3.2.1 The buffer systems

The pH in the blood must be closely controlled and kept stable, and for this to work we have different buffer systems. A buffer is a substance that can bind both acid (H⁺) and bases (OH^–) so that the pH does not change much even if the amount of acid or base increases. The buffer resists pH changes. The three buffer systems we use are:

• the bicarbonate buffer system (HCO₃)
• the phosphate buffer system (HPO₄)
• the protein buffer system