motor II

Question 1

what part of the brain compensate for any body postural change

Answer 1

brainstem vestibular nuclei and reticular formation nuclei

Question 2

when does a feedforward anticipatory adjustment happen

Answer 2

just before movement begins to stabilise posture

Question 3

where in the brain initiates the feedforward anticipatory adjustments

Answer 3

brainstem reticular formation nuceli

Question 4

what is the babinski sign

Answer 4

an upward extensor plantar response

Question 5

what does the babinski sign indicate

Answer 5

an upper motor neuron lesion

Question 6

what is spasticity

Answer 6

increased muscle tone, or hyperactive stretch reflex or clonus

Question 7

why does an UMN lesion cause spasticity

Answer 7

there is removal of the cortical inhibitory influences

Question 8

true/false UMN lesions cause spasticity immediately

Answer 8

false - it takes a few days. for the first few days there is flaccidity until spinal circuits regain function

Question 9

input to area 6 comes from…

Answer 9

the ventral lateral nucleus in dorsal thalamus

Question 10

input to ventral lateral nucleus comes from…

Answer 10

basal ganglia

Question 11

input from basal ganglia comes from…

Answer 11

prefrontal, motor and sensory cortexes

Question 12

loop of basal ganglia, ventral lateral nucleus and cortexes

Answer 12

ventral lateral nucleus –> cortex (esp area 6) –> basal ganglia –> ventral lateral nucleus

Question 13

corpus striatum is part of what brain group

Answer 13

basal ganglia

Question 14

components of corpus striatum

Answer 14

caudate and putamen

Question 15

what part of the basal ganglia are the input regions

Answer 15

caudate and putamen (corpus striatum)

Question 16

an inhibitory synapse releases glutamine/GABA

Answer 16

GABA

Question 17

which axons of the basal ganglia are GABAergic (inhibitory)

Answer 17

putamen and caudate projecting to the globus pallidus and substantia nigra

Question 18

which parts of the corpus striatum fire before which movements

Answer 18

putamen fires before limb and trunk movements

caudate fires before eye movements

Question 19

which tract of the brain is responsible for keeping eyes stable through movements

Answer 19

tectospinal tract

Question 20

cortex to putamen is excitatory/inhibitory

Answer 20

excitatory

Question 21

putamen to globus pallidus is excitatory/inhibitory

Answer 21

inhibitory

Question 22

globus pallidus to ventral lateral nuclei is excitatory/inhibitory

Answer 22

inhibitory

Question 23

ventral lateral nuclei to SMA is excitatory/inhibitory

Answer 23

excitatory

Question 24

cascade of cortical excitation

Answer 24

cortex excites the putamen –> putamen inhibits the globus pallidus –> releases ventral lateral nuclei from inhibition –> ventral lateral nuclei excites the SMA

Question 25

what part of the positive feedback loop that happens basal ganglia and cortex will trigger the GO for movement

Answer 25

when the SMA is boosted beyond a certain threshold

Question 26

if going via the corpus striatum is the direct pathway - what does the indirect pathway go via

Answer 26

the subthalamic nucleus

Question 27

disorders of the basal ganglia

Answer 27

parkinson's disease and huntington's disease

Question 28

pathophysiology of huntington's

Answer 28

atrophy of basal ganglia --> loss if inhibitory effects of basal ganglia --> hyperkinesia and uncontrolled movement and ticks

Question 29

pathophysiology of parkinson's

Answer 29

degeneration of neurones in substantia nigra --> loss of excitatory input to striatum --> hypokinesia, slow and rigid

Question 30

function of cerebellum in movement

Answer 30

coordination

Question 31

motor loop of cerebellum

Answer 31

cerebellum --> ventral lateral nuclei --> motor cortex (esp area 4) --> sensory cortex --> cerebellum

Question 32

presentation of cerebellar lesions

Answer 32

ataxia uncoordinated, inaccurate movements/finger-nose test) staggers when walking

Question 33

causes of cerebella damage

Answer 33

alcohol, MS, paraneoplastic syndrome

Question 34

cerebellar disorders have increased/decreased tone

Answer 34

decreased tone