The internal capsule is composed of all of the fibers going to and coming from the cerebral cortex, linking the cerebral cortex to other parts of the nervous system. These include the thalamus, brainstem, spinal cord, basal ganglia, diencephalon, and midbrain. The internal capsule can be divided into five regions: the anterior limb, posterior limb, genu, retrolentiform, and sublentiform.