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Human Movement > Motor Control > Flashcards

Motor Control Flashcards

1
Q

What are the subdivisions of nervous system

A
  • central nervous system (brain and spinal cord)

- peripheral nervous system

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2
Q

What are the subdivisions of the peripheral nervous system ?

A
  • autonomic nervous system

- somatic nervous system

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3
Q

What are the subdivisions of somatic nervous system ?

A
  • sensory (afferent)

- motor (efferent)

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4
Q

What are the subdivisions of autonomic nervous system ?

A
  • sympathetic nervous system

- parasympathetic nervous system

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5
Q

Describe the functioning of somatic nervous system

A

It contains the nerves that carry sensory information from the body to the CNS and nerves that carry motor signals from the CNS to the skeletal muscles : it’s a two way system

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6
Q

Describe the functioning of autonomic nervous system

A

It’s involuntary.
It is involved in the regulation of internal environnement of the body as it carries signals from the internal organs to the CNS and from the CNS to internal organs : it’s a 2 way system.

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7
Q

Which system is involved in the flight of fight response and why ?

A

The sympathetic nervous system which plays a role in mobilizing energy resources (ex : reaction to strong fear)

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8
Q

Which system is involved in the rest and digest response ?

A

The parasympathetic nervous system as it acts to conserve energy (ex : food absorption will cause salivation, digestion and slow down the hear rate)

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9
Q

Name the specialized areas of the brain

A
  • cerebrum
  • cerebellum («little brain») : coordinating muscular activity, balance and talk
  • encephalum
  • mid brain
  • pons
  • medulla oblongata
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10
Q

At what age does the brain reach full maturity ?

A

25 years old

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11
Q

What is the average weight of the brain ?

A

1200 to 1500 g

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12
Q

What is the average energy expenditure of the brain ?

A

15/20%

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13
Q

What is the percentage of water in the brain tissue composition ?

A

78%

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14
Q

What is the speed of information in the brain ?

A

250 miles per hour

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15
Q

What is an afferent information ? What is an efferent information ?

A
  • afferent information is sent by other regions

- efferent information is sent toward other regions

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16
Q

What composes the gray matter ? What composes the white matter ?

A
  • gray matter : neuronal cells’ bodies

- white matter : neuronal axons

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17
Q

What are the basic structures of central nervous system ?

A
  • neurons and glial cells
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18
Q

What are the different types of glial cells ?

A
  • Astrocytes
  • oligodendrocytes
  • ependymal cells
  • microglia
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19
Q

What are the functions of astrocytes ?

A

(Most present)

  • maintain blood-brain barrier
  • maintenance of water and ion homeostasis
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20
Q

What are the functions of microglia ?

A
  • immune defense
  • phagocytes
  • destroy pathogens and dead neurons
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21
Q
  • what are the functions of olygodendrocytes ?
A
  • myelisation of axons
  • neurotransmission
  • synaptic connexion
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22
Q

What is a myelin sheath ?

A

An insulation barrier which allows a faster transmission of the information.

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23
Q

What is the equivalent of oligodendrocytes in the peripheral nervous system ?

A

Schwann cells

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24
Q

What is the function of ependymal cells ?

A
  • the creation and circulation of cerebrospinal fluid
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25
Q

Define dendrites

A

Branch projections of the neuron that conduct the impulses that are received from other neural cells to cell body. Dendrites receives the impulse and transmit it to the soma.

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26
Q

What happens at the axon hillock ?

A

The generation of action potential

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27
Q

What is the role of the axon

A

It’s a long slender projection of a neural cell that conducts neural impulses away from the cell body to other neurons. They can also connect directly to muscles or organs.

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28
Q

What is a synapse ?

A

The junction between the terminal aspect of a neuron and either another neuron or a muscle or a gland.

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29
Q

What are the basic types of neurons ?

