Filiform papillae of human, rat and swine tongue.
In order to study the structure of filiform papillae (FP), tissue specimens were taken from the anterior part of the tongues of 8 humans, 8 rats and 8 swine. The formalin-fixed samples were processed routinely for scanning electron microscopy (SEM) and light microscopy. With SEM, FP of human tongue contained 5-12 hairs which were covered with a massive plaque of micro-organisms. FP of rat tongue, on the other hand, contained one papillary projection with smooth surface structure. Colonization of micro-organisms was seen on the anterior part of the body of FP, but not on the hairs. In the cross-section of FP of the rat tongue, the cells of the papilla were close to each other and no micro-organisms were seen within the papillae. On the contrary, the spaces between the squamous epithelial cells of the hairs of human FP contained numerous micro-organisms. The structure of FP of the swine tongue resembled that of the rat tongue. The hairs were smooth, and some micro-organisms were seen on the cell surface of the interpapillary areas. The structure of FP is discussed from the standpoint of different keratinization and colonization of micro-organisms.
D000818:Animals; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D004848:Epithelium / Q000648:ultrastructure; D006801:Humans; D007633:Keratins / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D051381:Rats; D011919:Rats, Inbred Strains; D013552:Swine; D013556:Swine, Miniature; D014059:Tongue / Q000382:microbiology / Q000648:ultrastructure*
D007633:Keratins