All Questions Flashcards
Which statement regarding renal function is true?
A. Glomeruli are far more permeable to H2O and salt than other capillaries
B. The collecting tubule reabsorbs sodium and secretes potassium in response to antidiuretic hormone (ADH)
C. The collecting tubule is permeable to H2O only in the presence of aldosterone
D. The thick ascending limb is highly permeable to H2O and urea
A. Glomeruli are far more permeable to H2O and salt than other capillaries
Which statement regarding normal salt and H2O handling by the nephron is correct?
A. The ascending limb of the tubule is highly permeable to salt but not H2O
B. The stimulus for ADH release is low arterial pressure in the afferent arteriole
C. The descending limb of the tubule is impermeable to urea but highly permeable to salt
D. Renin is released in response to high plasma osmolality
A. The ascending limb of the tubule is highly permeable to salt but not H2O
Which statement concerning renal tubular
function is true?
A. In salt deprivation, the kidneys will conserve sodium at the expense of potassium
B. Potassium is not excreted when serum
concentration is below 3.5 mmol/L
C. No substance can be excreted into urine at a rate that exceeds the glomerular filtration rate
D. When tubular function is lost, the specific gravity of urine will be below 1.005
A. In salt deprivation, the kidneys will conserve sodium at the expense of potassium
Which of the following is inappropriate when collecting urine for routine bacteriologic culture?
A. The container must be sterile
B. The midstream void technique must be used
C. The collected sample must be plated within 2 hours unless refrigerated
D. The sample may be held at 2°C-8°C for up to 48 hours prior to plating
D. The sample may be held at 2°C-8°C for up to 48 hours prior to plating
Which statement about sample collection for routine urinalysis is true?
A. Preservative tablets should be used for collecting random urine specimens
B. Containers may be washed and reused if rinsed in deionized H2O
C. Samples may be stored at room temperature for up to 2 hours
D. First morning voided samples are not acceptable when renal disease is suspected
C. Samples may be stored at room temperature for up to 2 hours
Which urine color is correlated correctly with the pigment-producing substance?
A. Smoky red urine with homogentisic acid
B. Dark amber urine with myoglobin
C. Deep yellow urine and yellow foam with
bilirubin
D. Red-brown urine with biliverdin
C. Deep yellow urine and yellow foam with
bilirubin
Which of the following substances will cause urine to produce red fluorescence when examined with an ultraviolet lamp (360 nm)?
A. Myoglobin
B. Porphobilinogen (PBG)
C. Urobilin
D. Coproporphyrin
D. Coproporphyrin
Which of the following conditions is associated with normal urine color but produces red fluorescence when urine is examined with an ultraviolet (Wood’s) lamp?
A. Acute intermittent porphyria
B. Lead poisoning
C. Erythropoietic porphyria
D. Porphyria cutanea tarda
B. Lead poisoning
Which statement regarding porphyria is accurate?
A. Porphyria is exclusively inherited
B. All types cause an increase in urinary porphyrins
C. All types are associated with anemia
D. Serum, urine, and fecal tests may be needed for diagnosis
D. Serum, urine, and fecal tests may be needed for diagnosis
Which is the most common form of porphyria?
A. Erythropoietic porphyria
B. Acute intermittent porphyria
C. Variegate porphyria
D. Porphyria cutanea tarda
D. Porphyria cutanea tarda
Which of the following methods is the least
sensitive and specific for measuring PBG in urine?
A. Watson-Schwartz test
B. LC-MS
C. Ion exchange chromatography-Ehrlich’s reaction
D. Isotope dilution-MS
A. Watson-Schwartz test
A brown or black pigment in urine can be
caused by:
A. Gantrisin (Pyridium)
B. Phenolsulfonphthalein
C. Rifampin
D. Melanin
D. Melanin
Urine that is dark red or port wine in color may be caused by:
A. Lead poisoning
B. Porphyria cutanea tarda
C. Alkaptonuria
D. Hemolytic anemia
B. Porphyria cutanea tarda
Which of the following tests is affected least by standing or improperly stored urine?
A. Glucose
B. Protein
C. pH
D. Bilirubin
B. Protein
Which type of urine sample is needed for a
D-xylose absorption test on an adult patient?