A
  • unipolar
  • pseudo unipolar
  • bipolar
  • multipolar
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30
Q

What is an unipolar neuron

A

Only found in invertebrates, it has only one process emerging from the soma.

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31
Q

Pseudo unipolar neurons

A

One axon emerges from the som but is split in two. One end possesses dendrites, the other end possesses the synapse. It receives essentially sensory information and the cell body is always found in ganglion.

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32
Q

What is a ganglion ?

A

It’s a group of neurons’ cell bodies in the peripheral nervous system working as relay points and intermediary connexions between different neurological structures in the body, usually between the peripheral nervous systems and the central nervous system.

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33
Q

Describe the bipolar neuron

A

Two processes are coming out of the soma, one are dendrites, the other the synapse. It is not very common, mainly found in the olfactive epithelium and the retina.

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34
Q

Describe the multipolar neuron

A

Most common type of neuron. Present every where. 1 axon with many dendrites. Ex : motor neuron

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35
Q

Describe the phases of Action Potential

A
  • membrane is at resting state : - 70 millivolts
  • neurotransmitters bind to receptors : beginning of depolarization, towards 0 millivolts
  • depolarization threshold is reached at - 55 millivolts causing the opening of Na+ channels
  • cell is positively charged = rising phase of AP = depolarization
  • peak is reached at 40 millivolts causing the K+ channels to open, allowing K+ to flow out of the cells
  • repolarization is the descending part of axion potential
  • overshoot : neuron doesn’t go back to resting membrane yet = the cell is hyper polarized and it is impossible to fire the neuron again at this stage
  • K+ channels close causing the membrane to come back to resting state
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36
Q

What about resistance in neurons ?

A
  • small neurons (small diameter) displays more resistance : current is slower
  • big neurons (big diameter) displays less resistance : current is faster
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37
Q

Define voltage

A

Is the measure of potential energy generated by separated charges (= action potential)

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38
Q

Define current

A

The flow of electricity from one point to another

Current = voltage / resistance

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39
Q

What is a motor neuron ?

A

It’s a type of neuron that carries information from the brain or the spinal cord and is involved in regulating activity in muscles or glands.

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40
Q

What is an upper motor neuron

A

Originate from multiple areas of the brain and carrying the info about movement in a descending tract along the spinal cord to the muscles. As such, it makes a connexion with lower motor neuron.

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41
Q

What are the different types of lower motor neurons ?

A
  • somatic motor neurons : extending to skeletal muscles (movement + muscle tone) and cause voluntary movement or reflex
  • branchial motor neurons : muscles in the neck and head
  • general visceral motor neurons : involved in the autonomic nervous system
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42
Q

What is a lower motor neuron

A
  • Located in the brain stem or spinal cord
  • it receives inputs from the brain or the sensory neurons
  • innervates muscle fibers
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43
Q

What is a motor unit ?

A

It is composed of the motor neuron and all the muscle fibers in berated by that motor neuron. The number of muscle fibers innervated but the neuron is variable.

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44
Q

Describe the specificities of the motor unit

A
  • 1 motor neuron innervates the same types of muscle fibers
  • 1 muscle fiber has only one axon connexion
  • action potential travelling through that 1 neuron reaches all the muscle fibers it is connected to at the same time.
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45
Q

What type of somatic motor neuron innervates muscle fibers ?

A

Alpha motor neuron

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46
Q

What is the specificity of small motor unit ?

A

It encloses less muscle fibers than big motor units and small muscles allowing precise and small movements to happen.

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47
Q

What is the specificity of big motor units ?

