n.外胚層

Any of the blastomeres from which the ectoderm develops. 外裂球任一種發(fā)育成外胚層的裂球

An inward fold on the surface of the embryonic ectoderm that develops into part of the anal passage. 原肛肛道胚胎消化道表面的凹陷，發(fā)育成直腸的一部分

Derived from two embryonic germ layers, the ectoderm and the endoderm. Used of lower invertebrates, such as sponges and coelenterates. 雙胚層的具有兩個(gè)胚層（外胚層和內(nèi)胚層）的。用于低等無(wú)脊椎動(dòng)物，如寄生蟲(chóng)和腔腸動(dòng)物

The resulting gastrula consists of an outer ectoderm, an inner endoderm, and a mesoderm layer positioned between them. 最終原腸胚由一個(gè)外腸胚，內(nèi)腸胚，和一個(gè)中腸胚構(gòu)成。

The primitie mouth, or stomodeum, is a slight depression on the surface of the ectoderm. 原始的口（或口凹）是外胚層表面的一個(gè)輕微的凹陷。

The outer layer of a blastula that gives rise to the ectoderm after gastrulation. 外胚層囊胚的外層，在原腸胚形成之后生后外胚層組織

外胚層的

神經(jīng)外胚層的