Physiological Basis of Motor Control Flashcards
1
Q
Movement arises from the interaction of what 3 internal systems
A
- Cognitive system
- Perception Systems
- Action systems
2
Q
What steps in the movement process are each system responsible for
A
- Perceptual/Cognitive systems: sensing -> perceiving -> interpreting -> conceptualizing
- Cognitive/Action systems: conceptualizing -> strategizing -> activating -> executing
3
Q
What are the steps to creating movement and their components responsible
A
- Sensing: peripheral receptors
- Perceiving: 1º & 2º sensory cortices
- Interpreting: higher level sensory processing areas inn the parietal, occipital, & temporal lobes
- Conceptualization: prefrontal cortex & other higher level association areas
- Strategy/Plan: supplementary motor cortex basal ganglia/cerebellum (BG/CB)
- Activation: 1º motor cortex basal ganglia/cerebellum (BG/CB)
- Execution: motor neurons & muscles/joints
4
Q
Describe hierarchical processing
A
- higher level of CNS are concerned with abstract processing of information & lower levels bring in/send information
- Perceptual system from sensing to interpreting
- Action system from planing to execute specific response
5
Q
Describe parallel processing
A
- the same signal might reach different brain structures simultaneously for processing (divergent) but different purposes
- Example: basal ganglia and cerebellum sharing information to motor cortex at same time
6
Q
Describe spinal cord connections
A
- hierarchically, ‘lowest level employees’ respond to sensory inputs & follow ‘orders’ from action systems
- involved in initial signal reception & final execution of in/voluntary movements (final common pathway)
- connections from different motor areas (motor cortex, premotor areas, brain stem) descend down to modulate spinal level responses
7
Q
Examples of basic/simple signal processing of spinal cord connections
A
- spinal reflexes
- basic flex/ext of muscles
8
Q
Describe brain stem connections
A
- ‘Middle management’: contain important control centers (sensory and motor) for postural control & locomotion
- Receives inputs from head/neck, vestibular, & visual systems, sends somewhat processed signals to sensory/perceptual centers
- contain motor nuclei for descending motor pathways to neck/face/eyes & extrapyramidal pathways (but not the corticospinal pathways) also receives modulating info from cortical structures, cerebellum, spinal cord
9
Q
What anatomy is included in the brainstem
A
- pons
- midbrain
- medulla
10
Q
Describe cerebellar connections
A
- ‘back-channel’ needed for comparing & calibrating movements
- receives inputs of ongoing movements (specially postural control-related movements) from spinal cord (feedback mechanism), outputs go to cortex to adjust ongoing movements
- important center for coordination and balance during movement control
- helps generate smooth coordinated movements by modulating force and sequence: receives info from cortex (for planning refining movements), compares planned movement commands to its consequences from ‘past experience’, refines planned movement & communicates back to cortex via brainstem, prior to execution of movement (feedforward mechanism)
11
Q
Describe thalamus connections
A
- the ‘doorkeeper to the boardroom’
- acts as a junction, a rely center for signal processing
- processes almost all sensory info coming from spinal cord pathways
- outputs are carried forward to different parts of the cortex
12
Q
Describe basal ganglia connections
A
- involved in higher order motor planning for coordinated movements
- receives inputs from many areas of cerebral cortex
- sends output back to motor cortex via thalamus
13
Q
Describe cerebral cortex connections
A
- highest executive level of motor control hierarchy
- direct control of voluntary movements by controlling motor neurons via corticospinal/corticobulbar pathways
- interacts with premotor/SMA (supplementary motor area) to form motor plan/strategy
14
Q
Advantages of having hierarchical and parallel control
A
- makes the motor control system dynamic, flexible, and resilient
- sufficient info to respond accurately
- one system can take over functions if tasks /environments require it
- can suppress unnecessary responses
- certain amount of functional recovery possible using alternate pathways after injury to one system
15
Q
Somatosensory components within perception system in order
A
- Incoming info sensed from environment
- Activation of the somatosensory receptors
- Type/intensity/area of sensation
- Info sent up towards the CNS to attach meaning for interpretation