Internal Capsule Flashcards
Internal capsule
Broad projection fibers bundle
Site
- Lies between lentiform nucleus (lateral) and caudate head and thalamus (medial)
- Almost completely divides corpus striatum into 2 parts
- Continuous above with corona radiata and below with basis pedunculi of midbrain cerebral peduncles
Shape
In horizontal section, it has V shaped appearance:
1. Short anterior limb
2. Apex (genu)
3. Longer posterior limb
4. Retro-lenticular part
5. Sub-lenticular part
Short anterior limb site
Lies between lentiform nucleus (lateral) and caudate nucleus head (medial)
Short anterior limb contents
- Fronto-pontine fibers
- Anterior thalamic radiation
Genu site
- Angle at junction of anterior and posterior limbs
- Fits into interval between caudate head (in front) and thalamus (behind)
Genu contents
Cortico-nuclear fibers
Longer posterior limb site
Lies between lentiform nucleus (lateral) and thalamus (medial)
Longer posterior limb contents
- Frontopontine fibers
- Corticospinal fibers
- Corticorubral fibers
- Corticostriate fibers
- Superior thalamic radiation
Retrolenticular part site
Lies behind lentiform nucleus
Retrolenticular part contents
- Optic radiation
- Parietopontine fibers
- Occipitopontine fibers
Sublenticular part site
Lies below lentiform
Sublenticular part contents
- Auditory radiation
- Temporopontine fibers
Blood supply
- Anterior cerebral artery
- Middle cerebral artery
- Anterior choroidal artery
Anterior cerebral artery supply
Posterior part of anterior limb is supplied by the central branches
Middle cerebral artery supply
Posterior part of anterior limb, genu and anterior part of posterior limb are supplied by the central branches
Anterior choroidal artery
Branch of the ICA
Posterior part of posterior limb, retrolentiform and sublentiform
