HA5 shows a filiform papilla. This image is perpendicular to HA2. You can see the layers of the stratified squamous keratinizing epithelium in this image. Filiform papillae do not have taste buds. They have a sensory function. Note the nerve bundles near the center (arrows). The epithelium on the dorsal surface of the tongue is keratinized, but it has only a few layers of stratum corneum (HA4-5).