Final answer:
Rapid breathing, or hyperventilation, causes the blood to become more alkaline due to the excessive exhalation of CO2. The body can adjust the breathing rate to maintain pH homeostasis either by increasing to counteract acidity, or decreasing to correct alkalinity.
Step-by-step explanation:
When an individual breathes very rapidly, resulting in hyperventilation, a significant amount of carbon dioxide is exhaled. This loss of CO2 leads to a reduction in blood levels of carbonic acid, subsequently causing an increase in blood pH. This condition is referred to as respiratory alkalosis, in which the blood becomes more alkaline (basic). The body typically maintains pH homeostasis by regulating the rate of breathing through the autonomic nervous system. If the blood becomes too alkaline, the opposite can happen—respiratory rate can decrease, conserving CO2, and making the blood more acidic to lower the pH back to normal levels.
During activities like strenuous exercise, the body produces excess CO2 and lactic acid, which can lead to increased acidity in the blood. The respiratory system compensates by increasing ventilation rate to remove excess CO2, therefore helping to balance the pH and prevent acidosis. This balancing act is an example of the body's remarkable ability to maintain homeostasis through physiological adjustments.