Constituents of Normal urine

1. Constituents of Normal urine

2. Urine is actually the liquid waste of the body which is secreted by the kidneys after filtration from blood. The Urine is excreted through the Urethra. Majority of waste products are excreted through urine. • Sample of normal urine contain number of substances which are called normal constituents of urine. • PHYSICAL PROPERTIES: • VOLUME: 1200_1500ml/day. It depends on amount of fluid taken, amount lost through extra renal channels, temperature & humidity diet e.gtea,coffee (diuresis)

3. COLOUR: • It is normally pale yellow. It depends upon the concentration and quantity of urine. • Colour of urine is mainly due to pigment urochrome and to some extent urobilin and hematoporphyrin. • Fresh urine is clear in appearance. On standing urine becomes cloudy consisting of mucoproteins and epithelial cells. • ODOUR: • Smell is partially due to volatile and organic acid. On standing urine develops unpleasant ammonical smell because urea acted upon bacteria lead to formation of NH3.

4. SPECIFIC GRAVITY: • 1.015_1.025 • Highly concentrated urine can have sp. Gravity upto 1.040 whereas dilute urine can have 1.003 • It is measured by urinometer. • pH: • Usually acidic i.e 4.8_6.8 with an average of 6.0 representing H ion conc of urine and the amount of organic and inorganic acids present. Monobasic sodium phosphate are present as NaH2PO4 which are acidic and which are responsible for acidic pH of urine.

5. Composition of 24 hr urine: • Water : 1200ml/day • Solids : 60g/ day • Urea : 30g • Uric acid : 0.7g • Creatinine : 1.2g • Hippuric acid: 0.7 • Protein : 0.1 • Ketone bodies : 0.003_0.015g • NaCl : 10g • Na : 4g

6. Potassium : 2g • Calcium : 0.2g • Phosphate : 1.1g • Total sulphur: 1g • Chloride: 6_9g • Magnesium: o.5g

7. To determine inorganic constituents of normal urine: • CHLORIDES: it is the chief inorganic constituent of urine. Daily excretion: 6 _ 9 g/day Causes of low conc: during fasting excessive sweating diarrhoea excessive vomiting diabetes pts with edema due to any cause egnephrosis & nephritis some infectious diseases eg pneumonia

8. Causes of excess excretion in urine: • Excessive water intake • Diuretics • Adrenalcortico insufficiency

9. Test for chloride: • Take 3ml of urine and add few drops of conc nitric acid , then add few drops of silver nitrate solution. • White precipitates of silver chloride appears showing the presence of chloride.

10. Calcium & phosphates: • Calcium and phosphates comes from the diet and dimineralization of of bones eg rickets and osteomalacia. • Causes of increased calcium excretion: • Hyerparathyroidism • Hyperthyroidism • Hypervitaminosis D • Renal stones • Acidosis • Drugs: steroids,diuretics

11. Causes of increased phosphate excretion: • Disease of bones eg rickets & osteomalacia • Hyperparathyroidism • Acidosis Causes of decreased phosphate excretion: • Diarhoea • In acute infection • Parathyroid hypofunction • Pregnancy due to the utilization of maternal phosphate in formation of fetal bones. • Galactosemis and hereditary fructose intelerance.

12. Test for inorganic phosphate: • Take 2ml of urine and add equal amount of conc nitric acid. • Add 4ml of ammonium molybdate solution. • Boil the test tube for few min then cool it under running tap water. • A yellow precipitates of ammonium phosphomolybdate shows the presence of inorganic phosphate.

13. Test for calcium: • Take 2ml of urine in a test tube . • Add 5ml of 5 % acetic acid. • Then add few drops of 10% potassium oxalate solution. • White precipitates of calcium oxalate shows the presence of calcium.

14. Organic constituents of urine: • UREA: • It is the principle end product of protein metabolism.80_ 90% of total nitrogen is present as urea. It is excreted at rate of 30g/day. • Normal range is 20_40g/day. • Its amount is directly related with protein intake in diet. • It is synthesized in liver and excreted by kidney as a component of urine. In addition a small amountis excreted in sweat. • Besides its role as carrier of waste nitrogen,urea also plays A role in the counter current exchange system of nephrons.

15. CAUSES OF INCREASED EXCRETION: Whenever protein metabolism is increased. • Fever • Diabetes • Renal failure • Carcinoma • CAUSES OF DECREASED EXCRETION: • Liver disease • Severe acidosis • nephritis

16. Uric acid: • It is breakdown product of purine metabolism • Normal value: 0.5_1 g/day • CAUSES OF INCREASED EXCRETION: • Renal failure • Gout • Leukemia • Burns • Crush injuries • Hemolytic anemia • Plasma cell myeloma • Wilson’s disease

17. Test for uric acid(schiff’s test) • Dissolve small amount of uric acid in 5ml of 10% sodium carbonate. • Moistened a filter paper piece with silver nitrate solution. • Place a drop of uric acid solution over the area moistened with silver nitrate. • Brownish black precipitates of reduced silver forms. Uric acid is a reducing agent. • Chloride ions interfere with this test.

18. Creatinine: • Creatinine is a nitrogenous waste product formed from the metabolism of creatine in skeletal muscle. • Crea means flesh. Meat and fish are very rich sources of creatinine. • Normal value: 1_1.8 g It is hydrated form of creatine.

19. Causes of creatinineuria: • During pregnancy • After childbirth • Hyperthyroidism • Starvation • Diabetes mellitis • Fever • Malnutrition • Muscular dystrophy • Mysthenia gravis • poliomellitis

20. Test for creatinine(picric acid test) • Also called jaffe’s test. • Take 5ml of 0.1% creatinine. • Add a few drops of saturated solution of picric acid. • Add 2_3 drops of 10% NaOH. • Orange red colour results due to the formation of red creatinine picrate.

21. Nitroprusside test • Take 5ml of 0.1% solution of creatinine. • Add 5 drops of freshly prepared solution of sodium nitroprusside. • Add drop by drop a 10% solution of sodium hydroxide untill an orange colour results.