Light and scanning electron microscopic study on the lingual papillae and their connective tissue cores of the Cape hyrax Procavia capensis

Abstract

We examined the epithelial surface and connective tissue cores (CTCs) of each lingual papilla on the Paenungulata, Cape hyrax ( Procavia capensis ), by scanning electron microscopy and light microscopy. The tongue consisted of a lingual apex, lingual body and lingual root. Filiform, fungiform and foliate papillae were observed on the dorsal surface of the tongue; however, fungiform papillae were quite diminished on the lingual prominence. Moreover, no clearly distinguishable vallate papillae were found on the tongue. Instead of vallate papillae, numerous domelike large fungiform papillae were arranged in a row just in front of the rather large foliate papillae. Foliate papillae were situated in the one-third postero-lateral margin of the lingual body. The epithelium of filiform papillae was covered by a keratinized layer with kerato-hyaline granules, whereas weak keratinization was observed on the interpapillary epithelium. The external surface of the filiform papillae was conical in shape. CTCs of the filiform papillae were seen as a hood-like core with a semicircular concavity in the anterior portion of each core. Large filiform papillae were distributed on the lingual prominence. The CTCs of large filiform papillae after exfoliation of their epithelium consisted of a concave primary core and were associated with several small protrusions. The surface of fungiform papillae was smooth and dome-like. After removal of the epithelium, CTCs appeared as a flower bud-like primary core and were associated with several protrusions that were arranged on the rim of the primary core. Several taste buds were found on the top of the dorsal part of the epithelium of both fungiform and large fungiform papillae. Well-developed foliate papillae were seen and numerous taste buds could be observed in the lateral wall of the epithelium in a slit-like groove. The morphological characteristics of the tongue of the Cape hyrax had similarities with other Paenungulata such as Sirenia. However, three-dimensional characteristics, especially CTCs of lingual papillae, exhibited multiple similarities with rodents, insectivores and artiodactyls.

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“…The CTCs of FiP of hamsters [a insectivore mole] and the Cape hyrax are conical-shaped with a semicircular concavity on the anterior surface [27,39,40]. Though the descriptions are slightly different from each other, their shapes are similar to the CTC shape of the round tip FiP observed in the present study.…”

“…Many kinds of artiodactyl have a large type of FiP with lenticular or conical shape, which is situated on the lingual prominence corresponding to the intermolar eminence [26]. The large FiP of the Cape hyraxes was found on the lingual prominence and progressively reduced in size as tracing more posteriorly [27]. In cats and pigs, FiP of the posterior tongue is of the simple conical type, while FiP of the anterior tongue had hairlike protrusions in its top [28,29].…”

Morphology of the Lingual and Buccal Papillae in Alpaca (Vicugna pacos) - Light and Scanning Electron Microscopy

“…The morphological and microscopy structures of the tongue in different species including herbivorous and carnivores animals were presented among the many earlier publications (Emura et al., , , , ,b,c, ; Kobayashi et al., ; Jackowiak et al., ; Abd Murad et al, ; Harem et al., ; Pastor et al., ). The tongue anatomy exhibits modification related to the suitable diet (Chamorro et al., ; Emura et al., ,b, ; Kobayashi et al., ; Nonaka et al., ; Pastor et al., ; Yoshimura et al., , ; Park and Lee, ; Ünsaldi, ). The tongue plays a principle role together with teeth, palate and cheeks during feeding, what determines the adaptation form to feeding habits and method of food acquisition.…”

New method for determining surface roughness of tongue

“…Although the degree of atrophy of the lingual papillae can be observed with microscopy and dermoscopy 2,6–11 , subjective diagnosis lacks objective factors, because of difficulties in precisely describing the surface structure of oral lesions 13 . In the present study, quantitative differences in lingual surface roughness values between healthy controls and elderly subjects divided into Normal, Smooth and Rough groups were investigated.…”

“…Atrophic, geographic and fissured tongue conditions each have unique histomorphological features that differ from the histological features of a normal appearing tongue 5 . However, histological diagnosis based only on visual images seen through a microscope is subjective 2,6–11 , whereas objective superficial findings of the macroscopic structure are some of the most important factors for clinical diagnosis and observation of the clinical course 12 . In addition, subjective diagnosis seems to have a low level of accuracy, because it is difficult to precisely describe the surface structures of oral lesions 13 .…”