Basal Ganglia Flashcards
what is the basal ganglia?
group of subcortical nuclei within the brain
what is the role of the basal ganglia?
motor control motor learning executive functions emotional behaviours reward reinforcement addictive behaviours habit formation
where is the basal ganglia located?
deep to cerebral hemispheres
what makes up the basal ganglia?
largest part = corpus striatum
substantia nigra
subthalamic nucleus
what is found within the corpus striatum?
caudate and lenticular nuclei
what makes up the lenticular nuclei?
putamen
globus pallidus internus and externus
corpus striatum
receives afferents from cortical and subcortical structures
dorsal and ventral divisions
dorsal striatum
involved in control over conscious motor movements and executive functions
consists of caudate nucleus and putamen, which is separated by the internal capsule
ventral striatum
responsible for limbic functions of reward and aversion
consists of nucleus accumbens and olfactory tubercle
substantia nigra
in the midbrain but part of basal ganglia
consists of pars compacta and pars reticulata
basal ganglia damage
tremors involuntary muscle movements abnormal increase in tone difficulty initiating movements abnormal posture
Lewy bodies
toxic alpha synuclein protein aggregates
what is hemiballism?
hyperkinetic involuntary forceful movements of the ipsilateral arm and leg
pathophysiology of hemiballism
lesion in the contralateral subthalamic nuclei
which reduces the indirect pathway signalling and leads to overabundance of activity in the firect pathway
causes of hemiballism
stroke traumatic brain injury amyotrophic lateral sclerosis nonketotic hyperglycaemia neoplasm vascular malformation
