What physiological process helps maintain the proper pH of body fluids?

The maintenance of proper pH levels in body fluids is largely influenced by the control of respiratory ventilation. This physiological process plays a crucial role in regulating the levels of carbon dioxide (CO2) in the blood. When CO2 levels rise, it leads to an increase in carbonic acid and consequently results in a drop in pH, making the blood more acidic. By increasing the rate and depth of breathing, the body can expel more CO2, helping to reduce acidity and raise pH back to normal levels.

Conversely, if the body needs to conserve CO2, such as during periods of hypoventilation, the respiratory system slows down to retain CO2, which can help increase acidity and decrease pH as needed. This rapid response mechanism, occurring within minutes, is vital for maintaining acid-base homeostasis, especially under changing physiological conditions.

While kidney filtration also contributes to acid-base balance by excreting hydrogen ions and reabsorbing bicarbonate, this process is slower compared to the immediate effects of respiratory ventilation. Blood circulation and endocrine regulation play supportive roles in the overall homeostasis of body fluids but are not primarily responsible for the rapid adjustments needed to maintain pH.