Elements of comparative anatomy (1878) Elements of comparative anatomy elementsofcompar00gege Year: 1878 BUCCAL CAVITY OF VERTEBEATA. 54<J number of organs, which were seen in the primitive arrangement, are assigned to the buccal cavity, while other organs appear only as later developments. The teeth, the tongue, and various, glandu- lar organs belong to the former series. The soft palate, or velum palati, which is only found in Mammals, is a new organ. This muscular apparatus forms the posterior boundary of the buccal cavity, and separates it from the pharynx. The uvula is a median prolon
Elements of comparative anatomy (1878) Elements of comparative anatomy elementsofcompar00gege Year: 1878 BUCCAL CAVITY OF VERTEBEATA. 54<J number of organs, which were seen in the primitive arrangement, are assigned to the buccal cavity, while other organs appear only as later developments. The teeth, the tongue, and various, glandu- lar organs belong to the former series. The soft palate, or velum palati, which is only found in Mammals, is a new organ. This muscular apparatus forms the posterior boundary of the buccal cavity, and separates it from the pharynx. The uvula is a median prolongation of the velum palati; this structure is apparently found in the Primates only. In Reptiles and Birds the anterior and lateral boundaries of the buccal cavity are formed by the margins of the jaws, which are invested by the integument, and by the hard structures which are found on the jaws. In the Saurii and Ophidii the integument de- velops pad-like lips along the edge of the jaw. In all Mammals, except the Monotremata, the integument is separated from the edge of the jaws, and invests a complicated muscular layer which has its origin in them ; this layer forms the ground-work of the lips, and gives them their mobility. In this way a space is developed which lies in front of the buccal cavity—the vestibulum oris. The lateral portions of this space form the cheek-pouches, and, when capable of great extension, develop into the pouch-like diverticula of many Mammals (buccal pouches of the Rodents and Apes). . Organs of the Buccal Cavity. § 414. Of these organs those hard structures which serve for the pre- hension and comminution of food are of various kinds. Some of them are formed by the cornification of epithelial cells. The sucker-shaped mouth of the Cyclostomata (Fig. 308) is beset with horny teeth of this kind, which are also present on a tongue- like organ in these animals. In the Am- phibia the edges of the provided with a similar covering; these structur
Size: 1103px × 1814px
Photo credit: © Bookworm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
