The part of the central nervous system that is contained within the skull. The developed brain consists of cerebrum, cerebellum, and others structures in the brain stem. Diseases of the of the central nervous system pertain to any component of the brain (including the cerebral hemispheres, diencephalon, brain stem, and cerebellum) or the spinal cord. Description adapted from: https://www.ncbi.nlm.nih.gov/mesh/68001921 & https://www.ncbi.nlm.nih.gov/mesh/68002493.