VPB 121: Veterinary Physiology - II (2+1)

FORMATION OF HCO₃ IN PLASMA

• The Chief buffers of plasma that provides for buffering action by combining with H⁺ is protein system (Proteinate / Protein)
• The reaction is plasma is as follows :

• The PCO₂ in tissues is higher than in arterial blood causes diffusion of CO₂ into blood and forces the preceding reversible reaction to the right causing an increase in HCO₃. This increase in HCO₃ represents transport due to plasma proteins.
• When venous blood reaches the lungs, CO₂ diffuses into alveolar air and is exhaled out. This causes the preceding reaction to shift to left.
• The pH of arterial plasma decreases about 0.025 units in becoming venous plasma.
• The transport of CO₂ as HCO₃^- by plasma proteins represents about 4% of total CO₂ transport.