Normal pH of arterial blood is
pH of blood is tightly controlled. Arterial blood pH is 7.40. Venous blood pH is slightly less than arterial blood. Acidosis is technically present if the pH is less than 7.4 and alkalosis more than 7.4. But, the ill effect of acidosis does not occur until pH falls below 7.35 and for alkalosis more than 7.45.
Types of acid-base disorders
|Disorder||pH 7.35 to 7.45||Bicarbonate HCO3- 24.1mEq/L||Carbon Dioxide PCO2 40mmhg|
CO2 + H2O ⇌ H2CO3 ⇌ H+ + HCO3-
pH is decreased due to an increase in CO2 levels this leads to compensation. when more carbon dioxide is present more carbonic acid is produced and this increases the Hydrogen ions thus acidosis and bicarbonate levels also go up. see the equation above Shift to right. Kidney retains bicornate ions
pH is increased due to the elimination of CO2 (hyperventilation), this leads to compensation see the equation below. when CO2 is reduced less carbonic acid is produced leading to fewer hydrogen ions and also fewer bicarbonate ions shift to left. Kidneys excrete bicornate ions
Three-week residence at 4000 m altitude
pH is decreased with the fall of bicarbonate this leads compensation from lungs i.e hyperventilation so more CO2 is eliminated thus even CO2 gets decreased.
pH is increased due to an increase in bicarbonate levels. This leads to the companization i.e. retention of CO2 by lungs so CO2 levels go up