現代ラテン語のplacenta uterina, placenta, pastryから、PIE*plak, flatから、PIE*pele, to unfold, to flatenから、語源的にはplan, placeと同じ。 胎盤の形が平らなお菓子であることから名付けられた。
英語の語源
placenta
placenta: [17] Latin placenta originally meant ‘flat cake’. It was borrowed from Greek plakóenta, the accusative form of plakóeis ‘flat cake’, which was derived from pláx ‘flat surface’ (possible relative of English plank). Its application to the afterbirth (originally in the phrase placenta uterīna ‘uterine cake’) is a postclassical development, inspired by the flat round shape of the afterbirth.
placenta (n.)
1670s of plants, 1690s of mammals, from Modern Latin placenta uterina "uterine cake" (so called 16c. by Italian anatomist Realdo Colombo), from Latin placenta "a cake, flat cake," from Greek plakoenta, accusative of plakoeis "flat," related to plax (genitive plakos) "level surface, anything flat," from PIE *plak- (1) "to be flat" (cognates: Greek plakoeis "flat," Lettish plakt "to become flat," Old Norse flaga "layer of earth," Norwegian flag "open sea," Old English floh "piece of stone, fragment," Old High German fluoh "cliff"), extended form of root *pele- (2) "flat, to spread" (see plane (n.1)). So called from the shape.
例文
1. The drug can be transferred to the baby via the placenta .
麻薬は胎盤を通じて胎児に伝えられる。
2.The fat-soluble vitamins（A，D and E）seem to be impeded by the placenta .
胎盤は脂溶性ビタミン（A，DとE）の通過を阻害しているようだ。
3.The virus traverses the placenta and，may seriously interfere with organogenensis.
ウイルスは胎盤を透過し、胎児器官の発生を深刻に妨げる可能性がある。
4.Starch grains present in the embroyo sac and placenta are utilized by the embryo.
胚嚢と胎座に存在するデンプン粒は胚に利用されている。
5.There is hollow in the thickened wall of a uterus into which the placenta grows.