Final answer:
When blood is too acidic, the kidneys maintain pH balance by excreting excess H+ ions and reabsorbing bicarbonate ions, which involves the action of intercalated cells in the kidney.
Step-by-step explanation:
The kidneys play a crucial role in maintaining homeostasis of mineral ions, and they are also instrumental in regulating the acid-base balance in the body. When blood pH is too acidic, the kidneys can respond by excreting excess hydrogen ions (H+) in the urine and by reabsorbing bicarbonate ions (HCO3-) from the urine back into the blood, which helps to neutralize the acid and increase the pH. Additionally, the intercalated cells of the kidney’s collecting ducts play a significant role; these cells have proton pumps that actively secrete H+ into the urine, further contributing to the reduction of acidity in the blood.