1. A severe protein deficiency would reduce the colloid osmotic pressure of the blood, which is a force opposing glomerular filtration. Thus the GFR would rise.

2. (a) Using the formula C = UV/P, the rate of renal clearance (C) is (8.6 mg/mL)(55 mL/hr)/(0.25 mg/mL) = 1,892 mL/hr = 31.5 mL/min. (b) Her rate of urea output is (8.6 mg/mL)(55 mL/hr)(24 hr/day) = 11,352 mg/day = 11.35 g/day. This is slightly below the normal range.

3. ACE inhibitors cause vasodilation and a drop in blood pressure. This patient was already exhibiting poor renal perfusion, and this condition would become even worse if the blood pressure dropped significantly. This would explain the renal failure brought on by the drug.

4. As the bladder filled and expanded upward, the ureters could become kinked like a garden hose. Urine would then accumulate in the ureters and kidneys, causing hydronephrosis.

5. The proximal convoluted tubule (PCT) is much longer than the distal convoluted tubule (DCT) and has prominent microvilli forming a shaggy brush border, whereas the cells of the DCT are smooth. The greater length and surface area of the PCT reflect the fact that it reabsorbs about 65% of the glomerular filtrate, whereas the DCT reabsorbs only 14% on average.

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