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| [[Image:Renal Diuretics.gif|thumb|300px|right|This illustration demonstrates the normal kidney physiology. It also includes illustrations showing where some types of diuretics act, and what they do.]]
| | <br><br>Only few folks know that homeopathy and the 'legislation of similars' related to have their point out in centuries old medical information. Nevertheless, this remedy strategy turned popular some 200 years ago when orthodox medicines have been examined to cause more harm than advantages. Right now, homeopathic medication has attained a great significance within the fashionable remedy system.<br><br>Heroin use throughout pregnancy may lead to miscarriages, stillbirths, or untimely deliveries of babies born physically depending on the drug. Those that inject heroin are introducing unsterile substances into their bloodstream, which can lead to extreme harm to the heart, lungs, and mind. As well as, sharing needles is likely one of the fastest ways to spread diseases; it is currently the leading reason for all new HIV and hepatitis B instances. Selective serotonin reuptake inhibitors (SSRIs), a category of antidepressants, are first selection remedy for generalized social phobia however a second line remedy. In comparison with older types of remedy, there is much less risk of tolerability and drug dependency associated with SSRIs. one zero one For power decrease back pain<br><br>Nervousness and panic are separate health issues out of your high blood pressure however controlling one will drastically help in controlling the other. Anxiety is simply an exaggerated type of our natural fight or flight response. This response is completely essential to our effectively being because it prepares the physique to take care of physical risks and emergencies. The issue happens once we trigger the response for a perceived hazard slightly than a real one. Lavender is a superb anxiousness therapy and among the finest natural panic attack remedies. Lavender is a common tonic for the nervous system and a pure relaxant. It may take the type of panic assaults, nervousness, sweating, intense worry, nervousness combined with despair, or other overwhelming signs.<br><br>Natural tinnitus therapies can be found for its hundreds of thousands of victims. Given the wide range of causes, there's not a one size suits all kind of remedy. Gingko biloba is a natural remedy for mental disorders such as dementia. The plant has been used to deal with varied problems for many years. The scientific community is blended on use of gingko biloba to deal with tinnitus signs; however a latest compilation examine notes the advantages of EGb 761 standardized extract.<br><br>In generalized nervousness disorder, there is an exaggerated tension and worry in every day life. There is a fixed destructive thought of all the things going wrong, although there isn't a reason to think the identical. Just as all of the fingers on a hand aren't related, children too have totally different talents to manage up with stress. They've an harmless mind that's simply influenced by household issues, like parental fights, divorce, financial dash diet struggles of the household, and so forth. They store these anxieties that may be real or imagined by their minds, which can burst out as panic attacks. The child is made to feel confident and asked to confront his/her fears. This helps him/her to beat the worry, and thus helps in lowering, and finally getting stopping, the assaults. |
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| '''Renal physiology''' ([[Latin language|Latin]] ''rēnēs'', "kidney") is the study of the [[physiology]] of the [[kidney]]. This encompasses all functions of the kidney, including reabsorption of [[glucose]], [[amino acid]]s, and other small molecules; regulation of [[sodium]], [[potassium]], and other [[electrolyte]]s; regulation of [[fluid balance]] and [[blood pressure]]; maintenance of [[acid-base balance]]; the production of various [[hormone]]s including [[erythropoietin]], and the activation of [[vitamin D]]
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| Much of renal physiology is studied at the level of the [[nephron]], the smallest functional unit of the kidney. Each nephron begins with a filtration component that filters blood entering the kidney. This filtrate then flows along the length of the nephron, which is a tubular structure lined by a single layer of specialized [[cell (biology)|cells]] and surrounded by [[capillary|capillaries]]. The major functions of these lining cells are the reabsorption of water and small molecules from the filtrate into the blood, and the secretion of wastes from the blood into the urine.
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| Proper function of the kidney requires that it receives and adequately filters blood. This is performed at the microscopic level by many hundreds of thousands of filtration units called [[renal corpuscle]]s, each of which is composed of a [[glomerulus]] and a [[Bowman's capsule]]. A global assessment of [[renal function]] is often ascertained by estimating the rate of filtration, called the [[glomerular filtration rate]] (GFR).
