Investigations on the Light and Scanning Electron Microscopic Structure of Tongue Papillae of Kangal Sheep: Taste and Mechanical

This study was conducted to examine the morphological, histological, and ultrastructural structure of the tongue papillae in Kangal sheep, which is the largest local type of the Akkaraman sheep breed, raised in Central Anatolia and especially in the Sivas region. After the tissues were prepared according to the necessary tissue processing protocols, they were examined using light (LM) and scanning electron microscopy (SEM). Histological examination revealed that the dorsal surface of the tongue was covered with stratified squamous keratinized epithelium, and the underlying layers contained lamina propria, submucosa, well-developed skeletal muscle bundles running in various directions, and serous/seromucous glands. SEM examinations revealed that the filiform papilla consisted of a main body and a pair of secondary papillae located on either side. Two types of lentiform papilla, pyramidal and irregularly shaped, were distinguished. Two types of taste papillae were identified: fungiform papilla and circumvallate papilla. It was observed that the fungiform papillae were typically mushroom-shaped and contained taste pores on their surfaces. It was determined that the circumvallate papillae were surrounded by a trench and contained taste pores. Although the tongue papilla structure of the Kangal sheep generally shows similarities with other ruminant species, specific morphological differences were identified, such as the consistent presence of a single pair of secondary extensions in the filiform papilla. These findings provide descriptive data for Kangal sheep and may serve as a basis for future comparative and functional studies.