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![PH REVIEW
pH
If [H+] is high
If [H+] is Low
• p stands for power and
• H for hydrogen ion conc.
• the solution is acidic; pH
< 7
• the solution is basic or
alkaline pH > 7](https://image.slidesharecdn.com/5-150927035840-lva1-app6891/75/5-sakina-respiratory-regulation-of-ph-3-2048.jpg)
![RESPIRATORY ACIDOSIS
Primary
changes
Excess of
carbonic acid
↑PCO2
[HCO-
3] / [H2CO3]
= <20:1
pH
decreased](https://image.slidesharecdn.com/5-150927035840-lva1-app6891/75/5-sakina-respiratory-regulation-of-ph-29-2048.jpg)
![RESPIRATORY ALKAOSIS
Primary
changes
Deficit of
carbonic acid
↓PCO2
[HCO-
3] / [H2CO3]
= >20:1
pH
increased](https://image.slidesharecdn.com/5-150927035840-lva1-app6891/75/5-sakina-respiratory-regulation-of-ph-30-2048.jpg)
Uploaded bysakina hasan
5.sakina respiratory regulation of ph
This document provides an overview of acid-base balance and pH regulation in the human body. It discusses the importance of maintaining pH levels, the various buffer systems that help regulate pH (including the bicarbonate buffer system and phosphate buffer system), and the roles of respiration and the kidneys in pH regulation. Blood gas analysis is described as a way to determine acid-base balance and oxygenation by measuring values like pH, pCO2, pO2, HCO3-, and oxygen saturation. Conditions like respiratory acidosis and alkalosis that disrupt acid-base balance are also summarized.
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5.sakina respiratory regulation of ph
- 1. PH REGULATION ANDACID BASE BALANCE DR SAKINA ,MBBS,M.D SENIOR LECTURER ,MSU
- 2. OUT LINE Introductionto Acid base balance Review- Importance of Ph Buffer System Respiratory regulation of Ph Acidosis and Alkalosis Blood gas analysis 2
- 3. PH REVIEW pH If [H+]is high If [H+] is Low • p stands for power and • H for hydrogen ion conc. • the solution is acidic; pH < 7 • the solution is basic or alkaline pH > 7
- 4. Basic pH neutral Acidic Death Normal andabnormal pH ranges of blood pH’s of common substances Death Acidosis Normal Alkalosis 8.00 7.45 7.35 6.8 Battery acid Concentrated lye Water Gastric juice Lemon juice Vinegar Household ammonia Baking soda Pancreatic juice Blood Milk Urine Coffee Orange juice 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
- 5. SOURCE OF H+ 1. •Anaerobic respiration of glucose produces lactic acid. 2. • Breakdown of phosphorus-containing proteins releases phosphoric acid 3. • Cellular metabolism produces CO2. 4. • Fat metabolism yields organic acids and keto acids
- 6. SOURCE OF H+ Volatileacid Carbonic acid(H2CO3) CO2 Non volatie(Fixed acid) Lactic acid, keto acids, sulfuric acid and phosphoric acid.
- 7. 1. volatile acids(The carbonic acid) is eliminated as CO2 by the lungs. 2.The fixed acids(non-volatile) are buffered and later the H+ are excreted by the kidney. lactate and keto acids are produced in relatively fixed amounts. e.g. 1 mol of glucose produces 2 mols of lactic acid. sulfoproteins yield sulfuric acid and phosphoproteins and nucleoproteins yield phosphoric acid. On an average 3 g each of phosphoric & sulfuric acid are produced/day
- 8. SMALL CHANGES INPH CAN PRODUCE MAJOR DISTURBANCES Most enzymes function only with narrow pH ranges Acid-base balance can also affect electrolytes (Na+, K+, Cl-) Can also affect hormones
- 9. MECHANISM OF REGULATIONOF PH First line of defence • Blood Buffer Second line of Defence • Respiratory Regulation Third line of Defence • Renal Regulation
- 10. BUFFER SYSTEM • Achemical substance that minimizes changes in pH by releasing or binding hydrogen ions1 • Most buffers composed of weak acid and weak base2 • The purpose of the buffer is to help the body maintain pH3
- 11. Buffer Systems Extracellular fluid(ECF) Bicarbonate Buffer System Protein Buffer Systems Protein buffer systems contribute to the regulation of pH in the ECF and ICF. These buffer systems interact extensively with the other two buffer systems. Hemoglobin buffer system (RBCs only) Amino acid buffers (All proteins) Plasma protein buffers Phosphate Buffer System intracellular fluid (ICF) occur in The carbonic acid– bicarbonate buffer system is most important in the ECF. The phosphate buffer system has an important role in buffering the pH of the ICF and of urine.
- 12. BICARBONATE BUFFERING SYSTEM Most important buffer system It accounts for 65% of buffering capacity in plasma The base, bicarbonate (HCO3–),is regulated by the kidney (metabolic component). Acid part, carbonic acid (H2CO3), is under respiratory regulation (respiratory component). The normal bicarbonate level of plasma is 24 mmol/liter The normal carbonic acid concentration in blood is 1.2 mmol/L.
