Motor control: basal ganglia Flashcards
what is the pyramidal system
pathways originating from cortex and decussating into cotricospinal and corticobulbar tract
what is extrapyramidal motor system
all brain structure not in pyramidal system – basal ganglia
what is unique about basal ganglia as a motor system
does not have direct input to spinal cord
what does BG get input from
almost everywhere
where does BG project to?
motor and associated cortex via motor thalamus
role of BG
planning
cog function
what is input portion of BG
caudate + putamen = striatum
what is output portion of BG
globus pallidus
where dopamine from and too?
from substania nigra to striatum
what are 2 BG pathways that involve dopa
- indirect
2. direct
what does DOPA do to direct
DOPA increases
what does DOPA do to indirect
DOPA inhibs
** overall effect of loss dopa
increased GP inhibtion of motor thalmus, leads to reduced excitatory drive of cortex – some Sx of parkinsons
6 classic Sx of BG probs
- dystonia, dyskinesia
- athetosis
- chorea
- parkinsonism
- hemiballism
- tics
what is dystonia
persistent muscle contraction about one or more joints - writers cramp
