Microlight » Human Factors » Hypoxia
Humans require oxygen which is transferred to the blood through the lungs and moved by a special molecule, haemoglobin.
The heart pumps the blood through the body to every cell, but the brain has the highest oxygen requirement.
After chemical reaction in the cells carbon dioxide is formed and this gas is also transported by haemoglobin in the blood to the lungs to be breathed out.
For normal body operation sufficient oxygen is required and if for any reason the amount of oxygen reduces the human body will start to degrade.
If the body cells do not receive enough oxygen the body organs - in particular the brain - will not function properly.
This condition of insufficient oxygen is known as hypoxia.
In flying, hypoxia is due to reduced atmospheric pressure at altitude.
The atmosphere is made up of 3 main gasses:
Nitrogen - 78%
Oxygen - 21%
Trace Gases - 1%