Final answer:
The respiratory system regulates the levels of carbonic acid in the blood by adjusting the rate and depth of respiration, allowing for the removal of excess carbon dioxide and maintenance of blood pH.
Step-by-step explanation:
The respiratory system helps to maintain the balance of carbon dioxide through respiration by regulating the levels of carbonic acid in the blood. When the carbon dioxide level in the blood rises, the excess CO2 reacts with water to form carbonic acid, lowering the blood pH. Increasing the rate and depth of respiration allows for more CO2 to be exhaled, reducing the levels of carbonic acid and adjusting the pH upward. Conversely, excessive deep and rapid breathing can reduce CO2 levels, making the blood too alkaline, but this can be remedied by rebreathing exhaled air.