Characteristics of filiform, fungiform and vallate papillae and surface of interface epithelium-connective tissue of the maned sloth tongue mucosa (Bradypus torquatus, Iliger, 1811): Light and Scanning Electron Microscopy Study.

The study of lingual surfaces and the surface of interface epithelium-connective tissue of the tongue of Bradypus torquatus was performed by employing the light and scanning electron microscopy (SEM) techniques. The results revealed that the rostral part of the tongue presents a round apex and covered by filiform and fungiform lingual papillae and a ventral smooth surface. It was observed that the epithelial layer of the dorsal surface possesses the basal, spinosum, granular and cornified epithelial cells. The lamina propria is characterized by a dense connective tissue forming the long, short and round papillae. Numerous typical filiform papillae are located especially in the rostral part intermingled for few fungiform papillae, which were revealed in three-dimensional SEM images. Usually, the fungiform papillae are located in the border of rostral apex of the tongue exhibiting the rounded form. They are covered by keratinized epithelial cells. In the fungiform papillae, several taste pores were observed on the surface. The vallate papillae presented numerous taste buds in the wall of epithelial cells, being that the major number of taste buds is located on the superior half of vallate papilla. The taste pores are surrounded by several laminae of keratinized epithelial cells. The samples treated with NaOH solution and examined by SEM revealed, after removal of the epithelial layer, the dense connective core in original disposition, presenting different sizes and shapes. The specimens stained with Picrosirius and examined by polarized light microscopy revealed the connective tissue, indicating the collagen fibres type I and type III.

Ultrastructure of the myelinated and unmyelinated nerve fibers of the tongue mucosa of albinus rat (Wistar) with aging / Ultraestructura de las Fibras Nerviosas Mielínicas y Amielínicas de la Mucosa Lingual de ratas Albinas (Wistar) Envejecidas

El objetivo de esta investigación fue estudiar las fibras sensitivas mielinizadas y amielínicas localizadas en la lámina propia subepitelial de la mucosa lingual de ratas. Se usó el método de impregnación argéntica, microscopía MET y mediciones morfométricas. Los resultados revelaron que los fascículos de fibras subepiteliales de las regiones anterior, media y posterior de la lengua provenían de su capa muscular profunda. Los grupos de fibras fueron localizados dentro del tejido conectivo de la lámina propia. Estas fibras nerviosas se ramificaron varias veces y en el tejido conectivo de las papilas formaron terminaciones simples o ramificados. Las papilas fungiformes y valadas contenían numerosas terminaciones nerviosas. La ultraestructura demostró en el axoplasma la presencia de neurofilamentos, mitocondrias y microtúbulos; aunque los registros morfométricos de las fibras mielinizadas mostraron que alrededor del 44 por ciento tenían un diámetro entre 3 y 4 µm, el valor promedio fue de 4.5 µm. El diámetro mayor fue de 12 µm y el menor de 1.4 um. Los rangos de menores diámetros fueron de 1 a 3 µm, siendo el promedio de 2.33 µm. En relación al espesor de las vainas de mielina, los valores obtenidos fueron de 0.2 a 0.8 um siendo el valor promedio de alrededor de 0,5 µm, en el 90 por ciento de ellas. En las fibras amielínicas los mayores diámetros (62 por ciento) variaron entre 0.25 y 0.75 µm. El valor promedio fue de 0.6 µm, siendo el valor máximo 3.17 µm y el mínimo 0.2 µm. El menor diámetro fue obtenido en 44 por ciento de las fibras amielínicas y los rangos variaron entre 0.2 y 0.4 µm. El valor máximo obtenido fue de 1 µm y el mínimo 0.12 µm.

The purpose of this paper was to study the sensory myelinated and unmyelinated nerve fibers found in the subepithelial lamina propria of tongue mucosa of aging rats. It was used the silver impregnation, transmission electron microscopy methods and morphometric measurements. The results revealed that subepithelial nerve fiber bundles of the anterior, medium and posterior regions of tongue were arise from deep muscular layer of tongue. The nerve fiber bundles were verified inside of the connective tissue of lamina propria. These nerve fibers branched several times and into the connective tissue papillae they form a single or ramified sensory nerve endings. The fungiform and vallate papillae contain numerous nerve terminals. The fine structure demonstrated that in the axoplasm were noted the presence of neurofilaments, mitochondria and microtubules. Although the morphometric data of myelinated fibers showed that about 44% having larger diameter between 3 to 4 µm and the mean value was 4.5 µm. The largest diameter was 12 µm and the smaller was 1.4 um. The smallest diameter ranges from 1 to 3 µm, being that the mean value was 2.33 µm. Concerning to the thickness of myelin sheets were revealed the values ranging from 0.2 to 0.8 µm being that the 90% present the values around 0.5 µm. The unmyelinated fibers showed the largest diameter (62%) varying from 0.25 to 0.75 µm. The mean value was 0.6 µm being the maximum value was 3.17 µm and the minimum was 0.2 µm. The smallest diameter was obtained in 44% of unmyelinated fibers which the diameter ranges from 0.2 to 0.4 µm.Then maximum value obtained was 1 µm and the minimum was 0.12 µm.

Light and scanning electron microscopic studies of the angioarchitecture of intrinsic muscle fibers of the anterior rat tongue.

Histological and scanning electron microscopy (SEM) characteristics of the microvasculature of muscle fibers in the anterior third of the adult rat tongue are described. For light microscopy, the specimens were embedded in paraffin and frontal sections were stained with Picro-Sirius. Thick sections were obtained from Spurr embedded samples and stained with toluidine blue solution. For SEM, specimens were obtained by the corrosion cast method and fractured specimens in dimethyl sulfoxide were observed with high-resolution SEM (HRSEM). The blood vessels, enveloped with a thin layer of connective tissue, had fibers running parallel to the muscular fibers. Capillary arterioles were noted following the endomysium, but their lateral branches often ran at right angles to the fibers. The capillary beds were clearly revealed in transverse sections where the individual capillaries appeared ring-like or elliptical in shape. The nuclei of endothelial cell cores could be seen on the vessel surfaces. Collagen fibers type I and III were noted in the connective tissue and in the fibrous layer of vessels.

Scanning electron microscopy of the rat tongue mucosa with special attention to the bacteria on epithelial cell membranes.

The authors examined the filiform and fungiform papillae surfaces of rat tongue by scanning electron microscopy showing the numerous groupings of bacteria on the epithelial cell membranes. The fungiform papillae were round in shape and present few bacteria. The epithelial cell of filiform papillae revealed numerous streptococci. The grouping of the bacteria are attached on the epithelial cell membrane, demonstrating three-dimensional SEM images.

Scanning electron microscopy study of the interface epithelium-connective tissue surface of the lingual mucosa in Calomys callosus.

The characteristics of the interface epithelium-connective tissue of the lingual mucosa of Calomys callosus was studied by employing scanning electron microscopy after removal of the epithelial cells. In the anterior part, the connective tissue papillae of filiform papillae are distributed at random in their original configuration, and the round-shaped fungiform papillae are scattered among the filiform papillae. In the middle part, the filiform papillae present several rod-shaped projections. In the posterior part, the vallate papilla are oval in shape, and the connective tissue reveals a large ridge separated by deep lateral grooves. The posterior adjacent area is a flat surface and shows several openings of salivary gland ducts. The foliate papillae are formed by several small ridges separated by grooves. In the areas adjacent to the foliate papilla, small pointed and laminar papillae were observed.