basal ganglia Flashcards
The basal ganglia (basal nuclei) are a group of —– ——nuclei.
The basal ganglia (basal nuclei) are a group of functionally related nuclei.
Subthalamic Nucleus (STN)
located in diencephalon
Substantia Nigra (SN)
Compact Part (SNc) and Reticular Part (SNr)
in midbrain
Dopaminergic neurons
are located in dorsal part of the substantia nigra
(cmpact part
also located medially in ventral tegmental area.
Dopaminergic neurons
The substantia nigra (reticular part) functions with the
—–as the output from the —-.
The substantia nigra (reticular part) functions with the GPi as the output from the BG.
ventral region of continuity btwn caudate and putamen
striatum
lenticular nucleus
putamen
gpe
gpi
dopamine
“reward system
cognition processes and control of movements.
dopamine
dopamine
enjoyment and pleasure, which reinforces and motivates
extrapyramidal system”
describes the nuclei and pathways of the BG
termed in 1900 by early 1900s Kinnier Wilson
influences motor and non motor sysem
basal ganglia
A lesion to —- —— of the BG will disrupt movement
A lesion to one or more of the BG will disrupt movement
Absence of spontaneous movement/ slowness of movement
Inability to inhibit unwanted movements
A lesion to one or more of the BG
TF BG directly innervate LMNs in the spinal cord or cranial nerve nuclei;
F BG do NOT directly innervate LMNs in the spinal cord or cranial nerve nuclei;
TF lesion to one or more of the BG produce paralysis
lesion to one or more of the BG does not produce paralysis
tf BG only influence motor actions
t BG only influence motor actions
Hypokinetic Disorder
Parkinson’s Disease
loss of dopaminergic neurons in the SNc
Parkinson’s Disease a hypokinetic disease
Akinesia/Bradykinesia: without (difficulty initiating) movement/ slowness of movement
Hypokinetic Disorder
Parkinson’s Disease
Rigidity: increase in muscle tone
Resting tremor:
rhythmic involuntary movement at rest
in Parkinson’s Disease
Hypokinetic Disorder like parkinsons dispkay
Postural instability
Chorea:
rapid, abrupt and random movements (limbs, face)
Hyperkinetic Disorders
Athetosis:
slow, writhing movements
Hyperkinetic Disorders
Hyperkinetic Disorders
Types of abnormal involuntary movements
Ballism(“ballistic movement ”)
:violent, large-amplitude mvmts
hyperkinetic disease
Huntington’s Disease (HD
progressive degeneration of projection neurons and local circuit neurons in the caudate and putamen.
TF in huntington;s disease a Hyperkinetic Disorders;
Neurons that give rise to the indirect pathway are preferentially lost.
F Neurons that give rise to the indirect pathway are preferentially lost.
extensive —– projections to the striatum;
extensive cortical projections to the striatum;
recivees info from cortical association areas and has a role in cognitive functions
Caudate
Putamen
input from motor and somatosensory cortices
influences motor output.
info from limbic cortex, hippocampus and amygdala
N. Accumben
emotional and behavioral functions.
N. Accumbens
cognitive functions
Dorsolateral prefrontal Loop:
motor output.
motor loop
Orbitofrontal loop:
planning and initiating socially appropriate actions
Limbic loop
emotional and behavioral functions.
Oculomotor loop:
control of orientation and gaze.
