Invagination: Meaning (information, definition, explanation, facts)

Invagination is one of the morphogenetic processes by which an embryo takes form, and is the initial step of gastrulation, the massive reorganization of the embryo from a simple spherical ball of cells, the blastula, into a multi-layered organism, with a differentiated endoderm, mesoderm, and ectoderm.

More localized invaginations also occur later in embryonic development.