A

Found in big muscles, providing big motions or requiring a lot of strength

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48
Q

Describe the muscles fiber Type 1

A

SLOW MOTOR UNIT

  • small red blood muscle : containing lots of mitochondria, well oxygenated
  • innervated by slow motor unit
  • generate small force, slowly
  • lasts long : fatigue resistant
  • required for posture

It is able to develop the same amount of strength up to and more than an hour

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49
Q

Describe the muscle fiber Type 2b

A

FAST FATIGABLE MOTOR UNIT

  • the motor unit is bigger than the type 1
  • it is less irrigated (pale muscle)
  • it provide large forces
  • it fatigues faster than type 1
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50
Q

Describe the muscle fiber Type 2a

A

FAST FATIGUE RESISTANT MOTOR UNIT

  • substantially more resistant to fatigue
  • generates about twice the force of Type 1
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51
Q

Explain the slow twitch vs the fast twitch

A

We will activate a specific type of muscle fiber depending on which type of movement we want to do.

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52
Q

How can we influence the strength that we generate with a muscle ?

A

Depends on
A) the force developed by the muscle fibers relying on :
- the frequency of stimulation up to tetanus
- the fiber length

B) the number of muscle fibers contracting simultaneously
C) the different types of muscle fibers activated

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53
Q

What is tetanus ?

A

The limit to which the muscle fiber can be stimulated

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54
Q

What is the brain stem ?

A

It’s the location of all cranial nerves involved in sensory organs and motor control of fascias.

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55
Q

What is the diencephalon ?

A

It is the «gate keeper» of the brain filtering informations. It has a neuroendocrine function served by the hypothalamus and it encloses the thalamus and the pituitary gland.

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56
Q

What is the cerebellum ?

A

50 millions neurons = 1/2 of all neurons.

Especially involved in motor learning as it activates to improve the movement, make it smooth and more efficient.

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57
Q

What are the 6 main structures of the brain ?

A

(- spinal cord)

  • medulla oblongata
  • pons
  • mesancephalon (mid-brain)
  • diancephalon (inter brain)
  • cerebellum
  • cerebrum (including : neocortex, basal ganglia, lambic system)
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58
Q

How many spinal nerves innervate each spinal segment ?

A

Cervical spine : 7 vertebrae 8 spinal nerves
Thoracic spine : 12 vertebrae 12 spinal nerves
Lumbar spine : 5 vertebrae 5 spinal nerves
Sacrum : 5 vertebrae 5 spinal nerves
Coccyx :1-4 vertebrae 1 spinal nerve

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59
Q

Where does the spinal cord ends inferiorly ?

A

L1-L2

The last part of the spine is innervated by caudal and spinal nerves

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60
Q

Regarding white/grey matter, what is the difference between the brain and the spinal cord ?

A

In the brain the grey matter is outside and the white matter is inside while in the spinal cord the withe matter is outside and the grey matter is inside.
Grey matter is composed of the somas and white matter is composed of the axons.

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61
Q

What are the 2 main tracts in the spinal cord ?

A
  • cortico spinal tract : motor fiber tracts

- antero/posterior spino thalami tract : sensory fibers tract

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62
Q

What is the function of the neuron joining the dorsal root of the spinal cord ?

A

They carry sensory information from the body to the spinal cord. Sending afferent information to the brain.

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63
Q

What is the role of neuron joining the ventral root of the spinal cord ?

A

Motor neurons carrying the motor information to the muscles. Sending efferent information to the body.

64
Q

What happens in the posterior horn of grey matter ?

A

It contains inter neurons and welcome neurons entering the ascending path carrying sensory info to the brain.

65
Q

What contains the anterior horn of the grey matter ?

A

Cell bodies of the motor neurons that activate skeletal muscles, these neurons are implicated in both voluntary and involuntary movements.

66
Q

What is the composition of white matter in the spinal cord ?

A

Bundle of ascending and descending fibers that carry sensory information to the brain and motor information to the body. Also called funiculi

67
Q

Describe the brainstem and its main functions

A

Composed of :

  • medulla oblongata
  • pons
  • mesancephalon (mid-brain)

Responsible for many basics system as breathing, consciousness, blood pressure, heart rate and sleep. Houses 10 of the 12 cranial nerves (the last 2 ones being associated with vision, providing motor and sensory function to tongue, pharynx, larynx).

