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BASAL GANGLIA

CREATED BY: TEJUS KAUR
: B P T 3 RD Y E A R

ANATOMY OF BASAL GANGLIA
➢ Basal ganglia is a group of nuclei in the forebrain and

upper part of brain stem that have motor function of
great importance
...

➢ Putamen and globus pallidus are together called
lenticular nucleus
...

➢ Substantia nigra is subdivided into:
• Dorsomedial pars compacta
• Ventrolateral pars reticulata

CONNECTIONS OF BASAL GANGLIA
➢ The basal ganglia forms extensive interconnection

with the cerebral cortex and the thalamus
...
They include
 Corticostriate projection: They form afferents from all four lobes of
cerebral cortex
...


Internulear connections
➢ Dopaminergic nigrostriatal tract: pars compacta of

substantia nigra contains cell body having
dopamine(inhibitory neurons)and its axon
terminate in neostraitum
...


➢ The subthalamic nucleus projects via glutamic acid
secreting excitory neurons to:
 Both internal and external segments of globus pallidus; and
 The substantia nigra

Efferent connections
➢ The input from basal ganglia is from globus pallidus & substantia nigra
...

 pars reticulata projects to ventrolateral & ventroanterior nuclei of
thalamus
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 The activity of basal ganglia increases during slow, steady








damp movements and is silent during rapid movement
...

Neostriatum regulates the subconscious gross movements
occurring in group of muscles
...

Globus pallidus provides appropriate muscle tone
...


Diseases
➢ Parkinson’s disease: (also known as shaking palsy)

This condition occurs usually in late middle age due to
degeneration of dopaminergic nigrostriatal tract
...

Characteristic features are: Rigidity
 Tremors
 Akinesia and bradykinesia

Diseases
➢ Chorea and Athetosis

These two disorders are characterized by spontaneous involuntary
movements due to interruption of the inhibitory pathway from area
4s via the caudate nucleus to the thalamus
 Chorea is mainly involvement of caudate nucleus and is
characterized by rapid ,irregular involuntary movements of short
duration
...

➢ Huntingson’s disease :It is an autosomal dominant inherited
disorder
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➢ Hemiballism: It is due to damage of subthalamic nucleus and is
characterized by spontaneous attack of incoordinated movements
affecting whole of the opposite side of the body
...
It id
characterized by muscular rigidity, tremor, cirrhosis of liver, and
emotional disturbances

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