voluntary control of movement

Question 1

spinal cord level integration

Answer 1

• reflex patterns - effect motor neurons exiting that level at the spinal cord, cant affect multiple different levels at once

Question 2

brainsstem level integration

Answer 2

posture - maintains tone

continuous modification of degrees of tone in different muscles - antigravity muscles

Question 3

cerebellum level integration

Answer 3

motor planning, coordination and assessment

assess motor output to provide predictive patterns of movement which also feeds into the cortex

Question 4

basal ganglia

Answer 4

essential to motor control

helps cortex execute subconscious learned patterns of movement

Question 5

heirarchy of control - strategy - what to do

Answer 5

prefrontal cortex
post parietal cortex
basal ganglia

Question 6

heirarchy of motor control - tactics - how to do it

Answer 6

pre-motor cortex and SMA

cerebellum

Question 7

heirarchy - execution - doing it

Answer 7

primary motor cortex
brain stem
spinal cord

Question 8

direct spinal tracts

Answer 8

direct contol of pathway - from cortex to spinal cord

Question 9

2 direct spinal tracts

Answer 9

corticospinal tracts - major - starts in primary motor cortex, synapses with lower motor neuron which innervated skeleton
rubrospinal tract - minor - starts in red nucleus and synpases to a lower motor neuron

Question 10

dominant spinal tract

Answer 10

corticospinal tract

Question 11

conrticospinal tract origin

Answer 11

motor cortex

Question 12

where does corticospinal tract go

Answer 12

lateral corticospinal tract (80%) decussates at medulla to innervate distal limb muscles for fine movements and coordination
ventral corticospinal tract (20%) innervates axial and proximal limb muscles for gross movement

Question 13

origin of the rubrospinal tract

Answer 13

red nucleus (midbrain) 
but - red nucleus recieves fibres directly from 1° motor cortex (corticorubral tract) and branching fibres from the corticospinal trcat

Question 14

rubrospinal tract innervates

Answer 14

innervates distal limb muscles - fine movements, coordination and skill

Question 15

brainstem centre facilitating the eyes

Answer 15

tectospinal nuclei

• revieve visual input (horizon)
• output descends tectospinal tract to correct head/neck muscles

Question 16

brainstem centre facilitating the ears and vestibules

Answer 16

vestibular nuclei

• recieve vestibular input (equilibrium/head rotation)
• output descend vestibulospinal tract and also feeds into cerebellum and reticular nucleus in the pons

Question 17

reticular nuclei

Answer 17

sense global brain acitivty

• tense muscles in high activity
• two of them: one in the pons and one in the medulla

Question 18

reticular nuclei in the pons

Answer 18

excitatory - rigidity in antigravity maucles

Question 19

reticular nuclei in the medulla

Answer 19

inhibits antogravity muscles - inhibitory

Question 20

tract for visual adjustments

Answer 20

tectospinal tract

Question 21

tract for gracity/equilibrium

Answer 21

vestibulospinal

Question 22

tract for rigidity adjustment

Answer 22

reticulospinal tract

Question 23

medial indirect tracts

Answer 23

• reticulospinal tract
• vestibulopinal
• tectospinal

influence, dont control

Question 24

reticulospinal tract

Answer 24

from reticular formation in central grey matter of brainstem
goes to thalamus and then spinal cord

Question 25

outputs of the reticulospinal tract

Answer 25

pontine (excitatory) RST - in the pons, excites axial and extensor muscles medullary (inhibitory) RST - in the medulla, inhibits extensor muscles and excite flexors

Question 26

the reason there are two outputs of the RST

Answer 26

antagonistic function | to modulate reflex actions during ongoing movements

Question 27

cerebellum and basal ganglia initiating movement

Answer 27

cannot initiate movement - only feed into areas that can initiate movement

Question 28

cerebellum

Answer 28

timing, smooth prrogression/control/intensity/interplay between agnist/antagonist muscle groups compares actual movement to intended movement

Question 29

basal ganglia

Answer 29

plan + control complex patterns/ relative intensities/direction/sequence/ complicated motor goals adjust based on cortical regions

Question 30

lesions of the cerebellum

Answer 30

lose coordination cerebellar ataxia - uncoordinated and inaccurate movements dysynergia - lose synergistic multi-joint movements dysmetria - overshoot or undersshoot target

Question 31

ataxia

Answer 31

uncoordinated and inaccurate movements

Question 32

dysynergia

Answer 32

lose synergistic multi-joint movements

Question 33

dysmetria

Answer 33

overshoot or undershoot target

Question 34

structure of the cerebellum

Answer 34

2 hemispheres with associated deep nuclei - vermis is located on the midline of the cerebellum - flocculondular lobe: causal aspect of the CB

Question 35

cerebellar input

Answer 35

continuous motor and sensory input from the brain and the periphery - from the brain: premotor area, vestibular, basal ganglia and spinal cord - from the periphery: muscle spindles, golgi tendon organs, activity in the spinal cord

Question 36

3 functional divisions of the cerrebellum

Answer 36

- vestibulocerebellum: balance - spinocerebellum: controlling motor areas of spinal cord - cerebrocerebellum: planning motor images and executing them

Question 37

vestibulocerebellum is located

Answer 37

flocolunodular lobes and adjacent vermis section

Question 38

spinocerebellum is located

Answer 38

vermis and adjacent intermediate zones

Question 39

cerebrocerebellum is lated

Answer 39

lateral zones of hemispheres

Question 40

role of the basal ganglia in movement control

Answer 40

input from cortex, output via thalamus complicated excitatory and inhibitory connections mediated by different nuerotramistters prevents hyper/hypo kinesis

Question 41

danage to the basal ganglia

Answer 41

tremor, involuntary movements, problems with posture

Question 42

putamen circuit

Answer 42

executing patterns of motor activity | directly to the primary motor cortex

Question 43

caudate circuit

Answer 43

cognitive planning of motor patterns assesses validity of a plan doesnt stimulate motor output directly directly stimulates premotor area to aid pattern control