Basal Ganglia.pdf..............................

anatomy of basal ganglia

1. Basal Ganglia

2. Learning Objectives
•List the different
nuclei of basal
ganglia.
•Mention their
functions,
connection and
applied aspects.

3. •Basal ganglia are the
large masses of gray
matter situated within the
white matter of the
inferior part of the each
cerebral hemisphere.
Basal Nuclei

4. Functions of corpus striatum (basal ganglia)
•Regulates muscle tone & smoothens the voluntary movements.
•Controls automatic associated movements like swinging of arms during
walking.
•Regulate group of movements for emotional expression.
•Initiates desired movements.
•Prevent unwanted movement /muscular activity.
•Basal ganglia, cerebellum and motor area responsible for planning ,
execution and control of voluntary movement.

5. 1.Corpus striatum
•Caudate nucleus
•Lentiformnucleus:
Putamen (lateral
part), Globus
pallidus(medial
part)
2.Amygdaloid body:
Amygdala
3.Claustrum
Basal Nuclei

6. Transverse section

7. Phylogenetic Classification of Basal Ganglia
•Neostriatum / striatum (Recent in development): Caudate nucleus and
Putamen
•Paleostriatum/ Paleopallidum(older in development): Globus pallidus
•Archistriatum(primitive in development): Amygdaloidnucleus and
claustrum
•Functionally Basal Ganglia also include (in Brainstem)
•Substantianigra
•Subthalamus
•Red nucleus

8. Caudate Nucleus
•C-shaped/comma shaped
•Has head ,body & tail
•Concavity of C encloses:
Thalamus & Internal
capsule
•Surrounded by lateral
ventricle
•Tail is in continuity with
amygdaloidbody
(amygdala)

9. Lentiform nucleus
•Lens shaped: biconvex.
•Forms lateral boundary
of internal capsule.
•Lies beneath the insula
and the claustrum.
Divided into two part by
thin external lamina of
white matter (lateral
medullary lamina)
i)Lateral part: Putamen
ii)Medial part: Globus
pallidus

10. Putamen:
•Larger lateral part
•Darker in color
•Structurally similar to caudate nucleus
Globus pallidus:
•Smaller medial part
•Lighter in color / pale: called pallidum
•Further divided into inner segment &
outer segment (Globus pallidus
externaand globuspallidusinternaby
internal medullary lamina)

11. Connections of Corpus
Striatum
•Neostriatum (Caudate nucleus &
Putamen):
Afferent(sensory) nuclei: receive
afferent fibers
•Globus pallidus(Paleostriatum/
pallidum):
Efferent (motor) nucleus: gives
efferent fibres
Schematic Diagram showing connections of Basal Ganglia

12. claustrum
•Saucer shaped nucleus.
•Situated between putamen
and the insula.
•Inferiorly continuous with
anterior perforating
substance.
•Function is unknown but it
seems to receive nerve
fibres through external
capsule.

13. Amygdaloid body
•An almond shaped nuclear
mass in the temporal lobe
•Continuous with tail of
caudate nucleus
•It is part of limbic
system(Developmentally it is related
to the basal nuclei but functionally it is
included in the limbic system)
•Related to anxiety and
rage
•Its lesion leads to orality
and hypersexuality

14. Applied Anatomy
•Lesion of Basal ganglia & cerebellum produce
1) abnormal movements
2) abnormal posture
3) abnormal muscle tone
•But not muscle paralysis

15. Parkinson’s disease (Parkinsonism)
•Cause:lesion of corpus stratum, and
substantianigra.
•Features:
•Rigidity–lead-pipe rigidity
(hypertonocity)
•Loss of automatic associated movements
like swinging of hand
•Loss of facial expression (mask like face)
•Tremors–resting tremor (pill rolling
tremor of hands)
•Flexor posture
•Difficulty in voluntary movements
(hypokinesia)

16. Chorea (means dancing)
Due to lesion of caudate nucleus
•Characterised by quick , jerky, purposeless involuntary movements of
tongue, face and limbs (hands & feet)
Huntington’s Chorea
sydenham’s
chorea
in
adult