Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 43

Clearance tests used to determine the glomerular filtration rate must measure substances that are:

A. Not filtered by the glomerulus

B. Completely reabsorbed by the proximal convoluted tubule

C. Secreted in the distal convoluted tubule

D. Neither reabsorbed or secreted by the tubules

Step 1 of 2

Clearance test:

The filtering ability of the glomeruli is measured using the standard tests which are called clearance test.

• It measures the capability of kidney to clear the filterable elements in blood.

• For this test the substance which is measured should be in regular level in blood, and must be available all times in body.

• It should not be absorbed or secreted by nephron’s tubule.

• If the substance is absorbed again or secreted, the test result will be false, because of fluctuation in the substance while evaluating it.

Therefore, determination of glomerulus filtration rate by clearance tests with the substance which is “neither reabsorbed nor secreted by the tubules”. Hence, the correct answer is option.