Block 17: Urinary System

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Block 17: Urinary System

Questions and Answers
  • 1. 
    A 79-year-old woman with a history of type II diabetes and hypertension is taken to the emergency department after being found unresponsive in a nursing home. Her records showed that she is taking furosemide, metformin, lisinopril, aspirin, and metoprolol to treat her afflictions. Her electrolytes indicated a potassium of 2.7, bicarbonate of 18, glucose of 71 and anion gap of 34. An arterial blood gas showed a pH of 7.40, pCO2 of 34, and a POof 88. What is the acid-base disturbance?
    • A. 

      Anion gap metabolic acidosis only

    • B. 

      Anion gap metabolic acidosis with respiratory alkalosis

    • C. 

      Anion gap metabolic acidosis with metabolic alkalosis

    • D. 

      No acid base disturbance

    • E. 

      Anion gap metabolic acidosis and non-anion gap acidosis

  • 2. 
    An 8-month-old infant boy presents with an enlarging abdominal mass. Laboratory evaluation finds normal urinary levels of vanillylmandelic acid (VMA). The mass is removed surgically and microscopic sections reveal undifferentiated mesenchymal cells, immature tubules, and abortive glomerular formation. This tumor is most closely associated with abnormalities involving which one of the listed genes?
    • A. 

      MET gene

    • B. 

      PRCC gene

    • C. 

      P16INK4a gene

    • D. 

      VHL gene

    • E. 

      WT-1 gene

  • 3. 
    A 67-year-old woman presents with signs of slowly progressive renal failure. Physical examination reveals mild hypertension, while laboratory tests find increased serum creatinine and BUN with mild proteinuria. A few scattered neutrophils and rare bacteria are seen microscopically in her urine. Grossly both of her kidneys are small and irregular with dilation of the renal pelvis and clubbing of the calyces, these changes being similar in appearance to those seen in the picture below. Histologic sections from her kidneys revealed chronic inflammation of the interstitium. Which one of the following additional microscopic findings should be present in these histologic sections?
    • A. 

      The renal papillae should have numerous activated macrophages

    • B. 

      The tubules should be dilated and filled with colloid casts

    • C. 

      The afferent and efferent arterioles should demonstrate fibroelastic hyperplasia

    • D. 

      The glomeruli should have multiple fibrin microthrombi

    • E. 

      The interstitium should have needle-shaped crystals

  • 4. 
    A 66-year-old man with a 15-year history of diabetes mellitus and benign prostatic hyperplasia (BPH) presents with dribbling of his urine. He has a sensation of abdominal fullness and inadequate emptying. Palpation of the lower abdomen reveals a smooth, round, tense mass. Prostate examination reveals an enlarged (50 g) symmetric, nonnodular gland. The patient's postvoid residual urine volume is 800 mL. Select the most likely explanation for the symptoms.
    • A. 

      Urge incontinence

    • B. 

      Stress incontinence

    • C. 

      Overflow incontinence

    • D. 

      Functional incontinence

    • E. 

      Urinary tract infection

  • 5. 
    A hypertensive patient develops chronic renal failure from progressive nephrosclerosis. Which of the following should you expect to occur as a result?
    • A. 

      A decrease in the fractional excretion of sodium

    • B. 

      An increase in the free water clearance

    • C. 

      A decrease in net acid excretion

    • D. 

      A decrease in the excretion of creatinine

    • E. 

      No change in the anion gap

  • 6. 
    A 53-year-old man presents with severe headaches, nausea, and vomiting. He also relates seeing spots before his eyes and is found to have a diastolic blood pressure of 160 mmHg. Microscopic examination of a renal biopsy demonstrates hyperplastic arteriolitis. Gross examination of his kidneys is most likely to reveal which one of the following changes?
    • A. 

      A finely granular appearance to the surface

    • B. 

      Multiple small petechial hemorrhages on the surface

    • C. 

      Diffuse, irregular cortical scars overlying dilated calyces

    • D. 

      Cortical scars overlying dilated calyces in renal poles

    • E. 

      Depressed cortical areas overlying necrotic papillae of varying stages

  • 7. 
    A 28-year-old man with a history of malaise and hemoptysis presents with the acute onset of renal failure. Laboratory examination reveals increased serum creatinine and BUN, but no antineutrophil cytoplasmic antibodies (ANCA) nor antinuclear (ANA) antibodies are present. Urinalysis reveals the microscopic presence of red blood cells and red blood cell casts, while a renal biopsy reveals crescents within Bowman's space of many glomeruli. Immunofluorescence reveals linear deposits of IgG and C3 along the glomerular basement membrane. Which of the following is the most likely diagnosis?
    • A. 