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| ==Functions of the kidney==
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| The functions of the kidney can be divided into three groups: secretion of hormones, [[gluconeogenesis]] and extracellular homeostasis of pH and blood components. The nephron is the functional unit of the kidney.
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| ===Secretion of hormones===
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| *Secretion of ''[[erythropoietin]]'', which regulates [[red blood cell]] production in the [[bone marrow]].
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| *Secretion of ''[[renin]]'', which is a key part of the [[renin-angiotensin-aldosterone system]].
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| *Secretion of the active form of [[vitamin D]] ([[calcitriol]]) and [[prostaglandin]]s.
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| ===Gluconeogenesis===
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| The kidney in humans is capable of producing [[glucose]] from [[lactic acid|lactate]], [[glycerol]] and [[glutamine]]. The kidney is responsible for about half of the total gluconeogenesis in fasting humans. The regulation of glucose production in the kidney is achieved by action of [[insulin]], [[catecholamines]] and other hormones.<ref name=Gerich2010>{{cite doi|10.1111/j.1464-5491.2009.02894.x}}</ref> Renal gluconeogenesis takes place in the [[renal cortex]]. The [[renal medulla]] is incapable of producing glucose due to absence of necessary [[enzyme]]s.<ref name=Gerich2001>{{cite pmid|11213896}}</ref>
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| ===Extracellular homeostasis===
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| The kidney is responsible for maintaining a balance of the following substances:
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| {| class="wikitable"
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| | '''Substance''' || '''Description''' || '''[[Proximal tubule]]''' || '''[[Loop of Henle]]''' || '''[[Distal tubule]]''' || '''[[Collecting duct]]'''
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| | [[Renal glucose reabsorption|Glucose]] || If glucose is not reabsorbed by the kidney, it appears in the urine, in a condition known as [[glycosuria]]. This is associated with [[diabetes mellitus]].<ref>[http://web.archive.org/web/20070715122822/http://www.lib.mcg.edu/edu/eshuphysio/program/section7/7ch06/7ch06p11.htm Sect. 7, Ch. 6: Characteristics of Proximal Glucose Reabsorption]. lib.mcg.edu</ref> || reabsorption (almost 100%) via [[sodium-glucose transport proteins]]<ref name="lib.mcg.edu">[http://web.archive.org/web/20070715122822/http://www.lib.mcg.edu/edu/eshuphysio/program/section7/7ch05/7ch05p13.htm Sect. 7, Ch. 5: Cotransport (Symport)]. lib.mcg.edu</ref> ([[Apical membrane|apical]]) and [[Glucose transporter|GLUT]] ([[basolateral]]). || – || – || –
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| | [[Renal oligopeptide reabsorption|Oligopeptides]], [[renal protein reabsorption|proteins]], and [[amino acids]] || All are reabsorbed nearly completely.<ref>[http://web.archive.org/web/20070715122822/http://www.lib.mcg.edu/edu/eshuphysio/program/section7/7ch06/7ch06p17.htm Sect. 7, Ch. 6: Proximal Reabsorption of Amino Acids: Site of Reabsorption]. lib.mcg.edu</ref> || reabsorption || – || – || –
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| | [[Renal urea handling|Urea]] || Regulation of [[Osmole (unit)|osmolality]]. Varies with [[antidiuretic hormone|ADH]]<ref>[http://web.archive.org/web/20070715122822/http://www.lib.mcg.edu/edu/eshuphysio/program/section7/7ch06/7ch06p10.htm Sect. 7, Ch. 6: Proximal Reabsorption of Urea]. lib.mcg.edu</ref><ref>[http://web.archive.org/web/20070715122822/http://www2.kumc.edu/ki/physiology/course/five/5_1.htm V. Excretion of Organic Molecules]. lib.mcg.edu</ref> || reabsorption (50%) via [[passive transport]] || secretion|| – || reabsorption in [[medullary collecting duct]]s
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| | [[Renal sodium reabsorption|Sodium]] || Uses [[Sodium-hydrogen antiporter|Na-H antiport]], Na-glucose symport, [[sodium ion channel]]s (minor)<ref name="www2.kumc.edu">[http://www2.kumc.edu/ki/physiology/course/six/6_1.htm VI. Mechanisms of Salt & Water Reabsorption<!-- Bot generated title -->]</ref>
