Study On The Histomorphology And Distribution Of Immunity-associated Cells In Tonsil Of The Yak

Yak is an important livestock in plateau, and has better adaptability in high altitude and low oxygen environment. As an important subsistence in plateau, yak provides food, labor force, fur and fuel production for pastoralists, is an important economic pillar for Tibetan Plateau. In order to reveal the composition of immune structure and distribution of mucosal immune cells in tonsils of adult yak, this study has researched distributed feature, organizational structure, the distribution of immune-related organizations and cells by staining techniques, image analysis, and transmission electron microscopy techniques in tonsil of adult yak. The results showed that: 1. The anatomy and histological feature of tonsil in YakThere are distributed six tonsils in Yak’s head, including palatine tonsil, soft palate tonsil, tongue tonsil, paraepiglottic tonsil, pharynx tonsil and Tubal tonsil. The basic structure of tonsil was divided epithelium and lamina propria. In the epithelium, the epithelium of palatine tonsil, soft palate tonsil, tongue tonsil and paraepiglottic tonsil were mainly composed of stratified squamous epithelium cells in oropharyngeal tonsil. And the epithelium recessed inward to form many ramose crypts, with the deepening of the crypt, the epithelium of crypts are becoming more and more thinning. The epithelium of pharyngeal tonsil and tubal tonsil were consist of pseudostratified ciliated columnar epithelium in nasopharyngeal tonsil, and the epithelium is thinner. In the aspect of structure, the epithelium of oropharynx and nasopharynx are quite different, and the thickness of epithelium have significant difference(P<0.01). The average area of soft palate tonsil is 26.09±3.9455cm2 in oropharynx, and the average area of pharyngeal tonsil is 25.17±3.1212cm2 in nasopharynx, the difference is not notable(P>0.05). The area of tubal tonsil and paraepiglottic tonsil are smaller, and have significant differences compare with pharyngeal tonsil and soft palate tonsil(P<0.01).In the lamina propria, there distributes a large number of lymphoid tissue in palatine tonsil and paraepiglottic tonsil of oropharynx, and have obvious germinal center in lymphoid follicles, the difference is not notable(P>0.05). The pharyngeal tonsil and tubal tonsil of nasopharynx have rich lymphoid tissue, the difference is significant(P<0.01). In addition, the number of blood vessels, lymphatic and collagen fiber are rich in lamina propria. 2. The distribution of immune-related cells in tonsil of yakThe intraepithelial lymphocyte is mainly distribute in mucous epithelium of tonsil. The epithelium of oropharyngeal tonsil is mainly composed of stratified squamous epithelium cell, they have more compact structure and less intraepithelial lymphocyte. The epithelium of nasopharyngeal tonsil is mainly composed of pseudostratified ciliated columnar epithelium, they have looser epithelial tissue and more intraepithelial lymphocytes. In unit view, the average quantity of intraepithelial lymphocyte is 10.16±3.2385 Bb, 4.48±0.7294 Cc and 6.96±1.4029 Cc in palatine tonsil, soft palate tonsil and tongue tonsil of oropharynx. The average quantity of intraepithelial lymphocyte is 20.84±1.9047 Aa and 20.32±1.0640 Aa in the pharyngeal tonsil and tubal tonsil of nasopharynx. The number of intraepithelial lymphocyte have significant differences in nasopharynx and oropharynx(P<0.01). The mast cell is mainly around the small vessel and small lymphatic vessel in the subcutaneous connective tissue and connective tissue of substance. The average quantity of mast cell is 8.04±0.8414 Bb and 6.96±0.8173 Bb in palatine tonsil and paraepiglottic tonsil of oropharynx, the average quantity of mast cells are 10.36±0.9317 Aa and 10.96±0.5177 Aa in tubal tonsil and pharyngeal tonsil of nasopharynx, the number of mast cell have significant differences in nasopharynx and oropharynx(P<0.01). The goblet cell is mainly distributed in the mucosal epithelium of palatine tonsil, pharynx tonsil and tubal tonsil, and the average quantity of goblet cell is 6.64±1.8515, 33.92±7.7982 and 9.28± 4.2863. 3. The ultrastructural feature in tonsil of Yak There showed that junctional complex existed among the stratified squamous epithelium of palatine tonsil and ciliated columnar epithelium of pharyngeal tonsil, such as tight junctions, intermediate junction and desmosome junction. And a large number of rows microvilli distributed in the free surface of epithelial cells in tubal tonsil. The intraepithelial lymphocytes has less cytoplasm, and the nucleus larger, clear-cut, stained chromatin along the nuclear membrane. The cytoplasm of mast cells have many higher electron density particle. A large number of rough endoplasmic reticulum in cytoplasm of plasma cell. In goblet cell, a lot of rough endoplasmic reticulum and ribosomes around the nucleus, cytoplasm was filled with lots of mucus particles.