hemochorial placenta
Quick Summary
The hemochorial placenta is a type of placenta found in some mammals, including humans, monkeys, and apes. In this type of placenta, the chorionic villi, which are fingerlike projections from the developing fetus, are bathed directly in maternal blood. This intimate contact allows for efficient exchange of nutrients, oxygen, and waste products between the mother and the fetus. Unlike other types of placentas where multiple layers of tissue separate maternal and fetal blood, the hemochorial placenta has no cellular layers between them, facilitating a more direct physiological exchange. This close association is a key characteristic of placental mammals (Eutheria) and is believed to have contributed to their evolutionary success.123
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primatePlacentaIn the second type (hemochorial), found in tarsiers, monkeys, and apes, the relationship is much more intimate, there being no cell layers separating the two circulations so that serum proteins can easily pass. In haplorrhines the endometrium becomes highly vascularised about two weeks after ovulation, in preparation for the…
Read MoreIn the second type (hemochorial), found in tarsiers, monkeys, and apes, the relationship is much more intimate, there being no cell layers separating the two circulations so that serum proteins can easily pass. In haplorrhines the endometrium becomes highly vascularised about two weeks after ovulation, in preparation for the…
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…for possible pregnancy, forming a hemochorial placenta (with intimate contact between maternal and fetal bloodstreams) if pregnancy occurs and requiring it to be shed, in menstruation, if there is no fertilization. Strepsirrhines have no uterine preparation, no menstruation, and a much-less-intimate epitheliochorial placenta. All indications are that these two suborders…
Read More…for possible pregnancy, forming a hemochorial placenta (with intimate contact between maternal and fetal bloodstreams) if pregnancy occurs and requiring it to be shed, in menstruation, if there is no fertilization. Strepsirrhines have no uterine preparation, no menstruation, and a much-less-intimate epitheliochorial placenta. All indications are that these two suborders…
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