外胚叶
Ectoblast \Ec"to*blast\, n. [Ecto- + Gr. ? bud, germ.] (Biol.) (a) The outer layer of the blastoderm; the epiblast; the ectoderm. (b) The outer envelope of a cell; the cell wall. --Agassiz.
ectoblast n : the outer germ layer that develops into skin and nervous tissue [syn: {ectoderm}, {exoderm}]