Changes

==Etymology==

==Etymology==

New Latin, from [[Latin]], flat cake, from [[Greek]] plakoenta,  accusative of plakoeis, from plak-, plax flat [[surface]]  

New Latin, from [[Latin]], flat cake, from [[Greek]] plakoenta,  accusative of plakoeis, from plak-, plax flat [[surface]]  

*Date: [http://www.wikipedia.org/wiki/17th_Century 1691]

*Date: [https://www.wikipedia.org/wiki/17th_Century 1691]

==Definitions==

==Definitions==

*1 : the vascular organ in [[mammals]] except monotremes and marsupials that unites the [[fetus]] to the maternal [[uterus]] and mediates its [[metabolism|metabolic]] exchanges through a more or less [[intimate]] [[association]] of uterine mucosal with chorionic and usually allantoic tissues; also : an [[analogous]] organ in another [[animal]]

*1 : the vascular organ in [[mammals]] except monotremes and marsupials that unites the [[fetus]] to the maternal [[uterus]] and mediates its [[metabolism|metabolic]] exchanges through a more or less [[intimate]] [[association]] of uterine mucosal with chorionic and usually allantoic tissues; also : an [[analogous]] organ in another [[animal]]

*2 : a sporangium-bearing [[surface]]; especially : the part of the carpel bearing ovules

*2 : a sporangium-bearing [[surface]]; especially : the part of the carpel bearing ovules

==Description==

==Description==

The '''placenta''' is an organ that [[connects]] the [[developing]] [http://en.wikipedia.org/wiki/Fetus fetus] to the uterine wall to allow nutrient uptake, waste elimination, and [[gas]] exchange via the mother's blood supply. Placentas are a defining characteristic of [http://en.wikipedia.org/wiki/Eutheria eutherian or "placental" mammals], but are also found in some snakes and lizards with varying levels of [[development]] up to [[mammalian]] levels. The [[word]] placenta comes from the [[Latin]] for cake, from [[Greek]] plakóenta/plakoúnta, accusative of plakóeis/plakoús  – πλακόεις, πλακούς, "flat, slab-like",  in [[reference]] to its round, flat [[appearance]] in [[humans]]. [http://en.wikipedia.org/wiki/Protheria Protherial] (egg-laying) and [http://en.wikipedia.org/wiki/Metatheria metatherial]  (marsupial) mammals produce a choriovitelline placenta that, while [[connected]] to the uterine wall, provides nutrients mainly derived from the egg sac. The placenta [[develops]] from the same [[sperm]] and [[egg]] cells that form the [http://en.wikipedia.org/wiki/Fetus fetus], and [[functions]] as a fetomaternal organ with two components, the fetal part (Chorion frondosum), and the maternal part (Decidua basalis).[http://en.wikipedia.org/wiki/Placenta]

The '''placenta''' is an organ that [[connects]] the [[developing]] [https://en.wikipedia.org/wiki/Fetus fetus] to the uterine wall to allow nutrient uptake, waste elimination, and [[gas]] exchange via the mother's blood supply. Placentas are a defining characteristic of [https://en.wikipedia.org/wiki/Eutheria eutherian or "placental" mammals], but are also found in some snakes and lizards with varying levels of [[development]] up to [[mammalian]] levels. The [[word]] placenta comes from the [[Latin]] for cake, from [[Greek]] plakóenta/plakoúnta, accusative of plakóeis/plakoús  – πλακόεις, πλακούς, "flat, slab-like",  in [[reference]] to its round, flat [[appearance]] in [[humans]]. [https://en.wikipedia.org/wiki/Protheria Protherial] (egg-laying) and [https://en.wikipedia.org/wiki/Metatheria metatherial]  (marsupial) mammals produce a choriovitelline placenta that, while [[connected]] to the uterine wall, provides nutrients mainly derived from the egg sac. The placenta [[develops]] from the same [[sperm]] and [[egg]] cells that form the [https://en.wikipedia.org/wiki/Fetus fetus], and [[functions]] as a fetomaternal organ with two components, the fetal part (Chorion frondosum), and the maternal part (Decidua basalis).[https://en.wikipedia.org/wiki/Placenta]

[[Category: Biology]]

[[Category: Biology]]