How does the body respond when blood becomes too alkaline?

When blood becomes too alkaline, the body initiates several physiological responses to restore pH balance to the normal range (which is approximately 7.35 to 7.45). One of the primary mechanisms to correct alkalosis is the retention of carbon dioxide (CO2) in the body.

When CO2 levels rise, they react with water in the body to form carbonic acid (H2CO3), which dissociates into bicarbonate (HCO3-) and hydrogen ions (H+). This increase in H+ ions leads to a decrease in pH, effectively countering the alkalinity. Therefore, by retaining CO2, the body can increase acidity in the blood, helping to bring the pH back to normal levels.

In contrast, increasing respiratory rate, decreasing body temperature, or increasing metabolic activity do not directly address the issue of alkalinity in the blood. An increased respiratory rate typically leads to more CO2 being expelled, which could exacerbate alkalosis rather than correct it. Decreasing body temperature does not play a role in pH balance, and increasing metabolic activity might produce more acids but is not a direct compensatory mechanism for correcting higher pH levels. Thus, the retention of CO2 is the most