Urinalysis and Body Fluids

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Urinalysis and Body Fluids
2013-05-03 00:59:06
Urine Microscopic Examination Crystals

Urine Microscopic Examination for Crystals
Show Answers:

  1. How are crystals in the urine formed?
    • Formed by the precipitation of urine salts, organic compounds, and meds
    • Can be altered by temperature, pH, and urine concentration
    • If an increased amount of a solute is present when the glomerular ultrafiltrate passes through the renal tubules, the ultrafiltrate becomes saturated - leading to the solute precipitating into a characteristic crystal form
  2. What is the most important factor when identifying crystals in urines?
  3. In what pH are all clinically significant crystals found?
    Acidic and neutral urine
  4. What acidic crystals are:
    Formed from the urate salts of Na, K, Mg, and Ca
    No clinical significance
    Small yellow-to-brown granules usually in large amounts
    May also be produced when refrigerated due to the presence of uroerythrin
    Amorphous urates
  5. How do you get ride of amorphous urates when you need to see the sediment behind them?
    • Dissolve at an alkaline pH
    • Heating above 60 degrees celcius
  6. Amorphous urates
  7. What acidic crystals are:
    Seen in gout, chemotherapy for leukemia, and Lesch-Nyhan syndrome
    Appear yellow-to-orange/brown but can be colorless
    Pleomorphic (many) shapes that include four sided flat plates, rhombic plates, wedges, and rosettes
    Uric acid
  8. Uric acid
  9. What acidic crystals are:
    Formed from oxalic acid (found in tomatoes, asparagus, spinach, berries, and oranges and Vit C)
    Colorless, dihydrate form appears as octahedral envelope or 2 pyramids joined at their bases
    Monohydrate form appears as dumbbell or oval shaped
    Associated with renal calculi formation and seen in poison centers where children have ingested ethylene glycol (antifreeze)
    Calcium oxalate
  10. Calcium oxalate
  11. What acidic crystals are:
    Formed when urine bilirubin exceed its solubility
    Appear as fine needles or granules that are yellow-brown in color
    Associated with liver disease
    Casts may contain these crystals in cases of viral hepaptitis when there is reanl tubular damage
    Bilirubin crystal
  12. Bilirubin crystal
  13. What acidic crystals are:
    Fine delicate needles, colorless-yellow found in clumps or rosettes
    Associated with severe liver disease and inherited diseases that affect amino acid metabolism
    May be seen with leucine in urines that test positive for bilirubin
  14. Tyrosine
  15. What acidic crystals are:
    Yellow-brown, oily looking spheres with concentric circles and radial striations
    May be found with tyrosine crystals
    Associated with severe liver disease and inherited diseases that affect amino acid metabolism
  16. Leucine
  17. What acidic crystals:
    Colorless hexagonal plates
    Associated with congenital disorder that inhibits renal tubular reabsorption of of cystine and renal calculi formation
  18. Cystine
  19. What acidic crystals:
    Clear, flat, rectangular plates with a notch in one or more corners
    Seen with fatty casts and oval fat bodies
    Associated with nephrotic syndrome and other disorders that produce lipiduria
  20. Cholesterol crystals
  21. Name the crystals that form due to meds
    • Ampicillin
    • Sulfonamide
  22. What alkaline crystal:
    Small, colorless granules
    Refrigerated samples appear as white sediment
    Not clinically significant
    Amorphous Phosphate
  23. Amorphous Phosphate
  24. What alkaline crystal:
    Colorless, 3-6 sided prism often resembling a coffin lid
    May be associated with UTIs but not clinically significant
    Triple phosphate
  25. Triple phosphate
  26. What alkaline urine:
    Colorless, thin prisms or rectangular plates
    May be associated with renal calculi formation but not clinically significant
    Calcium phosphate
  27. Calcium phosphate
  28. What alkaline urine:
    Seen in old urine samples
    Converts to uric acid crystals if acetic acid is added
    Yellow-brown spheres with striations on the surface, also can show irregular, thorny projections (thorny apples)
    Ammonium biurate
  29. Ammonium biurate
  30. What alkaline urine:
    Appears as small, colorless crystals having dumbbell or spherical shapes
    Not clinically significant
    Calcium carbonate
  31. Calcium carbonate