1 / 21

ACID BASE BALANCE and Disorders

ACID BASE BALANCE and Disorders. Acids :. Are any substance which tends to release H+ in water , either by simple dissociation or reaction

bryson
Download Presentation

ACID BASE BALANCE and Disorders

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. ACID BASE BALANCE and Disorders

  2. Acids : • Are any substance which tends to release H+ in water , either by simple dissociation or reaction • The strength of acids is measured by the extent to which it liberate H+ but not by the number of H+ in the acid molecule e.g. phosph . a. and carbonic a . are weaker than HCL ( the later is completely dissociated ). • The acidity of the solution is determined by H‑ expressed in gm ion/l. ( or nmol/l.).

  3. Bases: • Are substances which tends to accept H+, since the anion liberated along with H+ when acid dissociated were bases e.g. Cl in HCL, NH3 in NH+4 • The strong base is that substance with high tendency to accept H+ e.g. anion of weakly dissociated acid e.g H2CO3

  4. Aprote: • Metallic cation e.g Na+ , K+ which are not bases or acids

  5. HYDROGEION HOMEOSTASIS The buffer : • It is the substance which resists change in its PH, when excess acid or base is added • Usually are weak acids and its salts e.g. H2CO3

  6. Addition of acids → dissociation of the weak acid or its salt e.g. H2CO3 ( H+ , HCO3 0 slowely and the anion neutralize any excess acid ( H+) e.g HCL +NaHCO3 → NACl + H2CO3. ( weak acid is formed instead of strong one ). • Addition of bases → dissociation of the weak acid H+ + HCO3 , H+ neutralize the base added without great change in PH.

  7. →pH← • It is log10 Log10 of the reciprocal of (H+) • The Log10 of a number is the power to which 10 must be raised to produce this number e.g log10 102 = if log10 to "x" number = 7 so the number must be 107 • At pH6 (H+) =?? 1 H+

  8. 1 H+ pH = Log10 Log10 (H+) = 6 ( H+) 10-6 = 0.000001 mol = 1000nmol/L at pH7 , (H+) will be 100 nmol/L so each one unit change in pH mean 10 folds change in (H+)

  9. Blood Buffer systems • Bicarbonate / Carbonic acid • The most important buffer of plasma • It presents in RBCs , but in lesser concentration

  10. HANDERSON – HASSELBALCH equation dissoeiation hydration CO2 + H2O H2CO3 H++ HCO3 K hydration = H2CO3 → H+ + HCO3 H2CO3 CO2xH2O

  11. H+ x HCO3 H2CO3 K dissociation = K combined = x = H2O is constant and so K → K` H2CO3 CO2xH2O H+ xHCO3 H2CO3 H+ x HCO3 CO2xH2O

  12. H+ x HCO`3 dCO2 K` = ( H+) = K` x pH = Log10 = Log + log = pK + Log dCO2 HCO`3 1 (H+) 1 K HCO`3 dCO2 HCO`3 0.03xPCO2

  13. Note : ( dissociation constant of CO2 = 0.03) ( PK. For BiC. / Carb. Buffer system = 6.1)

  14. 2) Phosphate buffer :- • Inorganic phosphate accounts for 5% of the nonbicarbonate buffer value, at a plasma Ph of 7.4 , the ratio HPO4/H2PO4 is 80/20 ( 4/1) (PK=6.8)

  15. Organic phosphate in the RBCs in the form pf 2.3-diphosphoglycerate accounts for 16% of the non bicarbonate buffer. H2PO4+OH= HPO`4 + H2O HpO`4 + H= = H2Po4

  16. Plasma protein buffer:-3) • Albumin form 95% of the non bicarbonate buffer value of the plasma • The most important buffer groups of proteins are the imidazole group of histidine ( 16 in each albumin molecule)

  17. Hemoglobin buffer : • Account for 84% of the RBCs non bic buffer the most important buffer groups are imidazole groups of Hb. Histidine

  18. Carbamino Compoands : Combination of small amount of CO2 in RBCs with Hb.R – NH2 + Co2 R – NH – COO + H+

  19. Regulation of (H+) • Dilution • Buffer system → Plasma • HCO3/H2CO3 (20:1) • B2HPO4 / BH2PO4 ( 4:1) • Prot. /prot.H(95% of the non bic

  20. RBCs : • HbO2 / HHb ( 84% of the non bicarb.) • Carbamino compounds • HCO3 /H2CO3 ( to less extent) • 2.3 diph. glye.16%of the non bic.

  21. 3 . Respiratory Mechanism = C.R.C. ( Central chem.., Periph. Chem.) 4 . Renal Mechanism • Acid excrction • Na+ -H+ exchange • Ammonia formation and NH+4 excretion • H2PO4 excretion • HCO`3 reclamation

More Related