gastrula
Embryological term for the stage following the blastula, characterized by the formation of germ layers.
The gastrula forms three layers—ectoderm, mesoderm, and endoderm—during development.
神経胚 (neurula) follows the gastrula stage and involves the formation of the neural tube.
Compound of 原腸 (primitive gut) and 胚 (embryo), reflecting the formation of the archenteron during gastrulation.