scholarly journals Morphology of the tongue of the emu (Dromaius novaehollandiae). II. Histological features

Author(s):  
M.R. Crole ◽  
J.T. Soley

Although a number of brief, fragmented descriptions have been provided on the gross morphology of the ratite tongue, very few studies have documented the histological structure of this organ. This paper presents the first definitive histological description of the emu tongue and reviews, consolidates and compares the scattered information on the histology of the ratite tongue available in the literature. Five tongues were removed from heads obtained from birds at slaughter and fixed in 10 % neutral buffered formalin. Appropriate longitudinal and transverse segments were removed, routinely processed for light microscopy, and sections examined after staining with H & E and PAS. The entire tongue (body and root) is invested by a non-keratinized stratified squamous epithelium. The supporting connective tissue of the tongue dorsum displays only large, simple branched tubular mucussecreting glands, whereas the caudal tongue body ventrum and tongue root, in addition to these glands, also exhibits small, simple tubular mucus-secreting glands. Herbst corpuscles are associated with the large, simple branched glands. Lymphoid tissue is restricted to the tongue ventrum and is particularly obvious at the junction of the ventral tongue body and frenulum where a large aggregation of diffuse lymphoid tissue, with nodular tissue proximally, was consistently observed. A structure resembling a taste bud was located in the epithelium on the caudal extremity of the tongue root of one bird. This is the first reported observation of taste buds in ratites. Forming the core of the tongue body is the cartilaginous paraglossum lying dorsal to the partially ossified rostral projection of the basihyale. The histological features of the emu tongue are generally similar to those described for the greater rhea and ostrich, except that taste buds were not identified in these species. The results would suggest that the emu tongue functions as a sensory organ, both for taste and touch (by virtue of taste receptors and Herbst corpuscles, respectively), as well as fulfilling an immunological function.

Author(s):  
V. R. Indu ◽  
K. M. Lucy

Histological studies were conducted on the tonsil of soft palate in six month-old male crossbred goats. The tonsil was located on the nasopharyngeal side of the soft palate. The tonsillar surface epithelium presented small folds and was lined by pseudostratified ciliated columnar epithelium in the rostral half and stratified squamous epithelium in the caudal part. The epithelium mounting over the lymphoid accumulation or follicle associated epithelium was modified into a lympho-epithelium and was disrupted and heavily infiltrated by lymphocytes. Distinct crypts were not seen. In the lamina propria, lymphoid tissue constituted only a small portion of the tonsil and only two to three nodules were seen per low power microscopic field. Most of the lymphoid nodules had germinal centers. The average diameter of the nodules was 131.97±8.03 μm. Loose irregular connective tissue, lymphoid tissue and glands comprised the propria submucosa. The tonsil of soft palate was not encapsulated.


2015 ◽  
Vol 87 (2) ◽  
pp. 867-878 ◽  
Author(s):  
Marcella L. Dos Santos ◽  
Fábio P. Arantes ◽  
Kleber B. Santiago ◽  
José E. Dos Santos

The digestive tracts of 44 specimens of Schizodon knerii were studied using anatomical, histological and histochemical techniques. The mouth has terminal position, the lip epithelium is squamous stratified with mucous, claviform cells and taste buds, teeth have an incisive form and the tongue has a stratified squamous epithelium with mucous cells and taste buds. The oropharynx cavity is formed by gill apparatus and pharyngeal teeth. The oesophagus presented pleated mucosa, a stratified squamous epithelium with mucous cells, oesophageal glands and taste buds. The stomach presented cardiac, fundic and pyloric regions, simple prismatic epithelium with tubular glands, with none in the pyloric region. The intestine contains 11-15 pyloric caeca, a simple prismatic epithelium with brush border, goblet cells and lymphocytes. Mucosal cells, oesophageal glands and goblet cells reacted positively to PAS, amylase + PAS, Ab pH 2.5 and Ab pH 0.5. Gastric prismatic cells reacted positively to PAS, amylase + PAS, but only those in the pyloric region reacted positively to Ab pH 2.5 and Ab pH 0.5. The results improve the understanding of the anatomy of S. knerii feeding habits and the presence of mucosubstances in the epithelium, highlights the importance of glycoproteins for passing food through the digestive tract.


2019 ◽  
Vol 13 (2) ◽  
Author(s):  
Aliman Irfandi ◽  
Cut Dahlia Iskandar ◽  
Zainuddin Zainuddin ◽  
Dian Masyitha ◽  
Fitriani Fitriani ◽  
...  

Domestical catfish is grouped into omnivora, although the fish is tended into carnivora.  The aim of the present study was to investigate histology of alimentary tract of domestical catfish (Clarias batrachus). In order to determine alimentary tract of domestical catfish, oesophagus, gastric and intestines is investigated by Haematoxilin Eosin. Histology exploration was performed each layer of alimentary tract’s wall consist of lamina epithelia, propria, and muscularis mucosa. Collagen connective tissue was developed tunica submucosa. The muscle of tunica muscularis was performed circular and elongated. Dense connective tissue and blood vessels was located in the tunica serosa. Histology exploration revealed has stratified squamous epithelium, mucosit cells, eosinophilic club cells on the lamina epithelia, and taste buds on the lamina propria in oesophagus. Gastric was establised simple prismatic cells, and glands of gastric on the lamina propria. Furthermore intestine was showed villi and goblet cells. There were not showed Brunner and Liberkhun gland. In conclusion, histology of alimentary tract was revealed from tunica mucosa, submucosa, and serosa.


