Osmoregulation is the active regulation of the osmotic pressure of bodily fluids to maintain the homeostasis of the body's water content; that is it keeps the body's fluids from becoming too dilute or too concentrated. Osmotic pressure is a measure of the tendency of water to move into one solution from another by osmosis. The higher the osmotic pressure of a solution the more water wants to go into the solution. The pressure that must be exerted on the hypertonic side of a selectively permeable membrane to prevent diffusion of water by osmosis from the side containing pure water. This article or section does not adequately cite its references or sources. ... Homeostasis is the property of either an open system or a closed system,[1] especially a living organism, to regulate its internal environment to maintain a stable, constant condition. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... Making a saline water solution by dissolving table salt (NaCl) in water This article is about chemical solutions. ... Osmosis is the net movement of water across a partially permeable membrane from a region of high solvent potential to an area of low solvent potential, up a solute concentration gradient. ... This article does not cite any references or sources. ... A biological membrane or biomembrane is an enclosing or separating tissue which acts as a barrier within or around a cell. ... This article does not cite any references or sources. ...

Animals in all environments (aquatic and terrestrial) must maintain the right concentration of solutes and amount of water in their body fluids; this involves excretion: getting rid of metabolic wastes and other substances such as hormones which would be toxic if allowed to accumulate in the blood via organs such as the skin and the kidneys; keeping the water and dissolved solutes in balance is referred to as osmoregulation. Excretion is the process of eliminating waste products of metabolism and other materials that are of no use. ... Norepinephrine A hormone (from Greek όρμή - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ... Human blood smear: a - erythrocytes; b - neutrophil; c - eosinophil; d - lymphocyte. ... Beyond overall skin structure, refer below to: See-also. ... Kidneys viewed from behind with spine removed The kidneys are bean-shaped excretory organs in vertebrates. ... A substance is soluble in a fluid if it dissolves in the fluid. ...

Examples of osmotic pressure

• Hypertonic is a solution with higher solute concentration (higher osmotic pressure) than another thus water wants to move in.
• Hypotonic is a solution with lower solute concentration (lower osmotic pressure) than another thus water wants to move out of it.
• Isotonic is solution with the same solute concentration (same osmotic pressure) as another; no net movement of water.

Forms of osmoregulation

Two major types of osmoregulation are osmoconformers and osmoregulators. Osmoconformers match their body osmolarity to their environment . It can either be active or passive. Most marine invertebrates are osmoconformers, although their ionic composition may be different to that of seawater. An osmoconformer is a marine invertebrate whose internal salinity such that it is always equal to the surrounding seawater. ...

Osmoregulators tightly regulate their body osmolarity which always stays constant and are more common in the animal kingdom. Osmoregulators actively control salt concentrations despite the salt concentrations in the environment. An example is freshwater fish. The gills actively uptake salt from the environment. Water will diffuse into the fish so it excretes a very hypotonic urine to expel all the excess water. A marine fish has an internal osmotic concentration lower than that of the surrounding seawater so it tends to lose water and gain salt. It actively excretes salt out from the gills. Most fish are stenohaline, which means they are restricted to either salt or fresh water and can cannot survive in water with a different salt concentration than they are adapted to. However, some fish show a tremendous ability to effectively osmoregulate across a broad range of salinities; fish with this ability are known as euryhaline species. This article does not cite any references or sources. ... For other uses, see Fish (disambiguation). ... For other uses, see Salt (disambiguation). ... For other uses, see Gill (disambiguation). ... Stenohaline describes an organism, ussually fish, that cannot handle a wide fluctuation in the salt content of water. ... Euryhaline organisms are able to adapt to a wide range of salinities. ...

Osmoregulation in plants

There are no specific osmoregulation organs in higher plants. Control of water intake and loss is by means of those internal and external factors which affect the rate of transpiration. u fuck in ua ...

Plants share with animals the problems of obtaining water and in disposing of the surplus. Certain plants develop methods of water conservation. Xerophytes are creampie plants in dry habitats such as deserts which are able to withstand prolonged periods of water shortage. Succulent plants such as the cactus have water stored in large parenchyma tissues. Other plants have leaf modifications to reduce water loss, such as needle-shaped leaves, sunken stomata and thick, waxy cuticles as in the pine. The sand-dune marram grass has rolled leaves with stomata on the inner surface. A xerophyte describes a plant that has structural (xeromorphic) and physiological adaptations which enable them to survive, or even thrive, in areas with very little free moisture. ... Genera See Taxonomy of the Cactaceae A cactus (plural cacti, cactuses or cactus)SEE REBECCA I WAS RIGHT is any member of the succulent plant family Cactaceae, native to the Americas. ... Parenchyma is a term used to describe a bulk of a substance. ... Look up foliage in Wiktionary, the free dictionary. ... This is not about surgically created bowel openings; see stoma (medicine) In botany, a stoma (also stomate; plural stomata) is a tiny opening or pore, found mostly on the undersurface of a plant leaf, and used for gas exchange. ... Subgenera Subgenus Strobus Subgenus Ducampopinus Subgenus Pinus See Pinus classification for complete taxonomy to species level. ... Species Ammophila arenaria Ammophila breviligulata Marram Grass or Beach Grass is a genus of two species of grass growing almost exclusively on coastal sand dunes, where rhizomes on its extensive root system allow it to survive in a very harsh and windswept ecosystem. ...

