placenta develops from the outer cells of the trophoblast.
placenta develops from the outer cells of the trophoblast.
placenta develops from the outer cells of the?
trophoblast
the syncytiotrophoblast implants the blastocyst in the decidual epithelium by projections of chorionic villi, forming the embryonic part of the placenta. the placenta develops once the blastocyst is implanted, connecting the embryo to the uterine wall. the decidua here is termed the decidua basalis; it lies between the blastocyst and the myometrium and forms the maternal part of the placenta. the implantation is assisted by hydrolytic enzymes that erode the epithelium. the syncytiotrophoblast also produces human chorionic gonadotropin, a hormone that stimulates the release of progesterone from the corpus luteum. progesterone enriches the uterus with a thick lining of blood vessels and capillaries so that it can oxygenate and sustain the developing embryo. the uterus liberates sugar from stored glycogen from its cells to nourish the embryo. the villi begin to branch and contain blood vessels of the embryo. other villi, called terminal or free villi, exchange nutrients. the embryo is joined to the trophoblastic shell by a narrow connecting stalk that develops into the umbilical cord to attach the placenta to the embryo.
human embryonic development
in the endometrium there are straight and serial arteries. straight arteries specifically branch to the base of the endometrium therefore supplying blood to the base of the endometrium. spiral arteries supply blood to the rest of the endometrium. they grow rapidly, covering much of the space of the endometrium and end up coiled. when hormones levels are low, the endometrial arteries react by becoming narrow. endometrial arteries supply blood to the endometrium but are also beneficial during pregnancy. when a female is pregnant a placenta develops. the baby receives blood, nutrients and oxygen via the umbilical cord which is attached to the placenta. between the placenta and the myometrium are intervillous spaces where the endometrial arteries supply blood to. the placenta has villous trees which allow for blood to circulate and then be transported to the baby via the placenta.
endometrial arteries