White Matter of Cerebrum: Corpus Callosum and Internal Capsule
Classification of White Matter of Cerebrum:
- External white matter: lies between cerebral cortex and lateral surface of hemisphere.
- Internal white matter: lies between cerebral cortex and ventricles.
- Deep white matter: lies between cerebral cortex and basal ganglia.
Corpus Callosum:
- Largest commissural tract connecting two hemispheres.
- Connects corresponding regions of two hemispheres.
- Divided into five distinct parts:
- Rostrum: anterior part.
- Genu: bend in the corpus callosum.
- Body: main part.
- Splenium: posterior part.
- Tapetum: lower part of corpus callosum.
Internal Capsule:
- A deep white matter structure in the brain.
- Connects thalamus, basal ganglia, and cerebral cortex.
- Composed of two parts:
- Anterior limb.
- Posterior limb.
- Boundaries:
- Medially by thalamus.
- Laterally by lentiform nucleus.
- Anteriorly by anterior perforating substance.
- Posteriorly by posterior limb.
Blood Supply of Internal Capsule:
- Supplied by anterior cerebral artery, middle cerebral artery, and posterior cerebral artery.
- Areas of internal capsule receive different blood supply:
- Anterior limb: anterior cerebral artery.
- Posterior limb: middle cerebral artery and posterior cerebral artery.
- Blood supply is also influenced by the presence of perforating arteries.