Basal Ganglia (Nuclei) Flashcards
Basal ganglia
Grey matter collections which are deeply placed inside cerebral hemisphere white matter
Components
- Corpus striatum (formed of caudate and lentiform nuclei)
- Amygdaloid nucleus (smell center)
- Claustrum
Caudate nucleus
C-shaped mass of grey matter partly exposed in ventricular wall and partly buried in hemisphere
Caudate nucleus is formed of
- Head
- Body
- Tail
Head
- Large anterior end
- Forms lateral wall and floor of lateral ventricle anterior horn
Head laterally
it is separated from lentiform nucleus by internal capsule
Head inferiorly
Becomes continuous with putamen anterior end of lentiform nucleus and anterior perforated substance grey matter
Body
- Forms lateral part of body floor of lateral ventricle
- It’s lateral aspect is related to internal capsule
Tail
- Present in inferior horn roof of lateral ventricle
- Terminates in amygdaloid nucleus in most anterior part of inferior horn roof
Lentiform nucleus
Completely embedded in hemisphere
Consists of 2 parts:
1. Putamen
2. Globus pallidus
Putamen
Larger darker lateral part
Globus pallidus
Smaller pale medial part
Globus pallidus is subdivided by
- Internal and external segments by internal medullary lamina
- Both parts are separated by whitish streak
Globus pallidus shape
Looks like a biconvex lens having two convex surfaces:
1. Lateral
2. Medial
Lateral surface Globus pallidus
- Slightly convex
- Related to external capsule which separates it from claustrum
Medial surface Globus pallidus
- Markedly convex
- Related to internal capsule which separates it from thalamus and caudate nucleus
Lentiform nucleus relation
It is related to 2 capsules:
1. Internal capsule
2. External capsule
Amygdaloid nucleus
- Smell center
- It’s axons forms stria terminalis which ends in hypothalamus
Amygdaloid nucleus site
- Lies mostly in uncus at anterior end of caudate nucleus tail in inferior horn roof of lateral ventricle
- Fuses with cerebral cortex lateral to anterior perforated substance
Amygdaloid nucleus shape
Small round mass
External capsule
Thin layer of white matte covering lentiform nucleus lateral surface and separating it from claustrum
Claustrum
- Thin grey matter layer between lentiform nucleus lateral surface and insula
- Separated from lentiform nucleus by external capsule and from insula by extreme capsule
Blood supply of corpus striatum
- Anterior cerebral artery
- Middle cerebral artery
- Anterior choroidal artery (branch of ICA)
Anterior cerebral artery supply
- Anterior part of corpus striatum
- Anterior part of internal capsule anterior limb
By central branches
Middle cerebral artery supply
- Rest of corpus striatum
- Posterior part of anterior limb
- Genu
- Anterior part of internal capsule posterior limb
By central (striate) branches
Anterior choroidal artery supply
- Caudate tail
- Amygdaloid nucleus