How does elevated carbon dioxide levels affect blood pH?

• A. It increases blood pH, causing alkalosis
• B. It decreases blood pH, causing acidosis
• C. It has no effect on blood pH
• D. It stabilizes blood pH

Answer: (B)

Elevated carbon dioxide levels lead to a decrease in blood pH, resulting in acidosis. This occurs because carbon dioxide reacts with water in the blood to form carbonic acid, which dissociates into bicarbonate and hydrogen ions. The increase in hydrogen ions causes the pH to drop, creating a more acidic environment in the body. This mechanism is crucial for the regulation of acid-base balance, as the respiratory system plays a key role in managing carbon dioxide levels. When CO2 levels rise, the body responds by increasing the respiratory rate to exhale more CO2, thereby attempting to restore normal pH levels.