Final answer:
The respiratory system helps maintain acid-base balance by increasing respiratory rate to excrete excess CO2, thus reducing carbonic acid and increasing blood pH. Buffers like bicarbonate also play a role, absorbing hydrogen ions to prevent drastic pH changes.
Step-by-step explanation:
The respiratory system maintains acid-base balance through the excretion of acids and the regulation of carbon dioxide (CO2) levels. When blood pH decreases, indicating acidity, the respiratory rate increases to expel more CO2, which is converted from carbonic acid in the blood. This reaction lowers the concentration of carbonic acid, thereby increasing pH back toward normal levels.
Buffering is also crucial in maintaining the pH balance. The body contains buffers, such as bicarbonate (HCO3-), that can absorb excess hydrogen ions (H+) to resist dramatic changes in pH. Bicarbonate acts in conjunction with the lungs and the kidneys to regulate pH: the lungs can rapidly move CO2 in and out of the blood, while the kidneys manage bicarbonate reabsorption and hydrogen ion excretion at a slower pace.
Overall, this system allows people to respond to both immediate and long-term disruptions in acid-base homeostasis by altering respiratory and renal function.