General principles of motor control Flashcards
what are the three categories of movement
reflexive
rhythmic
voluntary
what are reflexive movements
involuntary, elicited by peripheral stimuli
what are rhythmic movements
chewng, swallowing, breathing, locomotion etc
circuits lie in brainstem and spinal cord
where are the circuits found for rhythmic movements
brain stem
spinal cord
what are voluntary movements
goal directed, involves higher centres, perhaps more improvement with practice due to feedbakc and feedforward control
how is the nervous system organised
hierarchically
what is the order of NS organisation
spinal cord
brain stem regions
cortical regions
generally speaking, how do the cerebellum and basal ganglia control movements
provide feedback to cortex via the thalamus to regulate planning and execution of movements
what are the main brain stem areas involved in locomotion
basal ganglia
cerebellum
which diseases are associated with basal ganglia
huntingtons and parkinsons so there is loss of smooth normal movement and posture
what disease is associated with loss of neurons in the cerebellum
cerebral ataxia
where are cell bodies located in SC
grey matter
where are most axons located in SC
white matter
what area of SC is for sensory processing
dorsal horn
what area of SC is for motor control
ventral horn
where are motorneurons found in SC and what is their purpose
in grey matter
final out put to the muscles
what are ventral interneurons for
complex motor control circuits
what are dorsal interneurons for
sensory processing
what are 4 different neuron types found in the spinal cord
motorneurons
local interneurons
propriospinal neurons
projection neurons
what are two nuclei types of the spinal cord
dorsolateral motor nucleus
ventromedial motor neurons
what is the function of motornuerons and describe their projection
to innervate muscles
form motor nuclei in lateral SC
send axons to axial muscles
describe axon projection in local interneurons
confined to same or adjacent segments of SC
pass info across left and right
describe axon projection in propriospinal interneurons
send axons larger distances up and down SC
project to distal spinal segments
describe axonal projection in projection neurons
into brain
describe axonal projection from dorsolateral motor nucleus
to limb muscles
describe axonal projection from ventromedial motor nucleus
to main body- trunk
what are the two pathways of the brainstem
lateral and medial
what are the three tracts of the medial brainstem pathway
vestibulospinal
reticulospinal
tectospinal
where do medial brainstem pathways terminate
ventromedial interneurons and some medial motorneurons
what is the main lateral brainstem pathway tract
rubrospinal
what is the medial brainstem pathway for
basic postural control
what is the lateral brainstem pathway for
goal directed limb movements
what are four examples of goal directed movements from the cortex
planning
organising
execution
learning
what are two tracts connecting cortex, brainstem and SC
ventral corticospinal
lateral corticospinal
what is the ventral corticospinal tract
for posture, neck and trunk control
terminate in medial motorneurons
what is the lateral corticospinal tract
limb conrol
occurs at pyrimidal decussation area
what happens when there is a loss of lateral corticospinal tracts
effects fine digit control
reaching and grabbing example
what are the two main areas of cerebrall cortex
M1- primary motor cortex
premotor areas
what are the premotor cortex areas for
more complex movements, motor planning, or motor learning
what are re entrant loops
the organisation for basal ganglia
what are the five parts of basal ganglia
caudate nucleus putamen globus pallidus subthalamic nucleus substantia nigra
what two basal ganglion areas make the striatum
caudate nucleus
putamen
what are two main pathways of basal ganglion- and main function
direct - facilitates movement
indirect-inhibits movement
