motor pathways Flashcards
what is the order of a motor plan
frontal lobes for motivation
premotor Cx for motor plan
primary motor Cx for action
What are the inputs for the motivation of a plan
sensory stimuli from parietal area
emotions and memory from limbic system
What BA is the premotor and supplementary Cxs
BA 6 and 8
Where are the UMN found
primary motor Cx and brainstem nuclei
What is the final common pathway
LMN always excitatory
Which motor neurons decussate
UMN not LMN
where are alpha LMN found
spinal cord ventral horn and CN motor nuclei
What are the inputs to LMNs
primary afferents in the reflex arcs
UMN
local pattern generators
What is a motor unit
1 LMN and all the mm fibers it innervates
each m fiber is inn by what
1 LMN
what is the AP of a motor unit
all or nothing
What do the lateral motor systems control
distal limb mm
fine fractionated movements
what do the medial motor systems control
axial/proximal limb mm
postural
What are the inputs to UMN
cerebellum
association cortices
basal ganglia
What are the 2 cortical UMN pathways
corticospinal tract (lateral) corticobulbar
which is the largest motor tract of humans
lateral corticospinal tract
where does lateral corticospinal tract originate
Area 4
frontal lobes and somatosensory cortices
Where is the supplementary motor cortex
medial BA 6
interconnected with the contralateral side to allow for bimanual movements
what type of LMNs does the corticobulbar tract work on
LMN for CN
and UMN to proximal limb postural mm
what is the laterality of corticobulbar
CN receive bilateral usually
What are signs of a LMN damage
hypo or areflexia
paralysis or paresis (flaccid)
rapid severe atrophy”neurogenic”
fasiculations and fibrillations
what are signs of UMN damage
normal to hypereflexia hypertonia pathological reflexes spastic paralysis disuse atrophy
what does the term plegia mean
stroke paralysis
The non cortical UMN systems primarily act on what
axial and proximal limb mm
