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Encyclopedia > Loop of Henle
Loop of Henle
Scheme of renal tubule and its vascular supply. (Loop of Henle visible center-left.)
Latin ansa nephroni
Gray's subject #253 1223
Precursor Metanephric blastema
MeSH loop+of+henle
Dorlands/Elsevier a_44/12138619

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. The loop has a hairpin bend in the renal medulla. The main function of this structure is to reabsorb water and ions from the urine. To do this, it uses a countercurrent multiplier mechanism in the medulla. It is named after its discoverer, F. G. J. Henle. Image File history File links Gray1128. ... For other uses, see Latin (disambiguation). ... This article or section is in need of attention from an expert on the subject. ... The Metanephric blastema (or metanephric mesenchyme) is one of the two embryological structures that give rise to the kidney (the other is the ureteric bud. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... Elseviers logo. ... The kidneys are the organs that filter wastes (such as urea) from the blood and excrete them, along with water, as urine. ... A nephron is the basic structural and functional unit of the kidney. ... In the biology of the kidney, the proximal convoluted tubule is the segment of the renal tubule that drains Bowmans capsule. ... The distal convoluted tubule (DCT) is a portion of kidney nephron between the loop of Henle and the collecting duct system. ... Road D2204 ascends to the Col de Braus using hairpin bends in the Alpes Maritimes in the French Alps ( ) The kind of hair pin (bobby pin) from which a hairpin turn gets its name Some of the 48 hairpin turns near the top of the northern ramp of the Stilfserjoch... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... This article is about the electrically charged particle. ... This article is about the urine of animals generally. ... Countercurrent exchange is a mechanism used to transfer some property of a fluid from one flowing current of fluid to another across a Semipermeable membrane or thermally-conductive material between them. ... Friedrich Gustav Jakob Henle Friedrich Gustav Jakob Henle (b. ...

Contents

Components

It can be divided into four parts:

descending limb of loop of Henle The descending limb has low permeability to ions and urea, while being highly permeable to water.
thin ascending limb of loop of Henle The thin ascending limb is not permeable to water, but it is permeable to ions.
medullary thick ascending limb of loop of Henle Sodium (Na+), potassium (K+) and chloride (Cl-) ions are reabsorbed from the urine by active transport. K+ is passively transported along its concentration gradient through a K+ channel in the basolateral aspect of the cells, back into the lumen of the ascending limb. This K+ "leak" generates a positive electrochemical potential difference in the lumen. The electrical gradient drives more reabsorption of Na+, as well as other cations such as magnesium (Mg2+) and importantly calcium Ca2+.
cortical thick ascending limb The cortical thick ascending limb drains urine into the distal convoluted tubule.

The descending limb of loop of Henle is the portion of the renal tubule constituting the first part of the loop of Henle. ... Urea is an organic compound with the chemical formula (NH2)2CO. Urea is also known as carbamide, especially in the recommended International Nonproprietary Names (rINN) in use in Europe. ... As the filtrate passes back up the thin ascending limb of loop of Henle, the concentration of the surrounding medulla decreases. ... The thick ascending limb of loop of Henle (or distal straight tubule) can be divided into two parts: that in the renal medulla, and that in the renal cortex. ... General Name, symbol, number potassium, K, 19 Chemical series alkali metals Group, period, block 1, 4, s Appearance silvery white Standard atomic weight 39. ... The chloride ion is formed when the element chlorine picks up one electron to form an anion (negatively-charged ion) Cl−. The salts of hydrochloric acid HCl contain chloride ions and can also be called chlorides. ... Sodium-Potassium pump, an example of Primary active transport secondary active transport Active transport (sometimes called active uptake) is the mediated transport of biochemicals, and other atomic/molecular substances, across membranes. ... Electrochemical potential is a thermodynamic measure that reflects energy from entropy and electrostatics and is typically invoked in molecular processes that involve diffusion. ... A cation is an ion with positive charge. ... General Name, symbol, number magnesium, Mg, 12 Chemical series alkaline earth metals Group, period, block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ... For other uses, see Calcium (disambiguation). ... The distal convoluted tubule (DCT) is a portion of kidney nephron between the loop of Henle and the collecting duct system. ...

Blood supply

The loop of Henle is supplied by blood in a series of straight capillaries descending from the cortical efferent arterioles. These capillaries (called the vasa recta; recta is from the Latin for "straight") also have a countercurrent exchange mechanism that prevents washout of solutes from the medulla, thereby maintaining the medullary concentration. As water is osmotically driven from the descending limb into the interstitium, it readily enters the vasa recta. The low bloodflow through the vasa recta allows time for osmotic equilibration, and can be altered by changing the resistance of the vessels' efferent arterioles. A nephron, the vasa recta is labelled arteria recta In the blood supply of the kidney, the vasa recta form a series of straight capillaries (recta is from the Latin for straight) that descend from the cortex into the medulla. ... Latin was the language originally spoken in the region around Rome called Latium. ... Countercurrent exchange is a mechanism used to transfer some component of a fluid from one flowing current of fluid to another across a permeable barrier between them. ...


Also, the vasa recta still has the large proteins and ions which were not filtered through the glomerulus, which provides an oncotic pressure for ions to enter the vasa recta from the interstitium. In blood plasma, the dissolved compounds have an osmotic pressure. ...


Additional images

References

  • Douglas C. Eaton, John Pooler (2004). Vander's Renal Physiology, 6th edition, McGraw-Hill Medical. ISBN 0-07-135728-9. 

External links


  Results from FactBites:
 
Loop diuretic - Wikipedia, the free encyclopedia (493 words)
Loop diuretics are diuretics that act on the ascending loop of Henle in the kidney.
Loop diuretics act on the Na-K-2Cl symporter in the thick ascending limb of the loop of Henle to inhibit sodium and chloride reabsorption.
Loop diuretics also cause vasodilation of the veins and of the kidney's blood vessels, mechanically causing a decrease in blood pressure.
Loop of Henle - Wikipedia, the free encyclopedia (548 words)
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.
The loop has a hairpin bend in the renal medulla.
The loop of Henle is supplied by blood in a series of straight capillaries descending from the cortical efferent arterioles.
  More results at FactBites »

 
 

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