The tongue of the red panda (Ailurus fulgens fulgens Cuvier, 1825)—a stereoscopy, light microscopy and ultrastructural analysis

In the light of recent molecular studies, there are two phylogenetic species of the red panda (Ailurus fulgens): Ailurus fulgens fulgens and Ailurus fulgens styani. The red panda belongs to the endangered species living in the wild only in Asia and is included in the CITES list. Although the biology and diet of this species has been extensively described, the histological structure of the tongue and lingual glands has not yet been characterized in detail in relation to the lifestyle of this mammal under specific conditions and as a basis for comparative anatomical studies of the biodiversity of endemic species. Study samples were collected from two adult males of Ailurus fulgens f. held in Wrocław Zoological Garden. Both tongues were examined macroscopically; moreover, samples with lingual papillae for light microscopy and scanning electron microscopy (SEM) were collected from the apex, body and root of the tongue. Both tongues of the Ailurus fulgens f. males were approximately 9 cm long. The dorsal lingual surface was covered with mechanical and gustatory lingual papillae. Filiform papillae were observed on the apex and the body of the tongue, while small conical papillae were observed on the root of the tongue. An elongated, 1–1.5 cm long cylinder-shaped lyssa was observed in the ventral part of the apex. Moreover, most numerous and largest round in shape fungiform papillae were observed on the apex and on the border of the body and root of the tongue, located directly rostrally to 12–13 round and oval in shape vallate papillae. The SEM study showed that filiform papillae on the apex had several long secondary processes, while filiform papillae on the body of the tongue were taller and their secondary papillae were shorter than the equivalent structures on the apex of the tongue. The SEM study showed numerous taste pores on the surface of the fungiform papilla, while irregular surface of the vallate papillae, however some of them had smoother surface. Mixed glands (comprised of mucous acini and serous acini) were present within the vallum (within the connective tissue core) of the vallate papilla. Beneath the papillae more serous glands were observed, while the posterior lingual glands in the caudal part of the root of the tongue were mucoserous (mucous units were prevalent). A characteristic feature of the tongue of Ailurus fulgens f. was the presence of lyssa, which is comparable to other representatives of Carnivora, but the number of vallate papillae was individually variable. The lack of strongly developed mechanical conical papillae probably may be related to the type of plant food that is particularly dominant in red panda. Further differences between Ailurus fulgens f. and Ailurus fulgens s. cannot be excluded. The results of these studies may be useful especially for veterinarians specializing in working with exotic animals and people dealing with wildlife conservation.

Microstructure of the Surface of the Tongue and Histochemical Study of the Lingual Glands of the Lowland Tapir (Tapirus terrestris Linnaeus, 1758) (Perissodactyla: Tapiridae)

Although the anatomy of the gastrointestinal tract has been characterized in the lowland tapir (Tapirus terrestris), the exact anatomy of its tongue has not been studied. Samples of the lingual papillae and lingual glands were collected from the tongue of an adult female lowland tapir. The microscopic analysis of the structure of the lingual papillae and the histochemical analysis of the secretion of the lingual glands were analyzed. The tongue of the tapir is divided into the apex, body with a distinct lingual prominence, and the root. Its ventral surface is smooth. The most numerous of the mechanical papillae were the filiform papillae, while numerous conical papillae with a sharp apex or more rounded papillae were present in the root of the tongue. There were also nine vallate papillae and pair of foliate papillae. The foliate papillae contained several folds parted by 12–14 grooves. The mucous secretion produced by the lingual glands was more obvious than the serous secretion. The features of the dorsal surface of the tongue as well as the shape and number of the lingual papillae on the surface of the tongue of the examined female tapir differ compared to Equidae or Rhinocerotidae, the other two representatives of Perissodactyla. However, further study is necessary for the synapomorpy of the tapir’s tongue.

