Exam 2 Study Guide 4 Flashcards
What are the BG functional loops connected with?
motor (pyramidal) tracts
What happens when BG are damaged?
abn behavior and movements
SNpc
- widespread control of BG, emotion, movement
- contains dopaminergic neurons
SNpr
- major output nucleus of BG
- involved in direct and indirect pathways
Perforating branches of posterior cerebral and posterior communicating arteries supply:
SN
STN
perforating branches of MCA (aka lenticulostriate) supply:
striatum
anterior choroidal artery (branch of internal carotid) supplies:
globus pallidus
anterior cerebral artery (medial striate) supplies:
caudate
Which structures make decisions about motor based on circumstances?
- head of the caudate
- prefrontal cortex
What is considered with decision making?
- emotions
- stress levels
- environmental considerations
How does the head of the caudate help with motor planning?
takes in sensory stimuli to make decisions
How do direct/indirect pathways work?
- antagonistic to one another
- neither is completely inactive
Lack of indirect pathway leads to
hyperkinesia
Lack of direct pathway input leads to
hypokinesia
overall function of indirect movement
modulates the direct pathway to produce smooth movements
What happens when you get disruption of the direct pathway?
hypokinesia
Which condition is associated with hypokinesia?
Parkinson’s
Which condition is associated with hyperkinesia?
Huntington’s
How does dopamine affect movement?
- favors movement via direct pathway
- increases movement
Which receptor increases direct pathway activity?
D1
Which receptor decreases indirect pathway activity?
D2
Huntington’s
- hyperkinesia
- lose GABAergic neurons in the striatum
- no indirect pathway control
Parkinson’s
- hypokinesia
- lose 80% of dopaminergic neurons
- can’t make switch in activating direct pathway
Both pathways from the motor cortex (with respect to the motor cortex and GPi) are (excitatory/inhibitory)
excitatory
GPi to VLPP is (excitatory/inhibitory)
inhibitory
VLPP to reticulospinal is (excitatory/inhibitory)
inhibitory
GPi to midbrain is (excitatory/inhibitory)
inhibitory
midbrain to reticulospinal is (excitatory/inhibitory)
excitatory
What types of info feeds into the cerebellum?
- sensory
- proprioception
- somatosensation
- GTO
- cutaneous mechanoreceptors
3 functional regions of the cerebellum
- vestibulocerebellum
- spinocerebellum
- cerebrocerebellum
systems feeding into vestibulocerebellum
vestibular
visual
vestibulocerebellum feeds into
- eye movements
- postural movements
spinocerebellum has to do with
- gross movements
- has effect on lateral and medial UMN systems
inputs for spinocerebellum
- somatosensory
- sensorimotor
- spiniocerebellar internal feedback tracts (SC)
outputs for spinocerebellum
- thalamus
- brainstem
projects to lateral and medial UMN
cerebrocerebellum has to do with
fine movement
inputs to cerebrocerebellum
somatosensory motor cortices via dentate nucleus
outputs of cerebrocerebellum
- motor thalamus
- cerebral cortex
inferior cerebellar peduncle receives afferents from
contralateral ION
middle cerebellar peduncle receives afferents from
pontine nuclei (mostly from cerebral cortex)
cortex» pons» cerebellum
superior cerebellar peduncle sends efferents to
thalamic nuclei
brainstem
What supplies blood to the cerebellum?
SCA
AICA
PICA
cerebellum helps to
coordinate movement
SCA is off the
basilar artery
AICA is off the
basilar artery
PICA is off the
vertebral arteries
