Wk 5 - Motor Control Flashcards

1
Q

Levels of the motor system, from muscle to neocortex (x7)

A
Spinal motor units
Brain stem motor nuclei
Cerebellum
Basal ganglia
Primary motor cortex
Secondary motor cortex
Association cortex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the characteristics of the motor system model (x5)

A

Parallel, hierarchical, circuit
Discrete functional areas
Sensory feedback up each level and back again (modulates output)

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

Lowest level of the motor system hierarchy is (name and describe x1)

A

motor unit = motor neurone and the muscle fibre(s) it innervates

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

Point of muscle innervation is (Name and describe x1)

A

Neuromuscular junction: motor end plate is where axon branches to synapse with muscle

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

NT for muscular activation is… (x1)

A

Ach

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

Two descending motor pathways are…

A

Dorsolateral tracts

Ventromedial tracts

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

Two types of dorsolateral tracts (in descending motor pathway)

A

Corticospinal tracts

Corticorbrospinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
Dorsolateral tracts of descending motor pathway terminate (x2)
And control (x1)
A

Contralateral half of spinal cord
Sometimes directly on motor neuron
Movement of distal limbs

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

Lawrence and Kuypers 1968 transected dorsolateral corticospinal tracts in medullary pyramids of monkeys, and found… (x3)

A

Could stand, walk and climb
But not other activities – reaching for objects, independent finger movement
(still proximal limb function)

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

Corticospinal tracts (descending motor pathway, dorsolateral tract) are (x4)

A

Direct pathway from cortices,
Through medullary pyramid (where they cross over to gives contralateral control),
To dorsolateral portion of spinal cord,
Then distal limb muscles

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

Coriticorubrospinal tracts (descending motor pathway, dorsolateral tract) are (x4)

A

Indirect pathways from cortex
Through red nucleus (crossover occurs here),
Down to nuclei of cranial nerve motor neurons (splitting out to contralateral facial muscles),
Before continuing to contralateral distal limb muscles

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

Two types of ventromedial tracts (in descending motor pathway)

A

Ventromedial corticospinal tracts

Cortico-brainstem-spinal tracts

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

Ventromedial tracts (describe x1, location x1, and function x 3)

A

More diffuse;
Axons innervate interneurons in several spinal cord segments;
Do the trunk and upper legs,
And posture and whole-body movements,
And limb movements involved in those activities

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

Lawrence and Kuypers 1968 transected ventromedialtracts in monkeys, finding (x2)

A

Postural abnormalities and impaired walking and sitting,

But could pick up food and small objects

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

Ventromedial corticospinal tracts (descending motor pathway, ventromedial tract) are (x3)

A

Direct pathways from cortex
Down to ipsilateral ventromedial portion of spinal cord (the forward centre of spine),
Then become diffuse to trunk and proximal limb muscles

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

Cortico-brainstem-spinal tracts (descending motor pathway, ventromedial tract) are (x7)

A

Indirect path from cortex,
Through tectum,
Then reticular formation, vestibular nucleus and cranial motor nerves;
Then bilaterally to ventromedial spinal cord,
And proximal limb muscles

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

Functions of the basal ganglia remain elusive because… (x3)
and are therefor termed (x1)

A

High number of structures,
Each nucleus can be inhibitory or excitatory – modulate each other
So difficult to isolate one structure/define its functions
Complex heterogenous interconnected nuclei

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

The cerebellum/’little brain’ receives input from (x2)

And feedback from (x2 systems plus functions)

A

Primary and secondary motor cortex
Somatosensory – vision, touch, hearing, smell; and
Vestibular – which way your pointing, how fast you’re moving

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

The cerebellum/’little brain’ is important for (x5)

A
Learning of routines
Navigation, 
Walking/gait – smooth movements, 
Speech and 
Balance,
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Functions of the basal ganglia/’mysterious basement’ remain elusive because… (x3)
and are therefor termed (x1)

A

High number of structures,
Each nucleus can be inhibitory or excitatory – modulate each other
So difficult to isolate one structure/define its functions
Complex heterogenous interconnected nuclei

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

The cerebellum/’little brain is important for (x6)

A
Learning of routines - fine-tuning and learning functions, 
Navigation, 
Cognitive functions of routines too, 
Walking/gait – smooth movements, 
Speech and 
Balance,
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Dysfunction of the cerebellum can lead to (name and symptoms x2)

A

Cerebellar ataxia
Wide-based gait
Stumble a little side to side to keep balance

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

Function of the basal ganglia (x2)

And is important for… (x1 plus 3 egs)

A

Modulate movement, plus Cognitive functions

Habitual/implicit responses/routines, eg instruments, typing, dancing

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

Indirect pathways of the basal ganglia run… (x2)

A

From primary motor cortices,

Also to thalamus

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

Direct pathways from the basal ganglia run… (x4)

A

Through thalamus,
Then supplementary motor area,
And on to primary motor cortices
(connected by direct pathway through corpus callosum)

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

The supplementary motor area has turned out to be… (x2)

