1 / 35

ACID-BASE BALANCE

ACID-BASE BALANCE. pH is a measure of H + pH = - log [H + ] Importance: Chemical reactions. Acid + Base = Salt Water (NEUTRALIZATION REACTION: HCl + NaOH  NaCl + H 2 O ). pH SCALE. Logarithmic 1.0 to 14.0 7.0 = neutral (chemical) 7.4 = normal (biological) <7.0 (7.4) = acidic

Download Presentation

ACID-BASE BALANCE

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 • pH is a measure of H + • pH = - log [H +] • Importance: • Chemical reactions

  2. Acid + Base = Salt Water(NEUTRALIZATION REACTION: HCl + NaOH  NaCl + H2O)

  3. pH SCALE • Logarithmic • 1.0 to 14.0 • 7.0 = neutral (chemical) • 7.4 = normal (biological) • <7.0 (7.4) = acidic • >7.0 (7.4) = alkaline (basic) • body pH range = 7.35 to 7.45

  4. ACIDS AND BASES • Acid = releases H+ = proton donor • Base = accepts H+ = proton acceptor • Strong acid vs. weak acid • Strong base vs. weak base

  5. SOURCES OF H+ • Metabolic reactions • Carbon dioxide • Exercise acids • Food

  6. pH MAINTENANCE • Buffer systems • Respiratory system • Urinary system

  7. BUFFER SYSTEMS • Buffer = substance preventing extreme fluctuations of pH • Strong acids/bases to weak ones • Work in buffer pairs; a base and an acid • Action: • BB + strong acid weak acid + salt • BA + strong base weak base + water • Systems: bicarbonate; phosphate; protein

  8. BICARBONATE BUFFERS • Important in blood • Buffer pair = NaHCO3/H2CO3 • HCl + NaHCO3 H2CO3 + NaCl • NaOH + H2CO3 NaHCO3 + H2O

  9. PHOSPHATE BUFFERS • Important in kidney • Buffer pair = Na2HPO4/NaH2PO4 • HCl + Na2HPO4 NaH2PO4 + NaCl • NaOH + NaH2PO4 Na2HPO4 + H2O

  10. PROTEIN BUFFERS • Important in cells • Amphoteric • Side groups: • COOH acts as acid – donates H+ • NH2 acts as base – accepts H + • Hb can act as a buffer

  11. Respiratory Control of pH • Review respiratory centers of brain • Review respiratory equation • Review chemoreceptors • It is fast acting when buffers need help • Control lasts relatively short time • NOT a long term solution • H+ = pH = resp. equation left = ventilation • Consider the opposite scenario

  12. Renal Control of pH • Kidney slow to respond to pH changes • Responds only after persistent changes • Compensates for a relatively long period • NOT a solution to chronic pH problems • Rids the body of H+ by tubular secretion • PCT, DCT, CD • Also: • Reabsorption of HCO3- • Regulation of PO4-3 • Production and elimination of NH3

  13. Summary of Kidney Action Blood Tubule Cells Filtrate CO2 CO2+ H2O H2CO3- HCO3- + H + H + + Na2HPO4 Na+ +NaH2PO4 HCO3- + Na+ Na+ NH3 NH3 + H+ (for excess H+) NH4+

  14. Coupling of H+ Secretion &Reabsorption of HCO3- p. 1007

  15. Buffers & New HCO3- p. 1008

  16. New HCO3- & Ammonia p. 1009

  17. Acidosis & Alkalosis • Look at the listed values in the above order

  18. Acidosis & Alkalosis

  19. Compensation • One system helping another to alleviate an acid/base problem: • An overload of the buffer system results in an increase in breathing rate; the respiratory system is compensating.

  20. Fluids & Electrolytes • Body water content • Fluid compartments: • Intracellular • Extracellular • Plasma • Interstitial fluid

  21. Fluid Compartments p. 1041

  22. Fluid Composition • Electrolytes • Nonelectrolytes • Comparison of intracellular & extracellular

  23. Fluid Composition • Note sodium and potassium • Note similarity of plasma & interstitial fluid except for protein p. 1043

  24. Fluid Movement • Water follows osmotic and hydrostatic pressure gradients

  25. Fluid & Solute Movement p. 1037

  26. Water Balance • Input must equal output p. 1037

  27. Regulation of Water Intake p. 1038

  28. Disorders of Water Balance • Dehydration • Water loss exceeds intake; When? • Diabetes • Decreased volume = hypovolemic shock • Water movement out of cells • Hypotonic hydration (Water intoxication) • Excess water • Diluted ECF • hyponatremia • Edema

  29. Disorders of Water Balance p. 1040

  30. Electrolyte Regulation - Sodium p. 1043

  31. ADH Action p. 1039

  32. Water: Pressure /Volume Relationships p. 1039

  33. Water: Pressure /Volume Relationships p. 1045

  34. Respiratory Centers • Medulla • Pons • Apneustic – works to smooth transition between inspiration and expiration • Pneumotaxic (pontine respiratory group) • Inhibits respiratory center • fine tunes rhythm • Prevents overinflation

  35. END

More Related