The pH of an avian blood is maintained by

Q. The pH of the avian blood is maintained by

The pH of the avian blood is maintained by HCO3 (bicarbonate).

The bicarbonate buffer system is an acid-base homeostatic mechanism involving the balance of carbonic acid (H₂CO₃), bicarbonate ion(HCO−
3), and carbon dioxide (CO₂) in order to maintain pH in the blood and duodenum, among other tissues, to support proper metabolicfunction. Catalyzed by carbonic anhydrase, carbon dioxide (CO₂) reacts with water (H₂O) to form carbonic acid (H₂CO₃), which in turn rapidly dissociates to form a bicarbonate ion (HCO−
3 ) and a hydrogen ion (H⁺) as shown in the following reaction:

${\displaystyle {\rm {CO_{2}+H_{2}O\rightleftarrows H_{2}CO_{3}\rightleftarrows HCO_{3}^{-}+H^{+}}}}$

As with any buffer system, the pH is balanced by the presence of both a weak acid (for example, H₂CO₃) and its conjugate base (for example, HCO−
3) so that any excess acid or base introduced to the system is neutralized.

Failure of this system to function properly results in acid-base imbalance, such as acidemia (pH<7.35) and alkalemia (pH>7.45) in the blood