19734 netter107

RENAL PHYSIOLOGY

Clearance principk*

Substance (X) filtered through glomeruli and not roabsorbed or secreted by tubules <inulin)

Clearance ot X equals glomerular filtration ratę C_x = GIK

Substance (X) filtered through glomeruli and secreted by tubules

Clearance of X equals glomerular filtration ratę plus tubular sch relion ratę C_x = GFR + T„

^Cx > C|NUUN

Substance <X) filtered through glomeruli and reabsorbed by tubules

Clearance of X equals glomerular filtration ratę minus tubular reabsorpfion ratę

C, = GFR-T,

C_x < Cinulin

Substance (X) filtered through glomeruli, reabsorbed by tubules, and also secreted by tubules

Clearance of X equals glomerular filtration ratę minus net reabsorption ratę or plus net secretion ratę C_x = GFR ± T,

Cx<°r> Cinuun

Figurę 6.5 Renal Clearance__

The renal clearanc e of a substance* provides intormation on how that tbat of inulin, then the substance is secreted by the nephron. Figurę substance is handled by the kidney. I he clearanc e of inulin provides    6.6 and 6.7 illustrale in greater detail lho handling of a substance tr

a measure of the GFR. Ii a substance is freely filtered at the glomeru-    is reabsorbed (e.g., glucose) and a substance that is secreted fe.g

lus and its clearance is less than that of inulin, the substance is reab- para-amino hippurate). sorbed by the nephron. Conversely, if the clearance is greater than

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