Vallate papillae in the domestic rabbit (Oryctolagus cuniculus f. domestica)

Abstract

On the root of the tongue in the rabbit there are two symmetrically located vallate papillae, covered by nonkeratinized stratified squamous epithelium. The epithelium is characterized by variable thicknesses, forming epithelial streaks of different length and irregular shape. Taste buds are found both in the epithelium covering the papillae and in the epithelium of the outer walls of the papillae from the side of the furrows. The outer wall of the vallate papillae is gradually transformed with no visible boundary into the surface of the root of the tongue devoid of papillae. The surface of the vallate papillae is uneven. The connective tissue core of the papillae is formed by numerous, irregularly shaped connective tissue papillae, between which epithelial streaks are arranged. Around the connective tissue core of the papillae there is a circular connective tissue fold, with a furrow located on its circumference and the core of the outer wall of the vallate papillae. Numerous excretory ducts of the posterior serous lingual glands (Ebner's glands) open on the fundus of the circular furrow of each vallate papilla. Sometimes excretory ducts of these glands open directly onto the surface of a vallate papilla and then in their vicinity taste buds are found. The results of this study show the structure of vallate papillae on the tongue of adult rabbits, at the same time indicating differences in their structure in comparison to the vallate papillae of other animal species.