Gastrulation

In developmental biology, gastrulation is a phase early in the embryonic development of most animals, during which the blastula (a single-layered hollow sphere of cells) is reorganized into a multilayered structure known as the gastrula. Before gastrulation, the embryo is a continuous epithelial sheet of cells; by the end of gastrulation, the embryo has begun differentiation to establish distinct cell lineages, set up the basic axes of the body (e.g. dorsal-ventral, anterior-posterior), and internalized one or more cell types including the prospective gut.

Gastrulation

In developmental biology, gastrulation is a phase early in the embryonic development of most animals, during which the blastula (a single-layered hollow sphere of cells) is reorganized into a multilayered structure known as the gastrula. Before gastrulation, the embryo is a continuous epithelial sheet of cells; by the end of gastrulation, the embryo has begun differentiation to establish distinct cell lineages, set up the basic axes of the body (e.g. dorsal-ventral, anterior-posterior), and internalized one or more cell types including the prospective gut.