SPECIFIC GRAVITY Flashcards

Question: What is the normal urine volume per day?
A) 600–1,000 mL
B) 1,200–1,500 mL
C) 2,000–2,500 mL
D) 800–1,100 mL

Answer: B) 1,200–1,500 mL

Question: Oliguria in adults is defined as urine output less than:
A) 600 mL/day
B) 1,000 mL/day
C) 400 mL/day
D) 200 mL/day

Answer: C) 400 mL/day

Question: Which condition is characterized by complete cessation of urination?
A) Oliguria
B) Polyuria
C) Nocturia
D) Anuria

Answer: D) Anuria

Question: Polyuria is defined as urine output greater than:
A) 1.5 L/day
B) 2.0 L/day
C) 2.5 L/day
D) 3.0 L/day

Answer: C) 2.5 L/day

Question: Which of the following conditions can cause polyuria?
A) Dehydration and vomiting
B) Diabetes mellitus or diabetes insipidus
C) Kidney damage or low blood pressure
D) Bacterial infection of the bladder

Answer: B) Diabetes mellitus or diabetes insipidus

Question: The minimum urine volume required for microscopic examination is:
A) 5 mL
B) 50 mL
C) 12 mL
D) 25 mL

Answer: C) 12 mL

Question: Labels on urine containers must be attached to:
A) The lid of the container
B) The container itself, not the lid
C) The requisition form only
D) Either the lid or the container

Answer: B) The container itself, not the lid

Question: Which urine specimen type is considered the ideal screening specimen?
A) Random specimen
B) Midstream clean-catch
C) First-morning specimen
D) 24-hour specimen

Answer: C) First-morning specimen

Question: The first-morning urine specimen is preferred for pregnancy testing because:
A) Estrogen levels are highest in the morning
B) HCG concentration is highest in the morning
C) The specimen is least contaminated in the morning
D) Protein levels are elevated in morning urine

Answer: B) HCG concentration is highest in the morning

Question: Which type of urine specimen is used to evaluate orthostatic proteinuria?
A) Random specimen
B) 24-hour specimen
C) Catheterized specimen
D) First-morning specimen

Answer: D) First-morning specimen

Question: In orthostatic proteinuria, which pattern is expected?
A) Protein positive in first-morning, negative in random
B) Protein negative in both specimens
C) Protein positive in random, negative in first-morning
D) Protein positive in both specimens

Answer: C) Protein positive in random, negative in first-morning

Question: The 24-hour urine collection must:
A) Begin and end with a full bladder
B) Begin and end with an empty bladder
C) Be collected only at night
D) Be kept at room temperature throughout

Answer: B) Begin and end with an empty bladder

Question: Which of the following is measurable using a 24-hour urine collection?
A) HCG
B) Glomerular filtration rate
C) Bilirubin
D) Urobilinogen

Answer: B) Glomerular filtration rate

Question: 24-hour urine specimens must be stored in what condition during collection?
A) At room temperature
B) Refrigerated or kept on ice
C) In a dark container at body temperature
D) Frozen throughout collection

Answer: B) Refrigerated or kept on ice

Question: Which specimen type bypasses the urethra and is ideal for cytology?
A) Catheterized specimen
B) Midstream clean-catch
C) Random specimen
D) Suprapubic aspiration

Answer: D) Suprapubic aspiration

Question: A midstream clean-catch specimen is preferred over random because it is:
A) More concentrated
B) Less contaminated
C) Easier to collect
D) Better for quantitative testing

Answer: B) Less contaminated

Question: Which of the following is a valid specimen rejection criterion?
A) Specimen collected in the morning
B) Urine volume of 30 mL
C) Nonmatching labels and requisition forms
D) Slightly turbid specimen

Answer: C) Nonmatching labels and requisition forms

Question: What is the mnemonic used to remember analytes that INCREASE in unpreserved urine?
A) BACON
B) PABON
C) BANOP
D) NAPOB

Answer: B) PABON

Question: Why does pH increase in unpreserved urine?
A) Oxidation of bilirubin to biliverdin
B) Glycolysis by bacteria consuming glucose
C) Breakdown of urea to ammonia by urease-producing bacteria
D) Loss of ketones through volatilization

Answer: C) Breakdown of urea to ammonia by urease-producing bacteria

Question: What happens to glucose in unpreserved urine?
A) Increases due to bacterial production
B) Decreases due to glycolysis and bacterial use
C) Remains unchanged
D) Increases due to oxidation

Answer: B) Decreases due to glycolysis and bacterial use

Question: Bilirubin decreases in unpreserved urine due to:
A) Bacterial metabolism
B) Volatilization
C) Photo-oxidation to biliverdin
D) Glycolysis

Answer: C) Photo-oxidation to biliverdin

Question: Which analyte decreases in unpreserved urine due to oxidation to urobilin?
A) Bilirubin
B) Nitrite
C) Urobilinogen
D) Ketones

Answer: C) Urobilinogen

Question: Why does nitrite INCREASE in unpreserved urine?
A) Oxidation of ammonia
B) Multiplication of nitrate-reducing bacteria
C) Breakdown of urea
D) Loss of CO2

