ANATOMY

Detailed explanation-1: -Under normal physiologic conditions, an increase in PCO2 causes a decrease in pH, which will increase minute ventilation and therefore increase alveolar ventilation to attempt to reach homeostasis. The higher the minute ventilation, the more exchange and loss of PCO2 will occur inversely.

Detailed explanation-2: -Concentration or partial pressure of CO2(pCO2) is 40 mm Hg in alveolar air and 32 mm Hg in expired air.

Detailed explanation-3: -Carbon dioxide influences the pH of blood by reacting with water to form carbonic acid (H2CO3), which can dissociate to form a hydrogen ion (H+) and a hydrogen carbonate ion (HCO3-). Increasing the concentration of carbon dioxide in the blood therefore results in more H+ ions and a lower pH.

Detailed explanation-4: -If you have a normal pCO2 and low HCO3 then you have a metabolic acidosis. SO REMEMBER: As your pCO2 will be inverse to your pH → as your pCO2 rises your pH will fall.