Question

How are the partial pressure of CO₂ and arterial pH directly linked?

1) They have an inverse relationship
2) They have a direct relationship
3) They are not related
4) Cannot be determined

Answer 1

The partial pressure of CO₂ and arterial pH have an inverse relationship, as increased CO₂ leads to lower pH due to the formation of carbonic acid which dissociates into hydrogen and bicarbonate ions.

Step-by-step explanation:

The partial pressure of CO₂ and arterial pH are directly linked through an inverse relationship. As the partial pressure of carbon dioxide (CO₂) in the blood increases, it converts to carbonic acid (H₂CO₃) which dissociates into hydrogen ions (H+) and bicarbonate ions (HCO₃⁻), leading to a decrease in pH. Conversely, if the partial pressure of CO₂ decreases, less H₂CO₃ is formed, resulting in fewer H+ ions and a higher pH.

This relationship is a reflection of the body's acid-base balance, which is tightly regulated. The primary way the body controls the pH of the blood is through the bicarbonate buffering system, which involves CO₂ and HCO₃⁻ in the blood.