Motor Control Flashcards
(76 cards)
1
Q
what is motor control
A
the ability to regulate or direct mechanisms essential to movement
2
Q
what are you looking for when it comes to motor control?
A
- coordination of movements
- accuracy
- speed
- stability
- selectiveness
- smoothness of movements
3
Q
What does motor control rely on?
A
Complex and coordinated interactions between various parts of the central nervous system
4
Q
Are the three stages of motor control
A
Perception
Cognition
Action
5
Q
Describe the perception stage of motor control
A
Sensing, perceiving, interpreting
6
Q
Describe the cognition stage of motor control
A
Conceptualisation, strategy planning
7
Q
Describe the action stage of motor control
A
Activation and execution
8
Q
What do nociceptors detect?
A
pain
9
Q
What do thermoreceptors detect?
A
Temperature changes
10
Q
What do proprioceptors detect?
A
Movement
11
Q
What is the job of receptors?
A
To detect information, which is then transmitted to the spinal cord via sensory nerves (afferent nerves)
12
Q
What do muscle spindles detect?
A
Changes in muscle length
13
Q
What do Golgi tendon organs detect
A
Tension in the muscle
14
Q
What do both muscle spindles and Golgi tendon organ stimulate?
A
To reflex arc
15
Q
what does the vestibular apparatus detect
A
- montion
- spatial orientation
- Head position
16
Q
Where is auditory information sent?
A
Temporal lobe
17
Q
Where is vision information sent
A
Occipital lobe
18
Q
What is the somatosensory system?
A
Conscious perception of touch, pressure, pain, temperature, position, movement, and vibration
19
Q
Describe the stretch reflex
A
- relies on muscle spindle information
- is triggered when a muscle is lengthened
- it is designed to prevent overstretching of the muscle by causing reflex contraction of the length and muscle
20
Q
how does stretch reflex occur
A
- in the spinal cord, the sensory impulses directly excite a single motor and you’re on leading to the agonist muscle
- the sensory impulses also stimulates an inhibitory association neuron in the spinal cord. This neuron inhibits the mating neuron, leading to the antagonist.
- reciprocal innovation results when the stretching muscle in the opposing muscle relaxes
21
Q
Describe the tendon reflex
A
- relies on Golgi tendon organ information
- is triggered when tension is building up.
- this is designed to prevent hearing of a muscle by causing a reflex relaxation of the muscle
22
Q
Explain how the tendon reflex works
A
- receptors respond to muscle tension via the Golgi tendon organ
- increased tension stimulates receptors which increases nerve impulses to the spinal cord
- this causes the muscle to relax by decreasing the nerve impulses to the spinal cord, so inhibits the agonist and activates the antagonist
23
Q
How is sensory information, processed and refined before sending to the motor cortex and muscles
A
Done through the cortical association area:
- sensory processing in the thalamus
- basal ganglia
- Cerebellum
24
Q
What happens once a movement is planned
A
It is supplied as a signal in a feedforward manner to be executed
25
What happens once a movement has started
Receptors can provide feedback about the movement and allow for signals to be altered and refine the movement
26
Which part of the brain plays an important role in relaying sensory information to the cerebral cortex
The thalamus
27
Where is sensory information organised
In the sensory homunculus
28
What are the different roots of the basal ganglia?
Direct pathway (excitatory)
Indirect pathway (inhibits, unwanted movement)
29
What is the basal ganglia influenced by?
Dopamine
30
What is the basal ganglia involved in?
- planning and control of complex motor behaviour
- initiating movement through outputs to supplementary motor areas
- prevents unwanted movements
31
Why does death of dopamine containing cells in the brain cause Parkinson's disease symptoms?
There's not enough dopamine to regulate the direct and indirect pathways which causes an unbalanced
32
Why is the cerebellum described as having an "auto pilot function"
Cerebellum continually compares the higher brains intention with the bodies performance and send out messages to initiate the appropriate corrective measures, e.g. take longer step to avoid tripping
33
What does the cerebellum control?
- balance
- coordination
- correction of movement
- comparator
34
What symptoms might you observe in someone with cerebellar damage?
- balance problems
- gait disorders
- difficulties in coordination resulting in ataxia
- uncoordinated movements
- imbalance
- speech problems(dysarthria),
- visual problems (nystagmus)
- vertigo as a part of the vestibulocerebellar system.
35
What is the role of the premotor cortex?
Assist with proximal, preparation and control of distal movements (e.g.shoulder movement for reaching to grasp objects)
36
What is the role of the supplementary cortex?
- coordinates bilateral movements e.g. clasping hands
- assist in assembly of central motor programs
37
What is the role of the motor cortex?
- it's interacts with sensory processing areas, basal ganglia, and cerebellum, to identify where we want to move, to plan the movement and execute our actions
- it initiates movements on contralateral
38
What symptoms you observe in someone with motor cortex damage?
- Weakness or paralysis
- Impaired coordination
- Spasticity
- Loss of voluntary movement control
- exaggerated or diminished reflex responses.
39
What are spinal tracts
Your pathways within the spinal cord that carry information to, and from the brain/body
40
What is an ascending spinal tract?
Sensory pathways that carry somatic sensory information up to the brain
41
What is a descending spinal tract?
Motor pathways that send information from the brain to the spinal cord
42
What are the three conscious ascending spinal tracts
- fasciculus cuneatus (supplies proprioception and vibration info to lower limbs)
- gascuculus gracilis (supplies proprioception and vibration info to upper limbs)
- spinothalamic tract (pain, temperature, pressure info)
43
What is the unconscious ascending spinal tract?
