Which statement correctly describes the renal threshold? A)It is the maximum amount of a particular substance that can be excreted in the urine per unit of time. B)It is the maximum amount of a particular substance that the tubular cells are capable of actively reabsorbing per unit of time. C) It is the plasma concentration of a particular substance at which its T_m is reached and the substance first appears in the urine. D) It is the maximum amount of waste product that can be concentrated in the urine per unit of time.

Question

Quizplus · Accepted Answer

The renal threshold is the plasma concentration of a particular substance at which its transport maximum (T_m) is reached and the substance first appears in the urine. This means that the renal threshold is the point where the kidneys can no longer effectively reabsorb the substance and it starts to be excreted in the urine. Therefore, option C correctly describes the renal threshold. Option A is incorrect because it describes the rate of excretion of a substance, not the threshold. Option B is incorrect because it describes the maximum amount of a substance that can be reabsorbed, not the threshold. Option D is incorrect because it describes the maximum amount of waste product that can be concentrated in the urine, not the threshold for a particular substance.

Which Statement Correctly Describes the Renal Threshold