Unit 3 Lecture Flashcards
Cause of urine color being yellow?
Normal urine; due to the normal pigment, urochrome (as well as uroerythrin (pink) and urobilin (orange))as a product of endogenous metabolism.
Why do abnormally colored urines cause such a problem with chemical examination?
They can cause interferences with chemical examination.
What are some factors that can effect that color of the urine?
- The amount of a substance present
- The pH of the urine
- Structures of the substances
Constituents of dark yellow or amber urine.
Concentrated urine or increase in bilirubin.
Clinical significance to dark yellow or amber urine.
Dehydration/fever/yellow foam
Constituents of orange urine
Food or drugs
Clinical significance of orange urine
carrots, pyridium/warfarin/rifampin
Constituents of pink urine
Blood or interited
Clinical significance of pink urine
UTI’s/mentration
Porphyria
Constituents of red urine
Blood, food, drugs
Clinical significance of red urine
RBC’s/Hemoglobin
Beets
Laxatives
Constituents of Purple to red urine
Interited
Clinical significance of purple to red urine
Porphyrins
Constituents of Brown urine
Blood
Drugs
Clinical significance of brown urine
Myoglobin/methemoglobin
Metronidazole
Constituents of Dark brown/black urine
Inherited
Clinical significance of dark brown/black urine
Melanin/Homogentisic acid
Constituents of blue/green urine
Infections, dyes, drugs
Clinical significance of blue/green urine
UTI(Pseudomonas), Chlorophyll, Medications (Amitriptyline, Indomethacin)
The concentration of a normal urine specimen can be estimated by which of the following?
(a) Color
(b) Clarity
(c) Foam
(d) Odor
(a) Color
The normal yellow color of urine is produced by which of the following?
(a) Bilirubin
(b) Hemoglobin
(c) Urobilin
(d) Urochrome
(d) Urochrome
Clarity
Describes the overall visual appearance of a urine specimen.
What are some pathologic examples that would cause a reduction in urine clarity?
RBCs WBCs Bacteria (fresh urine) Yeast Trichomonads Renal Epithelial cells Fat (lipids, chyle) Abnormal crystals Semen Feces Calculi Pus
What are some non-pathhologic examples that would cause a reduction in urine clarity?
Normal solute crystals (e.g. urates, phosphates, calcium oxalate) Squamous epithelial cells Mucus Semen Contaminants: powders, lotions, etc.
Freshly voided urine is usually clear; however, if it is an alkaline urine, a white turbidity may be present due to:
(a) Amorphous phosphates
(b) Porphyrins
(c) Red blood cells
(d) Lipids
(a) Amorphous phosphates
All of the following are considered pathogenic causes of turbidity EXCEPT?
(a) Squamous epithelial cells
(b) Renal tubular epithelial cells
(c) White blood cels
(d) Bacteria (fresh urine)
(a) Squamous epithelial cells
Specific gravity
An expression of urine concentration in terms of density (mass of solutes present per volume of solution). It is a ratio of urine density to the density of an equal volume of pure water under specific conditions.
How will a light urine effect specific gravity?
Low specific gravity
How will a dark urine effect specific gravity?
High specific gravity
Specific gravity of water
1.000
Urine specific gravity reference range
1.003 to 1.035
What two primary factors influence specific gravity?
Number of solutes, and molecular size (weight) of solutes.
Refractometry
An indirect measure of specific gravity, is based in the refractive index of light.
Refractive index
Velocity of light in air compared to the velocity of light in solution.
Light refracted on the prism is refracted at an angle that correlates with the number of particles in the solution (concentration). Angle is proportional to velocity.
Ionic specific gravity
An indirect colorimetric estimation of urine density based on the quantity of ionic or charged solutes (Na+, etc) present. Note that nonionic solutes are note measured.
Osmolality
The concentration of a solution expressed in terms of osmoles of solute particles per kilogram of water.
Osmole
The amount of a substance that dissolves to produce 1 mole of particles in a solution.
Reference interval for osmolality
Plasma: 275-300 mOsmol/kg
Urine: 275-900 mOsmol/kg
Freezing Point Osmometer
- 1 Osmole decreases the freezing point by 1.86C.
- The higher the number of solutes present the lower the temperature
Vapor Pressure Osometer
Indirectly measures the decrease in vapor pressure caused by solutes in a sample.
True or False: Specific gravity provides more diagnostic value than osmolality in evaluating the renal concentration ability.
False
Which of the following specific gravity results would correlate with a dark yellow urine?
(a) 1.005
(b) 1.010
(c) 1.020
(d) 1.030
(d) 1.030
What are some urine odors that are apart of the non-disease process?
Old specimens: Ammonia
Ingestion of some foods: Asparagus, onions, garlic, coffee
Contamination: bleach
What are some urine odors that are apart of the disease?
Bacteria infection: Ammonia
Ketones: Diabetes/starvation
Amino Acid Disorders: Phenylketonuria-Mousy; Maple Syrup disease - Maple Syrup; Tyrosinemia - Rancid
Polyuria
Over 1800 mL/day
Diuresis
Increased volume
Olguria
Less than 400 mL/day
Anuria
No urine production
Nocturia
Over 500 mL at night.
White foam present
Protein
Yellow foam present
Bilirubin
Which of the following will not influence the volume of urine produced?
(a) Diarrhea
(b) Exercise
(c) Caffeine ingestion
(d) Carbohydrate ingestion
(d) Carbohydrate ingestion
A yellow/brown specimen produces a yellow foam when shaken, which of the following can be suspected as being present in the urine?
(a) Lemonade
(b) Rhubarb
(c) Bilirubin
(d) Urochrome
(c) Bilirubin
