A treatise on the science and practice of midwifery . in the Conn of club*shaped digitations which are given off at every |•«>--i 1 >1«- angle fromthe stem of a parent trunk, just like the branches of a plant. With-in the transparent walls of the villi the capillary tubes of the con-tained vessels may he seen lying, distended with blood, and present- 102 PREGNANCY. ing an appearance not unlike loops of small intestine. The capilla-ries are the terminal ramifications of the umbilical arteries and veins,which, after reaching the site of the placenta, divide and subdivideuntil they at last
A treatise on the science and practice of midwifery . in the Conn of club*shaped digitations which are given off at every |•«>--i 1 >1«- angle fromthe stem of a parent trunk, just like the branches of a plant. With-in the transparent walls of the villi the capillary tubes of the con-tained vessels may he seen lying, distended with blood, and present- 102 PREGNANCY. ing an appearance not unlike loops of small intestine. The capilla-ries are the terminal ramifications of the umbilical arteries and veins,which, after reaching the site of the placenta, divide and subdivideuntil they at last form an immense number of minute capillaryvessels, with their convexities looking towards the maternal portionof the placenta, each terminal loop being contained in one of thedigitations of the chorionic villi. Each arterial twig is accompaniedby a corresponding venous branch, which unites with it to form theterminal arch or loop (Fig. 55). The foetal blood is carried throughthese arterial twigs to the villi, where it comes into intimate contact. Placental Villus, greatly magnified. (After Joulin.)1. 2. Placental vessels, forming terminal loops. 3. Chorion tissue, forming external walls of Tissue surrouudiug vessels. with the maternal blood, in consequences of the anatomical arrange-ments presently to be described; but the two do not directly mix, asthe older physiologists believed, for none of the maternal bloodescapes when the umbilical cord is cut, nor can the minutest injectionsthrough the foetal vessels be made to pass into the maternal vascularsystem, or vice versa. In addition to the looped terminations of theumbilical vessels, Farre and Schroeder van der Kolk have describedanother set of capillary vessels in connection with each villus (); This consists of a very fine network covering each villus, andvery different in appearance from the convoluted vessels lying in itsinterior, which are the only ones which have been usually Farre belie
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Keywords: ., bookcentury1800, bookdecade1870, bookidtre, booksubjectobstetrics
