1. Physical-chemical properties and chemical composition of normal urine.

4. PROPERTIES OF URINE Amount – 1500-2000 mL/day Poliuria – diabetes mellitus and insipidus Oliguria – heart failure, nephritis, vomiting, fever Anuria – kidney failure, acute intoxication by heavy metals Color – straw-yellow Pale – poliuria (diabetes insipidud) Dark – jaundice, concentrated urine Red – blood available Green-blue – decay of proteins in the intestine Transparency – transparent Cloudy – pus or mucin available

5. Density – 1,003-1,035 g/mL Increased density – organic or inorganic substances available (diabetes mellitus) Decreased density – diabetes insipidus Isostenuria – continuously low density in oliguria (kidney failure) pH – 5.5-6.8 Acidic – meat food, diabetes mellitus, starvation, fever Alkaline – plant food, cystitis, pyelitis

6. Urine formation Structures responsible for the urine formation:  glomeruli,  proximal canaliculi,  distal canaliculi. Mechanism of urine formation:  filtration  reabsorption  secretion

7. Mechanisms of elimination:  filtration  reabsorption  excretion

8. About 120 mL/min or 180 L/day of blood is filtrated. Filtration – passive process. After filtration – primary urine (180 L/day) Filtration Takes place in glomeruli. Substances with molecular mass below 40,000 Da pass through the membrane of glomerulus into capsula.

9. Filtration is caused by: -hydrostatic pressure of blood in capillaries of glomeruli (70 mm Hg) -oncotic pressure of blood plasma proteins (30 mm Hg) -hydrostatic pressure of ultrafiltrate in capsule (20 mm Hg) 70 mm Hg-(30 mm Hg+20 mm Hg)=20 mm Hg Hydrostatic pressure in glomeruli is determined by the ratio between diameter of ascendant and descendant arteriole

10. Reabsorption:  active  passive. Lipophilic substances - passive. Na/K АТP-аse is very active Reabsorption Takes place in proximal and distal canaliculi. What is reabsorbed? Glucose (100%), amino acids (93%), water (98%), NaCl (70%) etc. The urine is concentrated (toxins damages the proximal canaliculi)

11. Takes place in proximal and distal canaliculi. Secretion:  active  passive. Passive secretion depends on the pH. What is secreted? Ions of K, аmmonia, H + drugs xenobiotics Secretion Transport of substances from blood into filtrate.