In the presence of a respiratory infection with high fever, how do kidney tubules help maintain normal pH?

The role of the kidney tubules in maintaining acid-base balance is crucial, especially during a respiratory infection accompanied by a high fever. In such conditions, the body's metabolism can shift, potentially leading to acid-base imbalances, and the kidneys must respond effectively.

The kidneys primarily maintain normal pH by regulating the levels of bicarbonate ions and hydrogen ions. When the body experiences an increase in acidity, such as during infections that may lead to lactic acid build-up, the renal tubules can compensate by secreting more hydrogen ions into the urine. Simultaneously, they increase the reabsorption of bicarbonate from the filtrate back into the bloodstream. By doing this, bicarbonate acts as a buffer that raises the pH of the blood back towards normal levels.

The ability to secrete acids and reabsorb bicarbonate is a vital mechanism of the kidneys to counteract acidemia—a state in which the blood becomes overly acidic. This is particularly important during illness when the body's metabolic demands change, and the need for maintaining homeostasis becomes critical. Thus, the correct answer accurately reflects this physiological process, highlighting how the kidneys play a key role in regulating blood pH during times of metabolic disturbance.