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| || reabsorption (65%, [[isosmotic]]) || reabsorption (25%, thick ascending, [[Na-K-2Cl symporter]]) || reabsorption (5%, [[sodium-chloride symporter]]) || reabsorption (5%, principal cells), stimulated by [[aldosterone]] via [[ENaC]]
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| | [[Renal chloride reabsorption|Chloride]] || Usually follows [[sodium]]. Active (transcellular) and passive ([[paracellular]])<ref name="www2.kumc.edu"/> || reabsorption || reabsorption (thin ascending, thick ascending, [[Na-K-2Cl symporter]]) || reabsorption ([[sodium-chloride symporter]]) || –
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| | [[Water]] || Uses [[aquaporin]] water channels. See also [[diuretic]]. || absorbed osmotically along with solutes || reabsorption (descending) || – || reabsorption (regulated by ADH, via [[arginine vasopressin receptor 2]])
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| | [[Bicarbonate]] || Helps maintain [[acid-base balance]].<ref>[http://web.archive.org/web/20070219065040/http://lib.mcg.edu/edu/eshuphysio/program/section7/7ch06/7ch06p08.htm Sect. 7, Ch. 6: Proximal Reabsorption of Bicarbonate]. lib.mcg.edu</ref> || reabsorption (80–90%) <ref>[http://web.archive.org/web/20070715121612/http://www.lib.mcg.edu/edu/eshuphysio/program/section7/7ch12/7ch12p21.htm Sect. 7, Ch. 12: Proximal Tubular Reabsorption of Bicarbonate]. lib.mcg.edu</ref> || reabsorption (thick ascending) <ref>[http://web.archive.org/web/20070715122822/http://www.lib.mcg.edu/edu/eshuphysio/program/section7/7ch12/7ch12p22.htm Sect. 7, Ch. 12: Bicarbonate Reabsorption, Thick Limb of Henle’s Loop]. lib.mcg.edu</ref> || – || reabsorption (intercalated cells, via [[band 3]] and [[pendrin]])
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| | [[Protons]] || Uses [[vacuolar H+ATPase]] || – || – || – || secretion (intercalated cells)
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| | [[Potassium]] || Varies upon dietary needs. || reabsorption (65%) || reabsorption (20%, thick ascending, [[Na-K-2Cl symporter]]) || – || secretion (common, via [[Na+/K+-ATPase]], increased by [[aldosterone]]), or reabsorption (rare, [[hydrogen potassium ATPase]])
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| | [[Calcium]] || Uses [[calcium ATPase]], [[sodium-calcium exchanger]] || reabsorption || reabsorption (thick ascending) via [[passive transport]] || reabsorption in response to PTH and ↑ reabsorption with Thiazide Diuretics. <ref>en.wikipedia.org/wiki/Distal_convoluted_tubule</ref> || –
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| | [[Magnesium]] || Calcium and magnesium compete, and an excess of one can lead to excretion of the other. || reabsorption || reabsorption (thick ascending) || reabsorption || –
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| | [[Phosphate]] || Excreted as [[titratable acid]]. || reabsorption (85%) via [[sodium/phosphate cotransporter]].<ref name="lib.mcg.edu"/> Inhibited by [[parathyroid hormone]]. || – || – || –
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| | [[Carboxylate]] || || reabsorption (100%<ref name=boron799>{{cite book |author=Walter F., PhD. Boron |title=Medical Physiology: A Cellular And Molecular Approaoch |publisher=Elsevier/Saunders |location= |year= |pages= |isbn=1-4160-2328-3 |oclc= |doi=}} Page 799</ref>) via [[carboxylate transporter]]s. || – || – || –
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| The body is very sensitive to its [[pH]]. Outside the range of pH that is compatible with life, proteins are denatured and digested, enzymes lose their ability to function, and the body is unable to sustain itself. The kidneys maintain [[acid-base homeostasis]] by regulating the pH of the [[blood plasma]]. Gains and losses of acid and base must be balanced. Acids are divided into "volatile acids"<ref>[http://web.archive.org/web/20070715122822/http://www.lib.mcg.edu/edu/eshuphysio/program/section7/7ch12/7ch12p12.htm Sect. 7, Ch. 12: Physiological Definition of Acids: Volatile Acid]. lib.mcg.edu</ref> and "nonvolatile acids".<ref>[http://web.archive.org/web/20070715122822/http://www.lib.mcg.edu/edu/eshuphysio/program/section7/7ch12/7ch12p13.htm Sect. 7, Ch. 12: Nonvolatile Acids]. lib.mcg.edu</ref> See also [[titratable acid]].
