Morphohistological and histochemical study of oropharynx and tongue of duck (Anas platyrhynchos), partridge (Alectoris chukar) and ostrich (Struthio camelus) birds

The oropharynx and tongue of local duck (Anas platyrhynchos), partridge (Alectoris chukar), and ostrich (Struthio camelus) were studied to evaluate the morphological characteristics that influence nutrition, swallowing, and food intake. The findings revealed that a cartilaginous hard palate constituted the roof of the oropharyngeal cavity, with the exception of partridges, that it did not have any papillae on its mucosal surface. The median palatine ridge, a prominent longitudinal mucosal fold running along the middle of the mouth, was present in the studied birds. The lateral margins of the floor and roof of the oropharynx were formed by rows of lamellae. The tongue was situated on the oropharynx floor and featured a prominent dorsal median sulcus and many lateral brush-like projections on each side of the tongue. Except for the absence of the papillae in the ostrich, other characteristics of the organ were horned lingual papillae and a bell-shaped dorsal surface height, which served as the organ s foundation. The tongues have non-keratinized stratified squamous epithelial cells on lingual dorsal and ventral surfaces, a thick layer of connective tissue containing lingual glands, nerve fibers with blood vessels, central structure consisting of the paraglossum and its related striated muscle. In conclusion, the duck, partidage, and ostrich oropharynx and tongue show particular anatomical characteristics which were morphological modulations of this part of the digestive canal as an adaptation for the feeding habits of these birds.