First test examination of crystals Flashcards
nephrolithiasis
kidney stone disease
stones that are in the ureter
ureterolithiasis
urinary bladder stones which form or havepassed into the bladder
cystolithiasis
crystals can form before or after micturation
micturation=urination
Crystal precipitation after micturition is most commonly dueto:
- changes in urinary temperature, as can occur if theurine is stored at room temperature or ina refrigerator;- changes in urinary pH, as can occur in thepresence of contamination of urea-splittingorganisms.
abnormal crystals are usually seen in ___ urine
acidic
Prerequisites for identification of crystals:
– pH of urine– morphology of crystals– crystals solubility– crystals polarization
abnormal acidic crystals
metabolic origin
abnormal alkaline crystals
Iatrogenic orgin
In vitro factors of urinary crystal formation
-Temperature (solubilitydecreases withtemperature)- Evaporation (increasessolute concentration)- Urine pH (changes withstanding andbacterial overgrowth)
In vivo (body) factors:
Solute concentration- Kidney filtration rate- Urine pH- Diet- Excretion of diagnosticimaging andtherapeutic agents
most crystals are clinically
insignificant
Generally, clinically significant crystals are present infreshly voided urine, or in cases of ______
metabolic disorders(e.g. gout)
- Metabolic disorders may produce crystals (4)
• Cystine (inherited metabolic disease)• Leucine• Tyrosine• Cholesterol
- Iatrogenic disorders-high doses of some drugs and supplements may cause formation of crystals:
• Salicilates (Aspirin)• Sulfonamides• Ascorbic Acid (vitamin C)
_____ light is used for the identification of crystalsand other anisotropic substances.
Polarized
The first lens is referred to as the “_____ filter” and itis nearest the light source, below the condenser
polarizing
The second filtering lens is called the “______” and islocated between the objective and the eyepiece lenses
analyzer
It is used for differential diagnosis between variouscrystals
Birefringence
•Birefringence is a double refraction (or bending) of thelight into ___ rays, one is ____to the light axisand other is at angles to it
two, parallel, right
Birefringence demonstrates crystal’s ability to split ____into the spectrum
light
when examining with a polarizing filter and REDcompensator filter, the crystals are YELLOWwhen aligned parallel to the slow axis ofthe red compensatorbut they turn BLUE when aligned across thedirection of polarization
Negative birefringence: (Y-B)
hen examining with a polarizing filter and redcompensator filter, the crystals are BLUEwhen aligned parallel to the slow axis ofthe red compensatorbut they turn YELLOW when aligned across thedirection of polarization
• Positive birefringence
ACIDIC URINE CRYSTALS
Uric acid• Calcium Oxalates• Amorphous Urates