      Alport's syndrome

    • B. 

      Diabetic glomerulopathy

    • C. 

      Goodpasture's syndrome

    • D. 

      Henoch-Schönlein purpura

    • E. 

      Wegener's granulomatosis

  • 8. 
    Using laboratory micropuncture technique, samples of renal tubular fluid are collected from the end portions of the proximal tubule. Compared to the blood plasma entering the glomerulus, which of the following has the lowest tubular fluid/plasma concentration ratio?
    • A. 

      Chloride

    • B. 

      Bicarbonate

    • C. 

      Glucose

    • D. 

      Potassium

    • E. 

      Sodium

  • 9. 
    We have a patient with heart failure, unacceptably low cardiac output, and intense reflex-mediated sympathetic activation of the peripheral vasculature that is attempting to keep vital organ perfusion pressure sufficiently high. The patient is edematous, and has ascites, because of the poor cardiac function and renal compensations for it. Which one of the following drugs should be avoided in this patient because it is most likely to compromise function of the already failing heart and the circulatory system overall?
    • A. 

      Amiloride

    • B. 

      Ethacrynic acid

    • C. 

      Hydrochlorothiazide

    • D. 

      Mannitol

    • E. 

      Spironolactone

  • 10. 
    A 44-year-old woman presents with abdominal pain, fever, and chills. Physical examination reveals costovertebral angle tenderness, previously undiagnosed hypertension, and a mid-systolic click. Urine culture shows bacteriuria and free water clearance is positive, indicating excretion of dilute urine. The ability of the kidney to excrete concentrated urine will increase if which of the following occurs?
    • A. 

      The reabsorption of Na+ by the proximal tubule decreases.

    • B. 

      The glomerular capillary pressure increases.

    • C. 

      The flow of filtrate through the loop of Henle increases.

    • D. 

      The activity of the Na+-K+ pump in the loop of Henle increases.

    • E. 

      The permeability of the collecting duct to water decreases.

  • 11. 
    Which of the following drugs causes hyperchloremic metabolic acidosis and may cause hyperammonemia in a patient with cirrhosis?
    • A. 

      Acetazolamide

    • B. 

      Amiloride

    • C. 

      Furosemide

    • D. 

      Hydrochlorothiazide

    • E. 

      Spironolactone

  • 12. 
    A 10-year-old female patient is brought to the emergency room by her parents because of vague abdominal pain radiating to the back. The patient also has nausea and vomited during the trip to the hospital. Physical examination reveals a palpable lump in the abdomen and the attending physician orders a computerized tomography (CT) scan. The result shows in the patient a horsheshoe-shaped kidney fused at the lower pole with the isthmus lying anterior to the aorta and inferior vena cava but posterior to the inferior mesenteric artery. During development, the parenchyma of the kidney containing the nephrons develops from which of the following:
    • A. 

      Metanephric diverticulum

    • B. 

      Metanephric mass of intermediate mesoderm

    • C. 

      Notochord

    • D. 

      Paramesonephric ducts

    • E. 

      Pronephroi

  • 13. 
    An 8-month-old male infant presents with progressive renal and hepatic failure. Despite intensive medical therapy, the infant dies. At the time of autopsy, the external surfaces of his kidneys are found to be smooth, but cut section reveals numerous cysts that are lined up in a row. Which of the following is the mode of inheritance of this renal abnormality?
    • A. 

      Autosomal dominant

    • B. 

      Autosomal recessive

    • C. 

      X-linked dominant

    • D. 

      X-linked recessive

    • E. 

      Mitochondrial

  • 14. 
    A 58-year-old man presents with hematuria, abdominal pain, and fatigue. Physical examination reveals a flank mass and an abdominal CT reveals a large solid mass on the left kidney. Laboratory studies show anemia and increased creatinine and BUN suggestive of advanced disease. A decrease in GFR would result from which of the following?
    • A. 

      Constriction of the efferent arteriole

    • B. 

      An increase in afferent arteriolar pressure

    • C. 

      Compression of the renal capsule

    • D. 

      A decrease in the concentration of plasma protein

    • E. 

      An increase in renal blood flow

  • 15. 
    An anxious 19-year-old woman presents with perioral numbness and carpopedal spasm. Laboratory examination reveals decreased PCO2 and decreased bicarbonate. Which of the following is the most likely diagnosis?
    • A. 

      Metabolic acidosis due to ketoacidosis

    • B. 

