Physical Exam: Intro + Color Flashcards
is the oldest clinical laboratory test still performed.
The study of urine
Historically, only the physical characteristics of urine were evaluated-(4)
The latter characteristic-_____-has not been performed for centuries because of chemical methods that can be used to assess the “sweetness” of urine.
color
clarity
odor
taste
taste
_____ of urine continue to play an important part in a routine urinalysis.
The presence of disease processes and abnormal urine components can be evident during the initial physical examination of urine.
The physical characteristics
Urine color, which is normally various shades of yellow, can range from colorless to amber to orange, red, green, blue, brown, or even black.
These color variations can indicate the presence of a (3)
However, color variations can simply result from_____
disease process
a metabolic abnormality
an ingested food or drug
excessive physical activity or stress.
It is important to note that______ is often the initial or only reason why an individual seeks medical attention.
a change in urine color
The characteristic yellow color of normal urine is principally due to the pigment_______!
urochrome
A product of endogenous metabolism,_______ is a lipid-soluble pigment that is present in plasma and excreted in urine.
urochrome
Patients in _______, may exhibit a characteristic yellow pigmentation of their skin caused by deposition of urochrome in their subcutaneous fat.
chronic renal failure, with decreased excretion of urochrome
Because_______ production and excretion are constant, the intensity of the color of urine provides a crude indicator of urine concentration and the hydration state of the body.
urochrome
A_______ urine is dark yellow, whereas a_____ urine is pale yellow or colorless.
_______, similar to other lipid-soluble pigments, darkens on exposure to light.
This characteristic darkening is often observed in urine specimens that are______
concentrated
dilute
Urochrome
improperly stored
Small amounts of…
______ (an orange-brown pigment) and_______ (a pink pigment) also contribute to urine color.
Both are normal urine constituents;_______ is most evident when it deposits on urate crystals, producing a precipitate often described as brick dust.
urobilin; uroerythrin
uroerythrin
Different laboratories may use varying terms to describe urine color, leading to inconsistencies. A standardized terminology should be used to improve reporting accuracy. For example:
• Instead of “straw” → Use “_____”
• Instead of “beer brown” → Use “____”
• Avoid using “bloody” because it is not a color; instead, use “_____”
light yellow
amber
red” or “pink”
• A normal urine sample may contain abnormal components such as ______ or ______despite appearing yellow or colorless.
• An abnormally colored urine may not necessarily indicate disease. For example, red urine can result from_____ ingestion in genetically predisposed individuals rather than blood in the urine.
glucose or porphobilinogen
beet
Many substances are capable of modifying the normal color of urine.
The same substance can impart a different color to urine depending on (3)
(1) the amount of the substance present
(2) the urine pH
(3) the structural form of the substance, which can change over time.
In fresh______ urine, red blood cells can be present despite a typical yellow-colored urine, or the urine color may appear pink or red.
The color of the urine varies with the quantity of red blood cells present.
As red blood cells disintegrate,_____ is released and oxidizes to______, which causes the urine color to become_______.
acidic
hemoglobin > methemoglobin > brown or even black
Alkaline urine with red blood cells present is often______ in color.
In such specimens, disintegration of cellular components is enhanced by the_____ pH, and_____ oxidation is promoted.
When glomerular or tubular damage of nephrons occurs, blood enters the urinary tract and the hemoglobin becomes oxidized before it collects in the bladder.
In this case the urine appears brownish rather than the typical red color that is associated with the presence of blood.
red-brown
alkaline
hemoglobin oxidation
• Fresh brown urine can be due to (3)
• All three test positive for____ on chemical reagent strip tests.
•______ can confirm RBCs.
• To differentiate hemoglobin from myoglobin, additional_____ and _____ tests are required
blood, hemoglobin, or myoglobin
blood
Microscopic examination
urine and blood plasma tests
______is another substance that can contribute to urine color. It is a byproduct of hemoglobin catabolism and has a characteristic yellow color.
When present in sufficient amounts in urine or plasma, bilirubin imparts a distinctive_____ coloration.
However, upon standing or improper storage, it oxidizes to_____, causing the urine to take on a______ hue.
It is also susceptible to______ by artificial light or sunlight; therefore, specimens must be stored properly to avoid degradation of this compo-nent.
This photosensitivity is temperature dependent; optimal specimen stability is obtained by storing the specimens at low temperatures in the dark.
Bilirubin; amber
biliverdin > greenish
photooxidation
Some substances are colorless and normally do not contribute to urine color. However, upon standing or improper storage, they convert to colored compounds.
_______, a normal constituent in urine, is colorless, whereas its oxidation product______ is orange-brown.
Urobilinogen > urobilin
_______, a colorless and chemically similar (_____) substance, is a solute found in the urine of patients with abnormal porphyrin metabolism (heme synthesis).
Porphobilinogen; tetrapyrroles
_______, the oxidation product of______, can impart a pink color to urine.
As a result, urine that contains these substances can change color over time; this may alert the labo-ratorian to its presence and the need for additional testing.
However, these color changes are often subtle and take hours to develop.
Porphobilin; porphobilinogen
A multitude of urine colors results from______, and often the colors have no clinical significance.
Highly pigmented foods such as fresh beets, breath fresheners containing chlorophyll, candy dyes, and vitamins A and B can impart distinctive colors to urine.
Included in this group of ingested substances are numerous medications, some of which are used specifically to treat urinary tract infec-tion. Other medications are present because they are eliminated from the body in the urine.
ingested substances
It is worth noting that______, a urinary analgesic used in the treatment of urinary tract infections and often encountered in the clinical laboratory, imparts a distinctive yellow-orange coloration (similar to orange soda pop) with a thick consistency to the urine.
This drug-produced color frequently interferes with the color interpretation of chemical reagent strip tests; alternative chemical testing methods (e.g., tablet tests, chemistry tests) must be used with these urine specimens.
phenazopyridine
Certain foods, vitamins, and medications can impart color to urine without clinical significance. Examples include:
•_______ → Red or pink urine
•_______→ Green urine
•_______ → Bright yellow urine
•_______ (urinary analgesic) → Distinctive orange color with thick consistency (can interfere with reagent strip tests)
Beets
Chlorophyll-containing breath fresheners
Vitamin B complex
Phenazopyridine