Answer: B) Multiplication of nitrate-reducing bacteria

Question: RBCs, WBCs, and casts decrease in unpreserved urine because of:
A) Bacterial consumption
B) Oxidation by metabolites
C) Disintegration in dilute alkaline urine
D) Volatilization

Answer: C) Disintegration in dilute alkaline urine

Question: Trichomonas vaginalis becomes unidentifiable in unpreserved urine because it:
A) Gets oxidized and changes color
B) Loses motility and dies, resembling a WBC
C) Binds to bacteria and clumps
D) Undergoes glycolysis

Answer: B) Loses motility and dies, resembling a WBC

Question: The color of urine darkens in unpreserved specimens due to:
A) Bacterial multiplication
B) Oxidation/reduction of metabolites
C) Loss of CO2
D) Increased nitrite production

Answer: B) Oxidation/reduction of metabolites

Question: Clarity decreases in unpreserved urine due to:
A) Loss of pigments through oxidation
B) Bacterial growth and precipitation of amorphous material
C) Breakdown of glucose
D) Volatilization of ketones

Answer: B) Bacterial growth and precipitation of amorphous material

Question: Ketones decrease in unpreserved urine primarily because of:
A) Glycolysis
B) Bacterial reduction
C) Volatilization and bacterial metabolism
D) Photo-oxidation

Answer: C) Volatilization and bacterial metabolism

Question: What is the normal specific gravity range for random urine specimens?
A) 1.000–1.010
B) 1.010–1.020
C) 1.002–1.035
D) 1.005–1.040

Answer: C) 1.002–1.035

Question: A urine specific gravity of 1.010 is referred to as:
A) Hyposthenuric
B) Hypersthenuric
C) Isosthenuric
D) Normosthenuric

Answer: C) Isosthenuric

Question: Hyposthenuric urine has a specific gravity:
A) Above 1.010
B) Equal to 1.010
C) Below 1.010
D) Above 1.035

Answer: C) Below 1.010

Question: A specific gravity below 1.002 indicates:
A) Severely concentrated urine
B) The specimen is no longer urine
C) Renal tubular acidosis
D) Diabetes mellitus

Answer: B) The specimen is no longer urine

Question: A fixed specific gravity of 1.010 is associated with:
A) Diabetes mellitus
B) Diabetes insipidus
C) Renal failure
D) Dehydration

Answer: C) Renal failure

Question: In diabetes mellitus, what is the expected specific gravity pattern?
A) Low SG with polyuria
B) High SG with polyuria
C) Fixed SG at 1.010
D) Low SG with oliguria

Answer: B) High SG with polyuria

Question: In diabetes insipidus, the specific gravity is expected to be:
A) High due to excess glucose
B) Fixed at 1.010
C) Low due to ADH deficiency
D) High due to increased protein

Answer: C) Low due to ADH deficiency

Question: The principle of urinometry is:
A) Refractive index
B) Buoyancy
C) Sound wave oscillation
D) Change in pKa

Answer: B) Buoyancy

Question: The urinometer is designed to sink to a level of _ in distilled water:
A) 1.010
B) 1.005
C) 1.000
D) 1.015

Answer: C) 1.000

Question: In urinometry, the reading is taken at:
A) The upper meniscus
B) The midpoint of the stem
C) The lower meniscus
D) The top of the float

Answer: C) The lower meniscus

Question: The temperature correction for urinometry is:
A) Add/subtract 0.001 for every 1°C difference
B) Add/subtract 0.001 for every 3°C difference
C) Add/subtract 0.003 for every 3°C difference
D) Add/subtract 0.004 for every 5°C difference

Answer: B) Add/subtract 0.001 for every 3°C difference

Question: A urinometer reads 1.015 at a urine temperature 3°C above calibration temperature. What is the corrected SG?
A) 1.014
B) 1.012
C) 1.016
D) 1.018

Answer: C) 1.016

Question: For urinometry, how much correction is subtracted per gram of glucose present?
A) 0.001
B) 0.003
C) 0.004
D) 0.005

Answer: C) 0.004

Question: For urinometry, how much correction is subtracted per gram of protein present?
A) 0.001
B) 0.002
C) 0.003
D) 0.004

Answer: C) 0.003

Question: A urinometer reads 1.035 with 2 g/dL glucose and 1 g/dL protein. What is the corrected SG?
A) 1.030
B) 1.028
C) 1.026
D) 1.024

Answer: D) 1.024

Question: Protein/glucose correction in urinometry is NOT needed when levels are:
A) Greater than 2 g/dL
B) Less than 1 g/dL
C) Equal to 1 g/dL
D) Greater than 1 g/dL

Answer: B) Less than 1 g/dL

Question: What is the principle of refractometry?
A) Buoyancy of a float
B) Sound wave frequency changes
C) Refractive index — comparison of velocity of light in air vs. solution
D) Change in pKa of a polyelectrolyte

