Oxygen and Respiration: DGCA Air Regulations questions

Breathing at altitude is a matter of pressure, not proportion. Here you learn how the falling pressure of oxygen in the lungs leads to hypoxia and how oxygen equipment restores it.

The 26 questions lean on figures: alveolar partial pressures, the height at which pressure halves, equivalent altitudes on 100 per cent oxygen, and times of useful consciousness. Others cover hyperventilation, diving before flight and decompression sickness. Exam sessions have put 2 of these in front of candidates.

Do not assume the air holds a smaller share of oxygen high up. It stays near 21 per cent at every height; only its partial pressure falls. Hypoxia and hyperventilation share dizziness and tingling, so at altitude treat those symptoms as hypoxia and go on oxygen first.