胚层 pēicéng germ layer Origin Definitions Defs Strokes Stroke Words Sentences Sents 外胚层 wàipēicéng ectoderm ectoderm (cell lineage in embryology)中胚层 zhōngpēicéng mesoderm mesoderm (cell lineage in embryology)内胚层 nèipēicéng endoderm endoderm (cell lineage in embryology)三胚层动物 sānpēicéngdòngwù triploblastic animals triploblastic animals (having three germ layers)