Carpenter's principles of human physiology . chorion,forming what are termed the cotyledons; but in the higher orders, and in Man, * Kolliker, Entwickelungsgesck. des Mensch., 1879, p. 334. + Loc. cit., p. 367. £ The Placenta varies in form to a considerable extent in different animals. In Cetaceaand in many Ungulata, as the Llama, Horse and Zebra, the villi project from all parts of thechorion, and their placenta is consequently termed diffuse. In Carnivora, in Seals, in theElephant and Hyrax, the villi are only developed in a ring or zone around the chorion, andthe placenta is therefore call
Carpenter's principles of human physiology . chorion,forming what are termed the cotyledons; but in the higher orders, and in Man, * Kolliker, Entwickelungsgesck. des Mensch., 1879, p. 334. + Loc. cit., p. 367. £ The Placenta varies in form to a considerable extent in different animals. In Cetaceaand in many Ungulata, as the Llama, Horse and Zebra, the villi project from all parts of thechorion, and their placenta is consequently termed diffuse. In Carnivora, in Seals, in theElephant and Hyrax, the villi are only developed in a ring or zone around the chorion, andthe placenta is therefore called zonary. In Ruminants the villi are developed in certainspots, irregularly distributed over the chorion, forming the cotyledonous placenta. Finally,in Man and in Rodents the villi are limited to a single spot, and the Placenta is thencetemied discoid. See report of Turners Lectures delivered at the College of Surgeons in Lancet for June, 1875, and in Journal of Anat. and Physiol., vol. x. p. 127. 890 OF GENERATION : ACTION OF THE Portion of th& ultimate ramifications of the umbilicalvessels, forming tire Fwtal Villi of the Placenta. Fig. 323. they are concentrated in one spot, forming the Placenta. In some of the lowertribes the maternal and the foetal portions of the placenta may be very easilyseparated; the former consisting of the thickened Decidua, and the latter being composed of the prolongedFig. 322. and ramifying vascular tufts of the Chorion, dipping down into in the Human placenta thetwo elements are mingled togetherthrough its whole substance.—Onlooking at the foetal surface of theHuman placenta, we perceive thatthe umbilical vessels diverge inevery direction from the point atwhich they enter it; and theirsubdivisions form a large mass ofcapillaries, arranged in a peculiarmanner (Figs. 322, 323), and con-stituting what is known as the, foetalvilli. Each villus contains one ormore capillary loops, communica-ting with an artery on one side,and with
Size: 2079px × 1202px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectphysiology, bookyear1
