. A laboratory manual and text-book of embryology. Embryology. 184 THE ENTODERMAL CANAL AND ITS DERIVATIVES. This mass, a network of solid trabecule, is the glandular portion of the liver. The primitive, hollow, hepatic diver- t^"T~»,.,..--. ticulum later differentiates into the gall-bladder and the large biliary ducts. Referring to Figs. 83 and 176, it will be seen that the liver anlage lies between the vitelline veins and is in close proximity to them laterally. The veins send anastomosing branches into the ventral mesen- tery. The trabecular of the expand- ing liver grow between and ab
. A laboratory manual and text-book of embryology. Embryology. 184 THE ENTODERMAL CANAL AND ITS DERIVATIVES. This mass, a network of solid trabecule, is the glandular portion of the liver. The primitive, hollow, hepatic diver- t^"T~»,.,..--. ticulum later differentiates into the gall-bladder and the large biliary ducts. Referring to Figs. 83 and 176, it will be seen that the liver anlage lies between the vitelline veins and is in close proximity to them laterally. The veins send anastomosing branches into the ventral mesen- tery. The trabecular of the expand- ing liver grow between and about these venous plexuses, and the plex- uses in turn make their way between and around the liver cords. The vitelline veins on their way to the heart are thus surrounded by the liver and largely subdivided into a network of vessels termed sinusoids. The endothelium of the sinusoids is closely applied to the cords of liver cells which, in the early stages, con- tain no bile capillaries (Fig. 177). For the transformation of the vitelline veins into the portal vein and for the relations of the umbilical veins to the liver see Chapter IX. The glandular portion of the liver grows rapidly and in embryos of 7 to 8 mm. is con- nected with the primitive hepa- tic diverticulum only by a single cord of cells, the hepatic duct (Fig. 178 A). That portion of the hepatic diverticulum distal to the hepatic duct is now differentiated into the terminal solid gall-bladder and its cystic duct. Its proximal portion forms the Fig. 176.—The liver anlage of a 4 mm. human embryo (Bremer). /;/., intestine; Pa., pancreas; , veins in contact with liver 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 Prentiss, Charles William, 1874-1915. Philadelphia, London, W. B. Saunders
Size: 1458px × 1714px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectembryology, bookyear1
