Scanning and Transmission Electron-Microscopic Studies on the Lingual Tonsil of the Buffalo (Bubalus bubalis)

Abstract

The present study examined lingual tonsil of six buffaloes of the local mixed breed by scanning and transmission electron-microscopy to elucidate their ultrastructural features. The lingual tonsil presented folded mucosa having longitudinally oriented folds which were separated by grooves. The surface mucosa showed a squamous arrangement of cells which delineated from the adjacent cells. The surface of these cells at a higher magnification presented the microplicae of different arrangements which were mainly of closed pattern type and resembled fingerprints of humans. The luminal openings of glandular ducts on the free surface presented varying shapes. The transmission electron-microscopy described ultrastructural details of the different strata of the stratified squamous keratinised, nonkeratinised and reticular epithelia. The propria-submucosa contain reticular cells, fibroblast, lymphoid cells, plasma cells, granulocytes and interdigitating cells. Few high endothelial venules observed and the cytoplasmic process of these endothelial cells contained small vacuoles equivalent to vesiculo-vacuolar organelles, membrane-bound bodies and vacuolated structures.

Histological and Histochemical Studies on the Lingual Tonsil of the Buffalo (Bubalus bubalis)

“…A review on the tonsils of domestic animals reported that lingual tonsil in sheep and goat was entirely covered by keratinized stratified squamous epithelium [16], a finding that contrasted previous studies in the goat [17] where stratified squamous nonkeratinized epithelium was described as observed in the horse [4]; however, in pig, it was stratified squamous epithelium with varying degrees of keratinization [16,18]. The free surface of the epithelium was uneven and irregular whereas the deeper surface presented the papillary pegs, as reported in the horse [4] and the goat [17]. This epithelium was comprised of the strata basale, spinosum, granulosum and corneum as described in the keratinized epithelial lining of the lingual tonsil in the pig [18].…”

“…The mucosal surface of the lingual tonsil was lined by stratified squamous keratinized epithelium as reported in the camel [14], and the goat [15] in contrast to the non-keratinized epithelium in Egyptian buffalo calf [10]. A review on the tonsils of domestic animals reported that lingual tonsil in sheep and goat was entirely covered by keratinized stratified squamous epithelium [16], a finding that contrasted previous studies in the goat [17] where stratified squamous nonkeratinized epithelium was described as observed in the horse [4]; however, in pig, it was stratified squamous epithelium with varying degrees of keratinization [16,18]. The free surface of the epithelium was uneven and irregular whereas the deeper surface presented the papillary pegs, as reported in the horse [4] and the goat [17].…”

“…The stratum basale present towards the basement membrane was having a single row of the vertically oriented oval to elongated strongly basophilic nuclei with chromatin material irregularly aggregated into smaller clumps as reported in the buffalo calf [10], however, the reaction was comparatively less in the horse [4] and the pig [18]. The cell layers of stratum spinosum were 16-20 in contrast to 8-12 in the goat [17] and 3-4 in the pig [18]. These cells presented spicule like the arrangement as reported in goat [17] and pig [18], usually the spikes contained cytokeratin filaments [19].…”

“…The cytoplasm of these cells was eosinophilic and finely granular (Figure 2). The stratum spinosum was having a varying number of cell layers (16)(17)(18)(19)(20) depending on the thickness of the epithelium. The nuclei of these cells, towards the deeper part close to the stratum basale, were round to oval to elongate in shape (Figure 2).…”

“…This epithelium was comprised of the strata basale, spinosum, granulosum and corneum as described in the keratinized epithelial lining of the lingual tonsil in the pig [18]. However, the strata comprised of basale, spinosum and superficial in the buffalo calf [10] similar to those of horse [4], goat [17], and the non-keratinized epithelial portion in the pig [18]. The outer stratified squamous epithelium was infiltrated by occasional CD4 positive and CD8+ T cells in the horse [7].…”