A. Concentration in the tubular fluid is lower than in peritubular capillary blood.
B. Excretion is increased by cooling the kidney.
C. Renal clearance is lower than that of inulin.
D. Renal clearance rises at high plasma levels.
E. Urinary excretion rate: plasma concentration ratio is the same as for glucose.
Answer:
* (A) Concentration in the tubular fluid is lower than in peritubular capillary blood - TRUE because it suggests transportation into the blood against a concentration gradient.
* (B) Excretion is increased by cooling the kidney - TRUE because cooling impairs active metabolic processes
* (C) Renal Clearance is lower than that of inulin - FALSE because it indicates reabsorption but not whether it is active or passive.
* (D) Renal Clearance rises at high plasma levels - TRUE because this suggests saturation of the carrier system
* (E) Urinary Excretion rate: plasma concentrations ratio is same as the glucose - TRUE because anything filtered in the glomeruli and have zero clearance must be actively reabsorbed
Tubular reabsorption of a filtered substance is likely to be active rather than passive if its...