19. Voluntary motion

Question 1

what are the cortical areas associated with voluntary motion

Answer 1

primary motor cortex

supp. motor cortex

pre-motor cortex

(also parts of prefrontal & parietal)

Question 2

what is the role of the premotor cortex

Answer 2

recieve sensory info required to move

dorsal: determine whether its appropriate to move

identifies intent & decids what motion to produce

Question 3

what are the two divisions of the supp motor cortex

Answer 3

supplementary motor area (SMA)

pre-supp motor area (pre-SMA)

Question 4

what is the fxn of the SMA

Answer 4

organize motor sequence

aquire motor skills

& executive control (decide when to switch actions)

Question 5

what is the fxn of the primary motor cortex

Answer 5

control specific movements (esp with arm/leg toward body)

-fine motion = more represented in cortex

Question 6

how is the primary motor cortex arranged &

what are the fxns of the layers

Answer 6

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

Question 7

when controlling fine motion stimulation of the primary motor cortex will-

Answer 7

contract a single M

Question 8

when controlling a general motion, stimulation of the primary motor cortex will —

Answer 8

contract a GROUP of Ms

Question 9

what are organizations of the columns

Answer 9

neighboring columns - control related MOTION

2 kinds of columns

1. on/off for agonist
2. off/on for antagonist

Question 10

what is the dorsal visual pathway & what does it do

Answer 10

contain axons from occipital cortex & travel to parietal/frontal cortex

=input –> complete motor acts based on visual inputs (allow reaching & grasping)

Question 11

where is info relayed to from the visual cortex for reaching

Answer 11

V6A

PEc

MIP (medial intraparietal area)

VIP (ventral intraparietal area)

Question 12

what does the VIP do

Answer 12

create rough map of space you’re in

Question 13

where is info sent after the VIP for reaching motions

• what is the end result

Answer 13

sent to F4 (w/i premotor cortex)

F4 creates detailed map & neurons are excited based on proximity

Question 14

what is the second path for reaching & what is it for

Answer 14

rely on superior parietal cortex –> send input to F2

-tells you where your arm is based on visual info

Question 15

what are the roles of F2 & F4

Answer 15

F2: location of arm

F4: location of object

Question 16

what is the ant intraparietal area (AIA) & PFG

Answer 16

contain neurons that excite in response to seeing an object to grasp & grasping an object

Question 17

define visually dominant

motor dom

visuomotor neurons

Answer 17

visually dom = neurons for seeing an object

motor dom: neurons for grasping an object

visuomotor neurons: excite with both

Question 18

where do AIA & RFG relay info

Answer 18

F5

• neurons that excite based on GOAL of the action

Question 19

what are the roles of the cerebellum

Answer 19

1. sequence complex actions
2. correct force/direction
3. balance/eye movement
4. learning complex actions (M memory)

Question 20

what are the roles of the two regions of the spinocerebellum

Answer 20

central: postural control
lateral: force/direction

Question 21

what is the role of the cerebrocerebellum

Answer 21

plan complex motions

sequence

Question 22

what are the parts & function of the vestibulocerebellum

Answer 22

flocculus & nodulous

balance/eye movement (future)

Question 23

what are the inpots of the central resion of the spinocerebellum

Answer 23

vestibular/visual & auditory - proprioception

efferent copy: info about M thats contracting

Question 24

what are the deep cerebellar nuclei & outputs for the central region of the spinocerebellum

Answer 24

interpostius & fastigial

neurons to the rubrospinal tract

Question 25

what are the inputs/outputs of the lateral region of the spinocerebellum

Answer 25

input: M afferents & efferent copies
output: interpositis nucleus to rubrospinal tract
- correct ongoing motions & control ballistic motions

Question 26

what are the inputs & outputs of the cerebrocerebellum

Answer 26

inputs: all regions of the cerebral cortex (NO efferent bc no motion yet)
output: dentate –> back to cortex

= rapid movements & planning

Question 27

what are the inputs and outputs of the vestibulocerebellum

Answer 27

input: vestibular apparatus
output: fastigial nucleus to vestibular nuclei (ascend or descend)

Question 28

what does the basal ganglia do

Answer 28

control beginning & end of movement

-works by inhibition or removal of inhibition

Question 29

draw/explain direct path of basal ganglia

-what is the outcome

Answer 29

movement!

activate direct & inactivate indirect

Question 30

draw/explain the indirect path of basal ganglia

what is the outcome

Answer 30

inhibit movement

Question 31

what is the source of the DA in the direct/indirect path

Answer 31

SNpc

Question 32

what is the fxn of the prefrontal cortex

Answer 32

planning of complex motor action

& carrying out of “thought” process

Question 33

what occur when you plan a complex motor movement

Answer 33

prefrontal cortex interact with PTO association area & all levels of motor cortex/cerebellum

-frontal association area, supp motor cortex, premotor cortex & cerebrocerebellum

Question 34

what is the general path of activation of voluntary movement

Answer 34

1. plan & approve motion (communication of motor areas)
2. activate primary motor cortex
3. axons down pyramidal cells & activate alpha MN
4. innervate M –> complete motion

Question 35

if the brain activated alpha MNs, it will

Answer 35

also actiavte gamma MNs for M spindles in the contracting M (decrease sensitivity) –> allow contraction

& opposite if inhibiting -inhibit both to allow stretch