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| The major [[homeostasis|homeostatic]] control point for maintaining this stable balance is renal excretion. The kidney is directed to excrete or retain sodium via the action of [[aldosterone]], [[antidiuretic hormone]] (ADH, or vasopressin), [[atrial natriuretic peptide]] (ANP), and other hormones. Abnormal ranges of the [[fractional excretion of sodium]] can imply [[acute tubular necrosis]] or [[glomerular]] dysfunction. | |
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| ==Mechanisms==
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| [[File:Physiology of Nephron.png|300px|thumb|right|Diagram showing the basic physiologic mechanisms of the kidney]]
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| The kidney's ability to perform many of its functions depends on the three fundamental functions of ''filtration'', ''reabsorption'', and ''secretion'', whose sum is renal excretion. That is:
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| :Urinary excretion rate = Filtration rate – Reabsorption rate + Secretion rate<ref>p 314, Guyton and Hall, ''Medical Physiology'', 11th edition</ref>
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| ===Filtration===
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| {{Main|Renal ultrafiltration}}
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| The [[blood]] is filtered by [[nephron]]s, the functional units of the kidney. Each nephron begins in a [[renal corpuscle]], which is composed of a [[glomerulus]] enclosed in a [[Bowman's capsule]]. Cells, proteins, and other large molecules are filtered out of the glomerulus by a process of [[ultrafiltration (renal)|ultrafiltration]], leaving an ultrafiltrate that resembles plasma (except that the ultrafiltrate has negligible [[plasma protein]]s) to enter Bowman's space. Filtration is driven by [[Starling forces]].
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| The ultrafiltrate is passed through, in turn, the [[proximal convoluted tubule]], the [[loop of Henle]], the [[distal convoluted tubule]], and a series of [[collecting duct]]s to form [[urine]].
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| ===Reabsorption===
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| Tubular reabsorption is the process by which solutes and water are removed from the [[tubular fluid]] and transported into the blood. It is called ''reabsorption'' (and not ''absorption'') because these substances have already been absorbed once (particularly in the [[intestine]]s).
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| Reabsorption is a two-step process beginning with the [[active transport|active]] or [[passive transport|passive]] extraction of substances from the tubule fluid into the [[renal interstitium]] (the connective tissue that surrounds the nephrons), and then the transport of these substances from the interstitium into the bloodstream. These transport processes are driven by [[Starling forces]], [[diffusion]], and [[active transport]].
