heme externship - UA 7.1 Flashcards
which statement regarding renal function is true?
A. Glomeruli are far more permeable to H2O and salt compared with other capillaries
B, the collecting tubule reabsorbs sodium and secretes potassium in response tp 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 compared with other capillaries
which statement regarding normal sale and h2o handling by the nephron is correct
A. the thick ascending limb of the tubule is highly permeable to salt but not water
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 less than 3.5mmol/L
C. no substance can be excreted into the urine at a rate that exceeds the glomerular filtration rate (GFR)
D. when tubular function is lost, the sp gravity of urine is below 1.005
A.
- sodium is a threshold substance - it will not be excreted until plasma levels are 120 mmol/L
- potassium is always lost a little bit
which of the following is inappropriate when collecting a 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 he;kd at 2C to 8C 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 DI water
C. samples may be stored at room temp for up to 2 hours
D. a midday sample is preferred when renal disease is suspected
C.
which urine color is correlated correctly with the pigment-producing substance
A. smoley 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.
- homogentisic= black
- myoglobin = red
- biliverdin = green
which of the following substances will cause urine to produce red fluorescence when examined under a UV lamp
A. myoglobin
B. porphobilinogen
C. urobilin
D. coproporphyin
D.
- porphobili = dark brown
- uroporphyrin and coproporphyrin = fluoresece
which of the following conditions is associated with normal urine color but produces red fluorescence when urine is examined with a UV (Wood) lamp
A. acute intermittent porphyria
B. lead poisoning
C. erythropoietin porphyria
D. porphyria cutanea tarda
B.
- lead poisoning blocks heme synthesis = increase in prophobilinogen and coproporphyrin, enough to cause a fluorescence
which statement regarding porphyria is accurate
A. porphyria is exclusively inherited
B. all types cause an increase in uriany 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
B. acute intermittent
C. variegated
D. porphyria cutanea tarda
D.
- can be seen with hep infection
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 reaction
D. isotope dilution - MS
A.
- qualitative screening, others are diagnostic
a brown or black pigment in urine can be caused by:
A. pyridium
B. PSP
C. rifampin
D. melanin
D. melanin
urine that is dark red or port win colored by be caused by
A. lead poisoning
B. porphyria cutanea tarda
C. alkaptonuria
D. hemolytic anemia
B. PCT
which of the following tests is affected the least by standing or improperly stored urine
A. glucose
B. protein
C. pH
D. bilirubin
B. protein
- becomes more alkaline as standing
- glucose consumed by oxidation
- bilirubin converted to biliverdin
which one of the following characteristics would be a reason for performing a microscopic examination of urinary sediment
A. high vol
B. color intensity
C. turbidity
D. specimen from a foley catheter
C. turbidity
- inspect why
which of the following is appropriate when collecting a 24 hour urine sample for metanephrines
A. urine in the bladder is voided at the start of the test and added to the collection container
B. at 24 hours any urine in the bladder is voided and discarded
C. all urine should be collected in a single container that is kept refrigerated
D. ten milliliters of 1N sodium hydroxide should be added to the container before collection
C.
- first urine is discarded
- last urine is added to the container
urine production of less than 400 mL a day is
A. consistent with normal renal function and water balance
B. termed isothenuria
C. defined as oliguria
D. associated with diabetes mellitus
C.
which of the following contributes to sp grav but not osmolality
A. protein
B. salt
C. urea
D. glucose
A.
- if it can dissolve it relates to osmolality
urine with an SG consistenly between 1.002 and 1.003 indicates
A. acute glomerulonephritis
B. renal tubular failure
C. diabetes insipidus
D. Addison 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.
- drugs and glucose increase SG
- prerenal = tubules ok
which statement regarding the methods for measuring SG is true
A. refractometry is the most accurate way to determine dissolved solute concentration
B. colorimetric SG test results are falsely elevated when a large quantity of glucose is present
C. colorimetric SG readings are falsely low when pH is alkaline
D. refractometry should be performed before the urine is centrifuged
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 cheated 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 polyelectrode
which statement regarding urine pH is true
A. a high protein diet promotes an alkaline urine
B. pH tends to decrease as urine is stored
C. contamination should be suspected if the urine pH is less than 4.5
D. bacteriruia 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 on diet
B.
