Ch 32 Structure and Function of the Kidney
...
Which option identifies the function of the kidneys in maintaining normal composition of internal body fluids? You Selected: Filtration and reabsorption of physiologically essential substances Correct response: Filtration and reabsorption of physiologically essential substances Explanation: The kidneys filter physiologically essential substances such as sodium and potassium from the blood and selectively reabsorb those substances that are needed to maintain the normal composition of internal body fluids. Substances that are not needed, or are in excess of those needed, pass into the urine. In addition to regulating the volume and composition of body fluids, the kidneys also perform endocrine functions. They release renin, an enzymatic hormone that participates in the regulation of blood pressure and maintenance of the circulating blood volume; they produce erythropoietin, a hormone that stimulates red blood cell production; and they convert vitamin D to its active form.