frontal operculum

operculum frontale 1. [TA] the portion of the insular opercula within the frontal lobe; it corresponds to the pars orbitalis, pars triangularis, and pars opercularis of the inferior frontal gyrus together with the lower end of the precentral gyrus. 2. the portion of the insular opercula lying between the anterior and ascending rami of the lateral sulcus, corresponding to the pars opercularis gyri frontalis inferioris; when used this way, the term is contrasted with the operculum frontoparietale. It may also be expanded to include the pars orbitalis gyri frontalis inferioris, in which case the frontal operculum is said to have two parts: frontal and orbital. 3. the anterior portion of the operculum frontoparietale, corresponding to the pars opercularis gyri frontalis inferior.