A. 24-hour urine sample collected with 20 mL of 6 N HCl
B. 2-hour timed postprandial urine preserved with boric acid
C. 5-hour timed urine kept under refrigeration
D. Random urine preserved with formalin
C. 5-hour timed urine kept under refrigeration
Which of the following is inappropriate
when collecting a 24-hour urine sample for
catecholamines?
A. Urine in the bladder is voided and discarded at the start of the test
B. At 24 hours, any urine in the bladder is voided and added to the collection
C. All urine should be collected in a single container that is kept refrigerated
D. Ten mL of 1N sodium hydroxide should be added to the container before collection
D. Ten mL of 1N sodium hydroxide should be added to the container before collection
Urine production of less than 400 mL/day is:
A. Consistent with normal renal function and H2O balance
B. Termed isosthenuria
C. Defined as oliguria
D. Associated with diabetes mellitus
C. Defined as oliguria
Which of the following contributes to SG, but not to osmolality?
A. Protein
B. Salt
C. Urea
D. Glucose
A. Protein
Urine with an SG consistently between 1.002 and 1.003 indicates:
A. Acute glomerulonephritis
B. Renal tubular failure
C. Diabetes insipidus
D. Addison’s disease
C. Diabetes insipidus
In which of the following conditions is the urine SG likely to be below 1.025?
A. Diabetes mellitus
B. Drug overdose
C. Chronic renal failure
D. Prerenal failure
C. Chronic renal failure
Which statement regarding methods for
measuring SG is true?
A. To correct a urinometer, subtract 0.001 per each 3°C below 15.5°C
B. Colorimetric SG tests are falsely elevated when a large quantity of glucose is present
C. Colorimetric SG readings are falsely elevated when pH is alkaline
D. Refractometry should be performed before the
urine is centrifuged
A. To correct a urinometer, subtract 0.001 per each 3°C below 15.5°C
What is the principle of the colorimetric reagent strip determination of SG in urine?
A. Ionic strength alters the pKa of a polyelectrolyte
B. Sodium and other cations are chelated by a ligand that changes color
C. Anions displace a pH indicator from a mordant, making it water soluble
D. Ionized solutes catalyze oxidation of an azo dye
A. Ionic strength alters the pKa of a polyelectrolyte
Which statement regarding urine pH is true?
A. High-protein diets promote an alkaline urine pH
B. pH tends to decrease as urine is stored
C. Contamination should be suspected if urine pH is less than 4.5
D. Bacteriuria is most often associated with a low urine pH
C. Contamination should be suspected if urine pH is less than 4.5
In renal tubular acidosis, the pH of urine is:
A. Consistently acid
B. Consistently alkaline
C. Neutral
D. Variable, depending upon diet
B. Consistently alkaline
The normal daily urine output for an adult is approximately:
A. 0.2-0.5 L
B. 0.6-1.6 L
C. 2.7-3.0 L
D. 3.2-3.5 L
B. 0.6-1.6 L
The SG of the filtrate in Bowman’s space is
approximately:
A. 1.000-1.002
B. 1.004-1.006
C. 1.008-1.010
D. 1.012-1.014
C. 1.008-1.010
A patient with partially compensated respiratory alkalosis would have a urine pH of:
A. 4.5-5.5
B. 5.5-6.5
C. 6.5-7.5
D. 7.5-8.5
D. 7.5-8.5
Which of the following is most likely to cause a false-positive dry reagent strip test for urinary protein?
A. Urine of high SG
B. Highly buffered alkaline urine
C. Bence-Jones protein
D. Salicylates
B. Highly buffered alkaline urine
When testing for urinary protein with
sulfosalicylic acid (SSA), which condition
may produce a false-positive result?
A. Highly buffered alkaline urine
B. The presence of x-ray contrast media
C. Increased urinary SG
D. The presence of red blood cells (RBCs)
B. The presence of x-ray contrast media
A discrepancy between the urine SG determined by measuring refractive index and urine osmolality would be most likely to occur:
A. After catheterization of the urinary tract
B. In diabetes mellitus
C. After an intravenous pyelogram (IVP)
D. In uremia
C. After an intravenous pyelogram (IVP)
Which of the following is likely to result in a
false-negative dry reagent strip test for
proteinuria?
