Scanning Electron Microscopic Study of the Human Fungiform Papillae

Abstract

Human lingual mucosa reveals a highly differentiated papillary organization. The fungiform papillae are grouped as gustatory papillae as they contain taste buds and function as sensory end organs. Taste pores, the surface openings of the taste buds, play important roles both in preneural and neural phases of taste perception by receiving external chemical stimuli and its transduction. Scanning electron microscopy [SEM] of the dorsal lingual surface was used to study the morphology and ultrastructure of the fungiform papillae in human. The lingual samples were prepared from 20 unfixed cadavers at Burdwan Medical College and after proper processing they were examined under SEM at the University of Burdwan. The results demonstrated that these gustatory structures were dome shaped with round base and their diameters were approximately 300 – 800 µm. They were surrounded by shallow circular furrow with small mucosal pad encircling the furrow. The study verified that the covering epithelium of the fungiform papillae is stratified squamous type and frequent desquamation of lining cells was also noticed. Elevated cell margin with distinct intercellular borders were evident in the lining epithelium. Single or multiple circular taste bud pores opened on the upper surface of some of these papillae while in others taste pores were absent. Taste bud pores had diameter of about 3-6 µm. On higher magnification SEM images established the presence of lattice patterned microridges over the epithelial cell surfaces. Within these microridges microgrooves or mucous pits were observed. These observations were related with specific mechanical and gustatory roles.