Motor Control 1 Flashcards
Voluntary movement uses a functional hierarchy with 3 levels, what are these 3 levels?
What is the function of the high level of the functional hierarchy of voluntary movements?
Strategy
What is the function of the middle level of the functional hierarchy of voluntary movements?
Tactics
What is the function of the low level of the functional hierarchy of voluntary movements?
Execution
What structures are involved in the high level of the functional hierarchy of voluntary movements?
Association neocortex
Basal ganglion
What structures are involved in the middle level of the functional hierarchy of voluntary movements?
Motor cortex
Cerebellum
What structures are involved in the low level of the functional hierarchy of voluntary movements?
Brain stem
Spinal cord
What does strategy mean in terms of voluntary movements?
The goal and the movement strategy to best achieve this goal
What does tactics mean in terms of voluntary movement?
The sequence of spatiotemporal muscle contractions to achieve a goal smoothly and accurately
What does exectution mean in terms of voluntary movements?
Activation of motor neuron and interneuron pools to generate goal-directed movement
How is the brain connected to the spinal cord?
Lateral pathways
Ventromedial pathways
What do lateral pathways of the spinal cord control?
Voluntary movement of distal muscles
Lateral pathways of the spinal cord are under the control of what?
Direct cortical control
What do ventromedial pathways control?
Posture and locomotion
Ventromedial pathways of the spinal cord are under control by what?
Brain stem control
What are examples of lateral pathways?
Corticospinal tract
Rubrospinal tract
What are examples of vestromedial pathways?
Vestibulospinal tract
Tectospinal tract
Pontine reticulospinal tract
Medullary reticulospinal tract
What does CST stand for?
Corticospinal tract
What does RST stand for?
Rubrospinal tract
What is the longest and largest tract of the spinal cord?
Corticospinal tract (CST), with about 1 million axons
Where does the corticospinal tract originate?
2/3 in areas 4 and 6 of the fontal motor cortex
Rest is somatosensory
Does the corticospinal tract decusscate? And if so, where does this occur?
Yes it does, at the medulla/spinal cord junction so the right motor cortex controls the left side and vice versa
Where do axons of the corticospinal tract synapse?
Ventral horn motor neurons and interneurons to control muscles voluntarily
Where does the rubrospinal tract originate?
Red nucleus of midbrain and receives inputs from same cortical areas as CSF (2/3 if areas 4 and 6 of frontal motor cortex, rest is somatosensory)
What do lesions of the corticospinal and rubrospinal tracts cause?
Fine movement of arms and hands lost
Cannot move shoulders, elbows, wrist and fingers independently
What happens if lesions only occur in the corticospinal tract and not both the corticospinal and rubrospinal tract?
Deficits are seen for a few months, then functions reappear as they are taken over by the rubrospinal tract
For the rubrospinal tract, what side of the brain controls what side of the body?
Decussates above between medulla and midbrain so controls contralateral half of body