Mechanisms of acid-base balance regulation
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MECHANISMS OF ACID-BASE BALANCE REGULATION
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The ratio of base / acid proprtions of buffer system depends upon rate/ amount of acid production (H+) . The (H+) has to be eliminated by the body to maintain acid base balance normal.
The mechanisms of acid base balance regulation is
i. Respiratory Regulation
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By increasing or decreasing rate of respiration to eliminate Co2.
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Alveolar ventilation provides the oxygen needed for oxidative metabolism and eliminates the CO2 produced by metabolic processes.
- In the normal subject control mechanisms insure the maintenance of adequate oxygen supplies and keep pCO2 value in the region of 40+/- 5 mmHg.
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Even a slight elevation of paCO2 results in immediate stimulation of pulmonary ventilation.
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pO2 constitutes an effective stimulus to ventilation only when its value drops to less than 70 mmHg.
Renal Regulation
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All variations of body fluid hydrogen ion concentration stimulate the appropriate regulatory processes in the kidneys.
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The main functions of the renal regulation are:
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Increase of plasma bicarbonate leads to the production of new bicarbonates by the excretion of protons into urinary buffer systems.
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The protons are eliminated trough the formation of ammonium and the conversion of HPO42- to H2PO4-.
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High hydrogen ion concentration stimulates the secretion of hydrogen ions, leading to an increase of ammonium ion concentration.
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High pCO2 stimulates the renal reapsorption of bicarbonate while low pCO2 has the opposite effect.
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Last modified: Monday, 28 November 2011, 7:31 AM