Glomerular Filtration Rate (GFR)

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A Glomerular Filtration Rate (GFR) is a renal function measure that ...



References

2017

  • (Wikipedia, 2017) ⇒ https://en.wikipedia.org/wiki/Renal_function#Glomerular_filtration_rate Retrieved:2017-5-8.
    • Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal (kidney) glomerular capillaries into the Bowman's capsule per unit time. [1] Central to the physiologic maintenance of GFR is the differential basal tone of the afferent and efferent arterioles (see diagram). In other words, the filtration rate is dependent on the difference between the higher blood pressure created by vasoconstriction of the input or afferent arteriole versus the lower blood pressure created lesser vasoconstriction of the output or efferent arteriole.

      Glomerular filtration rate (GFR) is equal to the Clearance Rate when any solute is freely filtered and is neither reabsorbed nor secreted by the kidneys. The rate therefore measured is the quantity of the substance in the urine that originated from a calculable volume of blood. Relating this principle to the below equation - for the substance used, the product of urine concentration and urine flow equals the mass of substance excreted during the time that urine has been collected. This mass equals the mass filtered at the glomerulus as nothing is added or removed in the nephron. Dividing this mass by the plasma concentration gives the volume of plasma which the mass must have originally come from, and thus the volume of plasma fluid that has entered Bowman's capsule within the aforementioned period of time. The GFR is typically recorded in units of volume per time, e.g., milliliters per minute mL/min. Compare to filtration fraction. : [math]\displaystyle{ GFR = \frac { \mbox{Urine Concentration} \times \mbox{Urine Flow} }{ \mbox{Plasma Concentration} } }[/math] There are several different techniques used to calculate or estimate the glomerular filtration rate (GFR or eGFR). The above formula only applies for GFR calculation when it is equal to the Clearance Rate.

2017

  • (Wikipedia, 2017) ⇒ https://simple.wikipedia.org/wiki/Glomerular_filtration_rate Retrieved:2017-5-8.
    • Glomerular filtration rate (GFR) is a test used by physicians and other medical professionals to see if the kidneys are working correctly. In basic terms, it is a measurement of how much liquid and waste is passing from the blood through the tiny filters in the kidney, called the glomeruli, and out into the urine during each minute. The test measures how much creatinine is in the blood. This shows how well the kidneys are performing. In a normal healthy person the GFR stays close to the same value all of the time. The test is done by taking blood from a person and sending it to a laboratory. Normal values are between 90ml/min and 110ml/min. A value below 60ml/minute means the person has chronic renal disease and a value below 15ml/minute means the person's kidneys have stopped working.

  1. - "Glomerular Filtration Rate"