Type of cavity is a term used to describe the various hollow spaces in the body. NASAL cavities are two hollow spaces located in the skull, one on each side of the nose. They are lined with mucous membranes and are connected to the NASAL passages. Sinuses are air-filled cavities located in the bones of the face and skull. They are connected to the NASAL passages and help to humidify and filter the air that is breathed in.