1. URINE Urine Physical properties

2. The kidney is an organ which does not simply remove the metabolic waste products, but actually performs an important homeostatic function.

3. the internal environment
It regulates
the internal environment
of the body cells by
3 mechanisms:

4. 1) Glomerular filtration
1) Glomerular filtration. 2) Selective tubular reabsorption of substances that are necessary to maintain the internal environment; and 3) Tubular secretion of substances from the blood into the tubular lumen for excretion into the urine. These 3 mechanisms result in urine formation.

7. PHYSICAL PROPERTIES OF URINE

8. 7 ITEMS
Volume
Colour
Aspect
Deposits
Odour
Reaction
Specific Gravity

9. Volume:
It ranges between 1 and 1.5 L/day.
The volume depends on
water intake,
external temperature,
diet,
mental and physical state of the individual.

12. Physiological increase:
Volume
more than 2 L/day
Physiological increase:
In winter
After excessive fluid intake- Coffee
Nervousness or excitement
N.B. Normally, more urine is
excreted during the day than at night.

13. Hypercalcemia  -- Action of ADH
Abnormal increase (polyuria ):
More than 3 L/day
diabetes mellitus (may reach 5 L/day)
diabetes insipidus (10-15 L/day)
hyperparathyroidism.
Hypercalcemia  -- Action of ADH

14. Volume Physiological decrease: in summer due to increased sweating
during fasting or restricted fluids in diet.

15. Volume Abnormal decrease (Oliguria): Less than 200 ml/day
acute nephritis,
heart failure,
shock, burns
haemorrhage.
vomiting and diarrhoea.

16. Anuria: No urine at all (or < 50 ml /day)
Volume
Anuria:
No urine at all (or < 50 ml /day)
late stages of renal failure
and heart failure.

17. Colour Normal colour is amber yellow.
due to pigments called urochromes , urobilin or urobilinogen + peptide.
There are also other pigments (coproporphyrin, uroerythrin), but occur in small amounts.

19. in the following conditions
The colour is changed
in the following conditions

20. Diabetes insipidus: colourless or pale yellow.
Fever, deep orange.
Obstructive jaundice: Greenish brown due to presence of cholebilirubin.
Haemorrhage in urinary tract, reddish brown colour.
Alkaptonuria: Black (homogentisic acid is oxidized to give black colour when exposed to air.

21. Ingestion of :
food coloured with dyes or
coloured drugs result in discolouration of urine.

23. Odour This odour is changed by:
Fresh urine is normally aromatic (urineferous).
This odour is changed by:
Different types of food: Cabbage, garlic, onion.
Severe uncontrolled diabetes mellitus: Fruity odour due to presence of acetone/acetoacetoacetic acid.
Contaminated urine: Ammoniacal odour. In stagnant urine, this odour is due to bacterial action, e.g. on urea which is converted into ammonia.
Putrefaction: Putrid odour due to bacterial growth in urinary infection.

24. Odour Bacteria Normally aromatic (urineferous) Fruity odour
Severe uncontrolled DM
Ammoniacal
odour
Putrid
odour
Urease
Growth
Bacteria

25. Reaction
On mixed diet, it is acidic (pH is 6). It may be slightly acidic or slightly alkaline.
The urine pH depends on
the ratio of acid phosphate (NaH2PO4) to alkaline phosphate (Na2HPO4). The kidney mainly excretes acid phosphate to preserve the alkali.

27. Reaction: High protein diet gives acidic urine
due to excretion of excess phosphate and sulphate.

28. Reaction Vegetables and fruits give alkaline urine
due to their high sodium and potassium content with excretion of sodium and potassium bicarbonate in urine

29. Reaction Alkaline urine is passed an hour after a meal,
this is the so called
alkaline tide.

30. Aspect
Normal urine is clear (transparent).
On standing, it turns cloudy due to precipitation of muco- and nucleoproteins and epithelial cells (present in traces in normal urine).

31. It becomes turbid and opaque due to presence of albumin.
Exposed urine is a good medium for bacterial growth as its pH becomes alkaline, resulting in precipitation of phosphates.

33. Deposits Normal urine is: devoid from deposits.
In case of its presence, it depends on the colour and shape of deposit.
In order to examine the deposit, we make centrifugation to urine then microscopic examination.

34. a) Crystals : urates and oxalates (acid urine), tripple phosphate (ammonium magnesium phosphate [NH2MgPO4]) (alkaline urine) b) Casts : albuminoid substances released from epithelial c) Parasitic ova ; and d) Cells :Pus cells or RBCs.

35. Microscopic examination of the solid parts of urine: the picture shows red blood cells (above), white blood cells (middle) and a cast of clumped-together white blood cells (below).

37. A urinary cast is a protein or cellular debris, that forms within a renal tubule.
The material or cells that form a cast may have 
come through a damaged glomerulus, 
been part of an interstitial inflammatory infiltrate, 
have been dead tubular cells.
The cast is expelled into the urine, and maintains the shape of the tubule in which it formed.
Casts reflect conditions of the kidney proper and not the lower urinary tract.
In most cases they are significant and must be explained.

38. Specific gravity Normally, it ranges between 1.015 to 1.025
It varies inversely with the volume of urine, e.g.:  In diabetes insipidus, it is low (1.004).
In fever, it is high (more than 1.030) due to small amount of urine.
In diabetes mellitus, the specific gravity is due to the presence of glucose.

39. A diseased kidney loses its ability to dilute or concentrate urine

40. Water diuresis test Evacuate The Bladder Then, Drink 1.5 L of water.
Urine will be collected every half an hour for 5 hours
For each sample,  determine volume & specific Gravity.
Normally, after 5 hours,  shold void at least 800 ml + Sp. Gravity < 1.010
If the distal tubules function is impaired  Diuresis doesnot occur & Sp. Gravity doesnot drop below 1.010

41. Water Concentration test
Evacuate The Bladder
Then, No Drinking for hours to produce dehydration.
At the end of the 12 hours Urine will be collected
determine volume & specific Gravity.
Normally, Sp. Gravity shold rise to 1.025
If with dehydration, the Sp. Gravity remains below  it indicates that the function of Loop of Henle & distal Tubules is inhibited