Cytolysis is the lysis, or death, of cells due to the rupture of the cell membrane. Cytolysis is caused by excessive osmosis, or movement of water, towards the inside of a cell. The cell membrane cannot withstand the osmotic pressure of the water inside, and so it explodes. Osmosis occurs from a region of high-water potential to a region of low-water potential passing through a semipermeable membrane. Lysis (Greek lusis from luein = to separate) refers to the death of a cell by bursting, often by viral or osmotic mechanisms that compromise the integrity of the cellular membrane. ... Death is the cessation of physical life in a living organism, or the state of the deceased. ... Cells in culture, stained for keratin (red) and DNA (green). ... Drawing of a cell membrane A component of every biological cell, the selectively permeable cell membrane (or plasma membrane or plasmalemma) is a thin and structured bilayer of phospholipid and protein molecules that envelopes the cell. ... A girl in a swimming pool Water (from the Old English waeter; c. ... Osmotic pressure or turgor (also called turgor pressure) is the pressure produced by a solution in a space that is enclosed by a differentially permeable membrane. ... Gasoline explosions, simulating bomb drops at an airshow. ... Scheme of semipermeable membrane during hemodialysis. ...

Cause and effects

Osmotic lysis occurs in a hypotonic environment, where water diffuses into the cell. As the water continues to diffuse into the cell, the cell grows larger, and will eventually burst if too much water enters. The cell membrane is not strong enough to prevent and stop the swelling of the cell, and eventually will rupture, releasing the cell contents. In biology, a hypotonic cell environment is an environment with a lower concentration of solutes than the cytoplasm of the cell. ... Schematic drawing of the effects of diffusion through a semipermeable membrane. ...

Cytolysis does not occur in plant cells because plant cells have a strong cell wall that contains the osmotic pressure, or turgor pressure, which would otherwise cause cytolysis to occur. Contrary to organisms without a cell wall, plant cells must be in a hypotonic environment in order to have this turgor pressure, which provides the cells more structural support, preventing the plant from wilting. In a hypertonic environment, plasmolysis occurs, which is nearly the complete opposite of cytolysis: Instead of expanding, the cytoplasm of the plant cell retracts from the cell wall, causing the plant to wilt. Plant cell structure Plant cells are quite different from the cells of the other eukaryotic kingdoms organisms. ... A cell wall is a more or less solid layer surrounding a cell. ... In biology, a hypertonic cell environment has a higher concentration of solutes than in cytoplasm. ... Before Plasmolysis. ...

Osmotic lysis is often the result of a stroke, since a stroke leads to a malfunctioning of the cell's metabolism, which results in an inflow of extracellular fluid into the cell. Uses of recreational drugs such as LSD and Methylenedioxymethamphetamine will also cause the patient to drink excessive amounts of water without compensating with tonic substances appropriately, causing cytolysis. A stroke or cerebrovascular accident (CVA) occurs when the blood supply to a part of the brain is suddenly interrupted. ... Santorio Santorio (1561-1636) in his steelyard balance, from Ars de statica medecina, first published 1614 Metabolism (from μεταβολισμος (metabolismos)) is the biochemical modification of chemical compounds in living organisms anggjgjhnd cell (b). ... In some animals, including mammals, the two types of extracellular fluids are interstitial fluid and blood plasma. ... Recreational drug use is the use of psychoactive drugs for recreational rather than medical or spiritual purposes, although the distinction is not always clear. ... For other uses, see LSD (disambiguation). ... MDMA (3,4-methylenedioxymethamphetamine), most commonly known today by the street name ecstasy or XTC, is a synthetic entactogen of the phenethylamine family whose primary effect is to stimulate the secretion of and inhibit the re-uptake of large amounts of serotonin as well as dopamine and norepinephrine in the...

Preventing osmotic lysis

Different cells and organisms have adapted different ways of preventing cytolysis from occurring. For example, the paramecium uses a contractile vacuole, which rapidly pumps out excessive water to prevent the build-up of water and the otherwise subsequent lysis. Paramecium is a well-known genus of ciliate protozoa, commonly studied as a representative of that group. ... A contractile vacuole is a type of vacuole involved in osmoregulation. ...

Other organisms pump solutes out of their cytosol, which brings the solute concentration closer to that of their environment and slows down the process of water's diffusion into the cell, preventing cytolysis. If the cell can pump out enough solutes so that an isotonic environment can be achieved, there will be no net movement of water. ÃThe cytosol (as opposed fatty cytoplasm, which also includes the organelles) is the internal fluid of the cell, and a large part of cell metabolism occurs here. ... In chemistry, concentration is the measure of how much of a given substance there is mixed with another substance. ... An isotonic cellular environment occurs when an equal solute concentration exists inside and outside the cell. ...

See also

• Cell disruption