Oncophyorans are also osmoregulators.

Osmoregulation in protists and animals

Amoeba make use of contractile vacuoles to collect excretory waste, such as ammonia, from the intracellular fluid by both diffusion and active transport. As osmotic action pushes water from the environment into the cytoplasm, the vacuole moves to the surface and disposes the contents into the environment. Alternate meanings: Amoeboid, Amoebozoa For other uses, see Amoeba (disambiguation). ... Figure 1: A paramecium. ... Ammonia is a compound with the formula NH3. ...

Kidneys play a very large role in human osmoregulation, regulating the amount of water in urine waste. With the help of naturally producing hormones such as antidiuretic hormone, aldosterone, and angiotensin II, the human body can increase the permeability of the collecting ducts in the kidney to reabsorb water and prevent it from being excreted. Kidneys viewed from behind with spine removed The kidneys are bean-shaped excretory organs in vertebrates. ... Hormone is also the NATO reporting name for the Soviet/Russian Kamov Ka-25 military helicopter. ... Antidiuretic hormone (ADH), or arginine vasopressin (AVP), is a peptide hormone produced by the hypothalamus, and stored in the posterior part of the pituitary gland. ... Aldosterone is a steroid hormone (mineralocorticoid family) produced by the outer-section (zona glomerulosa) of the adrenal cortex in the adrenal gland to regulate sodium and potassium balance in the blood. ... Angiotensinogen, angiotensin I and angiotensin II are peptides involved in maintenance of blood volume and pressure. ...

A major way animals have evolved to osmoregulate is by controlling the amount of water excreted through the excretory system. Kidneys Nephron Urine Large Intestine Lung Carbon dioxide Skin Sweat Bile Malphigian tubule system (Arthropod excretory system) Menses The Excretory system is responsible for the elimination of wastes produced by homeostasis. ...

Vertebrate excretory systems

Waste products of nitrogen metabolism

Ammonia is a toxic by-product of protein metabolism and is generally converted to less toxic substances after it is produced then excreted; mammals convert ammonia to urea while birds and reptiles form uric acid to be excreted with other wastes via their cloacas. Ammonia is a compound with the formula NH3. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the production of milk in female mammary glands and by the presence of: hair, three middle ear bones used in hearing, and a neocortex region in... For other uses, see Bird (disambiguation). ... Reptilia redirects here. ... In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, urinary, and genital tracts of certain animal species. ...

How osmoregulation is achieved in vertebrates

Four processes occur:

• filtration - fluid portion of blood (plasma) is filtered from a nephron (functional unit of vertebrate kidney) structure known as the glomerulus into Bowman's capsule or glomerular capsule (in the kidney's cortex) and flows down the proximal convoluted tubule to a "u-turn" called the Loop of Henle (loop of the nephron) in the medulla portion of the kidney.
• reabsorption - most of the viscous glomerular filtrate is returned to blood vessels which surround the convoluted tubules.
• secretion - the remaining fluid becomes urine, which travels down collecting ducts to the medullary region of the kidney.
• excretion - the urine (in mammals) is stored in the urinary bladder and exits via the urethra; in other vertebrates the urine mixes with other wastes in the cloaca before leaving the body; ( frogs also have a urinary bladder).

A nephron is the basic structural and functional unit of the kidney. ... Glomerulus refers to two unrelated structures in the body, both named for their globular form. ... The Bowmans capsule(other names: capsula glomeruli, glomerular capsule) is a cup like sac at the beginning of the tubular component of a nephron in the mammalian kidney. ... In the kidney, the loop of Henle is the portion of the nephron that leads from the proximal convoluted tubule to the distal convoluted tubule. ... This article or section is in need of attention from an expert on the subject. ...

References

• E. Solomon, L. Berg, D. Martin, Biology 6th edition. Brooks/Cole Publishing. 2002

Also see: 2002 (number). ...

External links

• Prof. Chuck Holliday's Research Page, Prof. Chuck Holliday, Dept. of Biology, Lafayette College. Contains links to articles on osmoregulation in crustaceans.
• Excretion and osmoregulation.