motor pathways Flashcards
motor system maintains
posture, balance, moves limbs, head etc
upper motor neuron
directly or indirectly through interneurons connect to lower
axons form descending tracts
lower motor neurons
axons leave CNS
extend through PNS to skeletal muscles
cell bodies of lower motor neurons located in
anterior horns of spinal cord
cranial nerve nuclei of brain stem
initiation of voluntary movement begins
in premotor areas of cerebral cortex
cerebral cortex interacts with ____ and ____ for planning and coordination and execution of movements
basal nuclei and cerebellum
primary motor cortex
in precentral gyrus
fine motor movements
30% of upper motor neurons
cell bodies of upper motor neurons located in
cerebral cortex
premotor area
30% of motor neuros
anterior to cortex
motor functions organized here
prefrontal area
motivation, foresight to initiate moves, emotional behavior and moves
direct pathways
pyramidal
muscle tone, controlling speed and precision of skilled movements
skilled movements of face and distal limbs
direct synapse with upper motor neurons of cortex with lower of spinal cord or brainstem
indirect pathways
less precise movements
do not pass through pyramids
synapse with intermediate nucleus in brainstem
direct corticospinal
direct control of movements below the head
direct corticobulbar
direct of movements in head and neck
75-85% of upper motor neurons of the pyramids decussate to the other side on the ____tract
lateral corticospinal tract
