Invagination

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Invagination is the infolding of one part within another part of a structure,[1] a folding that creates a pocket.[2] The term, originally used in embryology, has been adopted in other disciplines as well. It has many meanings in each term or subject.

Biology[edit]

  • Invagination is the morphogenetic processes by which an embryo takes form, and is the initial step of gastrulation,[3] 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,
  • 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 adenosine triphosphate (ATP).[4]
  • Invagination occurs during endocytosis and exocytosis when a vesicle forms within the cell and the membrane closes around it.
  • Invagination of a part of the intestine into another part is called intussusception.[5]

Humanities[edit]

The term is used to explain a special kind of metanarrative. It was first used by Maurice Merleau-Ponty[6] (French: invagination) to describe the dynamic self-differentiation of the 'flesh'. It was later used by Rosalind E. Krauss and Jacques Derrida ("The Law of Genre", Glyph 7, 1980); for Derrida, an invaginated text is a narrative that folds upon itself, "endlessly swapping outside for inside and thereby producing a structure en abyme".[7] He applies the term to such texts as Immanuel Kant's Critique of Judgment[7] and Maurice Blanchot's La Folie du Jour.[8] Invagination is an aspect of différance, since according to Derrida it opens the "inside" to the "other" and denies both inside and outside a stable identity.[2]

Geology[edit]

In geology, invagination is used to describe a deep depression of strata. Used by Donald L. Baars in "The Colorado Plateau".

References[edit]

  1. ^ "Medical Dictionary". 
  2. ^ a b Wortham, Simon Morgan (2010). The Derrida Dictionary. Continuum International. p. 76. ISBN 9781847065261. Retrieved 12 January 2013. 
  3. ^ Alberts (2002). Molecular Biology of the Cell. New York: Garland Science. 
  4. ^ Cronk, Jeff. "Biochemistry Dictionary". [dead link]
  5. ^ Blanco, Felix. "Intussusception". Retrieved 1 November 2012. 
  6. ^ Merleau-Ponty, Maurice (1968). The Visible and the Invisible. Boston, MA: Northwestern University Press. p. 152. ISBN 0810104571. 
  7. ^ a b Chaplin, Susan (2004). Law, Sensibility, and the Sublime in Eighteenth-Century Women's Fiction: Speaking of Dread. Ashgate. p. 23. ISBN 9780754633068. Retrieved 12 January 2013. 
  8. ^ Jones, Amelia (2003). The Feminism and Visual Culture Reader. Psychology Press. p. 200. ISBN 9780415267069. Retrieved 12 January 2013.