What organ is critical for regulating acid-base balance in the body?

The kidneys play a vital role in regulating the acid-base balance of the body through a process called renal regulation. They manage this by excreting hydrogen ions and reabsorbing bicarbonate from urine, which helps maintain the optimal pH level in the bloodstream. By adjusting the amounts of these substances excreted or reabsorbed, the kidneys can effectively control the acidity and alkalinity of the body’s fluids.

Additionally, the kidneys contribute to metabolic processes that influence overall homeostasis, including the management of electrolytes and waste products. This role is crucial because the body's enzymatic functions and overall metabolic health depend heavily on maintaining a stable acid-base balance. Other organs, such as the lungs, also play a role in regulating acidity through gas exchange, but the kidneys have a more direct and sustained impact on long-term acid-base homeostasis.