If the Tmₐₓ for glucose in the nephron was 300 mg/100 ml and a person had a blood glucose level of 380 mg/100 ml,there would be:
A) 300 mg/100 ml of glucose in the urine.
B) 80 mg/100 ml of glucose in the urine.
C) 80 mg/100 ml of glucose in the blood leaving the kidney.
D) both A and C.

Question

Quizplus · Accepted Answer

The Tm (transport maximum) is the maximum amount of a substance that can be reabsorbed by renal tubules. If the blood glucose level is above the Tm, then the excess glucose will not be completely reabsorbed and will spill into the urine. Therefore, the amount of glucose in the urine would be the difference between the blood glucose level and the Tm. In this case, the amount of glucose in the urine would be 80 mg/100 ml (380 mg/100 ml - 300 mg/100 ml). Option A is incorrect as it only mentions the Tm level of glucose. Option C is incorrect as it incorrectly suggests that glucose will remain in the blood leaving the kidney, even if the Tm is exceeded. Option D is incorrect as it combines both A and C, both of which are incorrect.

If the Tmₐₓ for Glucose in the Nephron Was 300