The majority of carbon dioxide (CO2) in the blood is carried in which form?

The majority of carbon dioxide in the blood is carried in the form of bicarbonate ions. When carbon dioxide enters the bloodstream from the tissues, approximately 70% of it is converted into bicarbonate through a reaction facilitated by the enzyme carbonic anhydrase. In this process, carbon dioxide reacts with water to form carbonic acid, which then dissociates into bicarbonate ions and hydrogen ions. This bicarbonate is then transported through the plasma to the lungs, where it can be converted back into carbon dioxide and expelled from the body during exhalation.

Understanding this concept is crucial for those in the field of cardiovascular perfusion, as it relates to respiratory and metabolic processes as they impact gas exchange and acid-base balance in patients. It highlights the significant role that bicarbonate plays in the buffering system of the blood, aiding in maintaining pH homeostasis.