Discuss diseases that affect
kidney function and urinalysis results.
Describe proper urine
collection and preservation methods.
Perform a physical examination
of urine.
Perform a chemical examination
of urine.
Perform a microscopic
examination of urine sediment.
Explain how urinalysis results
can give important information about the status of a patient’s health.
OVERVIEW
Urine has long been used as an indicator of a person’s
health. Analysis of urine is the earliest recorded medical laboratory test.
References to testing urine date back to ancient Egyptian hieroglyphics and are
found in the writings of Hippocrates. By the middle ages, early physicians
often examined urine, sometimes without ever seeing the patient. Although these
physicians did not have the sophisticated tests that we have now, they did
examine the color, odor, volume, viscosity, and even sweetness of urine. With
the invention of the microscope, urine sediment could be examined and
identified microscopically.
In the first half of the 1900s, when laboratory medicine was
in its infancy, many chemical tests were developed for urine. For the most
part, however, these tests were complex and time-consuming, causing urine
testing to be rather impractical and infrequently done. With the development of
the rapid reagent strip test, urinalysis became an important part of the
routine physical examination.
Modern urinalysis has two major advantages: (1) urine is an
easily obtained specimen, and (2) much information can be obtained about the
body’s metabolism through rapid, simple, reliable, and inexpensive tests. Most
physical examinations include a routine urinalysis, in which several tests are
performed on one urine sample. The routine urinalysis is one of the most
frequently performed laboratory procedures.
Changes occur in urine when kidney disease or certain other
diseases are present. Urinalysis can be performed to detect physical, chemical,
and microscopic characteristics that indicate disease of, or damage to, the
urinary system. Urine tests can also detect metabolic end products that
indicate particular diseases unrelated to the urinary system. Urinalysis
results can give the physician valuable information about a patient’s health
and information useful in diagnosing disease or following the course of
treatment.
Systemic Diseases Affecting Urinalysis Results
1. Diabetes
2. Hypertension
3. Atherosclerosis
4. Autoimmune diseases
5. Nephrotic syndrome
6. Malignancies
Physical
Examination of Urine-------https://www.youtube.com/watch?v=xUP0tJPm4V4
LESSON OBJECTIVES After studying this lesson, the student will:
Name the physical
characteristics of urine evaluated during a routine urinalysis.
List three causes of
abnormal urine odor.
Explain why normal urine is
yellow.
List three abnormal urine
colors and give a cause for each.
List two conditions that can
affect the appearance or transparency of urine.
Explain what determines the
specific gravity of urine.
Demonstrate proper use of
the urinometer and refractometer.
Perform a physical
examination of urine.
Define the glossary terms.
GLOSSARY
hematuria / the presence of blood in the urine
ketones / a group of chemical substances produced during
increased fat metabolism; ketone bodies
melanin / a dark pigment of skin, hair, and certain tumors
myoglobin / a pigmented, oxygen-carrying protein found in muscle
tissue
opalescent / having a milky iridescence
porphyrins / a group of light-sensitive, pigmented, ringed
chemical structures that are required for the synthesis of hemoglobin
refractometer / an instrument for measuring the refractive index
of a substance
specific gravity / the ratio of the weight of a solution to the
weight of an equal volume of distilled water; a measurement of density
turbid / having a cloudy appearance
urinometer / a float with a calibrated stem used for measuring
specific gravity of urine; hydrometer
urochrome / the yellow pigment that gives urine its color
Chemical
Examination of Urine--https://www.youtube.com/watch?v=YrweUovK3s8
LESSON OBJECTIVES After studying this lesson, the student will:
Name 10 urine chemical tests
routinely performed by reagent strip and explain the principle of each.
Give the reference values
for the 10 urine chemical tests.
Explain the specimen
requirement for the chemical examination of urine.
Explain the importance of
quality assessment procedures in the chemical examination of urine.
Use a reagent strip for the
chemical examination of urine and interpret the results.
List a condition that can
cause an abnormal result in each of the chemical tests routinely performed on
urine.
Perform the copper reduction
test on urine.
Discuss the safety
precautions that must be observed in chemical testing of urine.
Perform confirmatory tests
for protein, ketones, and bilirubin in urine.
Define the glossary terms.
GLOSSARY
albumin / the most abundant protein in normal plasma; a
homogeneous group of plasma proteins that are made in the liver and help
maintain osmotic balance
bilirubin / a product formed in the liver from the breakdown of
hemoglobin
chromogen / a substance that becomes colored when it undergoes a
chemical change
glycosuria / glucose in the urine; glucosuria
hematuria / presence of blood in the urine
ketonuria / ketones in the urine
microalbumin / small amount of albumin in urine, not detectable
by routine reagent strip
microalbuminuria / condition in which small amounts of albumin
are present in the urine
proteinuria / protein in the urine, usually albumin
urobilinogen / breakdown product of bilirubin formed by the
action of intestinal bacteria
UTI / urinary tract infection
Microscopic
Examination of Urine Sediment---https://www.youtube.com/watch?v=rBSkVgFABFo
LESSON OBJECTIVES After studying this lesson, the student
will:
Name the preferred specimen
for the microscopic examination of urine.
Name four types of cells
that can be found in urine sediment and give their significance.
Explain how casts are formed
and name three types of casts that can be present in urine.
List the reference values
for red and white blood cells, casts, and bacteria in urine.
List six crystals that can
be present in normal urine and state the pH at which each usually occurs.
Describe how to prepare
urine sediment for microscopic examination.
List four abnormal crystals
that can occur in urine sediment.
Identify cells, casts,
crystals, and other sediment components in urine specimens or from visual aids.
Prepare a specimen for
microscopic examination of urine sediment.
Perform a microscopic
examination of urine sediment and identify the components.
Report the results of a
microscopic examination of urine sediment.
Describe safety precautions
that must be observed when preparing urine for microscopic examination.
Discuss the importance of
quality assessment procedures in performing the microscopic examination of
urine sediment.
GLOSSARY
amorphous / without definite shape
cast / in urinalysis, a protein matrix formed in the kidney
tubules and washed out into the urine
flagellum (pl. flagella) / slender, lash-like appendage that
serves as organ of locomotion for sperm cells and some protozoa
hyaline / transparent, pale
protozoa / unicellular eukaryotic organisms, both free-living
and parasitic
sediment / solids that settle to the bottom of a liquid
supernatant / the clear liquid remaining at the top of a
solution after centrifugation or settling out of solid substances; the liquid
lying above a sediment
yeast / a small, single-celled eukaryotic fungus that reproduces
by fission or budding
