Describe how carbon dioxide (CO2) is carried in the blood.
It was expected answers would describe each of the main categories of how CO2 is carried:
Dissolved (10%), Plasma Bicarbonate (70%) and conjunction with plasma proteins and Hb as
Carbamino Hb (20%). An opening statement quantifying the amount of CO2 dissolved in
arterial (48mL/100mL) and venous blood (52mL/100mL) (4mL/100mL) and how this
compares with Oxygen was expected (20 times more soluble).
For dissolved CO2, the application and description of Henry’s Law was awarded marks.
A description of the consequences of the Haldane effect: difference in CO2 carriage of
oxygenated and deoxygenated blood was expected. A diagram of pCO2 v CO2 content was