Anatomy of the Basal Ganglia

INTRODUCTION

the basal nuclei are the subcortical intracerebellar mass of grey matter forming important parts of the extrapyramidal system.

NUCLEI OF THE BASAL GANGLIA

The basal ganglia 3 main nuclei:

1. Corpus Stratum

2. Amygdaloid body - part of the limbic system

3. calustrum

CORPUS STRIATUM

The corpus striatum is further divided into 2 nucleus

Caudate Nucleus

• C-Shaped

• Surrounded by the lateral ventricle.

• The nucleus contains Head, body, and tail region.

Lentiform Nucleus

• Biconvex nucleus.

• formes the lateral boundary of the internal capsule.

• divided into 2 parts by the lamina of white matter.

• large lateral part - Putamen.

• small medial part - Globus Pallidus

CONNECTIONS OF BASAL GANGLIA

Basal ganglia give both afferent fibers and efferent fibers.

AFFERENT FIBERS - caudate nucleus and putamen.

EFFERENT FIBERS - globus pallidus.

FUNCTIONS OF CORPUS STRIATUM

• regulates muscle tone and smoothes voluntary muscles.

• controls automatically associated movements.

• controls coordinated movement for expression.

• influences the precentral motor cortex and the extrapyramidal activities of body.

• contributes to the cognitive functioning of brain.

• execution of patten movements.

• corpus striatum, motor cortex, and cerebellum join together to plan and execute voluntary movements.

• Basal Ganglia and cerebellum does not initiate movements, They adjust motor commanding.

image credits:

Wikipedia - https://en.wikipedia.org/wiki/Basal_ganglia#/media/File:Blausen_0076_BasalGanglia.png

Reference - BD chaurasias for dental students.