Describe how carbon (IV) oxide produced by the liver cell reaches alveoli cavities in the mammalian lungs.

-Carbon (IV) oxide is in higher concentration in tissues than in blood; it diffuses out of the tissues into blood; and then into red blood cells where it combines with water to form weak carbonic acid; catalyzed by enzyme carbonic anhydrase; weak carbonic acid then dissociates to form hydrogen carbonate ions and hydrogen ions; hydrogen carbonate ions diffuse out red blood cells into plasma; Some carbon (IV) oxide (10%) combines with haemoglobin to form carbaminohaemoglobin in red blood cells; About 5% of carbon (IV) oxide dissolves in plasma to form weak carbonic acid; which are transported in blood into to the vena cava; to the right atrium/ auricle; through tricuspid valve; into the right ventricle; through semi-lunar valve; and pulmonary artery; into the lungs; where it diffuses across the endothelium of capillary; and epithelium of alveolus into alveolar cavity;