Like all mucosae, the mucosa in the oral cavity is composed of an epithelium and underlying connective tissue, the lamina propria; a muscularis mucosae is lacking, however. Three types of mucosae line the oral cavity; the components of each type vary depending on location and function. 200x, 200x, 200x
Lining mucosa >
Lining mucosa is composed of a stratified squamous moist epithelium (black arrow) and its lamina propria (blue arrow). This mucosa lines all of the oral cavity except for the gingiva (gums), hard palate and the dorsal surface of the tongue.
Masticatory mucosa >
Masticatory mucosa lines the gingiva and hard palate, areas that undergo abrasive forces during mastication. The epithelium (black arrow) is stratified squamous, either para- or orthokeratinized. Parakeratinzed, seen here, does not fully keratinize, producing surface cells that retain pyknotic nuclei. Orthokeratinized fully keratinizes with flattened squames of dead cells at the surface. A lamina propria (blue arrow) underlies the epithelium.
Specialized mucosa >
Specialized mucosa lines the dorsal surface of the tongue. The epithelium of this mucosa is keratinized, but is modified into three types of papillae, only one type (arrows) is shown here. Some papillae serve mechanical functions, while others possess taste buds. Specialized mucosa is discussed more completely in the section on the tongue.