      Metabolic acidosis due to renal tubular acidosis

    • C. 

      Metabolic alkalosis due to thiazide diuretic

    • D. 

      Respiratory acidosis due to hypoventilation

    • E. 

      Respiratory alkalosis due to hyperventilation

  • 16. 
    A 16-year-old girl presents for her annual high school athletic physical. She states that she seems more tired than usual, that she has been having muscle cramps in her calves, and that her legs get very weak and sore after running and playing soccer. Her blood pressure is 160/100 mm Hg, and her EKG shows a prolonged QT interval and the presence of a U wave. Blood analysis shows hypokalemia and metabolic alkalosis. Plasma renin activity and aldosterone concentration are lower than normal. Her clinical condition is reversed after she is placed on the diuretic amiloride, which blocks tubular epithelial sodium channels. Based on this finding, which of the following renal transport processes is the major defect causing her metabolic disorder?
    • A. 

      Greater than normal sodium reabsorption by the proximal tubules

    • B. 

      Greater than normal sodium reabsorption by the distal tubules

    • C. 

      Inability of the distal nephron to secrete potassium ion

    • D. 

      Inability of the distal nephron to secrete hydrogen

    • E. 

      Inability of the distal nephron to concentrate urine

  • 17. 
    A 52-year-old man presents to your clinic for his first visit with you, after moving from a distant town. His only medications are a statin, aspirin (81 mg/day) and metolazone. The pharmacist who filled his prescriptions told the gentleman why he was taking the aspirin and the statin, but unfortunately referred to the metolazone as a "water pill." Thus, you're asked about it. Assuming proper prescribing, which of the following is the most likely reason why the metolazone was prescribed?
    • A. 

      Adjunctive management of an adrenal cortical tumor

    • B. 

      Adjunctive management of hepatic cirrhosis from years of excessive alcohol consumption

    • C. 

      Hypertension accompanied by a history of gout and diabetes

    • D. 

      Treatment of essential hypertension

    • E. 

      Treatment of edema and ascites from heart failure

  • 18. 
    An 83-year-old man has been effectively treated with hydrochlorothiazide to control his elevated blood pressure. He has had a recent onset of weakness. Blood chemistry analysis reveals hypokalemia. Another drug is added, and 1 month later his serum K+ is normal. Which of the following drugs most likely helped normalize his serum potassium levels?
    • A. 

      Acetazolamide

    • B. 

      Amiloride

    • C. 

      Furosemide

    • D. 

      Metolazone

    • E. 

      Mannitol

  • 19. 
    A patient with atherosclerosis shows signs of chronic renal failure attributed to poor renal perfusion and ischemic necrosis of the nephrons. Which of the following endogenous substances causes RBF to decrease?
    • A. 

      Nitric oxide

    • B. 

      Atrial natriuretic peptide

    • C. 

      Acetylcholine

    • D. 

      Angiotensin II

    • E. 

      Dopamine

  • 20. 
    A patient with mild heart failure and edema fails to respond adequately to maximum recommended dosages of chlorthalidone. Which of the following is the most likely appropriate and most fruitful next step in terms of restoring the diuretic response?
    • A. 

      Add hydrochlorothiazide

    • B. 

      Add metolazone

    • C. 

      Replace chlorthalidone with furosemide

    • D. 

      Replace chlorthalidone with hydrochlorothiazide

    • E. 

      Try increasing the chlorthalidone dose anyway

  • 21. 
    An 85-year-old woman presents with a fever and hypovolemic hypotension. To assess her renal function, the filtration fraction is determined using a freely filterable substance that is neither reabsorbed nor secreted. The infusate yields a renal artery concentration of 12 mg/mL and a renal vein concentration of 9 mg/mL. Which of the following is the filtration fraction?
    • A. 

      0.05

    • B. 

      0.15

    • C. 

      0.25

    • D. 

      0.35

    • E. 

      0.45

  • 22. 
    A patient taking an oral diuretic for about 6 months presents with elevated fasting and postprandial blood glucose levels. You check the patient's HbA1c and find it is elevated compared with normal baseline values obtained 6 months ago. You suspect the glycemic problems are diuretic-induced. Which of the following was the most likely cause?
    • A. 

      Acetazolamide

    • B. 

      Amiloride

    • C. 

      Chlorothiazide

    • D. 

      Spironolactone

    • E. 