68
Q

What are the main functions of medulla oblongata ?

A
  • associated with cardiovascular and respiratory functions such as keeping omeostasis in the cardiovascular function or generating breathing movement.
  • involved in reflexes such as coughing, vomiting, swallowing, sneezing.
69
Q

What are the effects of «decussation of the pyramids»

A

The right side of the brain controls the left side of the body

70
Q

What are the olives’ role ?

A

Composed of one big «olivary nucleus» they connect the brainstem to the cerebellum

71
Q

What is the role of the pons ?

A

It is the bridge between the cortex and the cerebellum

72
Q

What is the specificity of the mid brain

A

The mesancephalon includes the substantia nigra which is rich in dopamine

73
Q

What is the difference between cranial nerves and spinal nerves ?

A

They are purely sensory or motor or mixed, unless spinal nerves which are always mixed.

74
Q

Name sensory cranial nerves

A
  • optic
  • olfactory
  • vestibulocochlear
75
Q

Name the cranial motor nerves

A
  • oculomotor
  • accessory
  • hypoglossal
  • facial
76
Q

Name the cranial mixed nerves

A
  • trigeminal
  • glossopharyngeal
  • vagus
  • intermediate
77
Q

What is the role of the diencephalon ?

A

It encloses the thalamus and acts as a primary relay and processor for the sensory information and autonomic control. It is also a pathway to lymbic part (site of memory and motion) but also to the basal ganglia

78
Q

Describe the thalamus and its main role

A

There is one thalamus in each atmosphere.
It acts as a relay station : it is divided in a number of specialized nuclei (each nucleus has a specific function) so 1 specific stimulus will be processed by the corresponding nucleus and sent to the appropriate cortex area.
The thalamus decides which information becomes conscious, it helps us to focus on the information which is the most relevant.

79
Q

What are the anatomical subdivisions of the cerebellum and their roles ?

A
  • cerebrocerebellum : 2 hemispheres involved into planning movements and motor learning, and regulate coordination of muscle activation, also important is visually guided movements.
  • spinocerebellum
    —> paraverbal zone
    —> vermis
    Is involved in regulated movement by correcting errors. It also receives proprioceptive information.
  • vestibulocerebellum : is involved in controlling balance and ocular reflexes.
80
Q

What are the main functions of the cerebrum ?

A

Divided into right and left hemispheres on either sides of a longitudinal fissure, linked by the corpus callosum. It receives sensory information, processes it and regulates motor and conscious activity.
It also responds for a broad range of cognitive processes.

81
Q

Describe the basal ganglia

A

It is enclosed in the cerebrum and is composed of a group of subcortical nuclei. It is involved in motor control, motor learning, emotional behaviour, addictive behaviour and habits formation. It is composed of
- corpus striatum :
—> dorsal striatum : control over conscious movement
—> ventral striatum : associated with lymbic function of reward and aversion
- subtalamic nucleus
- substantia nigra

82
Q

Describe the lymbic system

A

It’s not a separate system but a collection of structures implicated in emotions (= emotional nervous system) behaviour, motivation, long term memory, olfaction, pleasure. It’s not really involved in motor control. It involves, amygdala, hippocampus, thalamus, hypothalamus, basal ganglia.

83
Q

What is the cerebral cortex ?

A

It is the outer layer of the cerebrum. It is made up of grey matter covering the white matter inside. It is subdivided into lobes.

84
Q

What are the lobes of the cerebral cortex and their role ?

A
  • frontal lobe : olfactory bulb, motor cortex responsible of planning and implementing movement
  • parietal lobe : processing somatic information
  • temporal lobe : processing and interpreting sounds
  • occipital lobe : implicated with vision
85
Q

What are the Brodmann areas ?

A

It’s an histological classification of the brain area. There are 52 Brodmann areas.

