basal ganglia
- BASAL GANGLIA
- Situation
- lateral to thalamus
- Parts
- divided by a band of nerve fibers internal capsule in to
- Caudate nucleus ( पुच्छ ज्ञान्ड (neostriatum / striatum)
- Lentiform nucleus ( चंद्र )
- dark lateral part
- putamen ( neostriatum / striatum)
- medial paler part
- globus pallidus ( also called paleostriatum / pallidum )
- Anteroinferior ends of these nuclei
- remain connected by a few bands of grey matter
- across anterior limb of internal capsule
- these bands give it a striated appearance
- corpus striatum
- Detailed Parts
- Caudate nucleus
- shape
- comma shaped mass of grey matter
- Round anterior part in front of interventricular foramen is called
- head
- large and rounded
- forms floor and lateral wall of anterior horn of lateral ventricle
- bands of grey matter connect it to putamen
- across anterior limb of internal capsule
- middle part
- head tapers in to body
- long and narrow
- forms floor of central part of lateral ventricle
- separated from thalamus by
- stria terminalis and thalamostriate vein
- posterior
- situation and extent
- surrounds thalamus
- itself is surrounded by lateral ventricle
- Lentiform nucleus
- shape
- lens shaped ( biconvex) mass of grey matter
- situation
- beneath insula
- forming lateral boundary of internal capsule
- 3 surfaces
- lateral surface
- convex
- related to thin sheet of white matter
- external capsule
- grooved by
- lateral striate arteries ( central branches of middle cerebral artery)
- medial surface
- more convex
- related to internal capsule ( limbs and genu )
- inferior surface
- related to sub lentiform part of internal capsule
- lies close to anterior perforated substance
- parts
- a vertical plate of white matter ( external medullary lamina ) divides it in to
- putamen
- globus pallidus
- smaller medial part
- lighter in colour
- consists large motor cells
- also called pallidum
- further subdivided by internal medullary lamina in to
- outer part or externa
- inner part or interna
- Connections of corpus striatum
- Afferent connections
- Corticostriate fibers
- Thalamostriate fibers
- Nigrostriate Fibers
- Efferent connections
- Globus pallidus is the main efferent component
Discussion