      Triamterene

  • 23. 
    A 36-year-old man suffers third-degree burns over 70% of his body while responding to a three-alarm fire. His effective circulating volume and renal perfusion pressure drop precipitously and the concentration of NaCl in the intraluminal fluid in the kidney decreases. These conditions cause the juxtaglomerular apparatus to release which of the following hormones?
    • A. 

      Adenosine

    • B. 

      Aldosterone

    • C. 

      Angiotensinogen

    • D. 

      Antidiuretic hormone

    • E. 

      Renin

  • 24. 
    A patient with renal failure is undergoing periodic hemodialysis while awaiting a transplant. Between dialysis sessions we want to reduce the body's phosphate load by reducing dietary phosphate absorption and removing some phosphate already in the blood. Which of the following drugs would be most suitable for this purpose?
    • A. 

      Aluminum hydroxide

    • B. 

      Bismuth subsalicylate

    • C. 

      Magnesium hydroxide/oxide

    • D. 

      Sodium bicarbonate

    • E. 

      Sucralfate

  • 25. 
    A trauma patient with multiple rib fractures requires intubation and mechanical ventilation. Mechanical ventilation causes an increase in the patient's vasopressin secretion and plasma levels. Which of the following is the effect of vasopressin on the kidney?
    • A. 

      Increased diameter of the renal artery

    • B. 

      Increased glomerular filtration rate

    • C. 

      Increased excretion of Na+

    • D. 

      Increased excretion of water

    • E. 

      Increased permeability of the distal nephron to water

  • 26. 
    A 47-year-old man presents with increasing peripheral edema and dark, tea-colored urine. Laboratory examination finds decreased serum albumin, while examination of a 24-h urine specimen reveals marked proteinuria. Microscopic examination of this patient's urine reveals numerous red cells along with rare red cell casts. Electron microscopic examination of a renal biopsy from this patient reveals dense, ribbon-like deposits in the lamina densa of the glomerular basement membrane. Which of the following is the most likely diagnosis?
    • A. 

      Acute glomerulonephritis

    • B. 

      IgA nephropathy

    • C. 

      Lipoid nephrosis

    • D. 

      Membranoproliferative glomerulonephritis

    • E. 

      Membranous glomerulopathy

  • 27. 
    A 16-year-old girl with Liddle's syndrome presents with hypertension, hypervolemia, and hypokalemia, but low levels of renin and aldosterone. Her clinical condition is reversed by administration of a diuretic, which acts by blocking epithelial sodium channels. Which of the following is the major defect in Liddle's syndrome?
    • A. 

      Increased sodium reabsorption by the proximal tubules

    • B. 

      Increased sodium reabsorption by the distal nephron

    • C. 

      An inability of the distal nephron to secrete potassium ion

    • D. 

      An inability of the distal nephron to secrete hydrogen

    • E. 

      An inability of the distal nephron to concentrate urine

  • 28. 
    A 28-year-old woman presents to her physician's office with fatigue, malaise, and orthostatic dizziness. When asked what medications she is taking, she stated that she has a prescription for oral contraceptives for her endometriosis and that she had been taking 800 mg ibuprofen 4 to 6 times a day for her painful menstrual cramps. Which of the following is most likely to produce an increase in GFR in patients with acute renal failure?
    • A. 

      Administration of angiotensin II

    • B. 

      Increased renin release from the juxtaglomerular apparatus

    • C. 

      Contraction of glomerular mesangial cells

    • D. 

      Dilation of afferent arterioles

    • E. 

      Volume depletion

  • 29. 
    A 54-year-old man presents with left-sided costovertebral pain and gross hematuria. A large mass is found in the upper pole of one of his kidneys, as seen in the picture. A biopsy from this mass reveals uniform cells with clear cytoplasm containing glycogen and lipid. What is the best diagnosis?
    • A. 

      Neuroblastoma

    • B. 

      Renal cell carcinoma

    • C. 

      Squamous cell carcinoma

    • D. 

      Transitional cell carcinoma

    • E. 

      Wilms tumor

  • 30. 
    While on an obstetrics rotation, a third year student delivers a term 8 lbs 2 oz baby boy by vaginal delivery. While performing the initial assessments, all appears normal including the two testicles within his scrota and the presence of a normal penis. The baby both breast-feeds normally, wets his diaper, and passes his meconium, so the baby and mother are released from the hospital about 30 hours after delivery. The parents are instructed to dampen the umbilical stalk with alcohol until it falls off. About a week later the mother brings the child back to the hospital and delivery service because the boy's umbilical cord is still slightly moist and there appears to be fluid coming from it. What is the tentative diagnosis and what does the physician tell the mother?
    • A. 

