Final answer:
During exercise, increased CO2 and lactic acid production lead to a temporary decrease in blood pH. The body corrects this through increased respiration, expelling excess CO2, and utilizing blood buffers to maintain the pH within its normal range of 7.35 to 7.45.
Step-by-step explanation:
How Blood pH Changes During Exercise
During exercise, the body's metabolism accelerates, leading to increased production of carbon dioxide (CO2) and lactic acid in the muscles. The increase in CO2 levels causes more hydrogen ions (H¹) to be produced when it reacts with water, forming bicarbonate (HCO3⁻). This process results in a decrease in blood pH. Conversely, when the blood pH drops too low, an increase in breathing rate helps to lower the blood concentration of CO2, which tends to correct the pH by decreasing the hydrogen ion concentration.
Lactic acid is also neutralized by bicarbonate ions in the blood, forming carbonic acid (H₂CO₃), which breaks down to CO2 and water that can be exhaled through the lungs. As breathing rate increases to exhale excess CO2, this mechanism helps prevent acidosis by regulating the blood pH.
Additionally, blood contains buffers that help regulate its pH and prevent drastic pH alterations. The blood's pH typically ranges between 7.35 and 7.45, and is slightly more alkaline than pure water which has a pH of 7.0. The body's buffers, along with respiratory adjustments, work together to maintain this crucial balance between acidity and alkalinity.