AskDefine | Define invaginate

Dictionary Definition

invaginate

Verb

1 sheathe; "The chrysalis is invaginated"
2 fold inwards; "some organs can invaginate" [syn: introvert]

User Contributed Dictionary

English

Verb

  1. In the context of "medicine|surgery": To fold up or enclose into a sheath-like or pouch-like structure, either naturally or as part of a surgical procedure.
  2. To turn or fold inwardly.
  3. Infolding to create a hollow space where none had existed, as with a gastrula forming from a blastula.

Extensive Definition

Invagination means to fold inward or to sheath. In biology, this can refer to a number of processes.
  • Invagination is 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 differentiated germ layers: endoderm, mesoderm, and ectoderm. More localized invaginations also occur later in embryonic development, to form coelom, etc.
  • The inner membrane of a mitochondrion invaginates to form cristae, thus providing a much greater surface area to accommodate the protein complexes and other participants that produce ATP.
  • Invagination occurs during endocytosis and exocytosis when a vesicle forms within the cell and the membrane closes around it.
In the humanities:
  • Used to explain a special kind of meta narrative. Used by Rosalyn Krauss and Jacques Derrida (The Law of Genre,” Glyph 7 (1980).
invaginate in German: Invagination
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