internal capsule

Function

• the internal capsule is the major route by which the cerebral cortex is connected with the brainstem & spinal cord

Structure

• layer of myelinated nerve fibers 8-10 mm thick separating the caudate nucleus & thalamus, medially, from the lentiform nucleus (globus pallidus & putamen)

The internal capsule consists of:

• fibers ascending from the thalamus to the cerebral cortex
• fibers descending from the cerebral cortex to the thalamus, subthalamic region, midbrain, hindbrain & spinal cord

The internal capsule is continuous with the corona radiata, superiorly & laterally

On horizontal section of the brain, it appears in the form of a V opening laterally on each side

The angle (pointing medially) is called the genu; the sides are called the anterior & posterior crus.

More general terms

• cerebral white matter
• CNS white matter tract

More specific terms

• anterior limb of internal capsule
• genu of internal capsule
• posterior limb of internal capsule
• retrolenticular part of internal capsule
• retrolenticular/retrolentiform limb of internal capsule
• sublenticular limb of internal capsule
• sublenticular part of internal capsule

Additional terms

• corona radiata

Component of

• cerebral white matter

Components

• corticobulbar tract
• corticospinal tract