PPL » Human Factors » Hypoxia
10.10.2 Define hypoxia.
Hypoxia is a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level.
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.
10.10.4 State the partial pressure of oxygen both inside and outside the lungs at sea level.
As we climb into the atmosphere, the pressure around us reduces.
For example, at 18’000 the atmosphere has approximately half the weight as at the surface.
Even though the pressure is reducing, the percentages of each gas remain the same.
The weight of any gas in the atmosphere is known as the partial pressure, and it is measured in mm of Mercury (Hg).