Chapter 6 covers the basics of urinalysis, including the types of urine specimens, urine formation and composition, and the significance of urinalysis in providing information about kidney function and metabolic processes. It details macroscopic, chemical, and microscopic examinations of urine, emphasizing the importance of timely analysis and specimen preservation. Additionally, the chapter includes protocols for collecting cerebro-spinal fluid (CSF) specimens.

1. CHAPTER 6
Basic Urinalysis
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2. Chapter objective
At the end of this chapter, students are expected
to:
To state different urine specimen type
Describe about urine formation and its
composition
Explain macroscopic, chemical and
microscopic examination on urine
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3. 1. Introduction to Urinalysis
 Urinalysis means the analysis of urine
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Produces urine
Transports urine
towards bladder
Temporarly
store urine
Transports urine
to exterior
1. Anatomy of Urinary system
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4. Significance of Urinalysis
1. Provides information about kidneys
2. Provides information about metabolic
processes
3. To test urinary tract infections (UTIs)
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5. Introduction to Urinalysis……..
2. Physiology of Urinary System:
1. Excretion & Elimination of wastes products
(urea, creatinine, uric acid) through urine
2. Homeostatic regulation of water-salt & acid-
base Balance
3. Endocrine function: Hormones production
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6. 2. Urine
1. Urine Formation: there are four processes
I. Filtration: small molecules move from the
capillaries into the bowman's capsule
II. Re-absorption: molecules are reabsorbed from the
nephron into the capillary blood. e.g. Glucose
III. Secretion: substances are actively removed from
blood & added to tubular fluid. e.g. H+,
IV. Excretion: removal of waste products through urine
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7. Urine consists of:
(96%) water
Inorganic:
• Cl-, Na, K.
• trace amounts of:
sulfate, HCO3 etc.)
(4%) dissolved solids:
(2%) Urea:
(half)
(2%) Other compounds
Organic:
• creatinine, uric
acid
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8. Factors Affecting Urine Composition
1. Dietary intake
2. Physical activity
3. Body metabolism
4. Endocrine function
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9. Types of Urine Specimens
1. Random: Collected any time of the day
2. First voided / first morning specimen: specimen
collected for routine test as it is most concentrated.
3. Timed specimens:
a. 2-Hours Postprandial: Patient emptying their bladder
& then all urine produced will be collected over a
specified period 2 hrs.
b. 24-Hour Specimen: The patient voids & discards
specimen and collects all urine for the next 24 hrs.
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10. Types of Urine Specimens…
4. Mid-stream: The patient begins voiding in toilet &
place container into the continuing urine stream until
the cup is ½ filled.
5. Clean Catch: Prior to the voiding process, the
patient should be provided clean cup.
6. Catheterized Specimen: Collected from a hollow
tube threaded up the urethra into the bladder.
7. Supra-pubic needle aspiration: For culture purpose
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11. Handling & Preserving Urine
Specimens
• When urine placed at room temperature
– Bacteria multiply
– Glucose decreases
– Casts and cellular elements decompose
• So, examine within 2 hrs of collection OR use of
preservatives like
A. Physical methods (Refrigeration @ 4-6° C for up to 8
hrs)
B. Chemical methods (boric acid, thymole, toluene,
formalin, chloroform, HCL, …)
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12. Types of Urine examination = Urinalysis
1. Macroscopic examination
2. Chemical examination
3. Microscopic examination
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13. 1. Macroscopic/Physical/ Exam
• Physical examination of urine, usually give hint for the
subsequent urinalysis
• Physical properties include….
 Volume
 Color
 Transparency
 Odor
 Foam
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14. 2. Chemical examination: using
Urine strip
• Strip is filter paper which has chemical substance
(reagent) coated on it on different pads.
• It gives color when react with substance in urine.
• The produced color is compared with chart color
visually assessed.
• It include proteinurea, glucoseurea, ketourea,
haematourea, hemoglobinuria, bilirubin (Bile),
nitrite & urine leucocytes
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15. Chemical examination
Glucose
Bilirubin
Ketones
Specific Gravity
Blood
pH
Protein
Urobilinogen
Nitrite
Leukocyte Esterase
Urine Dipstick
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16. 3. Microscopic examination
• It done by pouring 10 ml urine into a test tube &
centrifuging it for 5 minutes with the speed of 1500-
2000 rpm.
• The top liquid part (the supernatant) is discarded.
• The sediment (solid part in the bottom) is mixed with
the remaining drop of urine
• A drop is analyzed under a microscope to look for
cells, parasites, casts & crystals
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17. Classification of Urinary Sediments
• Urine sediments can grossly be
categorized into two based on the
substances they are composed of.
1. Organized
2. Non-organized sediments
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19. Microscopic Examination: Abnormal
Findings
Per High Power Field (HPF) (400x)
– > 3 erythrocytes
– > 5 leukocytes
– > 2 renal tubular cells
– > 10 bacteria
Per Low Power Field (LPF) (200x)
– > 3 hyaline casts or > 1 granular cast
– > 10 squamous cells (indicative of contaminated
specimen)
– Any other cast (RBCs, WBCs)
Presence of:
– Fungal hyphae or yeast, parasite, viral inclusions
– Pathological crystals (cystine, leucine, tyrosine)
– Large number of uric acid or calcium oxalate crystals
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21. Collection of Cerebro-spinal fluid (CSF)
CSF provides a physiologic system to supply
nutrients to the nervous tissue, remove metabolic
wastes, and produce a mechanical barrier to
cushion the brain and spinal cord against trauma.
CSF is produced in the choroid plexuses of the
two lumbar ventricles and the third and fourth
ventricles. In adults, approximately 20 mL of
fluid is produced every hour.
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CSF: in b/n subarachnoid space located
between the arachnoid and pia mater

23. CSF…
• Its volume is 90 to 150 mL in adults and 10 to 60 mL in neonates.
• The circulating fluid is reabsorbed back into the blood capillaries in
the arachnoid granulations/villae at a rate equal to its production
• Collection by lumbar puncture done by experienced medical
personnel
• About 1-2ml of CSF is collected for examination
– lumbar puncture is made from the space between the 3rd to 5th
lumbar vertebrae under sterile conditions.
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24. Collecting CSF specimen
Location of CSF
Can be Collected in three sequentially
labeled tubes
 Tube 1-Chemical and immunologic tests
 Tube 2-Microbiology
 Tube 3-Hematology (gross examination,
total WBC & Diff)
 This is the least likely to contain cells
introduced by the puncture procedure
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