A system of midwifery . ythe various lobuli of which the pla-centa is composed, so that each lo- bulus receives at least one of these Fmtal surface of the placenta. branches; for, although the umbili- cal cord consists of two arteries and one vein, this arrangement does notcontinue into the body of the placenta. Every branch of an artery,as Dr. Hunter observes, is attended with a branch of a vein: these cling * It has lately been supposed that the irregular nodules of wax in the Hunterian pre-parations were merely the result of extravasation, a rather hazardous conclusion againstthe authority
A system of midwifery . ythe various lobuli of which the pla-centa is composed, so that each lo- bulus receives at least one of these Fmtal surface of the placenta. branches; for, although the umbili- cal cord consists of two arteries and one vein, this arrangement does notcontinue into the body of the placenta. Every branch of an artery,as Dr. Hunter observes, is attended with a branch of a vein: these cling * It has lately been supposed that the irregular nodules of wax in the Hunterian pre-parations were merely the result of extravasation, a rather hazardous conclusion againstthe authority of such men as the Hunters. Mr. J. Hunter, has, however, expressly metthis objection in the following observation:— This substance of the placenta, now filledwith injection, had nothing of a vascular appearance, or that of extravasation; but hada regularity in its form which showed it to be a natural cellular structure, fitted to be areservoir for blood. (^Observations on Certain Parts of the Ajiimal Economy, p. 129.). DEVELOPMENT OF THE OVUM. ^ to one another, and frequently in the substance of the placenta entwineround one another, as in the navel string. {Ibid. p. 40.) Each cotyle-don receives its own vessels, so that the vessels of one cotyledon have nodirect communication with those of the adjacent ones, as proved by Wris-bergs examinations; for if we inject the vessel or vessels of one of theselobuli, the injection will not pass into those of the others. When the ves-sels have reached the cotyledons, they are divided and subdivided ad in-finitum; they are connected together by a fine cellular membrane, whichmay be very easily removed by maceration, and then they may be seenramifying in the most beautiful and delicate manner possible; the mainbranches having no communication or anastomosis with each other. The umbilical arteries anastomose freely with each other upon the fcetalsurface of the placenta, before dividing into the branches above-mentioned ;hence, if an inject
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Keywords: ., bookcentury1800, booksubjectmidwifery, booksubjectpregnancycompl
