A reference handbook of the medical sciences, embracing the entire range of scientific and practical medicine and allied science . rupturedand the surface of the tropho-blast is freely bathed in thematernal blood, this surfacehaving greatly increased by tliedevelopment of lacunie or a certain part of the tro-phoblast, the ectoplacenta, be-comes differentiated into thefetal placenta bj- the prohfera-tion of allantoic capillaries intothe trophoblastic villi. In many mammals the prohf-eration of the trophoblast isconfined to certain regions, therest of it remaining a simpleepithelial m
A reference handbook of the medical sciences, embracing the entire range of scientific and practical medicine and allied science . rupturedand the surface of the tropho-blast is freely bathed in thematernal blood, this surfacehaving greatly increased by tliedevelopment of lacunie or a certain part of the tro-phoblast, the ectoplacenta, be-comes differentiated into thefetal placenta bj- the prohfera-tion of allantoic capillaries intothe trophoblastic villi. In many mammals the prohf-eration of the trophoblast isconfined to certain regions, therest of it remaining a simpleepithelial membrane. Refer-ence has been made above tothe very precocious development embr>onal ectoderm; a,of the ectoplacenta in the guinea- fctodermal canity, thepig and in the mouse (Fig. 667). ^^ P°< ^^^ In some mammals such as thepig, the horse, and many lemurs,wliich present the extreme tjpeof diffused placenta there is noprohferation whatever of the trophoblast. The uterinemucous membrane remains intact, but is providedwith depressions which receive vascular projectionsfrom the chorion. There appears to be an interesting. Fig. 667.—Early Em-bryo of Mus , Endoderm; c, cavityof umbilical vesicle; ol,trophoblast; Tr, prolif-erating trophoblast: Ec, is afterward cut off toform the amniotic cav-ity. (From Minot, afterSelenka.) REFERENCE HANDBOOK OF THE MEDICAL SCIENCES Blastoderm
Size: 1100px × 2271px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbuckalbe, bookcentury1900, bookdecade1910, bookyear1913
