[LAB] Physical Examination of Urine Flashcards
What causes the yellow color of urine?
urochrome
Who named urochrome in 1864?
Thudichum
What signifies pale yellow urine?
dilute urine
What signifies dark yellow urine?
concentrated urine
What will be the color of the urine if the specimen has been refrigerated?
Pink
(presence of uroerythrin)
What will be the color of the urine if there has been an oxidation of urobilinogen?
Orange-brown (from urobilin)
What pigment causes the urine to be pink?
uroerythrin
(from refrigeration)
What pigment causes the urine to be orange-brown?
urobilin
What signifies the increase in the amount of white foam in urine?
high protein concentration
Specimens containing _______ produces yellow foam when shaken (mistaken for bilirubin)
phenazopyridine
(medicine for UTI)
What are the 2 drugs for UTI that causes yellow-orange pigment in the urine?
phenazopyridine and azo-gantrisin
What causes the dark yellow or amber color of urine?
bilirubin
What causes the red color of urine?
blood
What causes the brown color of urine?
oxidation of hemoglobin to methemoglobin
What is the difference between RBC and hemoglobin/myoglobin in terms of their effect on the urine’s physical characteristics?
- RBCs: red and cloudy
- Hemoglobin/Myoglobin: red + clear
What is the difference between hemoglobin and myoglobin?
Hemoglobin - red plasma
Myoglobin - clear plasma
What causes the port wine color of urine?
porphyrins
What food will cause a red color in alkaline urine?
fresh beets
What food will cause red color in acidic urine?
blackberries
What causes the black color to alkaline urine from persons with alkaptonuria?
homogentisic acid
metabolite of phenylalanine
homogentisic acid
What is the colorless pigment that produces melanin?
melanogen
What refers to the transparency or turbidity of a urine specimen?
clarity
What causes the haziness in normal urine?
squamous epithelial cells and mucus
pink brick dust precipitate in acidic urine
amorphous urates
Causes white precipitate in urine with alkaline pH.
amorphous phosphates and carbonates
What are the most commonly encountered pathologic causes of turbidity?
WBC and bacteria
“measure of density”
specific gravity
What is the specific gravity of water?
1.000
What is the only method in use in routine urinalysis that requires correcting for the measurement of specific gravity?
refractometer
What refers to the specific gravity of the plasma filtrate entering the glomerulus?
isosthenuric
What is the range of the specific gravity of a normal random urine specimen?
1.002-1.035
What is the principle of refractometry?
refractive index
In refractometry, what determines the velocity and angle at which light passes through a solution?
concentration of dissolved particles
In refractometry, what determines the angle at which the light beam enters the prism?
concentration of specimen
comparison of the velocity of light in air with the velocity of light in a solution
refractive index
What is the compensation temperature in the refractometer?
15-38℃
When calibrating the refractometer, how much NaCl is used?
5% NaCl
1g molecular weight of a substance divided by the number of particles into which it dissociates
osmole
Incorporation of _______ (indicator) on the reagent pad measures the change in pH
bromthymol blue
What method of measurement uses the principle of pKa changes of a polyelectrolyte by ions present?
reagent strip
