centrum semiovale

Beneath the grey matter of the cerebral surface lies the semioval centre, the white matter of the cerebral hemispheres. Taken as a whole, the white matter lying in each hemisphere between the cerebral cortex and the deep nuclei has a semioval shape, which is the origin of the name; the term is used synonymously with cerebral white matter. Its composition is described in three fibre classes: cortical projection fibres, association fibres, and cortical fibres. Because the region is defined by the fibre systems crossing it rather than by a cell population, it is treated in descriptive anatomy as a compartment of the cerebral hemisphere white matter, and its Latin designation is centrum ovale.