Carpenter's principles of human physiology . rve asrootlets, by which certain nutritious elements of the maternal blood (probablythose composing the liquor sanguinis) are taken into the system of the this, they closely correspond with the villi of the intestinal canal ; andthere is this further very striking analogy—that the nutrient material isselected and prepared by two sets of cells, one of which (the maternal) trans-mits it to the other (the fetal), in the same manner as the epithelial cells of theintestinal villi seem to take up and prepare the nutrient matter, which isdestined
Carpenter's principles of human physiology . rve asrootlets, by which certain nutritious elements of the maternal blood (probablythose composing the liquor sanguinis) are taken into the system of the this, they closely correspond with the villi of the intestinal canal ; andthere is this further very striking analogy—that the nutrient material isselected and prepared by two sets of cells, one of which (the maternal) trans-mits it to the other (the fetal), in the same manner as the epithelial cells of theintestinal villi seem to take up and prepare the nutrient matter, which isdestined to be still further assimilated by the cells that float in the circulatingcurrent. It is probable, too, that the Placenta is to be regarded as anexcreting organ; serving for the removal, through the maternal blood, ofexcrementitious matter whose continued circulation through the blood of thefetus would be prejudicial to the latter. And it will be in this mode that theblood of the mother may become impregnated with substances, or impressed. Section of a portion of a fully-formed Placenta, with the part of the Uterusto which it is attached:—a, umbilical cord; h, b, section of uterus, showingthe venous sinuses; c,c,c, branches of the umbilical vessels; d, d, curlipgarteries of the uterus. FORMATION OF THE PLACENTA. 893 with attributes, originally belonging to the male parent; so as to impart theseto the products of subsequent conceptions by a different father.* Thereis no more direct communication between the mother and foetus than thatwhich is afforded by this immersion of the foetal tufts in the maternal blood ;all the observations which have been supposed to prove the existence of realvascular continuity, having been falsified by the extravasation of fluid, pro-bably consequent upon the force used in injecting the vessels. Moreover, thedifferent size of the blood corpuscles in the foetus and in the parent shows thenon-existence of any such communication. 715. The formation
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectphysiology, bookyear1
