Final answer:
The kidneys maintain blood pH during acidosis by increasing bicarbonate reabsorption and hydrogen ion secretion in the renal tubules, a process which is essential for restoring acid-base balance and supporting metabolic compensation.
Step-by-step explanation:
The kidneys play a pivotal role in maintaining the acid-base balance in the body, especially during acidosis, when the blood pH is lower than normal. This physiological correction involves several renal processes. To counteract acidosis, the kidneys enhance the reabsorption of bicarbonate (HCO3-) and the secretion of hydrogen ions (H+). In the proximal convoluted tubule (PCT), cells secrete H+ into the forming urine, allowing for the reabsorption of sodium (Na+). Intercalated cells in the collecting ducts employ proton pumps that actively secrete H+ into the urine, effectively eliminating excess hydrogen and raising the blood pH. This adjustment helps to restore balance, contributing to metabolic compensation for conditions causing acidosis.
Through these mechanisms, the kidneys regulate the mineral ion concentration and water composition of the blood, while controlling the volume of extracellular fluids to maintain healthy blood pressure levels. The careful management of the body's mineral ions and acid-base balance is crucial for homeostasis and overall health and well-being.