During alkalosis, which ion does the kidney excrete more of?

During alkalosis, the body experiences an increase in blood pH, indicating a higher concentration of bicarbonate ions (HCO3-) or a loss of hydrogen ions (H+). To restore acid-base balance, the kidneys play a crucial role in regulating the excretion of ions.

When the body is in a state of alkalosis, the kidneys compensate by excreting more bicarbonate ions (HCO3-). This adjustment helps to decrease the bicarbonate concentration in the blood, which aids in lowering the pH back toward normal levels. Excreting HCO3- decreases the buffering capacity of the blood and contributes to restoring acid-base equilibrium.

The other ions in the list are not typically excreted in greater amounts during alkalosis. For instance, H+ ions would be retained or not excreted as much in response to a higher pH, as the body seeks to avoid further alkalinization. Calcium ions (Ca2+) and sodium ions (Na+) are also regulated differently and do not play a direct role in the immediate compensation for alkalosis like HCO3- does. This physiological response highlights the intricate balancing act that the kidneys perform in maintaining homeostasis during changes in acid-base status.