Basal Ganglia Flashcards
Are motor or sensory nuclei more medial?
motor
(sensory is lateral)
*remember paired on both sides
what are the two common basal ganglia disorders?
parkinson’s and huntintons disease
what does the cerebellum do?
coordinate movement unconsiously, helps with posture
what does limbic system do?
memory, learn from past experiences, influenced by emotion
basal ganglia are involved in the generation of _________ movement?
goal directed voluntary movement
- help prepare for movement and influence the execution of movement, not directly synapsing
- regulates sequencing of movements and motor pattern selection
ganglia is all ____ mater?
all gray matter in brain, all nuclei
what does it mean that the BS is an association loop?
from cortex back to cortex. no direct output to lower motor neurons
basal ganglia is made of _____ fibers
association fibers! bc its’ connecting one area to another area within the same hemisphere; stays IN BRAIN within SAME side to MODIFY MOVEMENT
what are the 5 major components of basal ganglia?
1) caudate nucleus
2) putamen
3) globus pallidus (internal and external segments; GPi and GPe)
4) subthalamic nucleus (STN)
5) substantia nigra (SN, in midbrain)
____ + _____ = striatum
causdate + putamen= striatum
the 5 components of BS are extensively interconnected SUBCORTICAL nuclei that function to?
plan and program motor function
the BG is organised into what 2 major pathways?
*with relays back?
direct and indirect
*2 pathways with relays back to the motor related areas of the cortex via the thalamus
what structurereceive virtually all INPUT into the BG circuitary from the cortex?
the caudate and putamen (aka striatum)
the striatum has spiny neurons that?
receive the input from cortex and are primary output neurons
On either side of the internal capsule is ____ matter?
gray
the spiney neurons of the striatum allow for?
a lot of opportunity for synapse; very extensive dendritic network for lots of info
where does the striatum output go?
globus pallidus
globus pallidus is found?
medial to the putamen and is ‘cupped’ by the causdate
What is the BS output center?
globus pallidus
What are the two parts of globus pallidus?
1) globus pallidus (lateral part)= EXTERNAL = GPe
2) globus pallidus (medial part)= INTERNAL =GPi
where is the substania nigra located?
in the midbrain (look like the dark inner part of Micker’s ears -part of cerebral peduncle)
what does the substania nigra house?
dopaminergic neurons, that act with globus pallidus internus (GPi)
for our purposes, we will think of the GPi and ____ together
substania nigra =GPi/SN
**for direct only
where is the subthalamic nuclei located? what does it do?
located below the thalamus
*used ONLY in the INDIRECT pathway. Receives input from the globus pallidus externus, sends output back to the globus pallidus internus, modifying the signal
GPi projects to the?
thalamus, which relays the infoback to the frontal cortex to the moduate motor output
path of association loop
1) start at cortex
2) striatum
3) globus pallidus
4) thalamus
5) ends back at cortex
direct pathway
1) cortex
2) striatum
3) GPi/SN ***unique to direct
4) thalamus
5) cortex (motor, premotor)
5) corticospinal tract
indirect pathway
1) cortex
2) striatum
3) GPe ** unique
4) STN *** unique to indirect
5) GPi
6) Thalamus
7) Cortex (motor, premotor)
8) Corticospinal tract
Main function of direct and indirect pathway?
Direct= facilitates movement *purposful Indirect= gates out all other movement *dominates at rest to prevent extra movement
What is ONLY in the direct pathway with GPI but not indiret?
substania nigra (SN)
when do direct and indirect occur?
simultaneously, a balance of the two
