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Crenation (from modern Latin ''crenatus'' meaning "scalloped or notched", from popular Latin ''crena'' meaning "notch") in botany and zoology, describes an object's shape, especially a leaf or shell, as being round-toothed or having a scalloped edge. The descriptor can apply to objects of different types, including cells, where one mechanism of crenation is the contraction of a cell after exposure to a hypertonic solution, due to the loss of water through
osmosis Osmosis (, ) is the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential (region of ...
. In a hypertonic environment, the cell has a lower concentration of
solutes In chemistry, a solution is a special type of homogeneous mixture composed of two or more substances. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. If the attractive forces between the solvent ...
than the surrounding
extracellular fluid In cell biology, extracellular fluid (ECF) denotes all body fluid outside the cells of any multicellular organism. Total body water in healthy adults is about 60% (range 45 to 75%) of total body weight; women and the obese typically have a lower ...
, and
water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
diffuses out of the cell by osmosis, causing the
cytoplasm In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. Th ...
to decrease in volume. As a result, the cell shrinks and the cell membrane develops abnormal notchings. Pickling cucumbers and salt-curing of meat are two practical applications of crenation.
Plasmolysis Plasmolysis is the process in which cells lose water in a hypertonic solution. The reverse process, deplasmolysis or cytolysis, can occur if the cell is in a hypotonic solution resulting in a lower external osmotic pressure and a net flow of wat ...
is the term which describes plant cells when the cytoplasm shrinks from the cell wall in a hypertonic environment. In plasmolysis, the cell wall stays intact, but the plasma membrane shrinks and the chloroplasts of the plant cell concentrate in the center of the cell.


Red blood cells

Crenation is also used to describe a feature of
red blood cells Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...
. These erythrocytes look as if they have projections extending from a smaller central area, like a spiked ball. The crenations may be either large, irregular spicules of
acanthocyte Acanthocyte (from the Greek word ἄκανθα ''acantha'', meaning 'thorn'), in biology and medicine, refers to an abnormal form of red blood cell that has a spiked cell membrane, due to thorny projections. A similar term is spur cells. Often ...
s, or smaller, more numerous, regularly irregular projections of
echinocyte Echinocyte (from the Greek word ''echinos'', meaning 'hedgehog' or 'sea urchin'), in human biology and medicine, refers to a form of red blood cell that has an abnormal cell membrane characterized by many small, evenly spaced thorny projections.Me ...
s. Acanthocytes and echinocytes may arise from abnormalities of the cell membrane lipids or proteins, or from other disease processes, or as an
ex vivo ''Ex vivo'' ( Latin: "out of the living") literally means that which takes place outside an organism. In science, ''ex vivo'' refers to experimentation or measurements done in or on tissue from an organism in an external environment with minima ...
artifact.


See also

* Crenellation * Cytorrhysis *
Hemolysis Hemolysis or haemolysis (), also known by several other names, is the rupturing (lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may occur in vivo o ...
*
Plasmolysis Plasmolysis is the process in which cells lose water in a hypertonic solution. The reverse process, deplasmolysis or cytolysis, can occur if the cell is in a hypotonic solution resulting in a lower external osmotic pressure and a net flow of wat ...


References

{{reflist, refs= {{cite encyclopedia, encyclopedia=Oxford Dictionaries, url=http://oxforddictionaries.com/definition/english/crenate, archive-url=https://web.archive.org/web/20120731043554/http://oxforddictionaries.com/definition/english/crenate, url-status=dead, archive-date=July 31, 2012, title=Crenate {{Cite book , last=Stoker , first=HS , title=General, Organic, and Biological Chemistry , year=2012 , edition=6th , isbn= 978-1133103943 {{Cite book , last=Kaushansky , first=K , author2=Lichtman, M , author3=Beutler, E , author4=Kipps, T , author5=Prchal, J , author6= Seligsohn, U. , title=Williams Hematology , publisher=McGraw-Hill , year=2010 , edition=8th , isbn= 978-0071621519


External links


Image from Cornell.eduCrenation
at medical-dictionary.thefreedictionary.com Animal physiology Membrane biology Solutions