Question

Write short notes on the renal threshold.

Answer 1

The renal threshold is the concentration of a substance dissolved in the blood above which the kidneys begin to remove it into the urine. When the renal threshold of a substance is exceeded, reabsorption of the substance by the proximal convoluted tubule is incomplete. Hence, part of the substance remains in the urine.

The renal threshold varies with the substance and it is altered with different disorders. For example, the most common reason for the glucose renal threshold to exceed is diabetes.