Plus eg

A

Several areas, acts as gatekeeper
(actions selected at lower levels, then released by supplementary to primary areas)
All objects on your desk elicit potential for action, appropriate ones get released, others get inhibited

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

Direct and indirect pathways from the basal ganglia depend on (x1)
Whose connections can be… (x2)

A

Dopaminergic connections from substantia nigra
Excitatory OR inhibitory:
Output of one nucleus either excites (enhances) or inhibits (suppresses) the output of the next nucleus

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

An imbalance in the system from the basal ganglia can lead to (x1)

A

Parkinson’s disease

29
Q

The mechanisms of Parkinson’s disease (x4)

A

Putamen in basal ganglia get connections from substantia nigra compacta (compact black stuff)
Receptors in the putamen – D1 are direct, enhancing, D2 are indirect, inhibiting –
Connections not functioning properly,
Affecting what info goes forward in the system = impaired selection and inhibition of actions/extra or reduced movement

30
Q

In Parkinson’s visible loss of black substantia nigra neurones in basal ganglia are due to (x4)

A

D1 (excitatory receptors of putamen) not getting boosted anymore
D2 (inhibitory receptors of putamen) has more pit stops to nuclei along way to thalamus =
Enhanced at one nucleus, or dampened down (so staggers progression of signal)
Unused pathways = neurone death

31
Q

Name and describe common positive Parkinson’s symptoms (x5)

A

Tremor - in resting head or limbs (starts in distal limbs, progresses to whole body).
Rigidity - too much movement (muscle in full use); = postural problems, loss of righting reflexes
Cogwheel rigidity – rigidity plus tremor; smooth movement, rigid section, then release
Leaning – muscles that hold us up affected through middle of disease
Postural Hypotension – lightheadedness, dizziness; many falls

32
Q

Name and describe common negative Parkinson’s symptoms (x7)

A

Hypokinesia - reduction in spontaneous movement
Akinesia - slow initiation of movement
Progressive slowing or freezing during a movement, and
Reduced scale: micrographia; small steps; reduced arm swing
Postural instability = many falls
Dull weak voice, slow speech
Mask-like expression = social isolateion

33
Q

L-Dopa is used to treat (x1)

Plus side-effects (x9)

A
Parkinson's•	Hypotension = More dizzy
•	Cardiac arrhythmia 
•	Nausea
•	Disorientation, confustion
•	Affect
•	Auditory/visual hallucination
•	Poor working memory
•	Paradoxical movement problems: Dyskinesias at peak dose; Extra movements at end of dose (when it wears off); on-off cycles; freezing
•	Eventual drug failure
34
Q

L-Dopa is used to treat (x1)

Plus side-effects (x9)

A
Parkinson's•	Hypotension = More dizzy
Cardiac arrhythmia 
Nausea
Disorientation, confusion
Affect
Auditory/visual hallucination
Poor working memory
Dyskinesias at peak dose; Extra movements at end of dose; on-off cycles; freezing
Eventual drug failure
35
Q

Huntingtons’ disease is named after researcher who described three specifics of disorder…

A

Hereditary nature: Autosomal dominant with complete lifetime penetrance, chromosome 4
Manifestation in adulthood
Tendency to ‘insanity and suicide’

36
Q
Huntinton's disease is due to (x1)
Resulting in (x2 neural damages)
A

Destruction of GABAergic (and some cholinergic) neurones in striatum (caudate and putamen, and some globus pallidus)
Progressive striatal atrophy
Defective metabolism precedes loss of tissue

37
Q

Initial symptoms of Huntington’s disease are usually (x1 plus 4 egs)

A
Affective
Depression
Anxiety
Irritability
Aggression
38
Q

Following initial affective symptoms, Huntington’s manifests in… (x10)

A
Restlessness, 
Clumsiness, 
Poor coordination, 
Forgetfulness 
Personality changes
Altered speech and writing, 
Bradyphrenia and bradykinesia (slow thought and movement)
Poor motor dexterity, unsteadiness, reduced speed
Athetosis (slow, writhing movements), 
Chorea (abnormal involuntary movement)
39
Q

Athetosis (slow, writhing movements), chorea (abnormal involuntary movement) in Huntntington’s patients… (x4)

A

Appear fragments of normal behaviours
Involve multiple joints, thus resemble voluntary action
Briefly suppressible, decrease during sleep
Increase with stress and voluntary movements like walking

40
Q

Neuropathology of Huntington’s disease shows… (x1)

A

Caudate nucleus shrunk to sharp thin strip, below the ventricle = ventricular enlargement

41
Q

Imaging studies of Tourette’s sufferers show (x2)

A

Limbic and paralimbic involvement – swearing is very emotional, hence the swearing in Tourette’s

42
Q

Symptoms of Tourette’s include… (x10)

A

Intermittent vocal and motor tics
Otherwise normal motor & sensory activity
Normal cognition
Echolalia – repeating the words of another
Coprolalia - swearing
Involuntary
Partly suppressible
Anxiety increases
Sleep deprivation increases
Premonitory sensory phenomena – feeling of knowing a tic is coming

43
Q

Tourette’s syndrome stems from (x1)

