Histology, Histochemistry and Scanning Electron Microscopy of Nasopharyngeal Tonsil of the Young Pigs

Abstract

The present study was conducted on 10 young male pigs of 8-10 months age, of local mixed breed. The nasopharyngeal tonsil was lined by pseudostratified columnar ciliated epithelium with goblet cells. The respiratory epithelium was modified into follicle associated epithelium (FAE) where a few superficially placed dome shaped cells were considered as the M-cells. This FAE was further modified into a single cell layer having simple cuboidal epithelium. This type of epithelia has been reported first time in the tonsils. The lymphoid tissue mainly concentrated into lymphoid follicles was separated by interfollicular areas. The goblet cells of respiratory cells and mucus glandular acini showed preance of different mucopolysaccharides. Scanning electron microscopy confirmed psence of different types of microvillus cells, brush cells and M-cells. Cluster of microvillus cells stacked one upon another like mulberry fruit or bunch of grapes pattern has never been documented earlier in any species and reported first time during the present study.