Countercurrent multiplication refers to the process by which a small osmolality difference, at each level of the outer medulla, between fluid flows in ascending and descending limbs of the loops of henle, is multiplied by the countercurrent flow configuration to establish a large axial osmolality difference. Countercurrent exchange biology accessscience from. Countercurrent shear flow control has been shown as an effective method of increasing volumetric heat release within a dump combustor due to an increase in turbulence, specifically the large turbulent structures present in the flow field. A model system for countercurrent transfer may be described in the following way. It is found widely in nature and especially in mammalian organs. Countercurrent definition of countercurrent by merriamwebster. Cold water is pumped through one, and hot water through the other the inlets are at the opposite ends of the construction countercurrent. Countercurrent exchange of solutes and water helping to preserve this gradient is indicated in the. For example, it can refer to the process that is underlying the process of urine concentration, that is, the production of hyperosmotic urine by the mammalian kidney.
Check out this collection of 30 pdf templates for cutandfold paper mechanisms and 3d optical illusions. Lever federal republic of germany and glasgow, scotland boilermakers have known and exploited the principle of countercurrent exchange since the early nineteenth century. Jpg to pdf convert your jpg to pdf for free online. The countercurrent heat exchange mechanism, if dominant, was suggested as an energy conservation means since it provides a direct heat transfer path between the vessels. Copy the file directly to your hard drive, rather than a thumb portable or network drive. Microsoft word q9 describe how the kidney maintains the medullary concentration gradient march 2011. Pdf a model of countercurrent shunting of oxygen in the. A countercurrent mechanism system is a mechanism that expends energy to create a concentration gradient it is found widely in nature and especially in mammalian organs. Countercurrent mechanism definition of countercurrent. The main function of this structure is to reabsorb water and ions from the urine. The stimulus for this recent burst of progress has been the introduction into the field of a revolutionary new concept. Links to pubmed are also available for selected references. Get a printable copy pdf file of the complete article 1. Countercurrent exchange of heat, respiratory gases, or nutrients is an important feature of the functional design of organisms, is.
Countercurrent mechanism article about countercurrent. Feb 15, 2009 video animation i did for some med students. Find out information about countercurrent mechanism. The plasma is the part of the blood that rernains when the cells been removed. To do this, it uses a countercurrent multiplier mechanism in the medulla. Countercurrent distribution, in chemistry, a multistage solventextraction process, one of many separation methods that can be employed in chemical analysis. A simple free tool to count pdf pages in a folder and export the summary to notepad or excel. For example, the rotor of an electric motor and the bearings in which it rotates do not form a mechanism, since in this case the electrical energy is transformed directly into the required motion without any intermediate transformation of mechanical motion. Ttre function of the kidney is to regulate the composition of the blood plasrna. An animation to explain the kidneys role in balancing h2o and electrolytes by creating a concentration gradient in the nephrons. An analytical model for the countercurrent heat exchange mechanism in animals has been formulated and a solution has been obtained. Counter current mechanism concentrated urine formation.
Countercurrent mechanism countercurrent multipliers the loop of henle produce high osmotic medullary gradient 1200 mosm lit at the bottom. Read and learn for free about the following article. This useful teaching aid was created for prof david poyner. Q9 describe how the kidney maintains the medullary. Industrial processes in chemical engineering or laboratory operations in which heat or mass or both are transferred from one fluid to another, with the fluids moving continuously in very nearly steady state or constant manner and in opposite directions through the unit. Scribd is the worlds largest social reading and publishing site. A current that flows in an opposite direction to the flow of another current. Plate heat exchangers were first produced in the 1920s and have since been widely used in a great number of sectors a plate exchanger consists of a series of parallel plates that are placed one above the other so as to allow the formation of a series of channels for fluids to flow between them. Jul 19, 2015 a detailed description on how counter current mechanism operates in our body. In fish a countercurrent system in the gills increases the amount of oxygen dissolved in the water which is absorbed. A method of multiple liquidliquid extractions is countercurrent extraction, which permits the separation of substances with different distribution coefficients ratios. Jpg to pdf convert file now view other image file formats technical details jpg is a graphical file format for editing still images, it offers a symmetrical compression technique which is processor intensive and time consiming in both compression and decompression. Counter current multiplication if youre seeing this message, it means were having trouble loading external resources on our website. To conserve water your body wants urine that is more concentrated than plasma when exreting extra water the osolarity of the urine will be less than that of plasma usually.
