AIIMS2008ZoologyBreathing and Exchange of Gases
When a man inhales air containing normal concentration of ( O ₂ ) as well as ( CO ) he suffers from suffocation because
Options
- A( CO ) reacts with ( O ₂ ) reducing its percentage in air
- Bhaemoglobin combines with ( CO ) instead of ( O ₂ ) and forms carboxyhaemoglobin
- C( CO ) affects diaphragm and intercostal muscles
- D( CO ) affects the nerves of the lungs.
Correct answer
B. haemoglobin combines with ( CO ) instead of ( O ₂ ) and forms carboxyhaemoglobin
Step-by-step solution
Affinity of carbon monoxide for haemoglobin is 200 times more than oxygen. At 0.5 partial pressure, CO combines with 50 % of haemoglobin. It produces a relatively stable compound called carboxy-haemoglobin. This causes low supply of oxygen to the body which is characterised by headache, dizziness, nausea, etc.