^ 



r 





yy_ 125 



P INULIN 



b; 



I 





 GLUCOSE 



125 XF 



^ 



/^ 



li 



i 



^ 



\ 



70 



UREA 



700 

 DIODRAST 



FIGURE 2 



Figure 2. Scheme to illustrate the excretion of (A) inulin, which is excreted solely 

 by filtration with no tubular reabsorption; (B) glucose, which is filtered, but at normal 

 plasma level and rate of filtration is completely reabsorbed by the tubule; (C) urea, which 

 is filtered, but in part escapes from the tubular urine by diffusion; (D) diodrast, which is 

 excreted both by filtration and tubular excretion. UV/P is the clearance in each in- 

 stance, i.e., the virtual volume of blood cleared per minute. (U and P are the concentra- 

 tions per unit volume of urine and plasma, and V is urine flow per minute.) The inulin 

 clearance is taken as equal to the rate of filtration of plasma. F is the per cent of diodrast 

 filtrable from the plasma, 1.00-F being the per cent bound to plasma proteins. 



