If the Tmₐₓ for glucose in the nephron was 300 mg/100 ml and a person had 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 Tmₐₓ is the maximum amount of a substance that can be reabsorbed by the nephron. If the blood glucose level is higher than the Tmₐₓ for glucose, the excess glucose cannot be reabsorbed and will be excreted in the urine. In this case, the blood glucose level is 380 mg/100 ml, which is higher than the Tmₐₓ for glucose of 300 mg/100 ml. Therefore, there will be some glucose excreted in the urine. The amount of glucose excreted will be the difference between the blood glucose level and the Tmₐₓ for glucose, which is 80 mg/100 ml. Therefore, the correct answer is B. Option D is incorrect because there will not be any glucose left in the blood leaving the kidney as all the excess glucose will be excreted in the urine.

If the Tmₐₓ for Glucose in the Nephron Was 300