86
Q

Explain the 10/20 system

A

This system helps divide the cerebral cortex on the outside using reference points. It’s used in neuro researches to get to know where the parts of our brain stand by measuring the skull.
Useful when there is a trans cranial electrical stimulation device used.

87
Q

Define reflex

A

An action that is an inborn central nervous system activity, not involving consciousness during which a particular stimulus exciting an afferent nerves, provokes an immediate stereotyped response of the muscles or glands.

An involuntary and nearly instantaneous movement in response to a stimulus.

88
Q

What is the name the anatomical pathway of the reflex, describe it

A

It is called reflex arc :

  • an efferent (sensory) nerve
  • one or more interneurons in the central nervous system
  • an afferent (motor, secretory, secretory motor) nerve
89
Q

What are the 2 main types of reflex arcs ?

A
  • mono synaptic

- poly synaptic

90
Q

What is the output of a somatic reflex ?

A

The lower motor neuron in the ventral horn of the spinal cord that projects to the skeletal muscles.

91
Q

What is the output of an autonomic reflex

A

Smooth muscle fibers and pre/post ganglionic fibers

92
Q

Define muscle spindle

A

Delicate sensory receptor contained in almost every muscle that inform the central nervous system about changes in the length of individual muscles and the speed of stretching.

Thanks to this information, the CNS computes the position and movement in space of our extremities which is a requirement for motor control, maintaining balance and a stable gait.

Muscle spindle are modified muscle fibers, enclosed in a capsule of connective tissue that identifies the absolute changes in the muscle fiber length.

It’s a protective proprioceptor

93
Q

Define motor neuron

A

It’s a type of neuron that carries the information from the brain or the spinal cord and is involved in regulating the activities in muscles or glands.

94
Q

Name the different somatic motor neurons

A
  • alpha : involved in muscular contraction
  • beta
  • gamma : involved in the sensitivity of muscle spindles
95
Q

What is the Golgi Tendon Organ ?

A

It’s a protective propriocepor (= a type of sensory receptor that senses the changes in muscle tension.
It lies at the interphase between a muscle and its interchange known as the myotendinous junction.

96
Q

Give an example of stimulus activating both monosynaptic and polysynaptic reflex arcs

A
  • patellar tendon reflex where :
    • one output will cause muscle contraction = monosynaptic
    • the other output will cause antagonist muscle relaxation = polysynaptic reflex
97
Q

What is the golgi tendon organ reflex useful for ? What is it’s name ?

A

The myotatic inverse reflex exists to protect the muscle from excessively heavy loads by provoking the the muscle to relax and drop the load.

98
Q

What is reciprocal inhibition

A

It happens when the Golgi tendon organs causes a myotatic inverse reflex and inhibits the contraction. Then the other part of the pathway will activate the muscle to release the dangerous weight (for instance), the agonist muscle and prevent injury.

99
Q

What are the main differences between muscle spindles and golgi tendon organ ?

A

Muscle spindle :

  • feel the stretch
  • cause muscle activation
  • protects against over stretching or stretching too fast

GTO :

  • feel the tension
  • cause muscle inhibition
100
Q

What is specific in polysynaptic reflex, give an example

A

The receptor is not muscular but it’s a cutaneous receptor
The impulse goes from sensory to motor neurons and creates multiple synaptic connexions
Ex : The withdrawal reflex

101
Q

In lower limb, for instance, what happens to the other supporting leg when the first one goes through withdrawal reflex

A

The information crosses on the other side of the spinal cord and activate motor neurons controlling the unharmed leg so this leg is ready to receive the body weight (allowing the painful leg to withdraw) it is called the CROSS EXTENSOR REFLEX

102
Q

What is a rhythmyc movement ?

A

It’s a stereotyped motor action constituted by a repetitive series of the same movement (ex : chewing, swallowing, scratching, rhythmic contraction of flexors and extensors during locomotion…). Neural circuits supporting rhythmic movements are located in the spinal cord and brain stem.

