Читать книгу Feline Dentistry - Jan Bellows - Страница 15

The oral cavity extends from the lips to the pharynx, bounded laterally by the cheeks, dorsally by the palate, and ventrally by the tongue and intermandibular tissues. The oral cavity is divided into the oral cavity proper and the oral vestibule. Within the oral cavity proper are the hard palate, soft palate, tongue, and the floor of the mouth. The hard palate is formed by the palatine processes of the incisive and maxillary bones and the horizontal laminae of the palatine bones. The mucosa covering the hard palate consists of cornified stratified squamous epithelium, which is developed into seven or eight transverse curved ridges (palatine rugae). The palatine rugae have thick tough connective tissue support, the mucoperiosteum, which is continuous with the periodontal ligaments of the upper teeth. The mucosa of the hard palate ends abruptly laterally at its junction with the short palatal free gingiva. The incisive papilla is located on the midline cranial to the first transverse ridge and just caudal to the upper central incisor teeth. On either side of this papilla are the incisive ducts that extend caudodorsally through the palatine fissures into the floor of the nasal fossae. This duct communicates with the vomeronasal organ. Caudally, the oral cavity proper ends at the palatoglossal folds.

The palatoglossal arch (also called palatoglossal fold) is a fold of mucous membrane which extends from the soft palate to the side of the tongue. The palatoglossal arch marks where the mouth becomes the pharynx. The palatoglossus muscle is one of the four extrinsic muscles of the tongue. The paired muscles create ridges of mucous membrane in the lateral pharyngeal wall called the palatoglossal arches (also known as the anterior pillars of the fauces). The palatoglossus muscle runs in the anterior palatoglossal arch, and the palatopharyngeus muscle runs in the palatopharyngeal arch of the tonsillar fossa. These muscles pull the back of the tongue upward toward the soft palate to seal the oral cavity from the pharynx. The palatine tonsils lie in shallow fossae located approximately 1.5 cm caudal to the palatoglossal folds.

The oral vestibule spans between the lips, cheeks, and dental arches. The labial vestibule is the space between the incisors, canines, and lips. The buccal vestibule is the space between the cheek teeth and the cheeks (Figure 1.1a–c).