外胚層;外細胞層
Ectoderm \Ec"to*derm\, n. [Ecto- + -derm.] (Biol.) (a) The outer layer of the blastoderm; epiblast. (b) The external skin or outer layer of an animal or plant, this being formed in an animal from the epiblast. See Illust. of {Blastoderm}.
ectoderm n : the outer germ layer that develops into skin and nervous tissue [syn: {exoderm}, {ectoblast}]