      Hypospadia; the boy is urinating when having an erection and thus keeps wetting the umbilical cord stump; nothing needs to be done.

    • B. 

      Epispadia; the boy's urine is passing upwards within the diaper, thus keeps wetting the umbilical cord stump; nothing needs to be done.

    • C. 

      Exstrophy of the bladder; the boy's bladder wall failed to form properly from the urogenital sinus/allantois which connects to the umbilicus, thus urine is seeping through the skin and wetting the umbilical cord stump; this can be surgically repaired.

    • D. 

      Normal; the boy's urine fills his diaper and thus keeps wetting the umbilical cord stump; nothing needs to be done.

    • E. 

      Urachal fistula; the boy's bladder developed from the urogenital sinus/allantois which connects with the umbilicus and the urachus has failed to completely close, so he is leaking urine at the umbilicus; this can be surgically repaired.

  • 31. 
    A 58-year-old man with a history of hypertension and hypercholesterolemia is diagnosed with heart failure. We start therapy with a loop diuretic. Which of the following would you expect to occur along with the increased urine volume caused by the diuretic?
    • A. 

      Dilute (hypotonic) urine because normal urine concentrating mechanisms are impaired

    • B. 

      Hypercalcemia due to impaired renal Ca2+ excretion

    • C. 

      Reduced net excretion of Cl–

    • D. 

      Metabolic acidosis due to increased renal bicarbonate excretion

    • E. 

      Reduced serum uric acid (urate) concentrations because of increased urate excretion

  • 32. 
    A 19-year-old female college student presents to the emergency department at 10:30 PM on a Friday night with severe left-sided flank and pelvic pain. While she has never had similar pain, she states that she thinks she has a kidney stone. The pain started in her mid back about a week ago and then subsided and now the pain has increased and moved inferiorly along her flank and also extends down into her labia majora. She is taking birth control pills, but is not currently sexually active. She is having her period, but denies the pain is menstrual. Abdominal and pelvic CT are ordered. What two specific locations will one look for in the CTs for obstructing calculi?
    • A. 

      At the junction of the renal papilla with the minor calyx and junction of the renal papilla with the major calyx

    • B. 

      As the ureter leaves the kidney and as the ureter forms the infundibulum

    • C. 

      As the ureter crosses the edge of the false pelvis and as the ureter crosses the edge of the true pelvis

    • D. 

      As the ureter crosses the external iliac artery at the pelvic brim and as the ureter passes through the wall of the bladder

    • E. 

      As the ureter passes through the wall of the bladder and as the ureter passes through the center of the trigone of the bladder

  • 33. 
    A 55-year-old male has a long-term history of alcoholism with associated cirrhosis of the liver. His medications include a potassium-sparing diuretic, spironolactone, which helps control his severe ascites. Which letter in the figure depicts the tubular location of epithelial cells that are inhibited by potassium-sparing diuretics such as spironolactone?
    • A. 

      A

    • B. 

      B

    • C. 

      C

    • D. 

      D

    • E. 

      E

  • 34. 
    A postoperative patient develops a thready pulse, tachycardia, and hypotension. A decision is made to take the patient back to surgery to check for bleeding. Laboratory analysis shows an increase in plasma angiotensin II accompanied by an increase in glomerular filtration rate (GFR). When GFR increases, proximal tubular reabsorption of salt and water increases by a process called glomerulotubular balance. Contributions to this process include which of the following?
    • A. 

      An increase in peritubular capillary hydrostatic pressure

    • B. 

      A decrease in peritubular sodium concentration

    • C. 

      An increase in peritubular oncotic pressure

    • D. 

      An increase in proximal tubular flow

    • E. 

      An increase in peritubular capillary flow

  • 35. 
    • A. 

      Acetazolamide

    • B. 

      Furosemide

    • C. 

      Hydrochlorothiazide

    • D. 

      Spironolactone

    • E. 

      Triamterene

  • 36. 
    A 65-year-old man presents in the emergency department with a fracture of his right arm after slipping and falling on the ice. He reports that he has had back pain for the past 6 months. Blood results show Hb = 9 gm/dL; Hct = 30%; BUN = 35 mg/dL; Creatinine = 3 mg/dL. Urinalysis shows pH >5.3 and is positive for Bence Jones proteins. The patient is diagnosed with type II (proximal) RTA secondary to multiple myeloma. The transport of H+ into the proximal tubule is primarily associated with which of the following?
    • A. 

      Excretion of potassium ion

    • B. 

      Excretion of hydrogen ion

    • C. 