103
Q

Considering rhythmic movements, what are the specificities of locomotion ?

A

Locomotion takes place in an unpredictable environment with irregularities and even if partly stereotyped (alternation of the 2 legs) it needs to be continuously modified and adapted to this environnement.
It is monitored by a neural network in the spinal cord called Central pattern generator
- locomotion is a purposeful, goal directed behaviour initiated by signals arising from volitional processes in the cerebral cortex and emotional processing in the lymbic system. It is accompanied by automatic controlled movement processes

104
Q

Define Central pattern generators

A

They are capable of producing rhythmic movements such as walking, swimming.
Supraspinal inputs play a major role not only in initiating locomotion but also in adapting the locomotor pattern to environmental and motivational conditions.

Sensory afférents involved in muscle and cutaneous reflexes have important regulatory functions in preserving balance and insuring stable phase transitions (especially in locomotion )

105
Q

Define central pattern generator

A

It is a neural network able to generate rhythmic movement schemes without physical input signals coming from peripheral receptors.
Each motor pattern has a specific CPG

106
Q

What does the experience of the decerebrated cat demonstrate ?

A
  • supraspinal commands are not required to generate gait motor pattern
  • the basic rhythmicity of locomotion is produced by neuronal circuits entirely based in the spinal cord
  • there is no influence of the motor cortex on motor pattern
  • rhythmic movement patterns can still happen without the brain and sensory informations
107
Q

What are the informations used to regulate gait ?

A
  • somatosenstivie signals
  • vestibular apparatus (balance)
  • visual
108
Q

What determines the tempo and the width of the stance ?

A

The proprioceptors

109
Q

What are the 3 categories of movement ?

A
  • reflexes
  • rhythmic movements
  • voluntary movements
110
Q

Describe the motor control central nervous system hierarchy

A

HIGH LEVEL
Function : strategy
Structures : association areas of neocortex and premotor area (plan motor activity) and basal ganglia (give the «go»)

MID LEVEL
Function : tactics
Structures : motor cortex (initiate motor activity) and cerebellum (tells primary motor cortex how to carry out the planned activity)

LOW LEVEL
Function : execution
Structures : brainstem and spinal cord

111
Q

Describe the way of sensory vs motor neuron in the spinal cord

A
  • motor neuron leaves the spinal cord via the ventral root
  • sensory neuron enter the spinal cord via the dorsal root
  • sensory and motor neurons merge to become the peripheral nerve
112
Q

Is the repartition of grey matter uniform in spinal cord ?

A

No, there is an increase of grey matter at C5/T1 (where the sensory input comes from and the motor outpost goes to the arms and the trunk) levels and L1-S3 levels (where the sensory input comes from and the motor output goes to the lower limbs)

113
Q

Define reticular formations (related to brainstem)

A

Groups of nuclei and related fibers in the brainstem responsible for :

  • control of level of consciousness
  • perception of pain
  • cardiovascular and respiratory systems regulations
114
Q

What are the pathways through which the motor cortex controls the motor neurons ?

A
  • cortico spinal tract

- cortico bulbar tract

115
Q

Describe the lateral cortico spinal tract

A
  • originate from 2 motor areas (primary cortex and pre motor cortex) and 3 sensitive areas
  • it crosses the midline at the level of the decussation of the pyramids and crosses the spinal cord on the contra lateral side
  • it descends into the dorso lateral column
  • it ends in the grey spinal cord
  • goes specifically to our hands and limbs = distal parts of the body and has a specific left/right processing
116
Q

Describe the anterior cortico spinal tract

A
  • it originates from region of the cortex controlling the trunk
  • fibers are not crossing
  • it shows bilateral terminations
  • primarily responsible for the gross and postural movements of the trunk and proximal musculature = controls the trunk near the midline
117
Q

