• Caudate nucleus
• Putamen
• Globus pallidus
• Amygdala
Category 2
Nil
Category 3
Nil
Overview
The basal ganglia consists of a number of subcortical grey matter nuclei grouped by neurological function rather than anatomical relation. They comprise part of a feedback circuit, receiving information from sources such as the cerebral cortex, modulating and refining cortical activity, then feeding the information back to the cortex via thalamus.
- Note: technically the term basal ganglia is a misnomer, as ganglia are collection of cell bodies outside of the central nervous system. Rather, basal nuclei is more accurate as this refers correctly to a collection of subcortical cell bodies inside the nervous system.
Caudate Nucleus
Overview
The caudate nuclei are paired deep subcortical structures which together with the globus pallidus and putamen comprise the corpus striatum (also known as dorsal striatum), a component of the basal ganglia. They are located in each cerebral hemiphere near the centre of the brain, shaped as a highly curved comma which arches superior and posteriorly around the thalamus. These deep brain structures together largely control voluntary skeletal movement.
- The putamen and globus pallidus are collectively termed the lentiform nucleus due to the lens-like shape.
Structure & Relations
- Head
- Large anterior bulbous shaped head which tapers posteriorly to the body
- Forms floor and lateral wall of the anterior horn of the lateral ventricle
- Anterior to anterior limb of internal capsule lentiform nucleus
- Body
- Lies lateral to the body of the lateral ventricle
- Tail
- The tail follows the temporal horn of the lateral ventricle and terminates immediately above it, forming its roof.
Arterial Supply
- Head: Recurrent artery of Heubner (small branch arising from the A1 or A2 segment of the anterior cerebral artery).
- Body: perforating lenticulostriate branches of the middle cerebral artery
- Tail: perforating anterior choroidal artery (branch of C7 (communicating) segment of internal cartoid artery)
Anatomical Variants
- Volumetric variations: larger caudate nucleus observed in multilingual patients
- Recurrent artery of Heubner maybe duplicated/triplicated/quadruplicated
- Variable origin of recurrent artery of Heubner (may branch from A1/A2 segments or anterior communicating artery)
Putamen
Overview
The putamen are round subcortical paired structures located at the base of the forebrain (telencephalon) and forms the lateral part of the basal ganglia.
- The putamen and globus pallidus are collectively termed the lentiform nucleus due to the lens-like shape.
- The putamen and caudate nucleus are collectively termed the corpus striatum.
Arterial Supply
Perforating lenticulostriate branches of the anterior cerebral artery and middle cerebral artery
Relations
- Laterally: external capsule, claustrum, insula cortex
- Medially: globus pallidus, internal capsule, thalamus
Normal Variants
- Variations in predominance of blood supply (either anterior cerebral artery or middle cerebral artery)
Globus Pallidus
The globus pallidi are paired subcortical structures that lie in the telencephalon consisting of an external and internal segment. It is a major component of basal ganglia, receiving input from the striatum and directly outputting to the thalamus and substantia nigra.
- The putamen and globus pallidus are collectively termed the lentiform nucleus due to the lens-like shape.
Structure
The globus pallidus is divided into two functionally different domains:
- Globus pallidus internus (GPi) – medially
- Globus pallidus externus (GPe) – laterally
- The GPi and Gpe are separated by the medial medullary lamina
- The globus pallidus and putamen are separated by the lateral medullarly lamina
Amygdala
The amygdala (Latin: almond) is one of two-almond shaped groups of nuclei located deep within the temporal lobes, primarily associated with emotional processes.
Relations
- Medial to the hypothalamus
- Adjacent to the hippocampus and inferior (temporal horn of the lateral ventricle)
Blood Supply
- Anterior choroidal artery