      Reabsorption of calcium ion

    • D. 

      Reabsorption of bicarbonate ion

    • E. 

      Reabsorption of phosphate ion

  • 37. 
    In a patient with diabetes mellitus of 30 years' duration, complications related to kidney function may include which of the following?
    • A. 

      Enhanced selectivity of the filtration barrier

    • B. 

      Decreased permeability to plasma proteins

    • C. 

      Increased glomerular filtration rate

    • D. 

      Decreased secretion of aldosterone

    • E. 

      Glycation of proteins in the basal lamina

  • 38. 
    An 18-year-old male presents with muscle weakness, cramps, and tetany. Blood pressure is normal and no edema is present. Laboratory analysis reveals hypokalemic alkalosis, hyperaldosteronism, and high plasma renin activity, diagnostic of Bartter's syndrome. Which of the following statements about renin is true?
    • A. 

      It is secreted by cells of the proximal tubule

    • B. 

      Its secretion leads to loss of sodium and water from plasma

    • C. 

      Its secretion is stimulated by increased mean renal arterial pressure

    • D. 

      It converts angiotensinogen to angiotensin I

    • E. 

      It converts angiotensin I to angiotensin II

  • 39. 
    A patient in hyperkalemic renal failure is given an infusion of glucose and insulin. The actions of insulin include which of the following?
    • A. 

      Converting glycogen to glucose

    • B. 

      Stimulating gluconeogenesis

    • C. 

      Increasing plasma amino acid concentration

    • D. 

      Enhancing potassium entry into cells

    • E. 

      Reducing urine formation

  • 40. 
    A 70-year-old female (83kg) is admitted to the hospital with acute renal failure. A basic metabolic panel is sent with the following results: Na 134, K 4.1, Cl 104, HCO3- 22, BUN 44, Cr 1.7, Glu 105 What is the patient's creatinine clearance?
    • A. 

      25

    • B. 

      40

    • C. 

      70

    • D. 

      95

    • E. 

      110

  • 41. 
    A 55-year-old man presents with prolonged epigastric pain and severe vomiting. Laboratory evaluation finds that his blood pH is increased to 7.46, while his serum bicarbonate is increased to 30 mM. Blood gases also reveal the arterial carbon dioxide to be increased. Physical examination finds the man to be afebrile with dry mucous membranes and decreased skin turgor. His heart rate is increased, but his respiratory rate is decreased in frequency. Which of the following is the most likely diagnosis?
    • A. 

      Metabolic alkalosis with respiratory compensation

    • B. 

      Mixed metabolic acidosis and metabolic alkalosis

    • C. 

      Respiratory acidosis with renal compensation

    • D. 

      Respiratory alkalosis with no compensation

    • E. 

      Respiratory alkalosis with renal compensation

  • 42. 
    A 42-year-old man presents with fatigue, loss of stamina, and frequent urination. He is not taking any medications currently. Physical examination is normal except for a blood pressure of 165/95 mm Hg. Serum electrolytes show: sodium, 152 mEq/L; potassium, 3.1 mEq/L; chloride, 112 mEq/L; and bicarbonate, 32 mEq/L. Aldosterone concentration is elevated and plasma renin activity is low, consistent with primary hyperaldosteronism. Aldosterone increases Na+ reabsorption at which of the points depicted in this schematic diagram of the nephron?
    • A. 

      A

    • B. 

      B

    • C. 

      C

    • D. 

      D

    • E. 

      E

  • 43. 
    A 7-year-old boy is brought to your office because he had developed some facial swelling and his urine was an unusual color. On physical examination, he is found to have moderate periorbital edema and mild hypertension. His mother states that, other than a sore throat 2 or 3 weeks ago, he has been in good health. Urinalysis reveals proteinuria with RBCs, WBCs, and cellular casts. Serum creatinine levels are increased. The most likely diagnosis is which of the following?
    • A. 

      Acute postinfectious glomerulonephritis

    • B. 

      Acute pyelonephritis

    • C. 

      Focal segmental glomerulonephritis

    • D. 

      Lupus nephritis

    • E. 