Pdf countercurrent exchange in the renal medulla researchgate. How to convert a jpg file to a pdf on a windows 10. The tubular fluid in the descending limb and the interstitial fluid quickly reach osmotic. This concentrated urine is produced when adh is present in the plasma normal physiological condition. Traumatologia forense eduardo vargas alvarado pdf download. Jul 01, 2008 the loop has a hairpin bend in the renal medulla. The mechanisms shown here are traditionally called the countercurrent multiplier and the countercurrent exchanger. Summary of the countercurrent mechanism the primary engineis active salt reabsorption without water by the thick ascending limb of henles loop. This could be maintaining an optimum core temperature, or optimum oxygen levels and water levels. Full text is available as a scanned copy of the original print version. Countercurrent definition is a current flowing in a direction opposite that of another current.
Countercurrent transfer in reproductive biology in. Renal capsule a layer of fibrous connective tissue covering the kidneys. The loop of henle is referred to as countercurrent multiplier and vasa recta as countercurrent exchange systems in concentrating and diluting urine. You can convert a jpg file into a pdf in windows 10 by changing some of the settings in your print menu. The first takes place in the region of the nephron called henles loop. There is large vertical gradient from the top to the bottom of renal medulla. Concurrent flow to understand countercurrent flow, it is easiest to start by looking at concurrent flow where water and blood flow over and through the lamellae in the same direction. Apr 23, 2009 countercurrent exchange is a mechanism organisms have evolved to maintain a certain optimality. An answer to query how to reduce pdf file size without losing quality compress pdf to chosen size.
Im sorry theres no sound, it wasnt my task to provide voice overs or narration. Explain counter current exchange giving one example from. Countercurrent mechanism in henles loop the nephrons involved in the formation of concentrated urine extend all the way from the cortex of the kidney to the medulla and are accompanied by. Countercurrent mechanism countercurrent multipliers the loop of henle produce high osmotic medullary gradient 1200 mosm lit at the. Countercurrent definition of countercurrent by the free. A system in which the inflow runs parallel to, counter to, and in close proximity to the outflow for some distance. The concentration of urine is controlled by antidiuretic hormone, which helps the kidneys to. Open the new copy on your hard drive and print again. The movement of ions like sodium into the interstitial space causes water to passively diffuse out the descending loop of henle. Countercurrent multiplier it is a mechanism involved in increasing the osmolarity of the interstitial fluid in the medulla of the kidney progressively to about 1200 to 1400 mosml. Anatomy of the urinary system kidneys a pair of bean shaped organs located retroperitoneally, responsible for blood filtering and urine formation. Biological countercurrent systems can be classified into two main types. This passive process is known as countercurrent exchange.
Countercurrently definition of countercurrently by the. Counter current mechanism by dr anita teli authorstream presentation. Loop of henle 1002 800 alh 400 402 200 dlh the countercurrent multiplier cortex medulla h 2o 1200 285 100 502 802 1100 1102 500 300 900 800 600 salt. A model of countercurrent shunting of oxygen in the intestinal villus article pdf available in the american journal of physiology 2624 pt 2. Countercurrent mechanism in henles loop the nephrons involved in the formation of concentrated urine extend all the way from the cortex of the kidney to the medulla and are accompanied by vasa recta. Plate heat exchanger working principle, how a plate heat. The principals of countercurrent multiplication, originally proposed by kuhn and ryffel in 1942. Problem 11 kidney countercurrent system is represented by. A mechanism is used when the required motion of bodies cannot be produced directly and the motion must be transformed. The renal handling of salts and water are independent of each other.
Countercurrent exchange is a mechanism occurring in nature and mimicked in industry and engineering, in which there is a crossover of some property, usually heat or some chemical, between two flowing bodies flowing in opposite directions to each other. Countercurrent flow definition of countercurrent flow by. Countercurrent mechanism helps penguin to stand on ice for long time. Within the past few years, there has been a remarkable advance in our understanding of the mechanism by which the kidney is able to produce a concentrated urine. When the blood first comes close to the water, the water is fully saturated with oxygen and the blood has very little. Countercurrent exchange biology accessscience from mcgraw.
