Lab exam Flashcards
Functions of the Kidney
❑ excretion of wastes in the form of urine
❑ regulation of blood volume and pressure through the production of
urine
❑ regulation of concentration of major ions in the body
❑ regulation of extracellular fluid pH
❑ regulation of red blood cell synthesis through hormonal control with
the hormone erythropoietin
❑ regulation of vitamin D synthesis
Urinalysis
❑ generally easily available and relatively inexpensive
simple test
❑ provides many useful information about various diseases
and conditions
❑ “a poor man’s kidney biopsy” because of the plethora of
information that can be obtained about the health of the
kidney or other internal diseases
❑ 30 to 60 mL clean catch or the midstream urine collection
❑ sample should be taken to the laboratory for analysis,
typically within one hour of collection
(if transportation to the lab could take more than one hour,
sample may be refrigerated)
Urinalysis composed of different types of examinations
o Physical examination
o Chemical examination
o Microscopic examination
Urine mostly water with ____% dissolved substances
Five
substances not normally present in urine
- serum proteins
- glucose
- ketones
- bicarbonate ions
- oxalate ions
Urine Physical
Characteristics
odorless or can be slightly
pungent
no cloudiness
usually slightly acidic (~pH 6.0)
but can range from 4.5-8.0
Urine Color
dark urine -
red urine -
orange or tea-colored -
tea-colored -
very foamy –
dark urine – dehydration
red urine – hematuria
orange or tea-colored – muscle breakdown
tea-colored – liver disease
cloudy – infection
very foamy – large amounts of protein in the urine
Substances that cause cloudiness but
are not considered unhealthy:
Mucus
Sperm
Prostatic fluid
Cells from the skin
normal urine crystals
Substances that cause cloudiness that
requires attention:
RBC’s
WBC’s
Bacteria
________ play an important role in
maintaining acid-base balance of the
body
Kidneys
Test for Protein:
Biuret Test
forms a violet/blue violet-colored
complex with the protein’s peptide bond
More sensitive test for small amounts of
urine albumin; routinely used to
screen people with chronic
conditions that put them at risk for
kidney disease
Urine albumin test
Test for Protein
Normal:
no protein or small amount
of protein in the urine
Elevated urine protein
Proteinuria
Maybe a sign of kidney disease
Test for Sugar
Benedict’s Test
Brick-red precipitate (may depend on the amount of sugar
in urine)
Test for Sugar
Normal:
no glucose in urine
presence of glucose because of
either excessive high glucose level in the blood
or a reduction in the “renal threshold”
Glucosuria
Can be caused by hormonal disorders, liver disease,
medications, pregnancy
Glucosuria
Test for Ketone Bodies
Results:
pinkish ring (+)
Red ring (++)
Deep purple ring (+++)
Presence of high levels of ketones in urine
Ketonuria
Test for Bicarbonate
Formation of gas bubbles
excess ketones and glucose dumped into the urine by the
kidneys to eliminate from the body
usually seen in persons with uncontrolled Type 1 diabetes
Diabetic ketoacidosis (DKA)
Highly alkaline blood or tissues =
significant presence of bicarbonate in urine (alkaline urine)
When bicarbonate levels are higher/lower than normal, it is
suggestive of the body’s trouble in maintaining its ______________
acid-base balance