A. Penicillin
B. Aspirin
C. Amorphous phosphates
D. Bence-Jones protein
D. Bence-Jones protein
Daily loss of protein in urine normally does not exceed:
A. 30 mg
B. 50 mg
C. 100 mg
D. 150 mg
D. 150 mg
Which of the following is least likely to cause a false-positive result with turbidimetric protein tests?
A. Tolbutamide
B. X-ray contrast media
C. Penicillin or sulfa antibiotics
D. Ascorbic acid
D. Ascorbic acid
Which statement best describes the clinical utility of tests for microalbuminuria?
A. Testing may detect early renal involvement in diabetes mellitus
B. Microalbuminuria refers to a specific subfraction of albumin found only in persons with diabetic nephropathy
C. A positive test result indicates the presence of orthostatic albuminuria
D. Testing should be part of the routine urinalysis
A. Testing may detect early renal involvement in diabetes mellitus
Dry reagent strip tests for microalbuminuria that compare albumin to creatinine determine the creatinine concentration based upon which
principle?
A. Formation of a Cu+2-creatinine complex
B. Enzymatic assay using sarcosine oxidase and peroxidase
C. Reaction of creatinine with alkaline sodium picrate
D. Change in pH as creatinine is converted to creatine
A. Formation of a Cu+2-creatinine complex
Which of the following conditions is least likely to be detected by dry reagent strip tests for proteinuria?
A. Orthostatic albuminuria
B. Chronic renal failure
C. Pyelonephritis
D. Renal tubular proteinuria
D. Renal tubular proteinuria
The normal renal threshold for glucose is:
A. 70-85 mg/dL
B. 100-115 mg/dL
C. 130-145 mg/dL
D. 165-180 mg/dL
D. 165-180 mg/dL
In which of the following conditions is glycosuria most likely?
A. Addison’s disease
B. Hypothyroidism
C. Pregnancy
D. Hypopituitarism
C. Pregnancy
In addition to ascorbate, the glucose oxidase reaction may be inhibited by which substance?
A. Acetoacetic acid (AAA)
B. ε-Aminocaproic acid
C. Creatinine
D. Azopyridium
A. Acetoacetic acid (AAA)
A positive glucose oxidase test and a negative test for reducing sugars indicates:
A. True glycosuria
B. False-positive reagent strip test
C. False-negative reducing test caused by ascorbate
D. Galactosuria
A. True glycosuria
A negative glucose oxidase test and a positive test for reducing sugars in urine indicates:
A. True glycosuria
B. A false-negative glucose oxidase reaction
C. The presence of a nonglucose reducing sugar such as galactose
D. A trace quantity of glucose
C. The presence of a nonglucose reducing sugar such as galactose
In what condition may urinary ketone tests
underestimate ketosis?
A. Acidosis
B. Hemolytic anemia
C. Renal failure
D. Excessive use of vitamin C
A. Acidosis
AAA is detected in urine by reaction with:
A. Sodium nitroprusside
B. o-Toluidine
C. m-Dinitrobenzene
D. m-Dinitrophenylhydrazine
A. Sodium nitroprusside
Nondiabetic ketonuria can occur in all of the following except:
A. Pregnancy
B. Renal failure
C. Starvation
D. Lactate acidosis
B. Renal failure
Which of the following statements regarding the classical nitroprusside reaction for ketones is true?
A. The reaction is most sensitive to acetone
B. Nitroprusside reacts with acetone, AAA, and β-hydroxybutyric acid
C. It may be falsely positive in phenylketonuria
D. The reaction is recommended for diagnosing ketoacidosis
C. It may be falsely positive in phenylketonuria
Hemoglobin in urine can be differentiated from myoglobin using:
A. 80% ammonium sulfate to precipitate
hemoglobin
B. Sodium dithionite to reduce hemoglobin
C. o-Dianisidine instead of benzidine as the color indicator
D. The dry reagent strip blood test
A. 80% ammonium sulfate to precipitate
hemoglobin
Which of the following conditions is associated with a negative blood test and an increase in urine urobilinogen?
