This MedLibrary.org supplementary page on Filtration fraction is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:
Related Sponsors
In renal physiology, the filtration fraction is the ratio of the glomerular filtration rate (GFR) to the renal plasma flow (RPF). RPF = 1-hematocrit(renal blood flow)
Filtration Fraction = GFR/(1-hematocrit)RBF
The filtration fraction therefore represents the proportion of the fluid reaching the kidneys which passes into the renal tubules.
The GFR on its own is the most common and important measure of renal function. However, in a condition such as renal stenosis, the blood flow to the kidneys is reduced. The filtration must therefore be increased in order to perform the normal tasks of the kidney in balancing fluid and electrolytes in the body. This would be reflected by a high filtration fraction, showing that the kidneys have to do more work with the fluid they are receiving.
Catecholamines (Norepinephrine and Epinephrine) increase the filtration fraction by vasoconstriction of Afferent and Efferent Arterioles which poss alpha 1 adrenergic receptors.
 |
This biology article is a stub. You can help Wikipedia by expanding it. |
Wikipedia content modification information:
- This page was last modified on 19 July 2008, at 18:34.
Wikipedia Authorship and Review
Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.
Wikipedia Usage Guidelines
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Filtration fraction".
The URL for this specific entry is:
All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.