Question 2

Describe the production of carbon dioxide in the body (60% of marks).

What are the physiological reasons why the PaCO2 may be high? (40% of marks)

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College Answer

The main points for a pass include a brief description of the citric acid cycle and a list of facts
such as storage of CO2 (120L), production (200ml/min) and that 2 molecules of CO2 are
produced for 1 molecule ATP. A statement that PaCO2 is proportional to CO2
production/alveolar ventilation would help answer the second part. An example of increased
CO2 production is fever, and of decreased alveolar ventilation is increased anatomical dead
Syllabus B1h 2e
Power and Kam 2nd edition p78-79,101
Stoelting and Hillier 4th edition p790-791
Nunn 6th edition p148-156