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 In chemical biology, tonicity is a measure of the effective osmotic pressure gradient; the water potential of two solutions separated by a partially-permeable cell membrane. Tonicity depends on the relative concentration of selective membrane ...

, due to the loss of water through

osmosis Osmosis (, ) is the spontaneous net movement or diffusion of solvent molecules through a selectively permeable membrane, selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of ...

. In a hypertonic environment, the cell has a lower concentration of

solutes In chemistry, a solution is defined by IUPAC as "A liquid or solid phase containing more than one substance, when for convenience one (or more) substance, which is called the solvent, is treated differently from the other substances, which are ...

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 50–60% (range 45 to 75%) of total body weight; women and the obese typically ha ...

, and

water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...

diffuses out of the cell by osmosis, causing the

cytoplasm The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell a ...

to decrease in volume. As a result, the cell shrinks and the

cell membrane The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extr ...

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 wa ...

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), referred to as erythrocytes (, with -''cyte'' translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood cel ...

. 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.M ...

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 refers to biological studies involving tissues, organs, or cells maintained outside their native organism under controlled laboratory conditions. By carefully managing factors such as temperature, oxygenation, nutrient delivery, and perfusi ...

artifact.

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

Red blood cells

See also

References

External links