1. Examination of Urine (physical properties & normal constituents)
Oct 2008
Tahani Al-Shehri
Examination of Urine (physical properties & normal constituents)

2. Objective : The simple examination of the Urine.
To detect some of the normal organic constituents of urine.
To detect some of the normal inorganic ions present in urine.

3. Introduction and Principle:
Urine formation :-
The basic steps in urine formation are :
1. Filtration. ( Glomerular)
2. Reabsorption.( Tubular)
3. Secretion. .( Tubular)
4. Excretion.

4. Kidney Function
The main function of kidney is Homeostasis which means :
-maintain internal environment constant
-excretion of all metabolic west product.

5. Nephron

6. Glomerular filtration
In a healthy adult about 650 ml of plasma (1200 ml of blood ) pass through functioning renal excretory tissue every minute, and about 125 ml of glomerular filtrate is formed.

7. Glomerular filtration
Water passes freely from the plasma through the glomeruli , and those unbound constituents of the plasma that have a molecular weight of less than about 70,000 are present in the glomerular filtrate at the same concentration as in the plasma .

8. Glomerular filtration
Substances of a higher molecular weight than about 70,000 do not pass freely through the glomeruli and are present in the glomerlar filtrate at a lower concentration than in plasma

9. Nephron

10. Tubular effect
The renal tubules conserve water and soluble constituent of the body by reabsorption using both passive ( high conc. To low conc. )
And the active transport ( use ATP + carrier ) from the glomerular filtrate.

11. Simple examination of the urine
Volume :
The normal 24 hours Urine volume of an adult is between 750 and 2000 ml .
This depend on
the fluid intake
loss of fluid by other routes.

12. Simple examination of the urine
In Disease :
Oliguria :
Urine output less than 500ml/day
Causese :
deficient intake of water ,
or excessive loss of fluid by other routes ,
for example : by :haemorrhage ,
diarrhea
vomiting

13. Simple examination of the urine
Polyuria
Urine output more than 2000m/day.
Physiological causes
chronic renal insufficiency .
Polyuria of low osmolality is also found in diabetes insipidus
Polyuria occur as an osmotic diuresis in any disease where there is an increased excretion of metabolites (diabetes mellitus ).

14. Simple examination of the urine
Polyuria
Physiological causes
Excessive water intake
Diuretic as tea, Cola, Coffee
Excessive salt intake

15. Simple examination of the urine
Colour :
Due to urinary pigments (urochromes).
Pale (low specific gravity ) to dark yellow (high specific gravity)
Coloured urines occur in :
certain disease
metabolic disorders,
after the administration of many drugs:
Beta carotine supplement ( orange urine )

16. Simple examination of the urine
 Appearance :
Casts :
The tubules secrete an α1-glycoprotein (Tamm-Horsfall protein ) , which , in the presence of albumin , comes out of solution in gel form as casts.

17. Simple examination of the urine
Appearance :
Mucus protein :
This may be from semen or from vaginal discharge.
Pathologically , it may be due to disease of the lower urinary tract or pus.

18. Simple examination of the urine
Appearance :
Crystals :
These are not normally pathological
Uric acid ( reddish – yellow) & calcium oxalate (colourless ) from acid urine
phosphate ( whitish) from alkaline urine .
Pathological
cystine crystals
dark reddish deposit of blood.

19. Simple examination of the urine
Smell:
unpleasant smell : urine infected with Gram-negative organisms .
ammonical smell: urine infected with urea splitting organisms
maple syrup disease (H.W)

20. Simple examination of the urine
pH:
Normal between 5.5 and 8
Alkalosis :
Vegetarine diet
Bacterial infection

21. Simple examination of the urine
Specific Gravity :
normal specific gravity in 24 hour urine sample is between and 1.010
Wt of the sample / Wt of the water
High urine volume ( low Sp.gravity )
low urine volume ( high Sp.gravity )