<P> The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake , thermo - regulation , waste elimination , and gas exchange via the mother 's blood supply ; to fight against internal infection ; and to produce hormones which support pregnancy . The placenta provides oxygen and nutrients to growing fetuses and removes waste products from the fetus 's blood . The placenta attaches to the wall of the uterus , and the fetus 's umbilical cord develops from the placenta . These organs connect the mother and the fetus . Placentas are a defining characteristic of placental mammals , but are also found in marsupials and some non-mammals with varying levels of development . The homology of such structures in various viviparous organisms is debatable , and in invertebrates such as Arthropoda , is analogous at best . </P>
<P> The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake , thermo - regulation , waste elimination , and gas exchange via the mother 's blood supply ; to fight against internal infection ; and to produce hormones which support pregnancy . The placenta provides oxygen and nutrients to growing fetuses and removes waste products from the fetus 's blood . The placenta attaches to the wall of the uterus , and the fetus 's umbilical cord develops from the placenta . These organs connect the mother and the fetus . Placentas are a defining characteristic of placental mammals , but are also found in marsupials and some non-mammals with varying levels of development . The homology of such structures in various viviparous organisms is debatable , and in invertebrates such as Arthropoda , is analogous at best . </P>
what passes through the placenta from mother to embryo
what passes through the placenta from mother to embryo
oxygen and nutrients
oxygen and nutrients