Question

In a submarine, the oxygen supply was accidentally interrupted, causing the oxygen content of the air to drop. A machine that removes carbon dioxide continued to function, so there was no corresponding buildup of CO₂. None of the sailors felt short of breath or noticed anything wrong until several individuals fainted. Explain, in detail, using correct terms, why you think they did not feel short of breath.

Answer 1

CO2 is more potent chemoreceptor reflex stimulant than O2, When the Co2 level elevates, it stimulate the Chemoreceptor reflex,as a result the vasomotor reflex is activates and respiratory centres are stimulated,resulting into the hyperventilation to remove CO2 from the body,and as the atmosphere Co2 is continously removed its partial pressure in atmosphere remain below the partial pressure of CO2 in blood .Thus fainting does not occur.But as the O2 supply is interrupted O2 is not availble for body.thus Oxygen supply to the organ is affecting .As soon as the O2 saturation level decreases ,O2 supply to brain is getting affected and unconciousness can be seen in person and after some time they start fainting due to insufficient supply of Oxygen to brain .