- 13. BICARBONATE BUFFERING SYSTEM •It tends to maintain a relatively constant plasma pH and counteract any force that would alter • In this (CO2) combines with (H2O) to form (H2CO3), which rapidly dissociates to form hydrogen ions (H+) and bicarbonate (HCO3 - )
- 14. THE CARBONIC ACID-BICARBONATEBUFFER SYSTEM
- 15. LIMITATIONS OF CARBONICACID–BICARBONATE BUFFER SYSTEM . • Ability to buffer acids is limited by availability of bicarbonate ions . • Functions only when respiratory system and respiratory control centers are working normally
- 16. PHOSPHATE BUFFER NaH2PO4- Na2HPO4constitute the phosphate buffer. It is mostly an intracellular buffer and is of less importance in plasma due to its low concentration. Phosphates are major anions in ICF and minor ones in ECF
- 17. PROTEIN BUFFER It isaccount for about 2% of the total buffering capacity The plasma proteins and hemoglobin together constitute the protein buffer system Carboxyl group gives up H+ Amino Group accepts H+
- 18. PROTEIN BUFFER Bufferingcapacity of protein depends on the pKa value of ionizable side chains. The most effective group is Histidine imidazole group with a pKa value of 6.1. The role of the hemoglobin buffer is considered along with the respiratory regulation of pH.
- 19. ACTION OF HAEMOGLOBIN 1 •Transport CO2 formed in tissue with minimal change in pH 2 • It serves to generate bicarbonate by activity of carbonic unhydrase system 3 • The reverse occurs in lungs during oxygenation and elimination of CO2
- 20. GENERATION OF BICARBONATEBY ERYTHROCYTES Step -1 • Plasma co2 diffuses into RBC ,combines with H2O to form H2CO3 • In the RBC, H2CO3 dissociates to produce H+ and HCO3 Step -2 • The H+ ions are trapped and buffered by hemoglobin. As the concentration of HCO3 increases in the RBC, it diffuses into plasma along with the concentration gradient, in exchange for Cl- ions, to maintain electrical neutrality CHLORIDE SHIFT
- 21. RESPIRATORY REGULATION OFPH • Achieved by Regulating the concentration of H2CO3 in blood. CO2 diffuses from cells into ECF & Reaches lungs through blood • The rate of respiration is controlled by chemoreceptors in respiratory centre • Fall in pH (acidosis) the respiratory rate is stimulated in hyperventilation to eliminate more CO2 ,thus lowering H2CO3 But This cannot continue for long
- 22. RATES OF CORRECTION Buffersfunction almost instantaneously Respiratory mechanisms take several minutes to hours Renal mechanisms may take several hours to days
- 23. BLOOD GAS ANALYSIS •1.To Determine if the patient is well oxygenated1 • 2.To Determine the patient’s Acid Base balance2 Blood Gas are obtained for two reasons Test are measured using arterial blood and procedure is known as “ABG”Arterial blood gas by (ABG Analyser).
- 24. MEASUREMENT – BLOODGASES pH, pCO2, pO2 – Measured directly HCO3 -, O2 saturation (usually) – Calculated from pH, pCO2, and pO2
- 25. Arterial Venous pH 7.35-7.457.32-7.42 PO2 80-100 mmHg 28-48 mmHg PCO2 35-45 mmHg 38-52 mmHg HCO3 - 22-26 mEq/l 19-25 mEq/l SOME NORMAL PARAMETERS
- 26. F THE BASICRELATIONSHIP BETWEEN PCO2 AND PLASMA PH PCO2 40–45 mm Hg HOMEOSTASIS If PCO2 rises When carbon dioxide levels rise, more carbonic acid forms, additional hydrogen ions and bicarbonate ions are released, and the pH goes down. H2O CO2 H2CO3 HCO3 H
- 27. THE BASIC RELATIONSHIPBETWEEN PCO2 AND PLASMA PH When the PCO2 falls, the reaction runs in reverse, and carbonic acid dissociates into carbon dioxide and water. This removes H ions from solution and increases the pH. pH 7.35–7.45HOMEOSTASIS If PCO2 falls H HCO3 H2CO3 H2O CO2
- 28.
- 29. RESPIRATORY ACIDOSIS Primary changes Excess of carbonicacid ↑PCO2 [HCO- 3] / [H2CO3] = <20:1 pH decreased
- 30. RESPIRATORY ALKAOSIS Primary changes Deficit of carbonicacid ↓PCO2 [HCO- 3] / [H2CO3] = >20:1 pH increased
- 31.
- 32. SOME IMPORTANT CAUSESOF RESPIRATORY ACIDOSIS RESPIRATORY ALKALOSIS • Respiratory depression1 • Obstructed airway2 • Chest wall injury • Pulmonary edema3 • Anaemia1 • High altitude2 • Sepsis ,Shock, • other Respiratory ailments 3
- 33.