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| ====Indirect reabsorption====
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| In some cases, reabsorption is indirect. For example, bicarbonate (HCO<sub>3</sub><sup>-</sup>) does not have a transporter, so its reabsorption involves a series of reactions in the tubule lumen and tubular epithelium. It begins with the active secretion of a hydrogen ion (H<sup>+</sup>) into the tubule fluid via a [[Na/H exchanger]]:
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| * In the lumen
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| ** The H<sup>+</sup> combines with HCO<sub>3</sub><sup>-</sup> to form carbonic acid (H<sub>2</sub>CO<sub>3</sub>)
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| ** Luminal [[carbonic anhydrase]] enzymatically converts H<sub>2</sub>CO<sub>3</sub> into H<sub>2</sub>O and CO<sub>2</sub>
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| ** CO<sub>2</sub> freely diffuses into the cell
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| * In the epithelial cell
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| ** Cytoplasmic carbonic anhydrase converts the CO<sub>2</sub> and H<sub>2</sub>O (which is abundant in the cell) into H<sub>2</sub>CO<sub>3</sub>
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| ** H<sub>2</sub>CO<sub>3</sub> readily dissociates into H<sup>+</sup> and HCO<sub>3</sub><sup>-</sup>
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| ** HCO<sub>3</sub><sup>-</sup> is [[facilitated transport|facilitated]] out of the cell's [[basolateral membrane]]
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| ====Hormones====
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| Some key regulatory hormones for reabsorption include:
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| * [[aldosterone]], which stimulates active sodium reabsorption (and water as a result)
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| * [[antidiuretic hormone]], which stimulates passive water reabsorption
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| Both hormones exert their effects principally on the [[collecting duct]]s.
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| ===Secretion===
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| {{Main|Clearance (medicine)}}
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| Tubular secretion is the transfer of materials from [[peritubular capillaries]] to renal tubular lumen. Tubular secretion is caused mainly by [[active transport]].
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| Usually only a few substances are secreted. These substances are present in great excess, or are natural poisons.
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| Many drugs are [[clearance (medicine)|eliminated]] by tubular secretion. ''Further reading: [[Table of medication secreted in kidney]]''
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| ==Measurement of renal function==
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| {{Main|Renal function}}
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| A simple means of estimating renal function is to measure [[pH]], [[blood urea nitrogen]], [[creatinine]], and basic [[electrolyte]]s (including [[sodium]], [[potassium]], [[chloride]], and [[bicarbonate]]). As the kidney is the most important organ in controlling these values, any derangement in these values could suggest renal impairment.
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| There are several more formal tests and ratios involved in estimating renal function:
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| {| class="wikitable"
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| | '''Measurement''' || '''Calculation''' || '''Details'''
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| | [[renal plasma flow]] || <math>RPF = \frac{\text{effective RPF}}{\text{extraction ratio}}</math> <ref>[http://web.archive.org/web/20070715122822/http://www.lib.mcg.edu/edu/eshuphysio/program/section7/7ch04/7ch04p28.htm Sect. 7, Ch. 4: Measurement of Renal Plasma Flow; Renal Clearance of PAH]. lib.mcg.edu</ref> || Volume of [[blood plasma]] delivered to the kidney per unit time. [[PAH clearance]] is a renal analysis method used to provide an estimate. Approximately 625 ml/min.
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| | [[renal blood flow]] || <math>RBF = \frac{RPF}{1 - HCT}</math> (HCT is [[hematocrit]]) || Volume of [[blood]] delivered to the kidney per unit time. In humans, the kidneys together receive roughly 20% of cardiac output, amounting to 1 L/min in a 70-kg adult male.
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| | [[glomerular filtration rate]] || <math>GFR = \frac{U_{[\text{creatinine}]}\times \dot{V}}{P_{[\text{creatinine}]}}</math> (estimation using [[creatinine clearance]]) || Volume of fluid filtered from the [[kidney|renal]] [[Glomerulus (kidney)|glomerular]] capillaries into the [[Bowman's capsule]] per unit time. Estimated using [[inulin]]. Usually a [[creatinine clearance]] test is performed but other markers, such as the plant polysaccharide inulin or radiolabelled EDTA, may be used as well.
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| | [[filtration fraction]] || <math>FF = \frac{GFR}{RPF}</math> <ref>[http://web.archive.org/web/20070715122822/http://www.lib.mcg.edu/edu/eshuphysio/program/section7/7ch04/7ch04p17.htm Sect. 7, Ch. 4: Filtration Fraction]. lib.mcg.edu</ref> || Measures portion of renal plasma that is filtered.
