Question 1
Q1A patient with chronic kidney disease presents with symptoms of metabolic acidosis and nutrient loss in their urine. A biopsy reveals damage specifically to the cells of the proximal convoluted tubule (PCT). Which renal function is most severely impaired in this patient?
Show answer & explanation
Correct answer: C
The proximal convoluted tubule (PCT) is the primary site for the reabsorption of about 65% of filtered water, as well as nearly all glucose, amino acids, and various essential ions. Damage to the PCT severely impairs this reabsorptive capacity, leading to the loss of vital nutrients in the urine and imbalances like metabolic acidosis due to failed bicarbonate reabsorption. Filtration occurs in the glomerulus, and secretion is a key function of the distal tubule. Regulation of final urine concentration occurs in the collecting duct.