Describe the cortico bulbar tract

A
  • run adjacent to the cortico spinal tract
  • terminates directly on alpha motor neurons in the brain stem
  • some axons decussation and some descend ipsilaterally resulting in bilateral descending control
  • directly innervate cranial nerves or through interneurons
118
Q

What are the anatomical subdivisions of the motor cortex

A 
Located in the frontal lobe of the cerebrum :
- primary motor cortex 
- secondary motor cortex 
	—> supplementary motor area 
	—> premotor cortex
119
Q

Define somatotopic organization

A

The motor areas of the cerebral cortex are organized in a somatotopic manner which means that specific motor cortical area controls specific of the contra lateral half of the body

120
Q

Describe the action of primary motor cortex

A

It controls individual movements or sequence of movements that require the activity of several muscle groups. Alpha motor neurons in the spinal cord in turn encodes the force of contraction of the muscle groups using the rate code and the size principle.

It encodes the parameters that define individual movements or simple movements sequences.

121
Q

How does the primary cortex encode information ?

A
  • it fires 5-100 milliseconds before the onset of a movement
  • encodes the force of the movement
  • encodes the direction of the movement
  • encodes the extend of the movement
  • encodes the speed of the movement
122
Q

How does the primary motor cortex encodes the speed of the movement

A

In a bell shape curve of velocity

123
Q

Describe the cerebellum in the tactic of performing a movement

A

When we want to move we send info to the muscles but also collateral information to the cerebellum. Then the cerebellum sends this information back to the primary motor cortex about required force, direction and duration.
This loop of feedback and change of motor plans allows us improve our movement.
This loop happens only for new movements. It is deactivated for known movements.

124
Q

What is the function of basal ganglia regarding strategy ?

A

Action selection = able to focus attention and emotional participation on a single event while suppressing all the other

125
Q

Regarding basal ganglia, name the 5 subcortical nuclei

A
  • caudate
  • putamen
  • globus pallidus
  • subtalamic nucleus
  • substantia nigra (pars reticula and pars compacta)
126
Q

What composes the afferent center of the basal ganglia ?

A
  • caudate
  • putamen
    Together named striatum
127
Q

What composes the efferent center of basal ganglia ?

A
  • globus pallidus

- substantia nigra (pars reticula)

128
Q

What is the function of the direct pathway involving basal ganglia ? How does it work (broadly) ?

A

It is a movement facilitator pathway. The striatum will inhibit the action of globus pallidus and substantia nigra pars reticula which ends up as an open gate for movement to occur.
In this pathway.
Substantia nigra pars compact secretes dopamin in the striatum to facilitate this activity of the direct pathway.

129
Q

What is the function of basal ganglia indirect pathway ? How does it work in broad terms ?

A

The subtalamic nucleus is sending and excitatory signal to the globus palludis and substantia nigra. We know that the efferent part of the basal ganglia inhibit activity of the thalamus.
So this activity of the indirect pathway is meant to antagonize the activity of the direct pathway and acts to keep unwanted movement from occurring.

130
Q

What perturbation is caused by a lesion in the premotor area, explain it

A

Apraxia + problem planning a specific movement

131
Q

What is the role of premotor area / supplementary motor area ?

A

Both are planning and executing actions based on internalized signals but the first is linked to sensory signals while the second is linked to internalized signals.
Supplementary motor area appears to be active in the planning of spontaneously initiated motor sequences independently from any external stimulus.
Promotor area appear to be active in programming movement provoked by sensory stimulus (stimulus-response context).

132
Q

What are the 4 signals of the premotor cortex ?

A
  • signals the preparation for movement (motor set neurons)
  • signals various sensory aspects associated with particular motors acts (mirror neurons)
  • is sensitive to the behavioural context of a particular movement
  • signal correct and incorrect actions
133
Q

What are the 2 role of supplementary motor area

A
  • responds to mentally rehearsed motor sequences

- transforms kinematic information into dynamic information

134
Q

Describe the feed forward control

A

Is anticipatory

Derives from the informations from our senses and experience

135
Q

Describe the feed back control

A

The signal picked up by the peripheral receptors is compared to the reference signal and the difference between the 2 (error signal) is used to regulate the motor output.

