Introduction To Basal Ganglia

1. BASAL GANGLIA
PUBALI KALITA
BPT STUDENT

2. Contents
• Anatomy
• Classifications
• Functions
• Disorders

3. Anatomy --
• Definition :
The basal ganglia are masses of grey
matter embedded within the white matter
of cerebrum .
The basal ganglia are now recognised
as basal nuclei , but the former term is
still commonly used .
The basal ganglia are situated at the base
of the forebrain and top of the midbrain.

4. • Anatomically , it consists of ----
1. CORPUS STRAITUM
2. CLAUSTRUM
3. AMYGDALOID BODY
• Functionally , it consists of ----
1. CORPUS STRAITUM
2. CLAUSTRUM
3. AMYGDALOID BODY
4. SUBSTANTIA NIGRA
5. SUBTHALAMUS
6. RED NUCLEUS .

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9. CORPUS STRAITUM
• Corpus striatum consist of caudate nucleus & lentiform nucleus .
• Caudate nucleus is a C- shaped or comma shaped nucleus . It has head , body
& tail .
• Lentiform nucleus is a large lens shaped (biconvex) nucleus . It is divided into
globus pellidus (medial part ) & putamen (lateral part ) .
• Corpus striatum functionally consist of 2 units – 1) Paleostriatum & 2)
Neostriatum .
• Globus pellidus is included under Paleostriatum .
• Putamen & Caudate nucleus is included under Neostriatum .

10. CLAUSTRUM
• It is a saucer – shaped nucleus situated between the putamen and the insula .
• The word claustrum means ‘hidden away’, and indeed, the claustrum is a thin,
irregular sheet of grey matter, one sheet on each side of the head, concealed
between the inner surface of the neocortex.
• It’s function may be playing a role in synchronizing perceptual, cognitive and
motor processes and knowledge processing

12. AMYGDALOID BODY
• It is a small mass of grey matter attaches to the tail of caudate body .
• Topographically , it is continuous with the tail of the caudate nucleus , but functionally it is
related to the striaterminalis . It is a part of limbic system .

13. SUBSTANTIA NIGRA
• It is located in the mid- brain between the crus cerebri & tegmentum .
• The neurons of substantia nigra produce dopamine .

14. SUBTHALAMIC NUCLEUS
• It is a small mass of grey matter present under the thalamus .
• It is a lens shaped nucleus .
• Only portion of basal ganglia that actually produces an “ excitatory” , glutamate
neurotransmitter .

16. RED NUCLEUS
• It is a paired oval-shaped nucleus .
• It is located in the tegmentum of the midbrain next to the substantia nigra .
• The red nucleus is pale pink, which is believed to be due to the presence of iron in at least
two different forms: hemoglobin and ferritin.

17. FUNCTIONS OF BASAL GANGLIA
1. Control of voluntary motor activity :
• Cognitive control of motor activity .
• Most of the motor actions occur as a consequence of thought process in mind .
• So , basal ganglia is involved in planning and programming of movements .
2. Control of reflex muscular activity :
• Inhibitory effect on spinal reflexes .
• Regulate muscle which maintains posture.
• Mainly visual & labyrinthine reflexes .

18. 3. Timing & scaling of intensity of movements .
4. Decrease muscle tone & unwanted muscular activity .
5. Subconscious execution of some movements :
• Swinging of arm while walking.
• Crude movements of facial expressions with emotions.
• Movement of limbs while swimming .
6. Role in arousal mechanism :
• By connections of globus pallidus and red nucleus with reticular formation .

19. DISORDERS OF BASAL GANGLIA
1. PARKINSONISM
2. BALLISMUS – a) Hemiballismus , b) Monoballismus
3. CHOREA
4. ATHETOSIS
5. WILSON’S DISEASE
6. HUNTINGTON’S DISEASE .

20. Thank You😀