Vol. 10, Special Issue 11 (2021)

Author(s):
Satish Kumar, Pawan Kumar, Pradeep Kumar and Sunil Punia

Abstract:
The present study was conducted on 30 broiler chicks divided into 5 groups having 6 birds in each group at 7, 11, 18, 25 and 32 days of age. The oro-pharynx of dead birds were collected at the mid-level and region of pharyngeal papillae. The result illustrated that Oropharynx was lined by stratified squamous non-keratinized epithelium. Variation in keratinization of mucosal epithelium among avian species may be a reflection of the evolutionary adaptations observed between different birds. The stratified squamous epithelium towards the infundibular cleft was modified into the respiratory epithelium. In its initial portion, it was associated with less number of the goblet cells whereas towards the deeper portion large number of goblet cells was observed. A strong positive Alcianophilic reaction indicated the presence of hyaluronic acid and weakly sulfated mucopolysaccharides. The glands also showed strong positive reaction for glycogen and mucins. The pterygoidae glands which were only seen towards the medial portion of the pharyngeal folds. The present study showed that glandular tissue formed a major component of the sub-epithelial connective tissue in both dorsal and ventral walls of the pharynx. Pharyngeal tonsil was demonstrated and these lymphocytic aggregations were part of the well-organized gut-associated lymphoid tissues (GALT).