A. Calculi of the kidney or bladder
B. Malignancy of the kidney or urinary system
C. Crush injury
D. Extravascular hemolytic anemia
D. Extravascular hemolytic anemia
Which statement about the dry reagent strip blood test is true?
A. The test is based on the reaction of hemoglobin with peroxidase
B. Abnormal color may be absent from the urine when the reaction is positive
C. A nonhemolyzed trace is present when there are 1-2 RBCs per high-power field
D. Salicylates cause a false-positive reaction
B. Abnormal color may be absent from the urine when the reaction is positive
A moderate-positive blood test and trace protein test are seen on the dry reagent strip, and 11-20 red blood cells per high-power field are seen in the microscopic exam. These results are most likely caused by which of the following?
A. Transfusion reaction
B. Myoglobinuria
C. Intravascular hemolytic anemia
D. Recent urinary tract catheterization
D. Recent urinary tract catheterization
Which of the following results are discrepant?
A. Small amount of blood but negative protein
B. Moderate amount of blood but no RBCs in microscopic exam
C. Negative blood but 6-10 RBCs/high-power field (HPF)
D. Negative blood, positive protein
C. Negative blood but 6-10 RBCs/high-power
field (HPF)
Which of the following statements regarding the dry reagent strip test for bilirubin is true?
A. A positive test is seen in prehepatic, hepatic, and posthepatic jaundice
B. The test detects only conjugated bilirubin
C. Standing urine may become falsely positive due to bacterial contamination
D. High levels of ascorbate will cause positive interference
B. The test detects only conjugated bilirubin
Which of the following reagents is used to detect urobilinogen in urine?
A. p-Dinitrobenzene
B. p-Aminosalicylate
C. p-Dimethylaminobenzaldehyde
D. p-Dichloroaniline
C. p-Dimethylaminobenzaldehyde
Which of the following statements regarding urinary urobilinogen is true?
A. Diurnal variation occurs with highest levels seen in the early morning
B. High levels occurring with a positive bilirubin test indicate obstructive jaundice
C. Dry reagent strip tests do not detect decreased levels
D. False-positive results may occur if urine is stored for more than 2 hours
C. Dry reagent strip tests do not detect decreased levels
Which of the following statements regarding the test for nitrite in urine is true?
A. It detects more than 95% of clinically significant bacteriuria
B. Formation of nitrite is unaffected by the
urine pH
C. The test is dependent upon an adequate dietary nitrate content
D. A positive test differentiates bacteriuria from in vitro bacterial contamination
C. The test is dependent upon an adequate dietary nitrate content
Which statement about the dry reagent strip test for leukocytes is true?
A. The test detects only intact white blood
cells (WBCs)
B. The reaction is based upon the hydrolysis of substrate by WBC esterases
C. Several antibiotics may give a false-positive reaction
D. The test is sensitive to 2-3 WBCs per HPF
B. The reaction is based upon the hydrolysis of substrate by WBC esterases
Which of the following statements about
creatinine clearance is correct?
A. Dietary restrictions are required during the 24 hours preceding the test
B. Fluid intake must be restricted to below 600 mL in the 6 hours preceding the test
C. Creatinine clearance is mainly determined by renal tubular function
D. Creatinine clearance is dependent upon lean body mass
D. Creatinine clearance is dependent upon lean body mass
A male patient’s eGFR is 75 mL/min. This
indicates:
A. Normal glomerular filtration rate
B. The patient is uremic and will be hyperkalemic
C. Renal tubular dysfunction
D. Reduced glomerular filtration without uremia
D. Reduced glomerular filtration without uremia
Which of the following tests is a specific measure of glomerular filtration?
A. p-Aminohippuric acid (PAH) clearance
B. Fishberg concentration test
C. Mosenthal dilution test
D. Cystatin C
D. Cystatin C
Which statement regarding urea is true?
A. Urea is 100% filtered by the glomeruli
B. Blood urea levels are independent of diet
C. Urea is not significantly reabsorbed by the tubules
D. Urea excretion is a specific measure of glomerular function
A. Urea is 100% filtered by the glomeruli
Given the following data, calculate the creatinine clearance.