      Minimal change disease

  • 44. 
    A 56-year-old man is postoperative day 0 from an elective abdominal aortic aneurysm repair. He is extubated and being monitored in the intensive care unit. On admission to the ICU, his labs reveal the following: - Serum chemistry: Na 134, K 4.1, Cl 104, HCO3- 22, BUN 25, Cr 1.2, Glu 105 - ABG: pH 7.39, pCO239, HCO3-22, pO2107 Over the next 8 hours, the patient becomes hemodynamically unstable with mean blood pressures in the 50s and tachycardia to the 120s. Fluid resuscitation is started. Repeat lab analysis shows the following: - Serum chemistry: Na 133, K 3.7, Cl 101, HCO3-14, BUN 28, Cr 1.3, Glu 145 - ABG: pH 7.29, pCO228, HCO3- 14, pO2110. Based on the clinical scenario, what is the patient's acid-base disturbance?
    • A. 

      Anion gap metabolic acidosis

    • B. 

      Non-anion gap metabolic acidosis

    • C. 

      Acute respiratory acidosis

    • D. 

      No acid-base disturbance

  • 45. 
    A 49-year-old male in end-stage renal failure is able to perform peritoneal dialysis at home. The osmolality of the solution chosen for peritoneal dialysis will determine the rate of ultrafiltration. Which of the following statements best characterizes a molecule whose osmolality is zero?
    • A. 

      It will not permeate the membrane

    • B. 

      It can only cross the membrane through the lipid bilayer

    • C. 

      It causes water to flow across the membrane

    • D. 

      It is as diffusible through the membrane as water

    • E. 

      It is transported across the membrane by a carrier

  • 46. 
    An 82-year-old man presents with polyuria and polydipsia. Blood analysis reveals hypernatremia and urinalysis shows hypotonicity and an increased free water clearance. In which of the following conditions is an increased free water clearance a hallmark of the disease?
    • A. 

      Diabetes insipidus

    • B. 

      Diabetes mellitus

    • C. 

      Diuretic therapy

    • D. 

      Heart failure

    • E. 

      Renal failure

  • 47. 
    A 78-year-old woman dies suddenly following a long history of chronic renal failure. Upon autopsy, the pathologist reports the gross finding of a wedge-shaped, sharply demarcated region of her left kidney that is pale and shrunken. On histological examination of a section of this kidney lesion, which of the following is the pathologist most likely to observe?
    • A. 

      Amorphous, eosinophilic material surrounded by giant cells and a rim of T-lymphocytes

    • B. 

      Complex, branching papillomatous structures with numerous fronds projecting into a cystic space

    • C. 

      Extensive collagen deposition with minimal fibroblasts and capillaries

    • D. 

      Mixture of neutrophils, extensive hemorrhage and necrotic debris

    • E. 

      Tubular necrosis and marked lymphocytic infiltration of the interstitium

  • 48. 
    A 71-year-old woman with a recent history of stroke is newly incontinent of large amounts of urine. She reports no fever or dysuria. She ambulates slowly with her walker and takes no medications. Her postvoid residual urine volume is 35 mL. Select the most likely explanation for the symptoms.
    • A. 

      Urge incontinence

    • B. 

      Stress incontinence

    • C. 

      Overflow incontinence

    • D. 

      Functional incontinence

    • E. 

      Urinary tract infection

  • 49. 
    A 52-year-old man presents to his internist for a 6-month check-up following diuretic therapy and recommended diet changes for his essential hypertension. His blood pressure is 145/95 mm Hg and serum aldosterone levels are increased. Aldosterone secretion is increased when there is a decrease in the plasma concentration of which of the following?
    • A. 

      ACTH

    • B. 

      Angiotensin II

    • C. 

      Potassium

    • D. 

      Renin

    • E. 

      Sodium

  • 50. 
    A 38-year-old man presents in the emergency department with severe back pain. He is writhing around, unable to find a comfortable position, and nauseated. A CT scan reveals nephrocalcinosis and urinalysis reveals decreased urinary chloride and calcium. Blood analysis reveals hypokalemia and hypochloremic metabolic alkalosis. The clinical findings suggest a defect in electrically neutral renal NaCl transport. Electrically neutral active transport of sodium and chloride occurs in which of the following areas of the kidney?
    • A. 

      Distal tubule

    • B. 

      Descending limb of the loop of Henle

    • C. 

      Thin ascending limb of the loop of Henle

    • D. 

      Cortical collecting duct

    • E. 

      Medullary collecting duct

  • 51. 
    A 54-year-old man with small cell lung cancer presents with lethargy, confusion, and muscle cramps. Blood work shows an increase in plasma levels of antidiuretic hormone (ADH), possibly from the ectopic production of ADH. In patients with the syndrome of inappropriate antidiuretic hormone (SIADH), which of the following will increase?
    • A. 

      The concentration of plasma sodium

    • B. 

      Intracellular volume

    • C. 

      Urinary flow

    • D. 