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| | [[anion gap]] || AG = [Na<sup>+</sup>] − ([Cl<sup>−</sup>] + [HCO<sub>3</sub><sup>−</sup>]) || [[Cations]] minus [[anions]]. Excludes K<sup>+</sup> (usually), Ca<sup>2+</sup>, H<sub>2</sub>PO<sub>4</sub><sup>−</sup>. Aids in the [[differential diagnosis]] of [[metabolic acidosis]]
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| | [[clearance (medicine)|Clearance]] (other than water) || <math>C = \frac{U \times \dot{V}}{P}</math> where U = concentration, V =urine volume / time, U*V = urinary excretion, and P = plasma concentration <ref>[http://web.archive.org/web/20090124041511/http://www2.kumc.edu/ki/physiology/course/four/4_2.htm IV. Measurement of Renal Function]. kumc.edu</ref> || Rate of removal
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| | [[free water clearance]] || <math>C = \dot{V} - C_{osm}</math> or <math>\dot{V} - \frac{U_{osm}}{P_{osm}}\dot{V}</math> <math>=C_{H_2O}</math><ref>[http://web.archive.org/web/20070715122822/http://www.lib.mcg.edu/edu/eshuphysio/program/section7/7ch08/7ch08p21.htm Sect. 7, Ch. 8: Free water clearance (CH2O)]. lib.mcg.edu</ref> || The volume of [[blood plasma]] that is [[renal clearance|cleared]] of [[solution|solute]]-free [[water]] per unit time.
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| | [[Net acid excretion]] || <math>NEA = \dot{V} ( U_{NH_4} + U_{TA} - U_{HCO_3} )</math> || Net amount of acid excreted in the [[urine]] per unit time
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| {{Renal physiology}}
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| ==References==
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| {{Reflist|30em}}
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| {{DEFAULTSORT:Renal Physiology}}
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| [[Category:Renal physiology| ]]
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Only few folks know that homeopathy and the 'legislation of similars' related to have their point out in centuries old medical information. Nevertheless, this remedy strategy turned popular some 200 years ago when orthodox medicines have been examined to cause more harm than advantages. Right now, homeopathic medication has attained a great significance within the fashionable remedy system.
Heroin use throughout pregnancy may lead to miscarriages, stillbirths, or untimely deliveries of babies born physically depending on the drug. Those that inject heroin are introducing unsterile substances into their bloodstream, which can lead to extreme harm to the heart, lungs, and mind. As well as, sharing needles is likely one of the fastest ways to spread diseases; it is currently the leading reason for all new HIV and hepatitis B instances. Selective serotonin reuptake inhibitors (SSRIs), a category of antidepressants, are first selection remedy for generalized social phobia however a second line remedy. In comparison with older types of remedy, there is much less risk of tolerability and drug dependency associated with SSRIs. one zero one For power decrease back pain
Nervousness and panic are separate health issues out of your high blood pressure however controlling one will drastically help in controlling the other. Anxiety is simply an exaggerated type of our natural fight or flight response. This response is completely essential to our effectively being because it prepares the physique to take care of physical risks and emergencies. The issue happens once we trigger the response for a perceived hazard slightly than a real one. Lavender is a superb anxiousness therapy and among the finest natural panic attack remedies. Lavender is a common tonic for the nervous system and a pure relaxant. It may take the type of panic assaults, nervousness, sweating, intense worry, nervousness combined with despair, or other overwhelming signs.
Natural tinnitus therapies can be found for its hundreds of thousands of victims. Given the wide range of causes, there's not a one size suits all kind of remedy. Gingko biloba is a natural remedy for mental disorders such as dementia. The plant has been used to deal with varied problems for many years. The scientific community is blended on use of gingko biloba to deal with tinnitus signs; however a latest compilation examine notes the advantages of EGb 761 standardized extract.
In generalized nervousness disorder, there is an exaggerated tension and worry in every day life. There is a fixed destructive thought of all the things going wrong, although there isn't a reason to think the identical. Just as all of the fingers on a hand aren't related, children too have totally different talents to manage up with stress. They've an harmless mind that's simply influenced by household issues, like parental fights, divorce, financial dash diet struggles of the household, and so forth. They store these anxieties that may be real or imagined by their minds, which can burst out as panic attacks. The child is made to feel confident and asked to confront his/her fears. This helps him/her to beat the worry, and thus helps in lowering, and finally getting stopping, the assaults.