Introduction to the upper gingiva: vertebrates cover the oral mucosa on the surface of the tooth neck and alveolar process. Normal and healthy gums should be solid and attached to the bone under the alveolar bone. People of different races have different gum colors, usually light pink, while black gums may be brown or gray.
Introduction of soft and hard jaws: the sides of soft palate are downward, with a pair of palatopharyngeal arches in front and extending to the outside of tongue base, and a pair of palatopharyngeal arches in the back. Palatal prolapse, free margin of palatine sail and palatoglossus muscles on both sides are the boundary between oral cavity and pharynx, and also the narrow parts of oral cavity and pharynx. The upward movement of soft palate is mainly accomplished by the contraction of levator veli palatini.
Fourth, the picture: