generate a goal directed movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is the brain connected to the spinal cord?

A

Lateral pathways

Ventromedial pathways

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

Function of lateral pathways

A

Control voluntary movements of distal muscles

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

Lateral pathways are under direct control of what?

A

Direct cortical control

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

Function of ventromedial pathways

A

Control posture and locomotion

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

What are ventromedial pathways under control of?

A

Brainstem

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

What are the lateral pathways?

A

Corticospinal tract

Rubrospinal tract

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

What are the ventromedial pathways?

A

Tectospinal tract
Vestibulospinal tract
Pontine reticulospinal tract
Medullary reticulospinal tract

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

What is the most important lateral pathway?

A

Corticospinal tract

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

Where does the corticospinal tract originate from?

A

2/3rds in areas 4 and 6 of the frontal motor cortex

Rest is somatosensory

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

Journey of the Corticospinal tract

A

At the medulla/spinal cord junction the CST crosses over (decussates) so that
- the right motor cortex controls the left side and the left motor cortex controls the right side
CST axons synapse on the ventral horn motor neurones and interneurons to control muscles

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

Where does the rubrospinal tract start?

A

Red nucleus of the midbrain

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

What are the inputs to the rubrospinal tract?

A

Same as the CST

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

Size difference CST vs RST

A

CST - larger, longer

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

If you have a lesion in CST and RST, what would happen?

A

Fine movements of arms and hands lost

Cant move shoulders, elbows, wrists and fingers indepdently

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

If you have a lesion in the CST alone, what would happen? Why?

A

Same deficits, but after a few months functions reappear.

Happens because been taken over by the RST

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What do the RST and the CST have?

A

Duality of function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the two ventromedial pathways which control posture and locomotion?

A

Vestibulospinal tract

Tectospinal tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Function of Vestibulospinal tract

A

Stabilises head and neck

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Function of the tectospinal tract

A

Ensures eyes remain stable as the body moves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

When are TST and VST critical?

A

When the body is carrying out complicated body movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Where does the VST originate?

A

Vestibular nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Where does the TST originate?

A

Superior colliculus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Which ventromedial pathways control the trunk and antigravity muscles?

A

Pontine and medullary reticulospinal tracts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Where do the pontine and medullary reticulospinal tracts originate?

A

Brainstem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How do the pontine and medullary reticulospinal tracts work?

A

Use sensory info about balance, body position and vision

Reflexly maintain balance and body position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What do antigravity muscles do?

A

Hold the body up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How does the lateral pathways work?

A

Motor cortex directly activates spinal motorneurones and frees them from reflex control by communicating via nuclei of ventromedial pathways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What parts of the brain plan and control precise voluntary movements?

A

Primary motor cortex and pre motor areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What do UMNs in the cortex and brainstem target?

A

LMN in the spinal cord

Some also form circuits that control reflexes such as the stretch reflex and withdrawal reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Medial tracts in the spinal c ord control what?

A

Axial and proximal limb muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Lateral tracts in the spinal cord control what?

A

Distal limb muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Medial tracts from the brainstem control what?

A

Posture balance and orientating mechanisms

43
Q

Lateral tracts from the cortex control what?

A

Precise skilled voluntary movements

44
Q

Where is the primary motor cortex found?

A

The Precentral gyrus

45
Q

Where do the mosaic of premotor areas lie?

A

Rostrally

46
Q

On the motor homunculus, which part of the body is the most medial?

A

Toes

47
Q

On the motor homunculus, which part of the body is the most lateral?

A

Tongue (swallowing)

48
Q

Order of the body parts on the motor homunculus, from medial to lateral

A 
Toes
Ankle
Knees
Hip 
Trunk 
Shoulder
Elbow
Wrist
Hand 
Little finger
Ring finger
Middle finger
Index finger 
Thumb 
Neck 
Eyebrow
Eyelid and eyeball 
Face
Lips
Jaw
Tongue 
Swallowing
49
Q

What is penfield electrical stimulation for?

A

In epileptics used to decide brain areas to be spared surgically

50
Q

What area of the brain is the primary motor cortex?

A

Area 4

51
Q

What does area 6 contain?

A

Neurones that drive complex movements of either side of the body

  • premotor area
  • supplementary motor area
52
Q

What does the supplementary motor area innervate?

A

Distal motor units directly

53
Q

What does the pre-motor area innervate?

A

Reticulospinal neurones innervating proximal motor units

54
Q

Is the somatotropic motor map precise? Why?

A

No

Does not represent UMNs causing individual muscle movements

55
Q

What does microstimulation in specific areas of the primary motor cortex cause?

A

Coordinated movements of hand and mouth

Movements that bring hands into central space to insert/manipulate objects

56
Q

How is the mental image of the body in space generated?

A

Somatosensory input
Visual input
Proprioceptive input

57
Q

Where are decisions made about what actions/movements to take and their likely outcome?

A

Prefrontal or parietal cortex

58
Q

When do decision making neurones in cortical PMA fire?

A

BEFORE a movement (one second before)

59
Q

When do PMA “mirror neurones” fire?

A

When self or others perform specific actions - the movement is imagined and mentally rehearsed
When others make the same specific movement; this allows understanding of actions or intentions of others

60
Q

What may mirror neurones underpin?

A

Emotions

Empathy

61
Q

How is overall movement direction encoded?

A

By the integrated activity of all the neurones

62
Q

What does a change in body position cause? (Feedback mechanism)

A

Rapid compensatory feedback messages from the brainstem vestibular nuclei to spinal cord motor neurones to correct postural instability

63
Q

How do feedforward mechanisms work?

