{{Short description|Scalloped edging}} 200px|thumbnail|right|Diagram of a crenated leaf '''Crenation''' (from modern Latin ''crenatus'' meaning "scalloped or notched", from popular Latin ''crena'' meaning "notch")<ref name="Oxford" /> in botany and zoology, describes an object's shape, especially a leaf or shell, as being round-toothed or having a scalloped edge.<ref name="Oxford" />
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.<ref name ="Stoker_2012_6" />{{rp|229-230}} In a hypertonic environment, the cell has a lower concentration of solutes than the surrounding extracellular fluid, and water diffuses out of the cell by osmosis, causing the cytoplasm 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.<ref name ="Stoker_2012_6" />{{rp|229}}
Plasmolysis 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== [[File:Gray453.png|200px|thumbnail|right|In (d) the RBCs are rendered crenated from a hypertonic solution]] Crenation is also used to describe a feature of red blood cells. 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 acanthocytes, or smaller, more numerous, regularly irregular projections of echinocytes.<ref name="Williams_2010_8" /> Acanthocytes and echinocytes may arise from abnormalities of the cell membrane lipids or proteins, or from other disease processes, or as an ex vivo artifact.
==See also== *Crenellation *Cytorrhysis *Hemolysis *Plasmolysis
==References== <references>
<ref name="Oxford">{{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}}</ref> <ref name ="Stoker_2012_6">{{Cite book | last=Stoker | first=HS |title=General, Organic, and Biological Chemistry | year=2012 |edition=6th |isbn= 978-1133103943}}</ref> <ref name="Williams_2010_8">{{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}}</ref>
</references>
==External links== *[https://www.diaglab.vet.cornell.edu/clinpath/modules/heme1/crenated.htm Image from Cornell.edu] *[http://medical-dictionary.thefreedictionary.com/Crenation+ Crenation] at medical-dictionary.thefreedictionary.com
Category:Animal physiology Category:Membrane biology Category:Solutions