What respiratory change occurs as a compensation for metabolic alkalosis?

In cases of metabolic alkalosis, the body attempts to compensate for the increased blood pH by decreasing the respiratory rate. This decrease in respiration helps retain carbon dioxide (CO2) in the blood, which can increase the level of carbonic acid, thereby lowering the alkalinity of the blood and bringing the pH closer to normal.

When metabolic alkalosis occurs, the body recognizes the lower levels of CO2 as a challenge to homeostasis. By slowing the breathing rate, this allows CO2 to accumulate and partially counteracts the alkalosis. The important concept here is that the respiratory system plays a crucial role in maintaining acid-base balance, and in the case of metabolic alkalosis, the compensation involves a response that leads to respiratory acidosis by holding onto CO2.

Other options, such as increasing the respiratory rate or hyperventilation, would actually lead to further lowering of CO2 levels, exacerbating alkalosis rather than correcting it. Therefore, it is the decreased respiratory rate that effectively serves as the compensatory mechanism in metabolic alkalosis.