Serum creatinine = 1.2 mg/dL;
urine creatinine = 100 mg/dL;
urine volume = 1.4 L/day;
body surface area = 1.80 m2
A. 47 mL/min
B. 78 mL/min
C. 100 mL/min
D. 116 mL/min
B. 78 mL/min
Which of the following dyes are used in
Sternheimer-Malbin stain?
A. Hematoxylin and eosin
B. Crystal violet and safranin
C. Methylene blue and eosin
D. Methylene blue and safranin
B. Crystal violet and safranin
Which of the following statements regarding WBCs in urinary sediment is true?
A. “Glitter cells” seen in the urinary sediment are a sign of renal disease
B. Bacteriuria in the absence of WBCs indicates lower urinary tract infection (UTI)
C. WBCs other than PMNs are not found in
urinary sediment
D. WBC casts indicate that pyuria is of renal, rather than lower urinary, origin
D. WBC casts indicate that pyuria is of renal, rather than lower urinary, origin
Which description of sediment with
Sternheimer-Malbin stain is correct?
A. Transitional epithelium: cytoplasm pale blue, nucleus dark blue
B. Renal epithelium: cytoplasm light blue, nucleus dark purple
C. Glitter cells: cytoplasm dark blue, nucleus dark purple
D. Squamous epithelium: cytoplasm pink, nucleus pale blue
A. Transitional epithelium: cytoplasm pale blue, nucleus dark blue
SITUATION: A 5-mL urine specimen is submitted for routine urinalysis and analyzed immediately. The SG of the sample is 1.012 and the pH is 6.5.
The dry reagent strip test for blood is a large positive (3+) and the microscopic examination shows 11-20 RBCs per HPF. The leukocyte esterase reaction is a small positive (1+), and the microscopic examination shows 0-5 WBCs per
HPF. What is the most likely cause of these
results?
A. Myoglobin is present in the sample
B. Free hemoglobin is present
C. Insufficient volume is causing microscopic results to be underestimated
D. Some WBCs have been misidentified as RBCs
C. Insufficient volume is causing microscopic results to be underestimated
Which of the following statements regarding epithelial cells in the urinary system is correct?
A. Caudate epithelial cells originate from the upper urethra
B. Transitional cells originate from the upper urethra, ureters, bladder, or renal pelvis
C. Cells from the proximal renal tubule are usually round in shape
D. Squamous epithelium line the vagina, urethra, and wall of the urinary bladder
B. Transitional cells originate from the upper urethra, ureters, bladder, or renal pelvis
Which of the statements regarding examination of unstained sediment is true?
A. Renal cells can be differentiated reliably from WBCs
B. Large numbers of transitional cells are often seen after catheterization
C. Neoplastic cells from the bladder are not found in urinary sediment
D. RBCs are easily differentiated from nonbudding yeast
B. Large numbers of transitional cells are often seen after catheterization
Which of the following statements regarding cells found in urinary sediment is true?
A. Transitional cells resist swelling in hypotonic urine
B. Renal tubular cells are often polyhedral and have an eccentric round nucleus
C. Trichomonads have an oval shape with a
prominent nucleus and a single anterior
flagellum
D. Clumps of bacteria are frequently mistaken for blood casts
B. Renal tubular cells are often polyhedral and have an eccentric round nucleus
Which of the following statements regarding RBCs in the urinary sediment is true?
A. Yeast cells will lyse in dilute acetic acid but RBCs will not
B. RBCs are often swollen in hypertonic urine
C. RBCs of glomerular origin often appear
dysmorphic
D. Yeast cells will tumble when the cover glass is touched but RBCs will not
C. RBCs of glomerular origin often appear
dysmorphic
Renal tubular epithelial cells are shed into the urine in largest numbers in which condition?
A. Malignant renal disease
B. Acute glomerulonephritis
C. Nephrotic syndrome
D. Cytomegalovirus (CMV) infection of the kidney
D. Cytomegalovirus (CMV) infection of the kidney
The ova of which parasite may be found in the
urinary sediment?