The Pseudolesions of the Oral Mucosa: Differential Diagnosis and Related Systemic Conditions

Pseudolesions are defined as physiological or paraphysiological changes of the oral normal anatomy that can easily be misdiagnosed for pathological conditions such as potentially malignant lesions, infective and immune diseases, or neoplasms. Pseudolesions do not require treatment and a surgical or pharmacological approach can constitute an overtreatment indeed. This review aims to describe the most common pseudolesions of oral soft tissues, their possible differential diagnosis and eventual related systemic diseases or syndromes. The pseudolesions frequently observed in clinical practice and reported in literature include Fordyce granules, leukoedema, geographic tongue, fissured tongue, sublingual varices, lingual fimbriae, vallate papillae, white and black hairy tongue, Steno’s duct hypertrophy, lingual tonsil, white sponge nevus, racial gingival pigmentation, lingual thyroid, and eruptive cyst. They could be misdiagnosed as oral potential malignant disorders, candidiasis, Human Papilloma Virus (HPV)-related affections, oral autoimmune diseases, or benign and malignant tumors. In some cases, pseudolesions feature in a syndromic panel, for example, fissured tongue in Melkersson–Rosenthal syndrome. It is strictly fundamental for dentists to know and to distinguish oral pseudolesions from pathological conditions, in order to avoid overtreatment.

Maturation of human lingual papillae during second and third trimesters: a fetal histo-morphological study

Introduction: The aim of this study was to describe the histological changes of tongue in a growing fetus. There are very few studies on histogenesis of tongue in human fetuses. Therefore the present study was carried out to describe the histogenesis of human fetal tongue at different gestational ages. Material and Methods: The present cross sectional study was conducted on 20 fetuses (both males and females). The tissue sections including both the anterior two thirds and the posterior one third of the tongue were dissected. The slides were stained with Hematoxylin and Eosin (H & E) for microscopic observation. The images were analysed digitally using ImagePro Premier 9.1 Software. Results: At 20th week, the tongue was lined by stratified squamous non keratinized epithelium and the different types of papillae were distinguishable. No taste buds were observed along the vallate papillae. The glandular and muscular components were well differentiated. At 24 weeks of gestation and the surface of the tongue was lined by non-keratinized stratified squamous epithelium. At 36 weeks the thickness of the epithelium was significantly reduced and the vascularity of lamina propria was increased. Conclusion: As the prenatal development of the human lingual papillae during the irst trimester is already known through the literature, the present study highlighted the structural maturation of the papillae during second and third trimesters.

Morpholoical Study of the Brandt’s Hedgehog, Paraechinus hypomelas (Eulipotyphla, Erinaceidae), Tongue

The morphology and histological structure of two adult Brandt’s hedgehog, Paraechinus hypomelas, (Brandt, 1836) tongue were examined by light and scanning electron microscopy. On the dorsal surface of the tongue, three types of papillae were observed: filiform, fungiform and vallate papillae. Apex and corpus of the tongue as well as the lateral surface of the corpus were covered with numerous filiform papillae with bifurcated tip, while the epithelium lining the ventral lingual surface was free from papillae. Discoid shape fungiform papillae were scattered over the entire surface of the lingual apex, corpus and lateral surface uniformly between the filiform ones without regional variation in number and size. Three elliptical or oval vallate papillae in an inverted triangle form were found on the root of the tongue. Each papilla had a lobulated and very irregular dorsal surface. Both fungiform and vallate papillae contain taste buds. The foliate papillae was absent. Overall, the present findings reveal that despite some similarities, the lingual papillae of the Brandt’s hedgehog as an omnivore animal has spices-specific characteristics compare to the Erinaceous auritus as an insectivore species. This finding provides a set of basic data about the morphology of tongue and its lingual papillae in Brandt’s hedgehog.

Scanning Electron Microscopic Studies of the Lingual Papillae in the English Horse

The purpose of this study was to describe the distribution and surface structure of the lingual papillary system in four male adult English horses by scanning electron microscopy. The animals were supplied from the Jockey Club of Turkey (TJK). Tissue samples were taken from the dorsal, ventral and lateral surface of the apex, corpus and radix of the tongue. Filiform papillae were distributed mainly on the dorsum, being abundant, very long and with a slim cylindrical form with pointed endings or multi-bifurcated terminations at the apex. These papillae were typically conical in shape with a wider base in the corpus of the lingua and absent on the radix of the lingua. Fungiform papillae were mainly on the lateral surfaces and lobulated forms were also observed. The horses have two large vallate papillae, located on the dorsum close to the caudal part of the tongue. These papillae were surrounded by a prominent gustatory groove. The vallate papillae had many taste pores opening into the papillary groove. The foliate papillae were observed just rostral to the palatoglossal arches. These papillae have many variable sized taste pores which open into the grooves between the papillary leaves. The papillary leaves were covered with concentrically arranged cornified cells of variable appearance. However, there were no lingual papillae on the ventral aspect of the horse’s tongue.