comp 3 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
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
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
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
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
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
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
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
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
Which is the most common form of porphyria?
A. Erythropoietic porphyria
B. Acute intermittent porphyria
C. Variegate porphyria
D. Porphyria cutanea tarda
d
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
A brown or black pigment in urine can be
caused by:
A. Gantrisin (Pyridium)
B. Phenolsulfonphthalein
C. Rifampin
D. Melanin
d
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
Which of the following tests is affected least by
standing or improperly stored urine?
A. Glucose
B. Protein
C. pH
D. Bilirubin
b
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
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
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
Which of the following contributes to SG, but
not to osmolality?
A. Protein
B. Salt
C. Urea
D. Glucose
a
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
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
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
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
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
In renal tubular acidosis, the pH of urine is:
A. Consistently acid
B. Consistently alkaline
C. Neutral
D. Variable, depending upon diet
b