Which of the following are methods of acid-base regulation in the body?

The methods of acid-base regulation in the body include various physiological mechanisms that help maintain the pH within a narrow range, essential for normal cellular functions. The correct answer identifies three key processes: hydrogen ion (H+) removal, carbon dioxide (CO2) exhalation, and urine excretion.

H+ removal refers to the body's ability to neutralize excess acids, primarily through buffer systems in the blood. One of the main buffering systems involves bicarbonate ions, which can accept H+ ions to mitigate changes in pH.

Exhalation of CO2 plays a critical role in regulating acid-base balance. When CO2 is produced from cellular metabolism, it combines with water in the body to form carbonic acid. By controlling the rate of CO2 exhalation, the lungs can influence the concentration of carbonic acid in the blood, thus affecting the pH.

Urine excretion helps to eliminate excess H+ ions and acids from the body. The kidneys filter the blood and can either excrete or reabsorb bicarbonate, a crucial buffer, depending on the body's needs. This process allows for long-term regulation of acid-base balance by adjusting the levels of acids and bases in the bloodstream.

Together, these mechanisms ensure that the body's