Motor Control: Voluntary Control Flashcards
What are the 4 areas of the cortex associated with the production of voluntary motion?
Primary Motor Cortex
Supplementary Motor Cortex
Pre-Motor cortex
Parietal cortex
What are the 2 cortical pathway responsible of Reaching?
First Pathway:
- From the visual cortex info. Is relayed to the parietal cortex (V6A), MIP, and VIP (ventral intraparietal area)
- The VIP creates a rough map of the space around you
- From VIP the info. Is sent to F4 with the promoter cortex
- F4 creates a detailed map of the space around you (neurons are particularly excited by proximity)
Second Pathway:
- Superior parietal cortex (V6A): receives visual info. About where your arm is in space
- Input is sent to F2 in the promoter cortex: F2 constructs a related map, where your arm is in relationship to body
What is pathway responsible for grasping?
Anterior intraparietal area and PFG (inferior parietal cortex) functions to:
Seeing an object to grasp: visually dominate
Grasping an object: motor dominate
Either condition: visuomotor neurons
Anterior intraparietal area and PFG relay info. To F5
F5 fire when with the goal, not motor act
How does the premotor cortex participate in the control of voluntary motion?
Receives the sensory information required to move (F4 and F5)
Dorsal-applies the ‘rules’ that determine whether it is appropriate to move
Identifies the intent of the motion and decides what motion to produce
How does the supplementary motor cortex participants in the control of voluntary motion?
Two divisions:
1. Supplementary motor area(SMA): postural control
Organize Motor sequences, acquire motor skills, executive control
2. Pre-supplementary area (pre-SMA): plans the motor program required to make the action occur
How does the Primary Motor Cortex participant is control of voluntary motion?
Controls specific movements
Regions of body that do fine motions have proportionally high representation
Arranged in columns
Describe the arrangement of columns w/in the primary motor cortex?
In layers
Layer 4: receives sensory input
Layer 5 becomes the outer for the corticospinal pathway
2 sets of neurons in each columns: one to start the motion, one set to maintain it as long as necessary
Two kinds of columns:
1. On/off for agonist muscles
2. Off/on for the antagonist muscles
What is the role of the cerebellum?
Sequence complex actions
Correct force/direction
Balance and eye movements
Learning of complex actions
How is the cerebellum divided? And what are the 3 parts?
Divided into functional divisions rather than anatomical divisions
Spinocerebellum: two regions
Central: postural control
Either side of vermis: force and direction
Cerebrocerebellum: lateral regions
Plans complex motions
Sequence
Vestibulocerebullum: balance/eye movements, future (not current)
What are the motor nuclei of the cerebellum?
Deep cerebellar nuclei
Dentate nucleus
Fastigial nucleus
Interpositus (globose, emboliformis)
What are the inputs and outputs of the spinocerebellum?
Inputs:
Vestibular
Visual and auditory
Efferent copy
Outputs:
interpositus n.
Fastigial n.
To the rubrospinal tract
Additionally: control ballistic motions
Input: muscles afferent
Output: interpositus nucleus to rubrospinal tract
What are the inputs and outputs of the cerebrocerebellum?
Function: sequencing of rapid movement
Input:
Cerebral cortex
Outputs: dentate back to cortex
What are the inputs and output of the vestibulocerebellum?
Functions: control eye movement and balance, particularly in future
Input: vestibular apparatus (direct or indirect)
Output: fastigial nucleus to vestibular nuclei which ascend or descend