- defect in renal tubular re-abs of bicarb = waste of sodium bicarb and potassium bicarb = alkaline and hypokalemia associated with acidosis
the normal dialy urine output for a an adult is approximately
A. 0.2-0.5L
B. 0.6-1.6L
C. 2.7-3.0L
D. 3.2-3.5L
C.
the SG of the filtrate in the bowman space is approximately
A. 1.000-1.002
B. 1.004-1.006
C. 1.008-1.010
D. 1.012-1.014
C.
- similar to plasma due to solutes filtered from the glomeruli
- about equal to an mOsm/kg of 280
a patient with partially compensated respiratory alkalosis would have a urine pH of
A. 4.5-5.5
B. 5.5-6.5
C. 6.7-7.5
D. 7.8-8.5
D.
- reabsorbing less bicarb and excreting more = more alkaline
which of the following is most liekly to cause a false pos result on the dry reagent strip test for protein
A. urine of a high sg
B. highly buffered alkaline urine
C. bence-jones proteins
D. salicylates
B.
- protein false pos by alkaline or ammonium
when testing for urinary protien with SSA, which condition may produce a false pos result
A. highly buffered alkaline urine
B. the presence of x-ray contrast media
C. increased urinary SG
D. the presence of RBCs
B.
- increases turbidity
a discrepancy between the urine SG determined by measuring refractive index and urine osmolality would be most likely to occur
A. after catheterization of urinary tract
B. in diabetes mellitus
C. after intravenous pyelography (IVP)
D. in uremia
C.
- IVP dye contains iodine that is refractile and will falsely elevate solute concentration
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 proteins
D.
- not read by strip test even if present
daily loss of protien in urine normally does not exceed
A. 30 mg
B. 50 mg
C. 100 mg
D. 150 mg
D. 150 mg/day
- eq to 30 mg/dL
which of the following is least likely to cause a false pos result on turbidimetric protein test
A. tolbutamide
B. x-ray contrast media
C. penicillin or sulfa antibiotics
D. ascorbic acid
D.
- ascorbic acid reduces diazo salts in bilirubin and nitrite and peroxide in blood
- does not interfere with protein testing
which statement best describes the clinical utility of test 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 indicates the presence of orthostatic albuminuria
D. testing should be part of the routine urinalysis
A.
dry reagent strip tests for microalbuminuria that compare albumin to creatinine determine the creatinine concentration based on which principle
A. formation of a Cu2+ - 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.
which of the following conditions is least likely to be detected by dry reagent strip testes for proteinuria
A. orthostatic albuminuria
B. chronic renal failure
C. pyelonephritis
D. ren tubular proteinuria
D.
the normal renal threshold for gluocse is:
A. 70-85 mg/dL
B. 100-115 mg/dL
C. 130-145 mg/dL
D. 165-180 mg/dL
D.
in which of the following conditions is glycosuria most likely
A. Addisons disease
B. hypothyroidism
C. pregnancy
D. hypopituitarism
C.
- addisons is an atrophy of adrenal glands impacting aldosterone and glucocorticoids
in addition to ascorbate, the glucose oxidase reaction may be inhibited by which substance
A. acetoacetic acid
B. aminocaproic acid
C. creatinine
D. azopyridium
A.
a positive glucose oxidase test and a negative test for reducing sugars indicates
A. true glycosuria
B. false pos strip
C, false neg reducing test
D. galactosuria
A.
a negative glucose oxidase test and a positive test for reducing sugars in urine indicates
A. true glycosuria
B. false neg glucose ox rxn
C. presence of a nonglucose-reducing sugar such as galactose
D. trace quantity of glucose
C.
in what condition may urinary ketone tests underestimate ketosis
A. acidosis
B. hemolytic anemia
C. renal failure
D. excessive use of vitamin C
A.
AAA (acetoacetic acid) is detected in urine by reaction with
A. sodium nitroprusside
B. o-Toluidine
C. m-dinitrobenzene
D. m-dinitrophenylhydrazine
A.