Normal renal function hebrew university of jerusalem. The nondimensional parameters that govern the mechanism have been determined in terms of the properties of the animal. Download these pdf files of incredible paper mechanisms. Countercurrent mechanism overview the countercurrent mechanism partially contributes to generation of the corticopapillary osmotic gradient and is the product of juxtamedullary nephrons which possess long loops of henle that extend far into the renal medulla. Global dynamics of a dump combustor using momentumdriven. The purpose of this countercurrent exchange system is to produce hyperosmotic interstitial fluid in the medulla and hyposmotic filtrate leaving the loop of henle the water that leaves the descending loop of henle is absorbed into the vasa recta, which prevents dilution of the interstitial fluid. Counter current mechanism everything you need to know.
The countercurrent flowarrangement of henles loop and the vasa recta traps salt and urea within the medulla and minimizes the volume of water entering the medullary interstitium. Countercurrent definition of countercurrent by merriam. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. In both cases, the basic mechanism is the sameexchange of a substance between fluids flowing in opposite directionsbut the consequences are very different.
To excrete water, the countercurrent mechanism generates urine with osmolality less than plasma. A clever design known as craig apparatus is used for this purpose lyman c. The counter current mechanism operating inside the kidney is the main adaptation for the conservation of water. Substances are separated by this method on the basis of their different solubilities in two immiscible liquids. The counter current multiplier or the counter current mechanism is used to concentrate urine in the kidneys by the nephrons of the human excretory system. Best pdf resize software which can resize pdf to chosen file size. Countercurrent multiplication was originally studied as a mechanism whereby urine is concentrated in the nephron. Although most programs can use either a jpg or pdf. Pdf the microcirculation of the renal medulla traps nacl and urea deposited to the interstitium by the loops of henle and collecting ducts. An analytical model of the countercurrent heat exchange. The function of the counter current mechanism is to create urine with a different concentration than that of urine. Introduction the countercurrent multiplier theory of the. Renal cortex outer region of the kidneys where most enthrones is located. How does the counter current mechanism concentrate urine.
Give a brief account of the counter current mechanism. The countercurrent mechanism partially contributes to generation of the corticopapillary osmotic gradient and is the product of juxtamedullary nephrons which possess long loops of henle that extend far into the renal medulla. If you downloaded the pdf from the web or received it in an email, download the pdf again or ask the sender to resend it. Adds more salt than water to the medullary interstitium, thereby osmotically concentrating the. Plan of a nephron, the fundamental unit of kidney function. Initially studied in the 1950s by gottschalk and mylle following werner kuhns postulations, this mechanism gained popularity only after a series of complicated micropuncture experiments. The effects of this enhanced countercurrent shear leads to a globally unstable flow field that is quite advantageous in combustion control. Medullary hyperosmolality and medullary gradient the interstitial fluid of the medulla is critically important in concentrating the urine,because the osmotic pressure of this fluid provides the driving force for reabsorbing water from both the descending thin segment and. For the record, i have no idea how this actually works.
The active ion pump of the thick ascending limb on the loop of henle reduces. Counter current mechanism by dr anita teli authorstream. Countercurrent exchange is a mechanism organisms have evolved to maintain a certain optimality. The flowing bodies can be liquids, gases, or even solid powders, or any combination of those. A 200 mosml gradient between the ascending limb and the surrounding fluids at each medullary horizontal level. Countercurrent mechanisms the mechanisms shown here are traditionally called the countercurrent multiplier and the countercurrent exchanger. A countercurrent mechanism system is a mechanism that expends energy to create a concentration gradient. To conserve water, the countercurrent mechanism generates urine with osmolality greater than plasma. Run multiple iterations online to achieve desired pdf file size. Assume that the loop of henle is filled with a concentration of 300mosml the same as. Countercurrent mechanism in kidney pdf writer bitbin. Sequestration of urea and nonurea solutes in renal tissues of. Linear stability theory was used to provide guidance into the global flow fields created within these facilities, all of which contain multiple unstable profiles, each having their own stability parameters. In a countercurrent multiplier, the combined action of active pumping and circulation and recirculation of solutes around the loop of henle create an osmotic gradient with the following properties.
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