Physical ua

1. Week 7: Intro to UA
• Urinalysis • Physical properties of
• Renal anatomy and urine
physiology • Color
• Nephron anatomy • Appearance
• Specific gravity
• Urine collection and
• Volume
preservation
• Odor
• Foam

2. Urinalysis
• One of the oldest “lab”
procedure
• Diabetes mellitus vs
diabetes insipidus
• Examination of urine
samples
• Physical properties
• Chemical components
• Microscopic sediments

4. Renal Anatomy
• Kidneys
• Renal artery and vein
• Medulla
• Cortex
• Calyx
• Ureter
• Bladder
• Urethra
• Adrenal glands

8. Nephron
• Functional unit of kidneys
• About one million per kidney
• Concentrate urine
• Filter blood
• Excrete waste products

9. Nephron
Anatomy
• Afferent and efferent
arterioles
• Glomerulus
• Bowman’s capsule
• Proximal convoluted
tubules
• Loop of Henle
• Distal convoluted
tubules
• Collecting duct

12. Nephron Function
• Ultrafiltration of blood
• 180 L/day of blood filtered
• >80% reabsorbed
• Antidiuretic hormone cause another 20%
absorption
• 1-2 L/day urinary output
• Reabsorption of minerals and nutrients
• Active secretion of waste

13. Antidiuretic Hormone ADH
• Also called vasopressin
• Made in hypothalamus and secreted from posterior
pituitary
• Increases porosity in distal tubule and collecting
duct
• Lack of ADH result in d. insipidus
• Unable to concentrate urine (isosthenuria):
constant specific gravity at 1.010

15. Normal Urine Contains…
• Urea from ammonia and
CO2
• Uric acid from DNA
metabolism
• Creatinine from muscle
• Electrolytes

16. Urine Collection
• Random
• 12 hour or 24 hour timed
• First morning void
• Clean catch
• Mid-stream
• Fasting
• Postprandial
• Urethral catheter
• Suprapubic aspiration

19. Decomposition of Urine
• Bacterial growth • Crystals
• Ammonia or acid • Cells and casts lyse
formation • Change in color
• Change in pH • Alkaptonuria
• Ketone evaporate • Change in specific
• Urobilinogen oxidized gravity
• Bilirubin degradation
with light

21. Urine Preservation
• Refrigeration up to 8 hours
• Thymol to prevent bacterial growth
• Formalin to preserve cells
• Acid or base to preserve compounds

22. More Terms to Study
• Polyuria • Glycosuria
• Oliguria • Proteinuria
• Anuria • Bacteriuria
• Dysuria • Cylindruia
• Hematuria • Hemoglobinuria

23. Color
• Normal: shade of yellow (straw to amber)
• Urochrome, uroerythrin
• Yellow due to bile in jaundice
• Red due to Hb or myoglobin
• Black in alkaptonuria after light exposure
• Other color due to medication

26. Appearance
• Normal: clear to slightly hazy
• Cloudy to turbid due to microscopic
sediments
• White and red cells
• Bacteria and yeast
• Crystals

28. Specific Gravity
• Normal: 1.015 - 1.025 (wider range with
random collection)
• Urinometer: true reading of specific gravity
• Refractometer: use light refraction by
dissolved substances
• Reagent strip: ionic concentration
• Osmometer: most accurate measurement of
total dissolved substance

33. Refractometer vs Dipstix SG
• Refractometer measures dissolved
substances
• Each gram of glucose raises SG by 0.004
• Each gram of protein raises SG by 0.003
• Correction gives more accurate measure of
kidneys’ concentration ability
• Reagent strip measures ionic concentration
• Urinary waste will ionize so good measure of
kidneys’ ability to concentrate
• Non-ionizing substances: glucose, protein, IVP

34. Other Information…
• Volume: 600 - 1,600 mL
per day
• For timed collection only
• Foam: white
• Yellow due to bile in
hepatitis
• Excessive due to
proteinuria

35. Other Information…
• Odor: faintly aromatic
• Foul due to bacterial growth
• Fruity due to ketones
• Maple Syrup Urine Disease
• Other due to food or medication