Body pH regulation

Body pH regulation

1. Blood pH

   • Normal blood pH is 7.35-7.45
     • Affected by conc of H+
   • Babies+elderly have poor control of h+ in blood
   • h+ Affected by metabolism, sig effected by high protein diet
   • Respiratory compensation deals with increase in H+ as metabolism increases, making more meta acids
     • Respiring more decreases CO2 blood content

2. Buffering H+ Changes

   • Cell proteins+Haemoglobin act as buffers
   • More respiration removes CO2+carbonic acids, increasing pH
   • Urinating reduces H+, renal tubule cells pump H+ into urine
     • Bicarbonate synthesis and h+ ion secretion

3. Acid-Base Imbalance

   • Respiratory Acidosis
     • Commonly low pH and high PCO2 (>45mmHg)
     • Caused by HYPOventilation, where body can't get rid of enough CO2
       • Could be caused by something like emphysema, or damage to the medulla (Respiratory centre)
     • Increase breathing rate to treat
     • Renal comp is increased H+ secretion, more reabsorption of HCO3-
   • Respiratory Alkalosis
     • High pH and low PCO2 (<35mmHg)
     • Caused by HYPERventilation
       • Which could be caused by fever, severe anxiety, high alt o2
     • Renal comp is decreased secretion of H+, less reabsorption of HCO3-
     • Could treat by re-breathing air, paper bag thing
   • Metabolic Acidosis
     • Low aterial HCO3- (<22 mmol/litre) and low pH
     • Caused by either acid accumaltion, or loss of HCO3-
     • Respiratory comp is HYPERventilation to lose more CO2
     • Treated with intravenous HCO3-
   • Metabolic Alkalosis
     • High Aterial HCO3- (<26mmol/litre) and high pH
     • Caused by loss of acid, e.g. vomming, severe dehydration, alkaline antacid drugs
     • Respiratory comp is HYPOventilation to decrease loss of CO2
     • Treated with fluid to correct K+ and CL- Levels