      Plasma oncotic pressure

    • E. 

      Plasma osmolarity

  • 52. 
    A patient undergoing surgery develops an increase in the secretion and plasma levels of ACTH, cortisol, and aldosterone. What best characterizes the production and actions of aldosterone in the body?
    • A. 

      It produces its effect by activating cAMP.

    • B. 

      It produces its effect by increasing distal tubular permeability to sodium.

    • C. 

      It causes an increased reabsorption of hydrogen ion.

    • D. 

      It has its main effect on the proximal tubule.

    • E. 

      It is secreted in response to an increase in blood pressure.

  • 53. 
    A 69-year-old man with chronic hypertension presents to his physician's office. His blood pressure is 165/105 mm Hg despite treatment with a diuretic, β-blocker, and an angiotensin receptor antagonist. It is decided that a fourth drug is needed for the patient's resistant hypertension, and he is prescribed the vasodilator diltiazem, a calcium channel antagonist. The effect of decreasing the resistance of the afferent arteriole in the glomerulus of the kidney is to decrease which of the following aspects of renal function?
    • A. 

      Filtration fraction

    • B. 

      Glomerular filtration rate

    • C. 

      Oncotic pressure of the peritubular capillary blood

    • D. 

      Renal plasma flow

    • E. 

      Renin release from juxtaglomerular cells

  • 54. 
    A 24-year-old man with a history of renal insufficiency is admitted to the hospital after taking a large amount of ibuprofen. His BUN is 150 mg/dL. This patient's high serum urea nitrogen was most likely caused by which of the following?
    • A. 

      Decreased secretion of urea by the distal tubules

    • B. 

      Decreased glomerular filtration rate

    • C. 

      Increased synthesis of urea by the liver

    • D. 

      Increased reabsorption of urea by the proximal tubules

    • E. 

      Increased renal blood flow

  • 55. 
    A 47-year-old male presents with pain and swelling in the left big toe. He has been on a high protein diet and training extensively for an iron man competition, which includes weight lifting, running, swimming, and biking. An aspirate of joint fluid demonstrated negative birefringent urate crystals and 24-hour urinary uric acid levels were elevated. For maintenance therapy, which of the following agents would be best to treat the cause of his gout?
    • A. 

      Aspirin

    • B. 

      Allopurinol

    • C. 

      Colchicine

    • D. 

      Nonsteroidal antiinflammatory drugs (NSAIDs)

    • E. 

      Uricosurics

  • 56. 
    A patient with congestive heart failure presents with jugular venous distention, ascites, and peripheral edema. Blood work shows elevated levels of plasma atrial natriuretic peptide (ANP). ANP decreases Na+ reabsorption within which of the following?
    • A. 

      The proximal tubule

    • B. 

      The thick ascending limb of Henle's loop

    • C. 

      The distal convoluted tubule

    • D. 

      The cortical collecting duct

    • E. 

      The inner medullary collecting duct

  • 57. 
    A patient's 24-hour urine output is lower-than-normal. Which of the following situations would reduce urinary flow?
    • A. 

      Diabetes insipidus

    • B. 

      Diabetes mellitus

    • C. 

      Sympathetic stimulation

    • D. 

      Increased renal arterial pressure

    • E. 

      Infusion of mannitol

  • 58. 
    • A. 

      75 mL/min

    • B. 

      100 mL/min

    • C. 

      125 mL/min

    • D. 

      200 mL/min

    • E. 

      275 mL/min

  • 59. 
    A 36-year-old African American man presents with low renin essential hypertension. Renin release from the juxtaglomerular apparatus is normally inhibited by which of the following?
    • A. 

      Aldosterone

    • B. 

      β-Adrenergic agonists

    • C. 

      Increased pressure within the afferent arterioles

    • D. 

      Prostaglandins

    • E. 

      Stimulation of the macula densa

  • 60. 
    Urinalysis on a sick 3-month-old baby boy shows negative results with the dipstick glucose test, but a subsequent Clinitest analysis gives a 4+ reading. Which of the following is the most likely reason for this discrepancy between the two tests?
    • A. 

      A high alkaline urinary pH of 8.5 does not allow for the normal dipstick enzymatic reaction.

    • B. 

      An increased fraction of urine solutes yields an erroneously negative glucose dipstick reaction.

    • C. 

      The baby has an undetected intrinsic renal disease.

    • D. 

      The baby is secreting a reducing substance that is not reactive with the glucose dipstick.

    • E. 

      The Clinitest has greater sensitivity than a dipstick for glucose measurement.