What mechanism helps maintain homeostasis when blood acidity increases?

The mechanism that helps maintain homeostasis when blood acidity increases is respiratory and renal compensation. When blood pH decreases, indicating increased acidity (often due to excess carbon dioxide or metabolic processes), the body initiates two primary responses to restore balance.

Firstly, the respiratory system responds by increasing the rate and depth of breathing. This hypoventilation helps to expel more carbon dioxide from the blood, which reduces the acidity (increases pH) because carbon dioxide can combine with water to form carbonic acid. Thus, reducing carbon dioxide levels leads to a decrease in the concentration of hydrogen ions, which are responsible for acidity.

Secondly, the renal system plays a crucial role by adjusting bicarbonate reabsorption and hydrogen ion secretion. The kidneys can excrete more hydrogen ions into the urine and reabsorb bicarbonate from the urine, thereby helping to neutralize the acid in the blood and restore normal pH.

Together, these compensatory mechanisms serve to correct the pH imbalance effectively, demonstrating the body's ability to adjust physiological functions to maintain homeostasis in response to changes in blood acidity.