Ch 17: Basal Ganglia Flashcards
what comprises the basal ganglia?
what does it modulate?
a network of subcortical nuclei of the telencephalon, subthalamus, and midbrain that modulate motor and cognitive functions of the cerebral cortex
how do the cerebral cortex and basal ganglia differ?
cerebral cortex influences motor function directly through the corticospinal and corticobulbar pathways
the basal ganglia and the cerebellum influence lower motoneurons indirectly through modulation of the cerebral cortex and brainstem
what are the 2 recurrent circuits that accomplish cortical modulation?
cortical-brainstem-cerebellar-thalamic-cortical loop
cortical-basal ganglia-thalamic-cortical loop
diseases affecting cerebellar and basal ganglia loops produce..
distinctive neurological deficits because they perform so many different functions
in comparison to the cerebellum, the basal ganglia makes limited _______ connections?
these principally involve what?
basal ganglia makes limited BRAIN STEM connections
these principally involve the reticular formation and the superior colliculus
cerebellum exerts over multiple descending brain stem pathways-rubrospinal, vestibulospinal and reticulospinal
where does the largest nuclei of the basal ganglia lie?
what do these nuclei include?
deep within the telencephalon and extend to the base of the cerebral hemisphere
these nuclei include:
- dorsal striatum
- ventral striatum
- dorsal pallidum
- ventral pallidum
what comprises the dorsal striatum?
what does it do?
caudate nucleus
putamen
receives excitatory input from the isocortex
inhibits the substantia nigra and the globus pallidus
what comprises the ventral striatum?
nucleus accumbens
anterior perforated subtance
what comprises the dorsal pallidum?
globus pallidus
what resides at the interface between the diencephalon and midbrain ?
other subcortical nuclei, the sub thalamic nucleis, the substantia nigra and the ventral segmental area
what forms the lentiform nucleus?
putamen and globus pallidus together - a thumb sized mass wedged on the lateral side of the internal capsule
what receives major inputs to the basal ganglia?
what provides these afferents?
the striatum
cerebral cortex, thalamus and substantia nigra provide these afferents
