. Comparative embryology of the vertebrates; with 2057 drawings and photos. grouped as 380 illus. Vertebrates -- Embryology; Comparative embryology. 618 THE DIGESTIVE SYSTEM ,ESOPHAGUS. Fig. 292. Developing stomach regions of the digestive tract. (A-C) Three stages in the development of the pig's stomach. Arrows indicate formation of omental bursa which forms from the pocket-like enlargement of the dorsal mesogastrium and proceeds to the left forming the omental bursa as the pyloric end of the stomach rotates toward the right. The ventral aspect of the stomach is indicated by crosses. (D) Diag
. Comparative embryology of the vertebrates; with 2057 drawings and photos. grouped as 380 illus. Vertebrates -- Embryology; Comparative embryology. 618 THE DIGESTIVE SYSTEM ,ESOPHAGUS. Fig. 292. Developing stomach regions of the digestive tract. (A-C) Three stages in the development of the pig's stomach. Arrows indicate formation of omental bursa which forms from the pocket-like enlargement of the dorsal mesogastrium and proceeds to the left forming the omental bursa as the pyloric end of the stomach rotates toward the right. The ventral aspect of the stomach is indicated by crosses. (D) Diagram of the ruminant stomach. The abomasum corresponds to the glandular stomach of the pig or human; the other areas represent esophageal modifications. (Redrawn from Kingsley, 1912. Comparative Anatomy of the Vertebrates, Blakiston, Phila.) developing tongue. The place of origin is near the anterior limits of the tongue. Two of these epithelial outpushings occur on either side (fig. 290B). The sub- maxillary-gland and sublingual-gland ducts open at the side of the frenulum of the tongue (fig. 290C). The parotid glands arise as epithelial evaginations, at the angle of the mouth, from the groove which separates the forming jaw and the lip (fig. 290B, C). The various oral glands, such as the palatine, labial, tongue, and cheek glands of mammals and lower vertebrates, the poison glands of snakes, etc., arise as epithelial buds which grow out from the developing oral cavity in a manner similar to those of the parotid, submaxillary, and sublingual glands of mammals. The original epithelial outgrowths may branch and rebranch many times to produce large, compound, alveolar glands, as in the parotid, sub- maxillary, and sublingual glands of mammals and the poison glands of snakes. b. Development of the Pharyngeal Area 1) Pharyngeal Pouches and Grooves. The pharynx is that region of the early digestive tube which lies between the oral cavity and the esophagus. In adult vertebrate species
Size: 3050px × 819px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodiversity, bookleafnumber644