A

Imbalance of GABAergic activity in basal ganglie

44
Q

Management of severe Tourette’s is achieved with (x1 plus 2 egs)
But…(x2)

A

Neuroleptics such as haloperidol and risperidone
Dampen all sensory and neuronal function, not specifically motor,
So get cognitive deficits too, unable to function through daily life

45
Q

The primary motor cortex is located (x1)

And functions as (x2)

A

Precentral gyrus of frontal lobe
Major hub of convergence of cortical motor signals
AND one of major outgoing point of signals

46
Q

Damage to the primary motor cortex can result in (name x1 and describe x2)

A

Hemiplegia –

Weakness (loss of power) in the body part represented by that site; Affects contralateral body part

47
Q

The secondary motor cortex provides (x1)

plus input and output to… (x2)

A

Higher level of control than primary
Input from association cortex in parietal areas
Output to primary motor cortex

48
Q

The secondary motor cortex consists of (x5)

A
preSMA – pre-supplementary motor area
SMA
Dorsal premotor
Ventral premotor
3X cingulate motor areas (at least 2 in humans)
49
Q

The secondary motor cortex is responsible for

A

Programming of specific patterns of movement, with input from the dorsolateral prefrontal cortex

50
Q

The sensory motor cortex is (x1)

And is located in (x1)

A

The highest level of our diagrammatic model…

Posterior parietal lobe

51
Q

The sensorimotor association cortex gets input from (x1)

And is responsible for… (x3)

A

More than one sensory system
Integrates knowledge of (position of) objects
Knowledge of position of body parts
Directs attention

52
Q

Damage to inputs to the sensorimotor association cortex can lead to (x2)

A

Ataxia and impaired body representation

53
Q

Damage to outputs of the sensorimotor association cortex can lead to (x2)

A
Apraxia
Contralateral neglect (not interacting with that side of space)
54
Q

The dorsolateral prefrontal cortex is located (x1)
Is responsible for (x2)
Gets input from (x1)
And outputs to (x3)

A

In front of premotor cortex
Decision to make an action
Not the action itself, or processing of target object
Input from posterior parietal cortex
Output to secondary and primary motor cortex, frontal eye fields

55
Q

The sensorimotor association cortex outputs to (x3)

A

Dorsolateral prefrontal association cortex
Secondary motor cortex
Frontal eye fields

56
Q
Ataxia is (x1)
And characterised by (x4)
A
Inability to use visual information to guide movement of hands
More severe in peripheral vision
Visual fixation preserved
Incorrect/awkward movements
Errors in accuracy (over/undershoots)
57
Q
Apraxia is (x1)
And is characterised by
A

Inability to move parts of the body in a purposeful manner

Disorder of skilled movement resulting from neurologic dysfunction

58
Q

Intrinsic spatial coding is Integral to (x1)

A

Knowing what our own body parts are doing

59
Q

Intrinsic spatial coding is Integral to (x2)

A

Knowing what our own body parts are doing

Planning and executing movements when body part obscured from vision

60
Q

Wolpert’s model of the basic components of a motor control system - three states

A

Desired, predicted and estimated actual states, connected directly through comparators

61
Q

Draw copies of Wolpert’s model of motor control system!

A

Go do it!

62
Q

You can’t tickle yourself because… (x2)

A

You know what’s coming

Cortical suppression shows in scanner when self-tickling

63
Q

Alien/anarchic hand synrome occurs quite commonly after… (x3)

A

Corpus collosum lesions,
Damage through twisting corpus collosum (head impacts),
Parietal lobe lesions

64
Q

According to Wolpert’s model of motor control, alien/anarchic hand syndrome occurs because of.. (x4)

A

Breakdown in the model between desired state and controllers:
Command for desired state isn’t executed properly, system left to mercy of affordances
So irrelevant actions not suppressed
Then predictor doesn’t go to parietal lobe, and patient gets erroneous template of actual movement

65
Q

Mirror neurons are…

A

Those that fire both when performing an action and when seeing another perform the same

66
Q

Gallesse, Rizolatti et al 1990s found that mirror neurons in monkeys resond (x4)

A

To sight of goal-directed actions only
As long as goal is achieved, even if it is out of sight
To sound of an action (multimodal)
When action is performed by an agent (hand-object interactions, not to tools) - ????? Recently overturned

67
Q

The action observation system is…(x1)

And in the human brain is a network consisting of (x5)

A

The remit of mirror neurons
Inferior parietal lobule,
Inferior frontal gyrus; and
Superior temporal sulcus/Middle temporal gyrus, premotor area

68
Q

Considerations of the action observation system (x6)

A

Action GOALS, rather than action per se
Non-human models CAN elicit action obs effects
Context matters
Experience matters - Long exposure to eg watching a robot will lead to same thing as watching human
Individual differences matter
Females are more prone to effects

69
Q
The hearing-doing action observation system is highly dependent on... (x1)
For instance (x3)
A

Individual’s motor repertoire:
Not just actions, also trained/untrained sequences
Music you’re familiar with elicit this meaning/knowledge
Experience-specific, eg watching dancing of opposite gender doesn’t activate action-observation system, while same gender does