Morphological and scanning electron microscopic studies of the lingual papillae of the tongue of the goat (Capra hircus)

The morphology of different lingual papillae of the Egyptian goats was studied by gross observation, scanning electron microscopy, and light microscopy. According to function, two types of papillae were present; mechanical (filiform, conical and lenticular papillae) and gustatory papillae (fungiform and vallate papillae). Two types of filiform papillae were detected with different shape and position. Moreover, two types of conical and lenticular papillae could be recognized on the lingual torus. Abundant fungiform papillae were found on the dorsal and ventral surfaces of the tip of the tongue. The vallate papillae had also different shapes. Taste buds were demonstrated within the epithelium of the dorsal surfaces of the fungiform papillae and the lateral surfaces of the vallate papillae. In addition, a longitudinal row of large papillae was located on the lateral aspect of the tongue in relation to the filiform papillae. These papillae were suggested to be called elongated conical papillae and may be considered as ones of the lingual papillae. In conclusion, the current study provides a detailed description of the different lingual papillae of the Egyptian goat's tongue. Presence of different types and shapes of mechanical and gustatory lingual papillae in goats' tongue suggests a high degree of functional adaptation to their diet.