19. Voluntary motion Flashcards
what are the cortical areas associated with voluntary motion
primary motor cortex
supp. motor cortex
pre-motor cortex
(also parts of prefrontal & parietal)
what is the role of the premotor cortex
recieve sensory info required to move
dorsal: determine whether its appropriate to move
identifies intent & decids what motion to produce
what are the two divisions of the supp motor cortex
supplementary motor area (SMA)
pre-supp motor area (pre-SMA)
what is the fxn of the SMA
organize motor sequence
aquire motor skills
& executive control (decide when to switch actions)
what is the fxn of the primary motor cortex
control specific movements (esp with arm/leg toward body)
-fine motion = more represented in cortex
how is the primary motor cortex arranged &
what are the fxns of the layers
6 layers w/ columns w/i
2 sets of neurons in each column: 1 to start & other to maintain
layer 4: sensory input (M/joint proprio)
layer 5: output for CST (pyramidal) path - synapse with alpha/gamma MN
when controlling fine motion stimulation of the primary motor cortex will-
contract a single M
when controlling a general motion, stimulation of the primary motor cortex will —
contract a GROUP of Ms
what are organizations of the columns
neighboring columns - control related MOTION
2 kinds of columns
- on/off for agonist
- off/on for antagonist
what is the dorsal visual pathway & what does it do
contain axons from occipital cortex & travel to parietal/frontal cortex
=input –> complete motor acts based on visual inputs (allow reaching & grasping)
where is info relayed to from the visual cortex for reaching
V6A
PEc
MIP (medial intraparietal area)
VIP (ventral intraparietal area)
what does the VIP do
create rough map of space you’re in
where is info sent after the VIP for reaching motions
- what is the end result
sent to F4 (w/i premotor cortex)
F4 creates detailed map & neurons are excited based on proximity
what is the second path for reaching & what is it for
rely on superior parietal cortex –> send input to F2
-tells you where your arm is based on visual info
what are the roles of F2 & F4
F2: location of arm
F4: location of object
what is the ant intraparietal area (AIA) & PFG
contain neurons that excite in response to seeing an object to grasp & grasping an object
define visually dominant
motor dom
visuomotor neurons
visually dom = neurons for seeing an object
motor dom: neurons for grasping an object
visuomotor neurons: excite with both
where do AIA & RFG relay info
F5
- neurons that excite based on GOAL of the action
what are the roles of the cerebellum
- sequence complex actions
- correct force/direction
- balance/eye movement
- learning complex actions (M memory)
what are the roles of the two regions of the spinocerebellum
central: postural control
lateral: force/direction
what is the role of the cerebrocerebellum
plan complex motions
sequence
what are the parts & function of the vestibulocerebellum
flocculus & nodulous
balance/eye movement (future)
what are the inpots of the central resion of the spinocerebellum
vestibular/visual & auditory - proprioception
efferent copy: info about M thats contracting
what are the deep cerebellar nuclei & outputs for the central region of the spinocerebellum
interpostius & fastigial
neurons to the rubrospinal tract
what are the inputs/outputs of the lateral region of the spinocerebellum
input: M afferents & efferent copies
output: interpositis nucleus to rubrospinal tract
- correct ongoing motions & control ballistic motions
what are the inputs & outputs of the cerebrocerebellum
inputs: all regions of the cerebral cortex (NO efferent bc no motion yet)
output: dentate –> back to cortex
= rapid movements & planning
what are the inputs and outputs of the vestibulocerebellum
input: vestibular apparatus
output: fastigial nucleus to vestibular nuclei (ascend or descend)
what does the basal ganglia do
control beginning & end of movement
-works by inhibition or removal of inhibition
draw/explain direct path of basal ganglia
-what is the outcome
movement!
activate direct & inactivate indirect
draw/explain the indirect path of basal ganglia
what is the outcome
inhibit movement
what is the source of the DA in the direct/indirect path
SNpc
what is the fxn of the prefrontal cortex
planning of complex motor action
& carrying out of “thought” process
what occur when you plan a complex motor movement
prefrontal cortex interact with PTO association area & all levels of motor cortex/cerebellum
-frontal association area, supp motor cortex, premotor cortex & cerebrocerebellum
what is the general path of activation of voluntary movement
- plan & approve motion (communication of motor areas)
- activate primary motor cortex
- axons down pyramidal cells & activate alpha MN
- innervate M –> complete motion
if the brain activated alpha MNs, it will
also actiavte gamma MNs for M spindles in the contracting M (decrease sensitivity) –> allow contraction
& opposite if inhibiting -inhibit both to allow stretch