Spinalcerebellar
44
What are the pyramidal descending spinal tracts?
pyramidal tract: in cerebral cortex - conscious control of movement
- corticospinal: fine, skilled, consious movement (helps produce output via motor cortex)
- corticobulbar: movements of the face
45
describe the extrapyramidal descending spinal tracts
extrapyramidal (in brainstem - unconscious control of movement)
- vestibulo spinal: increase extensor tone, inhibits flexor tone
- rubrospinal - decreases extensor tone, inhibits flexor tone
- recticulo spinal: regulation of vuluntary movement
- tectospinal - postural adjustments to visual stimuli
46
How are motor programs learned and refined?
Repetitive use
47
Explain how most programs are learned and refined
- ongoing movement is detected by proprioceptors muscles and joints and feedback control allows corrections to be made whenever of the outcome does not match the goal
- overtime this feedback will influence feedforward signals designed by the cortex
48
What are features of the early cognitive phase of motor learning?
- trial and error
- repetition
- performance-based focus
- person needs to work out what's relevant and organise a movement pattern that leads to successful task completion
- multiple regions involved: cerebellum, visual and pre-frontal cortices
- extrinsic feedback – hands-on, verbal, visual
49
What are the features of the autonomous phase of motor learning?
- automatic
- Motor programs are stored
- Cognitive demand decreases
- effortless
- primarily motor cortex
- intrinsic feedback
50
What are the features of the associative phase of mator learning?
- Learning how to perform a skill, refining and adapting
- intrinsic feedback
- more outcome based
51
Define Neuroplasticity
The ability of the brain and nervous system to change structurally and functionally as a result of input from the environment.
RELEARNING
52
How does Neuroplasticity occur?
Neurons in the brain sprout and form synapses.
A
s the brain processes, sensory information frequently use synapses are strengthened, while unused synapses are weakned
53
What is synaptogenesis?
The formation of synapses
54
What are the principles of Neuroplasticity?
1. Use it or lose it: you're all connections lose strength when they are not being used
2. Use it and improve it.: neural pathways grow stronger than more they are used
3. Specific: your brain forms a specific circuitry response to specific activities
4. Salience Matters: brain exercises must be meaningful to you in order to yield lasting change
5. Transference: working to improve one skill may transfer its benefits to enhancing others
6. Interference: neuroplastic changes that result from maintaining a bad habit can interfere with learning and adopting a new good habit
7. Time matters: it takes avrying amounts of time for the brain to change depending on how complex or foreign the new behaviour or skill is to you
8. Age matters: younger brains are more plastic but neurogenesis and plasticity continue at any age and phase of life
9. Repitition matters: consistency is the key to building new synapses and solidifying new skills
10. Intensity matters: neuroplstic changes result from incremental progressive challenges to elicit a positive growth response
55
what are some key principles on how we can influence motor learning
- increase feedback
- proprioceptive input
- facilitation
- normal movement
- repitition and practice
- whole and part task practice
consider the individual, task and environment
- keep it functional
56
how is motor movements controlled
- cerebrum and basal ganglia are essential for successful motor performance
- they project directly into upper motor neurons
- these upper motor neurons then project to lower motor neurons which then stimulate muscle activity
- continual sesnory feedback is provided to inform the brain about the bodies position and movement
57
where are upper motor neurons located
cerebral cortex and brainstem
58
what are upper motor neurons
first order neurons which are responsible for carrying the electrical impulses that initiate and modulate movement.
59
what do upper motor neurons synapse directly onto
lower mototr neurons
60
what are lower motor neurons
transmit impulses via spinal peripheral nerves or cranial nerves to skeletal muscles
61
what are the 3 types of lower motor neuron and what target do they innervate
- branchial - cranial nerves
- visceral - autonomic nervous system (smooth muscle and glands)
- somatic - skeletal muscle
62
what do upper motor neurons excite
alpha and gamma motor neurons
63
what are the negative problems of upper motor neurons
lack of excitation means less stimulus to the lower motor neurons and therefore less/ no activity
leads to:
- weakness
- sensory loss
- hypotonia
- fatigue
64
what are the positive probelms of nupper motor neurons
excition with reduced inhibition
so
- inscreased tone
- hyperreflexia
65
what is spasticity
abnormally high muscle tone, which often affects antagonistic muscle groups
66
what is spasticity dependent on
amplitude and velocity
speed and force
67
how is spasticity best assessed
using rapid movements of the relevant joint to effect muscles involved.
when a threshold velocity, angle, or amplitude is reached then a sudden increase in tone can be detected as a characteristic 'catch'
68
how is spasticity shown in upper limbs
affects flexors
69
how is spasticity shown in the lower limbs
affects extensors
70
what are common adult spasticities in the upper limb
flexed elbow
clenched fist
flexed wrist
71
what are common adult spasticities in the lower limb
equinivarus foot
plantar flexed foot or ankle
flexed toes
72
define rigidity
where the increased tone remains constant throught the range of moevement
73
how can rigidity be detected
can be detectable with very slow movements
74
in what muscles is rigidity present
equally present in flexor and anxtensor muscles so has a 'uniform quality' in all directions so is often refered to lead-pipe rigidity
75
why can there be cogwheeling type of rigidity
rigidity frequently rises in diseases of the basal ganglia so a tremor can coexist
76
