the brain is a part of the central nervous system
frontal_lobe is brain. central_nervous_system is nerve_tissue. central_nervous_system is internal_body_part. nervous_system is body_part. central_nervous_system is body_part. peripheral_nervous_system is body_part. peripheral_nervous_system is brain. central_nervous_system is organ_system. central_nervous_system is system. human_nervous_system is body_part.