Role of Kidney in pH control
Proteins, hydrogen carbonate and phosphate buffers in blood prevent excess hydrogen ions (H+), produced by metabolic activities from decreasing the pH of blood. Carbon dioxide released into the blood during respiration is regulated by this system and prevented from causing changes in blood pH prior to excretion in the lungs.
However, changes in pH of blood is counteracted by the distal convoluted tubules. In the distal convoluted tubules, carbon dioxide reacts with water to form hydrogen ions and hydrogen carbonate.
H2O + CO2 ↔ H+ + HCO3–
When the blood pH decrease, the distal convoluted tubules secretes H+ into tubules and retain HCO3–. H+ react with ammonia for form ammonium ions (NH4+) that is excreted in urine.
When the pH of blood rises, the tubules secretes HCO3– ions and retain H+ lowering pH.
Please find free downloadable notes, exams and marking guides of agriculture, biology, and chemistry from digitalteachers.co.ug website.
Dr. Bbosa Science
