mouth [AS, muth] , 1. the nearly oval oral cavity at the superior, anterior end of the digestive tube, bounded anteriorly by the lips and containing the tongue and the teeth. It consists of the vestibule and the oral cavity proper. The vestibule, situated in front of the teeth, is bounded externally by the lips and the cheeks, internally by the gums and the teeth. The vestibule receives the secretion from the parotid salivary glands. The oral cavity proper is bounded by the alveolar arches and the teeth, communicates with the pharynx, and is roofed by the hard and the soft palates. The tongue forms the greater part of the floor of the cavity. The rest of the floor is formed by the reflection of the mucous membrane from the sides and the bottom of the tongue to the gum lining the inner part of the mandible. The oral cavity proper receives the secretion from the submandibular and sublingual salivary glands. 2. an orifice.
