Fine Structure of Lingual Papillae in the Markhoz Goat (Iranian Angora): A Scanning Electron Microscopic Study

The aim of this study was to investigate the morphostructure of lingual papillae in Markhoz goat. Tissue samples were taken from the dorsal surfaces of the apex, body and root of the tongues of five adult goats. After routine procedure of preparation, the samples were observed under the scanning electron microscope. Three mechanical and tow gustatory types of papillae were seen. Filiform papillae were distributed on the dorsal surface of the anterior two-thirds of the tongue. A bulb-like structure formed the basal portion of the papilla. Between six and eight secondary papillae with sharp pointed tips emerged at the base of filiform papillae. The conical papillae were found on the torus linguae and elongated with a round base while their tips were blunt and sharp, differing structurally from the filiform papillae which posses larger size, a tip without projections and lack of secondary papillae. The round-shaped type I lenticular papillae had a flat surface whereas, those of the leaf-shaped type II lenticular papillae were protruded from the lingual surface with a blunt apex. The round to oval shaped vallate papillae on both rims of the torus linguae were encircled by a prominent gustatory furrow and a thick annular pad. The fungiform papillae were scattered among filiform papillae in the anterior two-thirds of the dorsal surface and each papilla was surrounded by a distict papillary groove. Accordingly, despite of some specific morphological features in lingual papillae, the tongue of markhoz goat is well equipped for mechanical functions similar to that of the other ruminants.