Microarchitecture of the Palatine Tonsil in Sheep (Ovis aries) / Microarquitectura de la Tonsila Palatina en Oveja (Ovis aries)

The tissue pieces of palatine tonsil were collected from different postnatal age groups of sheep from the Corporation Slaughter House, Perambur, Chennai. The palatine tonsil consisted of a surface epithelium, capsule, tonsillar lobes, crypts, crypt epithelium and tonsillar follicles. The surface epithelium over the palatine tonsil was made up of non-keratinized stratified squamous epithelium in all the postnatal age groups studied. The palatine tonsil was clearly demarcated from the surrounding structures by a distinct connective tissue capsule and one septa dividing the tonsil into two lobes. The surface epithelium was invaginated into the substance of the tonsil to form primary and secondary crypts in each lobe. The crypt epithelium covered the regions of lymphoid follicles became lymphoepithelium. The macrophages were also observed in the epithelium. In the areas of lymphoepithelium the basement membrane was interrupted since lymphocytic infiltration was heavy into the epithelium. Numerous secondary tonsillar follicles with germinal centers separated by interfollicular areas were observed in the palatine tonsil. The tonsillar follicles consisted of a mantle zone, which was heavily populated with small darkly stained lymphocytes. These mantle zones were always oriented towards the crypts. The tonsillar follicles of young sheep showed many medium and small sized lymphocytes, lymphoblasts and also reticulocytes. The reticular cells usually appeared larger than lymphocytes and had a more abundant and organized cytoplasm with vacuoles.

Fueron recolectadas piezas de tejido desde la tonsila palatina de ovejas con diferentes edades postnatales, desde la Corporación Slaughter House, Perambur, Chennai. La tonsila palatina consistía en un epitelio de superficie, cápsula, lóbulos de las tonsilas, criptas, epitelio de las criptas tonsilares y folículos. El epitelio superficial sobre la tonsila palatina estaba compuesto, en todos los grupos estudiados, de epitelio escamoso estratificado no-queratinizado. La tonsila palatina se delimitó claramente de las estructuras circundantes por un tejido conectivo capsular y un septo dividiendo la tonsila en dos lóbulos. El epitelio superficial se invaginó dentro de de la tonsila para formar criptas primarias y secundarias en cada lóbulo. El epitelio de las criptas cubrió las regiones de folículos linfoides transfomándose en linfoepitelo. También se observaron macrófagos en el epitelio. En las áreas de linfoepitelo la membrana basal estaba interrumpida por la infiltración linfocitaria y fue mayor en el epitelio. Fueron observados numerosos folículos tonsilares secundarios con centros germinales separados por áreas interfoliculares. Los folículos tonsilares consistían en una zona del manto que estaba densamente poblada con pequeños linfocitos intensamente teñidos. Estas zonas del manto se orientaron siempre hacia las criptas. Los folículos tonsilares de las ovejas jóvenes mostraron muchos linfocitos de tamaño medianos y pequeños, linfoblastos y también reticulocitos. Las células reticulares usualmente aparecían más grandes que los linfocitos y tenían un citoplasma más abundante y organizado con vacuolas.

Histology and ultrastructure of the palatine tonsils of the buffalo [Bos bubalus]

The palatine tonsils are the first lymphoid tissues along the digestive tract and play a key role in initiating immune responses against antigens entering the body through the mouth. They are also replication sites of some diseases. In spite of the importance of the palatine tonsils, there is no available data about the structure of these tonsils of the Egyptian water buffalo. Palatine tonsils of 10 clinically healthy buffalo bulls [2-3 years old] were obtained directly after slaughtering for human consumption. The tonsils were examined macroscopically and microscopically with light, and transmission electron microscopes. The tonsils were elongated kidney shape with a central hilus containing a single macroscopic opening leading to a small central cavity. Beside this hailer opening, there are a number of smaller macroscopical crypt openings [external crypts]. A number of macroscopic crypts were originating from the central cavity [internal crypts]. The tonsils were enclosed with a thin connective tissue capsule and septa which divided the tonsils into incomplete lobules. Each crypt was highly branched and extended deeply through the tonsils. These crypts were lined with stratified squamous non keratinized epithelium. Several lymphocytes infiltrated between the epithelial cells forming patches of reticular- and lymphoepithelium. The crypt lumen contains lymphocytes, neutrophils and erythrocytes. Lymphoid follicles with clear germinal centers extended under the epithelial surface. Diffuse lymphocytes extend in the narrow interfollicular region. High endothelial venules, interdigitating cells, macrophages and plasma cells were observed among the diffuse lymphocytes. Mucous glands were distributed among the lobules enclosed with connective tissue septa