A

Before movements begin, the brainstem reticular formation nuclei (controlled by the cortex) initiate feedforward anticipatory maintenance of body posture

64
Q

What would cortical damage cause?

A 
Immediate flaccidity of contralateral muscles
Initial hypotonic "spinal shock"
Days later spinal circuits regain function 
Spasticity
- increased muscle tone
- hyperactive stretch reflex 
- clonus 
Loss of fine finger movements
65
Q

In Babinksis sign, what does extension indicate?

A

Both indicate incomplete upper control of spinal circuits

66
Q

What selects and initiates willed movements?

A

Basal ganglia

67
Q

Where does major subcortical input to area 6 come from? What is this input called and where does it arise from?

A

Ventral lateral nucleus in the dorsal thalamus

The input is called VLo and arises from basal ganglion

68
Q

What is the basal ganglia targets of?

A

Frontal Cortex
Prefrontal cortex
Parietal cortex

69
Q

What is the main component of basal ganglia?

A

Corpus striatum

70
Q

Features of corpus striatum

A

Includes two principle nuclei (caudate and putamen)

The input zone of the basal ganglia

71
Q

Where does corpus striatum receive input from?

A

All over the cortex via the corticostriatal pathway

72
Q

What information do the putamen and caudate receive?

A

Medium spiny neurones which contain excitatory (glutamatergic) cortical inputs on dendrites

73
Q

Features of the cortical axons in basal ganglia

A

Inhibitors (GABAergic) and project to globus pallidus and to substantia nigra pars reticulata

74
Q

When does the putamen fire?

A

Before limb / trunk movements

75
Q

When does the caudate fire?

A

Before eye movements

76
Q

What is the motor loop?

A

Cortex - basal ganglia - cortex

77
Q

What is the cortex to putamen?

A

Excitatory

78
Q

What is the putamen to globus pallidus?

A

Inhibitory

79
Q

What is the globus pallidus to VLo neurones?

A

Inhibitory

80
Q

What is the VLo to the SMA?

A

Excitatory

81
Q

What is the functional consequence of cortical activation of putamen?

A

Excitation

82
Q

Why does cortical activation of the putamen boost cortical excitation?

A

At rest globus pallidus neurones are spontaneously active and inhibit VL
Cortical excitation excites the putamen
Inhibits globus pallidus which therefore releases VLo which boots SMA activity

83
Q

What may cause a “go” signal” for voluntary movement?

A

When the SMA is boosted beyond a threshold level by activity coming through the basal ganglia funnel

84
Q

What can cortical excitation of the putamen act as?

A

A positive feedback loop focussing or funnelling activation of widespread cortical areas onto cortical SMA

85
Q

What is the direct pathway loop in the basal ganglia?

A

Acts as a positive feedback loop, a GO signal to the SMA in the cortex

  • enhances initiation of movements by the SMA
  • Globus pallidus neurones are spontaneously active at rest so they tonically inhibit (restrain) VL thalamus
  • input from the cortex releases this inhibition
86
Q

Function of the indirect pathway loop in the basal ganglia

A

Antagonises the direct route

87
Q

How does the indirect pathway loop in the basal ganglia work?

A

Striatum inhibits GPe (globus pallidus external) which then inhibits both GPi (GP internal) and STN (subthalamic nuclei)
Cortex excites STN; this excites Gpi; which inhibits the thalamus
Direct pathway selects specific motor actions, indirect pathway suppresses competing/inappropriate action

88
Q

What % of people > 60 y/o have parkinsons?

A

1%

89
Q

Presentation of parkinsons

A

Hypokinesia

90
Q

What is hypokinesia?

A

Slowness
Difficult to make voluntary movements
Increased muscle tone (ridigity)
Tremors of hand and jaw

91
Q

Pathology of Parkinsons

A

Degeneration of neurones in the substantia nigra (SN) and their dopaminergic (excitatory inputs) to the striatum
The depletion of dopamine closes down activation of focused motor activities that funnel through the thalamus to the SMA

92
Q

Function of dopamine in basal ganglia

A

Can enhance cortical inputs through the “direct pathway” and suppress inputs through “indirect” pathway

93
Q

Presentation of Huntingtons disease

A

Hyperkinesia
Dementia
Personality disorders
Chorea

94
Q

How do people get huntingtons?

A

Hereditary

95
Q

Features of chorea caused by Huntingtons

A

Spontaneous
Uncontrolled
Rapid flicks and major movements of no purpose

96
Q

Pathology of Huntingtons

A 
Genetic
Profound loss of 
- caudate
- putamen 
- globus pallidus
97
Q

What % of the brain does the cerebellum make up?

A

10%

98
Q

What % of total CNS neurones does the cerebellum contain?

A

50%

99
Q

Alcohol effect on cerebellum

A

Depresses cerebellar circuits

100
Q

Function of the cortico-ponto-cerebellae projection

A

Connects cortex, pontine nuclei and cerebellum

101
Q

What makes up parts of the huge ponto-cerebellae projection?

A

Layer 5
Areas 4 and 6
Somatosensory cortex

102
Q

Function of the cerebellum back to cortex via ventrolateral thalamus

A

Instructs direction, timing and force

103
Q

How does motor loop for voluntary movement through basal ganglia and VLo undergo ongoing refinement?

A

Involvement of feedback loop through pons, cerebellum, thalamus and back to cortex

Neuro Physiology (15 decks)

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