Crenation 2142202 220345215 2008-06-19T12:07:30Z Jeepday 2604600 Wikipedia:Unreferenced articles; [[Wikipedia:Unreferenced articles|you can help!]] {{nofootnotes|date=June 2008}} '''Crenation''' is the contraction or formation of abnormal notchings around the edges of a cell after exposure to a [[Tonicity#Hypertonicity|hypertonic solution]], due to the loss of water through [[osmosis]]. The word is from the Latin "crenatus" meaning scalloped or notched, and is named for the scalloped-edged shape the cells take on when crenated. Crenation occurs because in a hypertonic environment, (that is, the cell has a lower concentration of solutes than the surrounding extracellular fluid), [[osmosis]] (the [[diffusion]] of [[water]]) causes a net movement of water out of the cell, causing the cytoplasm to decrease in its volume. As a result the cell shrinks. The effects of crenation are especially visible in [[red blood cells]], or erythrocytes, as they become distorted in shape rather than maintaining the usual disc-like shape with the dimple that the blood cell normally has. Instead, the red blood cell looks as if it has ''legs'' extending from a smaller central area, like a spiked ball. [[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 mebrane shrinks and the chloroplasts of the plant cell concentrate in the center of the cell. [[Cytolysis]] is the term which describes the bursting of cells without [[cell wall]]s in a [[hypotonic]] environment. If a red blood cell were exposed to pure water with a solute concentration of zero, the diffusion of the water or osmosis would diffuse from a concentration of low to high. The pure water is considered a hypotonic solution and enters the red blood cell. Hemolysis occurs if too much water enters the red blood cell, causing it to burst. Hemolysis gets its name from the prefix hemo- which means blood and the suffix -lysis which means destruction or dissolution. In an [[Tonicity#Isotonicity|isotonic solution]], the concentration of the solute in the solution outside of the cell equals the concentration of the solute inside of the cell so there is no movement of solution. ==See also== *[[Plasmolysis]] *[[Osmosis]] *[[Hemolysis]] *[[Cytorrhysis]] *[[Red blood cells]] ==External links== *[http://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]] {{Cell-biology-stub}} [[es:Crenación]] [[id:Krenasi]] [[pt:Crenação]]