136
Q

Define skill

A
  • an activity or a task that has a specific purpose or a goal to achieve
  • an indicator of quality of performance
137
Q

Which questions do you ask (3) to assess motor skill ?

A
  • the extend to which to person can consistently achieve the goal of the task
  • the to which a person can achieve the goal of a task under a range of different conditions
  • what is the degree of efficiency
138
Q

Define motor skill

A
  • the voluntary control of movement to achieve a specific goal
    Motor skills have a goal, they are an indicator of performance and they are performed voluntarily.
    Skills have to be learnt/ re-learnt and they include movements
139
Q

Define motor performance

A

The observable production of a voluntary action or motor skill. The motor performance can fluctuate as it can be affected by motivation, fatigue, arousal and physical condition.

140
Q

Define motor development

A

The human development from infancy to old age with specific interest in issues related to either motor control or motor learning.

141
Q

Define motor learning

A

How we learn new skills. The consequence of motor learning is neuroplsticity.

142
Q

Give examples of motor skills classification

A
  • muscle mass involved
  • start and end of motion
  • environmental variability
  • cognitive involvement
  • Base of support
  • upper limb involvement
143
Q

What are the 3 factors impacting movement ?

A
  • the resources of the individual
  • the characteristics of the environnement
  • the nature of the task
144
Q

Why understanding task helps treatment ?

A

An understanding of tasks attributes can provide a framework for structuring tasks into at taxonomy. Tasks can then be sequenced from least to most difficult based on their relationship to a shared attribute.

145
Q

Describe 2 dimensional taxonomy

A

Also called Gentile’s 2 dimensional taxonomy.
It’s a multi dimensional classification of skill. It takes into consideration 2 dimensions :
- environmental context
- motor skill

146
Q

What are the 2 ways to measure motor skill performance ?

A
  • performance outcomes measures

- performance production measures

147
Q

What is the formula to calculate absolute error ?

A

AE = (S I Xi-T I) / N

Xi being the trial number
T being the target
N the total number of trials

148
Q

What is the formula to calculate constante error ?

A

CE = S (Xi-T) / N

149
Q

How to calculate Variable error ?

A

1) calculate average constante error

CE avg = S (Xi - T) / N

2) calculate variables error

VE = Racine (CEi -CEavg) squared / N

150
Q

Define reaction time

A

It the interval of time between the onset of a signal (stimulus) and the initiation of a response

151
Q

Define movement time

A

The interval between the initiation of a movement and the completion of the movment

152
Q

Name some devices used to measure performance production

A
  • electroencephalography
  • functional magnetic resonance imaging
  • near infrared spectroscopy
  • transcranial magnetic stimulation
153
Q

In EEG tracing what shows the curve ?

A
  • the amplitude of the curve under and above the horizontal axis shows the number of synchronized neurons.
154
Q

Why are motor control theories useful for our practice ?

A

A motor control theory can provide us a base of support for developing effective skill instructions and practice environments. If we know why people can adapt we can use this knowledge to develop practice to facilite this adaptation capacity.

155
Q

Describe the open loop control system

A

Movement control center —> instructions —> movement effectors
Contains all the informations required for movement execution —> Executes the complete movement —-> produce afferent feedback information but it’s not integrated by the movement control center.

156
Q

Describe the closed loop control system

A

Movement control center —> instructions —> movement effectors —> feedback —> movement control center
Contains informations to initiate the movement —> start movement executions —> produce afferent feedback information —>

157
Q

What aspect is lacking the the open loop control system and why ?

A

The feedback because :

  • it’s not required
  • it’s detrimental to performance
  • it’s not fast enoug

Human Movement (11 decks)

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