Movement Control Flashcards
What 5 elements aid in postural stability
How do they do this
What can happen to these elements when you don’t use them?
POSTURAL CONTROL VIA REFLEXES
- ay coactivation
- changes sensitivity of spindles by changing proportional contractions
Postural sway
-dynamic spindle control
Vestibular
-input from vestibular apparatus => vestibular nuclei => SC => reflex ext, flexor innervation
Visual
-eye => LGN => sup coll =(TST)=> SC
Pressure
-skin pressure receptors, especially in feet
These reflexes can be reset
What is tabes dorsalis
What are the consequences of this
Loss of pressure receptors in the feet
-close eyes => fall
What 3 elements must you have before you even start thinking about moving
-where do you get feedback from
TONE => POSTURE => BALANCE
- visual
- vestibular
- proprioception
What is the 1st step in movement
What part of the brain is needed
What is the blood supply
What happens if this region is damaged
-how can it be damaged
Prefrontal cortex
-idea and motivation
ACA
Vulnerable to head injury => lose motivation to move
What is the 2nd step in movement
What 2 brain parts coordinate this
What is the blood supply
What happens if these regions are damaged
Premotor cortex
- planning
- apraxia, dyspraxia
Supplementary motor cortex
- programming
- akinesia, bradykinesia, hypokinesia
MCA, ACA
What brain region supplies sensory info to the premotor and supplementary motor areas
What is the blood supply
What happens if this region is damaged
Post parietal
- analysis of sensory info from visuals
- apraxia, dyspraxia
MCA
What brain region is involved in both the retrieval of motor memory and error corrects during movement
What is the blood supply
What happens if this region is damaged
Cerebellum
- motor memory, balance
- coordinates motor commands and proprioceptive feedback and corrects errors
Dysmetria (faulty error correction)
Ataxia (errors in mv)
Asynergia (faulty coordination)
Intentional tremor (Parkinsons)
MS (affects myelinated neurones
SC
AIC
PIC
What brain region is involved in the programming of movement
-what specifically does it affect
-how does it do this
What is the blood supply
What happens if this region is damaged
Basal ganglia
- amplitude and frequency of contractions programmed via many nuclei
- direct and indirect pathway
Parkinsons
- chorea, athetosis
- resting tremor
- akinesia/bradykinesia/hypokinesia
MCA, ACA, AchA
What brain region carries out the movement after planning and programming
- how does it do this
- describe the route of the fibres and the respective blood supplies
Primary motor cortex (CST)
-MCA, ACA
Internal capsule
- post limb (peripheral) MCA + AchA
- genu (face) MCA
SC
-AH => peripheral nerve => NMJ
Where do we receive sensory feedback from to stop the movement
-how?
Visual Vestibular Peripheral -spindles, GTO -joint -cutaneous pressure
What can happen when the motor cortex, CST is damaged
Flaccid paralysis (damage in cortex?)
- acute => contralateral paralysis
- chronic => motor cortex reorganization and extrapyramidal dominance
Spastic paralysis (damage in UMN)
- withdrawal reflex dominant
- increased a motor activity => increased stretch reflex