Final answer:
The kidneys compensate for acidosis by conserving bicarbonate and secreting hydrogen ions into the urine to help maintain a balanced blood pH and mineral ion concentration.
Step-by-step explanation:
The kidneys play a crucial role in maintaining the body's acid-base balance and compensating for acidosis. When the blood pH drops and becomes too acidic, the kidneys respond by increasing the conservation of bicarbonate (HCO3-) and secreting hydrogen ions (H+) into the urine. This process involves the proximal convoluted tubule (PCT) cells actively secreting H+ as sodium (Na+) is reabsorbed back into the bloodstream, thus helping to raise the blood's pH back towards normal levels. Additionally, the intercalated cells of the collecting duct have proton pumps that actively secrete H+ into the urine, further contributing to the elimination of excess acid from the body. By managing the levels of H+ and bicarbonate, the kidneys help augment mineral ion concentration and water composition of the blood, achieving a proper balance and preventing the potentially serious consequences of an unregulated pH.