Basal Ganglia Flashcards
1
Q
what are basal ganglia
A
collection of deep nuclei near the base of each cerebral hemisphere
2
Q
function of BG
A
- basic feedback circuit: receiving information from several sources (including cerebral cortex), and feeding this information back to the cortex via the thalamus
- –> modulates and refines cortical activity
- –> facilitate purposeful movement, inhibit unwanted movements and have a role in posture and muscle tone
3
Q
what substance facilitates BG activity, and where is this supplied from
A
- neurotransmitter dopamine, supplied by substantia nigra
4
Q
contralateral or ipsilateral brain
A
contralateral
5
Q
A
6
Q
which nuclei make up the stratium
A
caudate nucleus and putamen
7
Q
where is the caudate nucleus found
A
- lateral wall of the lateral ventricle
- separated from putamen by internal capsule
8
Q
what is the lentiform nucleus composed of
A
- putamen and external and internal globus pallidus
- only anatomically related, not functionally
9
Q
how does the BG act to refine motor movement
A
- prevents unwanted movements to start, largely by reducing the excitatory input to the cerebral cortex
- this prevents excessive and exaggerated movements
10
Q
A
