6. Voluntary Motion (Karius) Flashcards
Which visual pathway allows us to complete motor acts, like throwing a ball, or reaching for objects?
The dorsal visual pathway (the “where pathway”)
What is the general function of the supplementary motor cortex in voluntary movement?
Generally the supplementary motor cortex is responsible for organizing motor sequences, acquiring new motor skills, and executive control to switch strategies.
What is the function of the cerebrocerebellum?
Planned motor movement and learned motor functions.
What are the inputs to the vermis portion of the spinocerebellum?
Vestibular nuclei
Visual and auditory
Efferent copy of outgoing motor commands
Describe the pathway for creating a plan for reaching for an object.
Information from the primary visual cortex runs to the superior parietal cortex: areas V6A, PEc, Middle intraparietal area, Ventral intraparietal area.
This information is then sent to area F4 in the premotor cortex.
There is a parallel pathway that utilizes F2 to determine the location of your arm in space. Both F2 and F4 come together to create a map of how reaching should occur (planned the reach).
What are the inputs and output tracts for the lateral part of the spinocerebellum?
Inputs: Afferents from muscles and efferent copy of motor commands
Output tracts: Emboliform and globose nuclei
What are the inputs and outputs to the vestibulocerebellum?
Input: vestibular apparatus
Output: Fastigial nucleus to the vestibular nuclei
Describe the pathway for creating a plan for grasping an object.
The anterior intraparietal area and prefrontal gyrus contain visually dominant, motor dominant, and visuomotor neurons.
This information is sent to F5 in the premotor cortex.
What are the four parts of the cortex that contribute to the superior parietal cortex and are involved in creating a map for reaching?
V6A, PEc, Medial intraparietal area, Ventral intraparietal area
What is the function of the premotor cortex in the control of voluntary motion?
Determines if a motion is appropriate.
Identifies the intent of the motion, and the kind of motion to produce.
What is the function of the ventral intraparietal area?
Creates a map of the space around you, and then sends the signal to F4 in the premotor cortex.
What are the inputs and outputs for the cerebrocerebellum?
Input: Cerebral cortex
Output: Dentate nucleus
What is the function of the lateral aspect of the spinocerebellum?
Control of ongoing movements of the body.
Gait and station
Correction of ballistic motions.
Where is F4 located, and what is its function?
F4 is located in the premotor cortex and refines the information from the ventral intraparietal area to create a map of the object you want to reach for.
What are the outputs tracts for the vermis portion of the spinocerebellum?
The globose, emboliform, and fastigial nuclei.
(Not the dentate, because it does higher functions.)
What is the function of the vestibulocerebellum?
Helps to control movements related to the eyes.
Important in balance and eye movements.
Alpha motor neurons and gamma motor neurons work together to
contract the agonist (activated by brain)
or
relax the antagonist (inhibtied by the brain)
What double checks our voluntary motion to make sure it is correct once it has started?
Spinocerebellum
What does the brain do to the gammoa motor neurons of the muscle spindle in the antagonist muscle?
reduces the sensitivity to stretch
What is the big picture for voluntary motion?
What is the source of dopamine
Direct pathway
Indirect pathway
SNPC for both
What is the location of dopaminergic synapse
Direct pathway
Indirect pathway
Striatum for both
What is the receptor on the striatal neuron
Direct
Indirect
D1
D2
what is the effect of dopamine binding
Direct pathway
Indirect pathway
Excitation
Inhibition
