Final answer:
The test that measures the blood filtered by the kidneys' glomeruli is the glomerular filtration rate (GFR), commonly estimated using the creatinine clearance test.
Step-by-step explanation:
The correct option is D
The test that measures the amount of blood that is filtered by the glomeruli of the kidneys is the glomerular filtration rate (GFR). GFR can be estimated by measuring naturally occurring creatinine, a protein-derived molecule produced by muscle metabolism that is not reabsorbed and only slightly secreted by the nephron.
The GFR is an important indicator of kidney function, representing the volume of blood filtered at the glomerulus into the Bowman's space per minute. A commonly used method to estimate GFR is the creatinine clearance test. Creatinine, a byproduct of muscle metabolism, is filtered by the glomeruli with minimal reabsorption or secretion by the tubules, thus making it a reliable indicator for GFR. The creatinine clearance is calculated using the concentrations of creatinine in urine and plasma, along with the urine flow rate. For more accurate results corrected for body size variations, it's adjusted and expressed as ml/min/1.73 m². Other tests like BUN (Blood Urea Nitrogen), UA (urinalysis), and inulin clearance also provide insights into kidney function, but creatinine clearance specifically pertains to GFR assessment.