BODY FLUID ANALYSIS
Urine Mini-review for UA COURSE
Final Exam part 1
Urine Anatomy & Physiology
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Anatomy of the Urinary System
Urine Anatomy & Physiology

Micro-Anatomy of the Urinary System
 Nephron – functional or working unit of the kidney
 @ 1 million / kidney
Urine Anatomy & Physiology

Micro-Anatomy of the Urinary System - nephron
 Glomerulus
 Renal Tubules
Urine Anatomy & Physiology
 Micro-Anatomy of the Urinary System
 Nephron

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What size substances are filtered?
Examples of substances that cannot filter.
Urine Anatomy & Physiology
 Physiology of the Urinary System
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What are Functions of the kidney?
Urine Anatomy & Physiology
 Physiology of the Urinary System

What are Functions of the kidney?
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Elimination of excess water
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Elimination of waste products of metabolism. ie. Urea,
creatinine, etc. ** These two substances are sometimes
measured to determine if unknown fluid is urine.
Urine Anatomy & Physiology
 Physiology of the Urinary System

What are Functions of the kidney?
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Elimination of foreign substances
If not by filtration, then may secrete some:

Secretion of unwanted substances not filtered
 drugs,
 some waste products
 Acid – base balance through the
 reabsorption of filtered bicarbonate ion
 secretion of H+ ions attached to bicarbonate
 secretion of H+ ions attached to phosphate
 secretion of H+ ions attached ammonia
Urine Anatomy & Physiology
 Physiology of the Urinary System

What are Functions of the kidney?
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Retention of substances necessary for normal body function (
glucose, amino acide, etc)

Regulation of electrolyte balance and osmotic pressure of body
fluids (BP)
Urine Anatomy & Physiology
 Physiology of the Urinary System

What are Functions of the kidney?

Hormone production
 What hormones are produced by the kidney?
Urine Anatomy & Physiology
 Physiology of the Urinary System

What are Functions of the kidney?

Hormones produced by the kidney:
 Erythropoietin – RBC stimulus
 Renin – enzyme like substance that acts on plasma
angiotensinogen ---- Angiotensin I….which becomes
Angiotensin II and causes vasocontriction of arteries , and
other things…– Kidneys responsible for long term
regulation and maintenance of blood pressure.
Urine Anatomy & Physiology
 Physiology of the Urinary System

What hormones affect the kidney?
Urine Anatomy & Physiology
 Physiology of the Urinary System

What hormones affect the kidney?
 Aldosterone
 From adrenal cortex
 Acts on distal and collecting tubules
 Promotes active reabsorption of sodium from the
glomerular filtrate (and concurrent secretion of
potassium).
 Also increases water retention
Urine Anatomy & Physiology
 Physiology of the Urinary System

What hormones affect the kidney?
 Anti-diuretic hormone (ADH) / Vasopressin
 from posterior pituitary gland
 Makes tubules more permeable to water
 Effects

decrease urine volume

concentrates urine

increases water into circulation

dilutes blood’s solids
Urine Anatomy & Physiology

Provide an example of Renal threshold /
maximal re-absorptive capacity?
Urine Anatomy & Physiology

Physiology of the Urinary System
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Acid – Base balance
 What 2 body systems are most involved with body
acid / base balance?
 What is the overall goal?
Urine Anatomy & Physiology

Physiology of the Urinary System
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Acid – Base balance
 Generation of bicarbonate ions
 Filtered buffers - kidney secretes buffers into the
urine (when the pH is < 4.5) to protect its tissues.
 Secretion of ammonia (ammonium)
Routine Urinalysis
 What substances make-up urine?
Routine Urinalysis
 Composition –
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Normal constituents
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@ 95% water
Urea, organic &
inorganic chemicals
Routine Urinalysis
 How should the urine specimen be collected?
Routine Urinalysis
 How should the urine specimen be collected?

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Container characteristics
Times / types of collection
Routine Urinalysis
 How should the urine specimen be
preserved? Why?
Routine Urinalysis
 What happens to the urine sample over time?
Why?
Urine Testing
 Physical properties

What are the physical properties of urine that
are evaluated ?
Urine Testing
 Physical properties

What are the physical properties of urine that
are evaluated ?
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
Color – review the normal and abnormal colors of
urine - *** and what causes them (urochrome,
bilirubin, blood, homogentisic acid, etc.)
Know the abnormals as well.
Urine Testing
 Physical properties

What are the physical properties of urine that
are evaluated ?

