Final answer:
An indicator of the normalcy of the excretory function of the kidneys is the ability of the kidneys to concentrate urine. This can be measured using a concentration test or clearance tests. The glomerular filtration rate (GFR) is also an important measure of kidney function.
Step-by-step explanation:
An indicator of the normalcy of the excretory function of the kidneys is the ability of the kidneys to concentrate urine. This can be measured by testing the specific gravity of the urine using a concentration test. In this test, a preparation of ADH called pituitrine is injected, and the specific gravity of the urine is measured. If the specific gravity is 1.020 or higher, the kidneys are functioning normally. If it is lower, there may be a defect in the reabsorption of water by the kidneys. Another way to assess kidney function is through clearance tests. Clearance tests measure the volume of plasma that is cleared of a particular substance by renal excretion in a specific amount of time. These tests can provide information about the excretory function of the kidneys. The glomerular filtration rate (GFR) is another important measure of kidney function. It is the rate at which the kidneys filter waste products from the blood. GFR can be estimated by measuring naturally occurring creatinine, a protein-derived molecule produced by muscle metabolism.