- acetoacetic acid = ketones
nondiabetic ketonuria can occur in all of the following except
A. pregnancy
B. renal failure
C. starvation
D. lactate acidosis
B.
which of the following statements regarding the classic nitroprusside reaction for ketones is true
A. the rxn is most sensitive to acetone
B. nitroprusside reacts with acetone, AAA, and beta-hydroxybutyric acid
C. it may be falsely positive in phenylketonuria
D. the reaction is recommended for diagnosing ketoacidosis
C.
hemoglobin in urine can be differentiated from myoglobin by using
A. 80% ammonium sulfate to precipitate hemoglobin
B. sodium dithionite to reduce hemoglobin
C. o-Dianiside instead of benzidine as the color indicator
D. the dry reagent strip blood test
A.
- hgb will precipitate and result pos on a repeat strip test
which of the following conditions is associated with a negative blood test result 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.
which statement about the dry reagent stip blood test is true
A. the test is based on the reaction of hgb with peroxidase
B. abnormal color may be absent from the urine when the reaction is positive
C. a nohemolyzed trace is present when there are 1-2 RBCs/hpf
D. salicylates cause a false pos rxn
B.
- based on pseudo peroxidase activity of hemoglobin, not being tested with an external peroxidase
a moderately pos result on the blood test and trace protein test are seen on the dry strip, and 11-20 RBCs/hpf are seen on microscopic. These results are most likely caused by which of the following
A. trxn
B. myoglobinuria
C. intravascular hemolytic anemia
D. recent urinary tract catheterization
D.
which of the following results are discrepant
A. small amt of blood, negative protein
B. mod blood, no RBCs in microscopic
C. neg blood but 6-10 RBCs/hpf
D. neg blood, pos protein
C.
- strip detects 4-5 intact rbcs/hpf roughly
which of the following statements regarding the dry reagent strip test for bilirubin is true
A. a pos test result is seen in prehaptic, hepatic and posthepatic jaundice
B. test detects only conjugated bili
C. standing urine may become falsely pos because of bacterial contamination
D. high levels of ascorbate will cause positive interference
B.
- only conjugated bilirubin is excreted in the urine
- prehepatic jaundice results in unconjugated bilirubin build up
which of the folliwing reagents is used to detect urobilinogen in urine
A. p-dinitrobenze
B. p-aminosalicylate
C. p-dimethylaminobenzaldehyde
D. p-dichloroaniline
C. aka ehrlichs reagent
which of the following statements regarding urinary urobilinogen is true
A. diurnal variation occurs and the highest levels are seen in the early morning
B. high levels accompanied by a positive bilirubin test result indicate obstructive jaundice
C. dry reagent strip tests do not detect decreased levels
D. false pos results may occur if urine is stored for more than 2 hours
C.
- if pos bili and increased urobili = hemolysis
which of the following statements regarding the test for nitrite in urine is true
A. it detects more than 95% of clinically significant bacteruira
B. formation of nitrite is unaffected by the urine pH
C. the test is dependent on adequate dietary nitrate
D. a positive test differentiates bacteriruia from in vitro bacterial contamination
C.
- detects bacterial reduction of nitrate to nitrate, the strip tests for the nitrite
which statement about the dry reagent strip test for leukocytes is true
A. the test detects only intact WBCs
B. the rxn is based on the hydrolysis of substrate by WBC esterases
C. several antibiotics may give false positive results
D. test is sensitive to 2-3 WBC/hpf
B.
- tests for PMNs but will miss lymphs due to granule esterase activity
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 on lean body mass
D.
- diet creatinine is rapidly filtered by glomeruli but produced constantly by muscle use
a male patient eGFR is 75 mL/min. This indicates
A. normal GFR
B. patient is uremic and will be hyperkalemic
C. renal tubular dysfunction
D. reduced GFR w/o uremia
D.
- RR is 90-120 mL/min
- between 60-90 mL/min indicates glomerular damage but not uremia
which of the following substances can be used to calculate eGFR
A. p-aminohippuric acid
B. glycine
C. cysteine
D. cystatin C
D.
- cleared only by glomerular filtration
which statement regarding urea is true
A urea is 100% filtered by the golermuli
B. blood urea levels are independent of diet
C. urea is not significantly reabsorbed by the tubules
D. urea excretion is specific measure of glomerular function
A.
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
- BSA: 1.8
A. 47 mL/min
B. 78 mL/min
C. 100 mL/min
D .116 mL/min
B.
- creatinine clearance = (urine creat/serum creat) x (urine vol mL / minutes) x (1.73/BSA)
- urine vol = 1.4 L * 1000 = 1400mL
- 1 day = 1440 minutes