A. T. vaginalis
B. Entamoeba histolytica
C. Schistosoma hematobium
D. Trichuris trichiura
C. Schistosoma hematobium
Oval fat bodies are often seen in:
A. Chronic glomerulonephritis
B. Nephrotic syndrome
C. Acute tubular nephrosis
D. Renal failure of any cause
B. Nephrotic syndrome
All of the following statements regarding urinary casts are true except:
A. Many hyaline casts may appear in sediment after jogging or exercise
B. An occasional granular cast may be seen in a normal sediment
C. Casts can be seen in significant numbers even when protein tests are negative
D. Hyaline casts will dissolve readily in alkaline urine
C. Casts can be seen in significant numbers even when protein tests are negative
Which condition promotes the formation of casts in the urine?
A. Chronic production of alkaline urine
B. Polyuria
C. Reduced filtrate formation
D. Low urine SG
C. Reduced filtrate formation
The mucoprotein that forms the matrix of a
hyaline cast is called:
A. Bence-Jones protein
B. β-Microglobulin
C. Tamm-Horsfall protein
D. Arginine-rich glycoprotein
C. Tamm-Horsfall protein
“Pseudocasts” are often caused by:
A. A dirty cover glass or slide
B. Bacterial contamination
C. Amorphous urates
D. Mucus in the urine
C. Amorphous urates
Which of the following statements regarding urinary casts is correct?
A. Fine granular casts are more significant than coarse granular casts
B. Cylindruria is always clinically significant
C. The appearance of cylindroids signals the onset of end-stage renal disease
D. Broad casts are associated with severe renal tubular obstruction
D. Broad casts are associated with severe renal tubular obstruction
A sediment with moderate hematuria and RBC casts most likely results from:
A. Chronic pyelonephritis
B. Nephrotic syndrome
C. Acute glomerulonephritis
D. Lower urinary tract obstruction
C. Acute glomerulonephritis
Urine sediment characterized by pyuria with bacterial and WBC casts indicates:
A. Nephrotic syndrome
B. Pyelonephritis
C. Polycystic kidney disease
D. Cystitis
B. Pyelonephritis
Which type of casts signals the presence of chronic renal failure?
A. Blood casts
B. Fine granular casts
C. Waxy casts
D. Fatty casts
C. Waxy casts
SITUATION: Urinalysis of a sample from a
patient suspected of having a transfusion reaction reveals small yellow-brown crystals in the microscopic examination. Dry reagent strip tests are normal with the exception of a positive blood reaction (moderate) and trace positive protein.
The pH of the urine is 6.5. What test should be performed to positively identify the crystals?
A. Confirmatory test for bilirubin
B. Cyanide-nitroprusside test
C. Polarizing microscopy
D. Prussian blue stain
D. Prussian blue stain
When examining urinary sediment, which of the following is considered an abnormal finding?
A. 0-2 RBCs per HPF
B. 0-1 hyaline casts per low-power field (LPF)
C. 0-1 renal cell casts per LPF
D. 2-5 WBCs per HPF
C. 0-1 renal cell casts per LPF
SITUATION: A urine sample with a pH of
6.0 produces an abundance of pink sediment after centrifugation that appears as densely packed yellow- to reddish-brown granules under the microscope. The crystals are so dense that no other formed elements can be evaluated. What is
the best course of action?
A. Request a new urine specimen
B. Suspend the sediment in prewarmed saline, then repeat centrifugation
C. Acidify a 12-mL aliquot with three drops of glacial acetic acid and heat to 56°C for
5 minutes before centrifuging
D. Add five drops of 1N HCl to the sediment and examine
B. Suspend the sediment in prewarmed saline, then repeat centrifugation
How can hexagonal uric acid crystals be
distinguished from cystine crystals?
A. Cystine is insoluble in hydrochloric acid but uric acid is soluble
B. Cystine gives a positive nitroprusside test after reduction with sodium cyanide
C. Cystine crystals are more highly pigmented
D. Cystine crystals form at neutral or alkaline pH, uric acid forms at neutral to acidic pH
B. Cystine gives a positive nitroprusside test after reduction with sodium cyanide
The presence of tyrosine and leucine crystals together in a urine sediment usually indicates:
A. Renal failure
B. Chronic liver disease
C. Hemolytic anemia
D. Hartnup disease
B. Chronic liver disease