Histology Text Of The Oral Cavity
The oral cavity is subdivided into two parts: the vestibule and oral cavity proper. The vestibule is the external space in the oral cavity that is pounded anteriorly and laterally by the lips and cheeks, and internally by the dental arches. The ducts of the parotid glands open in the vestibule to deliver their secretory products. The oral cavity proper is the space that lies internal to the teeth and is bounded by the tongue and the floor of the mouth inferiorly, and the hard and soft palates superiorly and the oropharynx posteriorly.
Both the vestibule and the oral cavity proper are covered by the stratified squamous epithelium. This epithelium is modified into a stratified squamous keratinized (parakeratinized) epithelium in regions that are subjected to abrasive forces, such as in the gingiva and filiform papillae. The oral cavity structures include the tongue, the teeth and their supporting structures (peridontium), the major and minor salivary glands and the tonsils. Oral MucosaThe oral cavity is lined with the oral mucosa, which is composed of the epithelium and underlining connective tissue. The oral mucosa may be classified into the masticatory mucosa, lining mucosa and a specialized mucosa.
a. Masticatory Mucosa It covers the gingiva, hard palate, and the dorsal surface of the tongue.
b. Lining Mucosa
The lining mucosa covers most of the oral cavity including the lips, cheeks, alveolar mucosal surface, floor of the mouth, inferior surface of the tongue and soft palate. It covers the striated muscles of the lips, cheeks and tongue, the bone of the alveolar mucosa and the glands of the soft palate, cheeks and inferior surface of the tongue.
c. Specialized Mucosa
The specialized mucosa possesses intraepithelial structures, known as taste buds, and functions in taste perception. The anterior two-thirds of the dorsal surface of the tongue possess most of the taste buds; however, a few of these structures are also present in the palate and pharynx. In the oral cavity, there are numerous minor salivary glands in the connective tissue underlying the epithelium, the submucosa. These glands secrete saliva to the oral cavity via short ducts to maintain a moist environment and assist in lubricating dry foods. In addition, saliva contains enzymes to initiate the digestion of carbohydrates and secretory antibodies to protect the body against antigenic substances. Posteriorly, the tonsillar ring, which is composed of the lingual, pharyngeal and palatine tonsils, guards the entrance of the pharynx against bacterial invasion. |
Histology Text of Oral Cavity
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