In cases of respiratory acidosis, what is true about the renal response?

In cases of respiratory acidosis, the body's pH level decreases due to an increase in carbon dioxide (CO2) levels, which leads to the accumulation of carbonic acid. To compensate for this condition, the kidneys play a crucial role in restoring acid-base balance.

The correct choice highlights that the kidneys increase ammonia production in response to respiratory acidosis. The ammonia (NH3) can combine with hydrogen ions (H+) to form ammonium ions (NH4+), which are then excreted in the urine. This process helps to remove excess hydrogen ions, effectively reducing acidity and assisting in the regulation of blood pH. Thus, by increasing ammonia production, the kidneys enhance their ability to buffer excess acids and restore homeostasis.

The other options do not accurately reflect the renal compensatory mechanisms at play during respiratory acidosis. Decreased production of ammonia would be counterproductive, as it would hinder the kidneys' ability to manage the increased acidity. Similarly, increased reabsorption of hydrogen ions or increased excretion of bicarbonate would not align with the body's need to counteract acidosis; instead, the kidneys actively work to excrete excess hydrogen ions and retain bicarbonate to help neutralize acidity.