Final answer:
When carbonic acid releases a hydrogen ion, it causes the pH to drop, prompting the brain to increase the rate and depth of breathing to exhale more carbon dioxide and restore normal pH levels.
Step-by-step explanation:
When carbonic acid releases a hydrogen ion, this leads to a decrease in the pH, making the blood more acidic. This change in pH is detected by chemoreceptors in the brain, particularly in the medulla and major arteries. The medulla responds to the acidity by sending signals to increase the rate and depth of breathing. This process helps to excrete excess carbon dioxide, which in turn reduces the levels of hydrogen ions, thereby raising the blood pH back toward normal.
The increase in hydrogen ions due to carbon dioxide leads to more carbonic acid in the blood, further reducing the pH level. The body maintains homeostasis by increasing ventilation to expel the excess carbon dioxide, effectively moderating the blood's acidity. This respiratory response is critical for maintaining the delicate balance of acids and bases in the body.