2020 ◽  
Vol 21 (17) ◽  
pp. 6000 ◽  
Author(s):  
Wakako Sakaguchi ◽  
Nobuhisa Kubota ◽  
Tomoko Shimizu ◽  
Juri Saruta ◽  
Shinya Fuchida ◽  
...  

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor, angiotensin-converting enzyme 2 (ACE2), transmembrane protease serine 2 (TMPRSS2), and furin, which promote entry of the virus into the host cell, have been identified as determinants of SARS-CoV-2 infection. Dorsal tongue and gingiva, saliva, and tongue coating samples were examined to determine the presence of these molecules in the oral cavity. Immunohistochemical analyses showed that ACE2 was expressed in the stratified squamous epithelium of the dorsal tongue and gingiva. TMPRSS2 was strongly expressed in stratified squamous epithelium in the keratinized surface layer and detected in the saliva and tongue coating samples via Western blot. Furin was localized mainly in the lower layer of stratified squamous epithelium and detected in the saliva but not tongue coating. ACE2, TMPRSS2, and furin mRNA expression was observed in taste bud-derived cultured cells, which was similar to the immunofluorescence observations. These data showed that essential molecules for SARS-CoV-2 infection were abundant in the oral cavity. However, the database analysis showed that saliva also contains many protease inhibitors. Therefore, although the oral cavity may be the entry route for SARS-CoV-2, other factors including protease inhibitors in the saliva that inhibit viral entry should be considered.


Author(s):  
Sunao Fujimoto ◽  
Raymond G. Murray ◽  
Assia Murray

Taste bud cells in circumvallate papillae of rabbit have been classified into three groups: dark cells; light cells; and type III cells. Unilateral section of the 9th nerve distal to the petrosal ganglion was performed in 18 animals, and changes of each cell type in the denervated buds were observed from 6 hours to 10 days after the operation.Degeneration of nerves is evident at 12 hours (Fig. 1) and by 2 days, nerves are completely lacking in the buds. Invasion by leucocytes into the buds is remarkable from 6 to 12 hours but then decreases. Their extrusion through the pore is seen. Shrinkage and disturbance in arrangement of cells in the buds can be seen at 2 days. Degenerated buds consisting of a few irregular cells and remnants of degenerated cells are present at 4 days, but buds apparently normal except for the loss of nerve elements are still present at 6 days.


Author(s):  
Al W. Stinson

The stratified squamous epithelium which lines the ruminal compartment of the bovine stomach performs at least three important functions. (1) The upper keratinized layer forms a protective shield against the rough, fibrous, constantly moving ingesta. (2) It is an organ of absorption since a number of substances are absorbed directly through the epithelium. These include short chain fatty acids, potassium, sodium and chloride ions, water, and many others. (3) The cells of the deeper layers metabolize butyric acid and to a lesser extent propionic and acetic acids which are the fermentation products of rumen digestion. Because of the functional characteristics, this epithelium is important in the digestive process of ruminant species which convert large quantities of rough, fibrous feed into energy.Tissue used in this study was obtained by biopsy through a rumen fistula from clinically healthy, yearling holstein steers. The animals had been fed a typical diet of hay and grain and the ruminal papillae were fully developed. The tissue was immediately immersed in 1% osmium tetroxide buffered to a pH of 7.4 and fixed for 2 hrs. The tissue blocks were embedded in Vestapol-W, sectioned with a Porter-Blum microtome with glass knives and stained with lead hydroxide. The sections were studied with an RCA EMU 3F electron microscope.


Development ◽  
1997 ◽  
Vol 124 (7) ◽  
pp. 1333-1342 ◽  
Author(s):  
C.A. Nosrat ◽  
J. Blomlof ◽  
W.M. ElShamy ◽  
P. Ernfors ◽  
L. Olson

A combination of anatomical, histological and physiological data from wild-type and null-mutated mice have established crucial roles for BDNF and NT3 in gustatory and somatosensory innervation of the tongue, and indeed for proper development of the papillary surface of the tongue. BDNF is expressed in taste buds, NT3 in many surrounding epithelial structures. Absence of BDNF in mice leads to severely malformed taste bud-bearing papillae and severe reduction of taste buds, a loss of proper innervation of remaining taste buds and a loss of taste discrimination although not of the suckling reflex per se. In contrast, absence of NT3 leads to a massive loss of somatosensory innervation of lingual structures. These findings demonstrate distinct roles for BDNF and NT3 in the establishment of the complex innervation apparatus of the tongue with non-overlapping roles for the lingual gustatory and somatosensory systems. The distinction between different sensory modalities, being dependent on either BDNF or NT3 may also have clinical implications.


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