Question

All of the following are true about glucose recovery from the tubule fluid, except (choose the ncorrect statement):

A. All filtered glucose is reabsorbed in the PCT unless plasma glucose is abnormally high
B. Glucose recovery is made possible by low intracellular Na+ concentrations created by the Nak pump.
C. It is reabsorbed by coupling with Na+ recovery via a sodium-glucose cotransporter, SGLT
D. The CD recovers any glucose that is not reabsorbed by the PCT, nephron loop, and DCT

Answer 1

The incorrect statement is that the collecting duct (CD) recovers any glucose not reabsorbed by the PCT, nephron loop, and DCT; glucose is normally reabsorbed entirely by the PCT unless plasma glucose levels are abnormally high.

Step-by-step explanation:

All of the following are true about glucose recovery from the tubule fluid, except the statement: The CD recovers any glucose that is not reabsorbed by the PCT, nephron loop, and DCT. In normal physiological conditions, almost 100 percent of glucose is reabsorbed in the proximal convoluted tubule (PCT) unless plasma glucose levels are excessively high, which would exceed the transport maximum (Tm) of the renal glucose transporters. Glucose recovery is indeed facilitated by low intracellular Na+ concentrations established by the Na+/K+ ATPase pump, and glucose is reabsorbed via a sodium-glucose cotransporter mechanism. However, the collecting duct (CD) is not involved in glucose reabsorption; by the time filtrate reaches the CD, all glucose should have already been reabsorbed in the earlier segments of the nephron unless pathological conditions such as diabetes mellitus are present.