Biology
Comparative Anatomy of Renal Tubular Segments and Diuretic Actions
Quick fact
Loop diuretics, like furosemide, are the most potent diuretics because the thick ascending limb of the loop of Henle reabsorbs about 25% of the filtered sodium, and blocking it disrupts the medullary osmotic gradient, reducing the kidney's ability to concentrate urine.
Why this is interesting
You've probably heard of diuretics as 'water pills,' but did you know that different parts of your kidney's tiny tubes are targeted by different ones? The location of action explains why one diuretic can spare potassium while another causes you to lose it.