. Comparative anatomy. Anatomy, Comparative. DORSAL PANCREAS —VENTRAL RfiiNCREAS' DUODENUM BILE DUCT. WIRSUNG'S DUCT A EARLIER STAGE. B. LATER STAGE. Fig. 273.—A and B, two stages in the development of the pancreas. The duct of the dorsal pancreas, Santorini's duct, may degenerate in ontogenesis. The two gland anlagen unite into a single organ in the adult. (Redrawn after Broman.) primary connexions with the intestine, the ventral becoming Wirsung's duct and the dorsal Santorini's, the two connecting wathin the body of the gland. The dorsal pancreas grows much faster than the ventral, and form
. Comparative anatomy. Anatomy, Comparative. DORSAL PANCREAS —VENTRAL RfiiNCREAS' DUODENUM BILE DUCT. WIRSUNG'S DUCT A EARLIER STAGE. B. LATER STAGE. Fig. 273.—A and B, two stages in the development of the pancreas. The duct of the dorsal pancreas, Santorini's duct, may degenerate in ontogenesis. The two gland anlagen unite into a single organ in the adult. (Redrawn after Broman.) primary connexions with the intestine, the ventral becoming Wirsung's duct and the dorsal Santorini's, the two connecting wathin the body of the gland. The dorsal pancreas grows much faster than the ventral, and forms the body and tail of the gland and part of the head. The connec- tive tissue of the gland comes from mesenchymatous cells which penetrate between the acini and lobules. History of the Pancreas. The pancreas seems to be an emergent trait of vertebrates, since no comparable structure is found in the invertebrates or even in the lower chordates. In cyclostomes, the pancreatic tissue remains buried in the substance of the hver or in the wall of the small intestine. Since no duct appears in these forms, it is assumed that the pancreas was primarily endocrinal and not digestive. Higher verte- brates, beginning with the elasmobranchs, have both dorsal and ventral Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Neal, Herbert V. (Herbert Vincent), 1869-1940; Rand, Herbert W. (Herbert Wilbur), 1872-1960. Philadelphia : P. Blakiston's Son
Size: 1950px × 1281px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookpublisherphi, booksubjectanatomycomparative
