A patient with type 2 diabetes has their blood plasma, glomerular filtrate, and urine analysed. The concentrations of various substances are measured at three different points along the nephron, as shown in the diagram below:
Creatinine is filtered freely at the glomerulus but is neither reabsorbed nor actively secreted along the nephron.
Based on these data, what percentage of the filtered water has been reabsorbed by the nephron, and what is the physiological explanation for the presence of glucose in this patient's urine?
2%2\%2% water reabsorption; the renal threshold for glucose has been exceeded.
98%98\%98% water reabsorption; the glomerular basement membrane has become permeable to glucose.
98%98\%98% water reabsorption; the renal threshold for glucose has been exceeded.
50%50\%50% water reabsorption; active secretion of glucose into the loop of Henle has occurred.