Answer: C) Refractive index — comparison of velocity of light in air vs. solution

Question: How many drops of urine are needed for refractometry?
A) 5–10 drops
B) 1–2 drops
C) At least 15 mL
D) 3–5 drops

Answer: B) 1–2 drops

Question: Which is an advantage of refractometry over urinometry?
A) No correction needed for protein or glucose
B) Requires large sample volume
C) Small specimen volume and no temperature correction needed
D) More accurate with turbid specimens

Answer: C) Small specimen volume and no temperature correction needed

Question: A refractometer reads 1.045 with 2 g/dL protein and 1 g/dL glucose. What is the corrected SG?
A) 1.038
B) 1.035
C) 1.040
D) 1.032

Answer: B) 1.035

Question: In the refractometry procedure, the reading is taken at:
A) The top of the scale
B) The boundary line where it intercepts the scale
C) The lower meniscus
D) The midpoint of the eyepiece

Answer: B) The boundary line where it intercepts the scale

Question: Which calibration solution gives an SG of 1.022 ± 0.001 for refractometry?
A) Distilled water
B) 9% sucrose
C) 5% NaCl
D) Potassium phosphate

Answer: C) 5% NaCl

Question: Which calibration solution gives an SG of 1.034 ± 0.001?
A) Distilled water
B) 5% NaCl
C) 9% sucrose
D) Urine control

Answer: C) 9% sucrose

Question: The reagent strip method for specific gravity measures:
A) Refractive index of urine
B) Buoyancy of dissolved solutes
C) Change in pKa of a polyelectrolyte in alkaline medium
D) Freezing point depression

Answer: C) Change in pKa of a polyelectrolyte in alkaline medium

Question: The color indicator used in the reagent strip for specific gravity is:
A) Phenolphthalein
B) Bromthymol blue
C) Methyl red
D) Litmus

Answer: B) Bromthymol blue

Question: The reagent strip SG color change goes from:
A) Yellow (1.000) to blue (1.030)
B) Blue (1.000) to green to yellow (1.030)
C) Red (1.000) to orange to yellow (1.030)
D) Green (1.000) to blue (1.030)

Answer: B) Blue (1.000) to green to yellow (1.030)

Question: The reagent strip for SG measures in what intervals?
A) 0.001
B) 0.010
C) 0.005
D) 0.002

Answer: C) 0.005

Question: The reagent strip for SG is NOT affected by which of the following?
A) Sodium
B) Chloride
C) Ammonia
D) Radiographic dye

Answer: D) Radiographic dye

Question: The most acceptable method for measuring urine concentration is:
A) Urinometry
B) Refractometry
C) Reagent strip
D) Osmolality

Answer: D) Osmolality

Question: Osmolality measures the number of solute particles per:
A) Liter of solvent
B) Kilogram of solvent
C) Liter of solution
D) Deciliter of urine

Answer: B) Kilogram of solvent

Question: The principle of osmolality measurement is based on:
A) Sound wave frequency
B) Refractive index
C) Colligative properties of solutions
D) pKa change of polyelectrolytes

Answer: C) Colligative properties of solutions

Question: Which colligative property DECREASES when solutes are added to a solvent?
A) Boiling point
B) Osmotic pressure
C) Freezing point
D) Viscosity

Answer: C) Freezing point

Question: The key difference between osmolality and specific gravity is:
A) SG measures only ionic solutes; osmolality measures all solutes
B) Osmolality is affected by particle number only; SG is affected by particle number and size
C) SG uses osmometer; osmolality uses refractometer
D) Osmolality is less accurate than SG

Answer: B) Osmolality is affected by particle number only; SG is affected by particle number and size

Question: The principle of harmonic oscillation densitometry is based on:
A) Buoyancy
B) Refractive index
C) Sound wave frequency changes proportional to solution density
D) Change in pKa

Answer: C) Sound wave frequency changes proportional to solution density

Question: The maximum specific gravity result valid for harmonic oscillation densitometry is:
A) 1.040
B) 1.060
C) 1.080
D) 1.035

Answer: C) 1.080

Question: A urine SG greater than 1.040 most likely indicates the presence of:
A) Excess protein
B) Radiographic dye, dextran, or plasma expanders
C) Renal failure
D) Diabetes insipidus

Answer: B) Radiographic dye, dextran, or plasma expanders

Question: Which specific gravity classification indicates the kidney is excreting more water, suggesting adequate hydration?
A) Isosthenuric
B) Hypersthenuric
C) Hyposthenuric
D) Fixed SG

Answer: C) Hyposthenuric

Question: In which classification of urine SG does the kidney retain more water, suggesting dehydration?
A) Hyposthenuric
B) Isosthenuric
C) Hypersthenuric
D) Oligosthenuric

Answer: C) Hypersthenuric

Question: Which of the following labeling requirements must be included on a urine specimen container?
A) Patient's weight and blood type
B) Patient's name, ID number, date and time of collection
C) Collector's name and lab technician ID
D) Color and odor of the specimen at collection

Answer: B) Patient's name, ID number, date and time of collection