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Volume – For routine UA, not normally measured
Review the terms used to describe urine volume
characteristics.
Urine Testing
 Physical properties

What are the physical properties of urine that
are evaluated ?

Clarity / transparency
Urine Testing
 Physical properties

What are the physical properties of urine that
are evaluated ?

Odor & foam not routinely reported
Urine Testing
 Physical properties

What are the physical properties of urine that
are evaluated ?

Specific Gravity
 What is it? / what does it say about the specimen?
 What is isosthenuria ?
Urine Testing
 Chemical properties
 Review dipstick chemical reactions,

Know indicators
Urine Testing
 Chemical properties
 Handling and Storage
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Keep strips in original container, stored at RT
Protect from moisture and volatile fumes
Use before expiration date
Do not touch reagent pad areas
Urine Testing
 Chemical properties
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Review sources of error

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
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Testing cold specimens
Not mixing samples before dipping
Leaving the dipstick in the specimen too long
Not blotting away the excess
Inadequate / improper timing
Bad lighting
Not being familiar with color chart and changes
Urine Testing
 Chemical properties

Use of commercial controls and course of
action if results are not as expected
Urine Testing
 Chemical properties
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Back-up tests?

Are they always performed?

Which ones for which test?
Urine Testing
 Chemical properties

Which urine test is most sensitive to
impending kidney disease?
Urine Testing
 Chemical properties

Which urine test(s) are more liver disease
oriented?
Urine Testing
 Chemical properties

What dipstick results indicate UTI?
Urine Testing
 Chemical properties

What characteristics (physical, chemical,
microscopic) does a urine from a diabetic
exhibit?
Urine Testing
 Chemical properties

What urine results would you expect to see
from a child with a fever lasting 2 days?
Diseases & UA correlation
 Pathways of renal infections

Ascending: Most often infectious agents
ascend up the urethra - bladder ureters - into
the kidney (if unchecked)


Common organisms: E. coli, Proteus, &
Enterobacter
Descending: Infection result of circulating
organisms getting trapped in kidney.

Common organisms: Staphlococcus, E. coli
Review kidney diseases
 Terms


Cystitis – inflammation of the bladder wall,
often associated with infection
Urethritis - inflammation of the urethra
Review kidney diseases
 Terms

Nephritis – general term for inflammation of
kidney tissue.


Glomerular nephritis - refers to sterile
inflammatory process affecting glomerulus
Pyelonephritis - When the inflammation is caused
by an infection, the term pyelonephritis is used
Diseases & UA correlation
 Nephrotic syndrome (pg. 125)
 Increased urine protein

Massive proteinuria > 3.5 g/dL
 NV = 30-150 mg/24 hr

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Decreased serum albumin

Many abnormal UA (as well as chemistry and
clinical) results
Uremia – old term no longer used; literal
meaning is ‘urine in the blood’
Microscopic Sediment
 A number of slides with microscopic
elements
 RBC, WBC, yeast
Microscopic Sediment – Epithelial Cells
 Squamous epithelial cells (stained with SternheimerMalbin)
Microscopic Sediment – Epithelial Cells
 Transitional epithelial cells
 Spherical, polyhedral and caudate are terms
describing shapes.
 All have distinct centrally located nuclei.

Sometimes called bladder cells, may be more often found in
elderly. Can be found as fragments or as reactive.
Microscopic Sediment – Epithelial Cells
 RTEs; 250x magnification
 Also WBC and RBCs
Microscopic Sediment – Casts
Microscopic Sediment – Casts
 RBC cast
Microscopic Sediment
 A number of slides with microscopic
elements


CRYSTALS,
Uric acid
Microscopic Sediment – Crystals
 Calcium oxalate –
envelope; may be dumbbell
shaped. Usually appear
as a square with a
retractile cross
Microscopic Sediment
 A number of slides with microscopic
elements

Alkaline
Microscopic Sediment
 A number of slides with microscopic
elements
 The rarely ever seen, abnormal crystals
 Cystine
 Tyrosine
 Leucine
 Bilirubin (occasionally seen in premies)
 Cholesterol
Microscopic Sediment
 A number of slides with microscopic
elements

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Mucous threads
Bacteria, yeast, trichomonas
sperm
Lots of artifacts
Microscopic
 What are oval fat bodies?
 How can you (quickly,cheaply) provide
tentative proof they contain fat?
Microscopic