卵らん黄おう嚢のうMeanings1nounyolk sacembryologyEmbryological term for the membranous sac that provides early nourishment to the embryo.卵らん黄おう嚢のうは初しょ期きの胚はいに栄えい養ようを供きょう給きゅうする。The yolk sac supplies nutrients to the early embryo.