1. Medical Physiology Lab.
ACTIVITY 9 URINALYSIS
Medical Physiology Lab.

2. Urinalysis
A urinalysis is a group of manual and/or automated qualitative and semi- quantitative tests performed on a urine sample.
It is a test that checks many body functions in one exam.
Once you know what to look for, you can see what’s going on with various systems.

3. Purpose Routine urinalyses are performed for several reasons:
1. general health screening to detect renal and metabolic diseases.
2. diagnosis of diseases or disorders of the kidneys or
urinary tract.
3. monitoring of patients with diabetes.

4. Functions of kidney:
The human kidneys have four major functions. They are to:
1. Remove metabolic waste and toxins from the body.
2. Regulate the volume and composition of the
body fluids through secretion and reabsorption.
3. Maintain the balance of acids to bases in the
body (i.e., pH).
4. Produce metabolites such as renin and vitamin
D that are important to other body tissues and
cells.

6. Physical Characteristics of Urine:
1. Color
Normal = pale yellow due to a pigment called urochrome.
Color is associated with solute concentration. Increased solutes = darker urine;
Decreased solutes = colorless urine, like water.
Solute concentration is measured using a urinometer to determine specific gravity.
Specific gravity of water = 1.000
Specific gravity of normal urine = to 1.030

7. Color

8. 2. Transparency Normal = clear
Abnormal = cloudy, which may be caused by bacteria, blood, cells, crystals, etc.

9. 3. Odor Normal = slightly aromatic when freshly voided.
Bacteria = ammonia odor
Asparagus, drugs and diseases my also impart a characteristic odor.
Diabetes mellitus = urine smells "fruity" or like acetone.

10. 4. pH Normal pH = 4.5 to 8.0 (average is about 6.0)
High protein diet = acid urine
Vegetarian diet = alkaline urine

11. 5. Specific gravity Normal = 1.001 to 1.030.
Low Specific Gravity may be due to:
Excess fluid intake
Use of diuretics
Diabetes insipidus
Chronic renal failure
High Specific Gravity may be due to:
Low fluid intake
Fever
Pyelonephritis

12. Excessively concentrated urine may lead to kidney stones (renal calculi), that are made of crystals of salts that are present in urine such as uric acid, calcium oxalate or calcium phosphate.
Decreased water intake and increased calcium intake may also cause kidney stones.

13. Normal Constituents of Urine
Water
Urea
Sodium and potassium
Phosphate and sulfate ions
Creatinine
Uric acid
Calcium
Magnesium
Bicarbonate ions

14. Abnormal Constituents of Urine
Glycosuria = glucose
Hematuria = Red blood cells
Pyuria = White blood cells
Bacteriuria = bacteria
Ketonuria = ketones

15. Terminology of Urine Output
Polyuria = excessive production of urine
Anuria = decreased production of urine
Dysuria = painful urination

16. Urinary Disorders:
Diabetes mellitus = decreased production or utilization of insulin. (Ketonuria with glycosuria is usually diagnostic for diabetes mellitus).
Diabetes insipidus = large amounts of dilute urine is excreted, usually 5-20 liters per day.
Caused by inadequate secretion of antidiuretic hormone (ADH).
UTI = bacterial infection of the urinary tract.

17. Urethritis = inflammation of the urethra
Cystitis = inflammation of the urinary bladder
Pyelonephritis = inflammation of the kidneys
Glomerularnephritis = inflammation of glomeruli in kidneys
Acetonuria = ketone bodies in the urine
Azotemia = presence of urea in the blood
Enuresis = bed wetting

18. Nephrotic syndrome = protein in the urine due to increased permeability of the glomerular capillary endothelium
Cystocele = hernia of the urinary bladder
Polycystic kidney disease = most common inherited disorder of the kidneys
Nephrotosis = floating kidney
Micturition = urination

19. Urine Dipstick:
Each of the squares corresponds to something being tested.
You are supposed to compare the colors of each square to a suggested color on the box to determine if things are normal.

23. 1. Glucose
Renal threshold for glucose is such that after a certain point is reached, the glucose spills over. The specific threshold level depends on the patient. Even within an individual, the personal threshold varies daily.
Therefore the dipstick test for glucose is really inaccurate.

24. 2. Ketones Produced from fatty acids.
Causes of ketones in the urine are starvation and diabetes mellitus, ketoacidosis, etc.
Two major ketones in the body
Beta hydroxybutyric acid
Acetoacetate
The dipstick test is non-specific and only sensitive to the second type of ketone (acetoacetate).
If you do a dipstick test, and it comes back ketone +, perform a serum ketone level because something is definitely going wrong.

25. 3. Blood in the urine: Two situations
HEMOGLOBINURIA = blood in the urine but the red blood cell (RBC) are NOT intact. The cause is hemolysis.
HEMATURIA = intact red blood cells in the urine. This points to the urinary tract as the source of the problem.
Kidney
Ureter
Bladder

26. 4. Protein:
a. Proteins are NOT supposed to be in the urine
b. Prevention of proteins into the urine is done by glomerular membrane.
5. Bilirubin:
NOT supposed to be in the urine

27. 6. Urobilinogen: 7. Nitrates:
Grade this from 1 – 5 (5 being the highest)
a. with high RBC destruction
7. Nitrates:
Made by many bacteria species (with the exception of Staph & Strep)
a. e.g. E. coli, Proteus, Pseudomonas etc.
b. If nitrate +, urinary tract infection is suggested (UTI)
c. a – test does NOT rule out a UTI

28. 8. Leukocyte esterase: enzyme
White blood cell (WBC) in urine noted by implication
The enzyme esterase is normal in urine
+ for this enzyme then probably a UTI

29. 9. Casts:
Lots of different material clumped together inside of the renal tubule.
As a general rule if a cast is present, then something is going on.
Exception to the above rule is if you see a hyaline cast, which is a normal finding.
Clumped cells come from the kidney
Casts can be RBC or WBC casts
If you see these in the urine, tells you that there is a disease from the bladder  kidney (moving up).

30. If you see RBC – kidney problem
Casts
If you see RBC – kidney problem
Could be:
Pyelonephritis
SLE
Kidney stones
Trauma (e.g. hit in the flank/abdomen)
If you see WBC casts – probably due to infection.

31. 10. Crystals: 11. Bacteria: Very small amount is normal
Could be due to gout or liver disease
11. Bacteria:
urine is considered sterile, therefore bacteria in the urine is not normal
If + for bacteria, probably due to a UTI.

32. Microscopic Analysis of urine sediment
Unorganized sediments – chemical substances that form crystals or precipitate from solution.
Calcium oxalates, carbonates and phosphates;
Uric acid
Ammonium urates
Cholesterol
Crystals are frequently found in the urine. They are formed by the precipitation of urine salts subjected o changes in pH, temperature or concentration, which affect their solubility. Crystals are identified by their appearance, solubility and pH.

37. Organized sediments – Epithelial cells, WBC, RBC, casts.
Cells can be anywhere in the urinary tract from the tubules to the urethra.
Casts are cylindric structures formed primarily within the lumen of the distal convoluted tubule and collecting duct. The major constituent of casts is Tamm-Horsfall protein, a glycoprotein excreted by the renal tubular cells.
Normal – negative