[Fine morphological studies on the connective tissue core and the epithelial cells of the lingual papillae in Mogella wogura wogura].

Abstract

The three-dimensional structure of the connective tissue core (CTC) of each type of lingual papillae of Mogella wogura wogura was studied by scanning electron microscopy after removal of the epithelial cell layer and compared with the results obtained from light microscopy as well as transmission electron microscopy. Filiform papillae are densely distributed on the dorsal surface of the anterior part of the tongue. They were conical in shape and their connective tissue cores (CTCs) resembled wooden spoons at the tip of the tongue, while they were flower-shaped (Lysichiton camtschatense) at the middle part of the tongue. Fungiform papillae which had a round depression on the top were distributed sporadically among the filiform papillae, and contained columnar CTC with several plane striations running longitudinally along the lateral surface. A pair of vallate papillae was located at the boundary between the anterior and posterior tongue. Their CTC were flower shaped closely resembling a carnation. Giant conical papillae occupied the posterior marginal region of the tongue. These papillae contained much smaller conical CTC similar to the outer form. Light and transmission electron microscopic observations of the dorsal lingual epithelium revealed three different regions: anterior region to the filiform papillae, posterior to the papillae and interpapillary region. In the intermediate layers between the germinal layer and the surface layer of the anterior region to the filiform papillae, a large number of keratohyaline granules was observed, but the cornified layer was obscured. In the posterior region, keratohyaline granules were fewer in number and the cornified layer was clear and thick. In the interpapillary region, keratohyaline granules were few and a thin cornified layer was recognized. At higher magnification, small sized keratohyaline granules contained a large number of free ribosomes, suggesting a close relationship between the two. Odland bodies were found only on the interpapillary region.