Function
As a person breathes, the body consumes oxygen and produces carbon dioxide. The oxygen metabolised is generally about 4% to 5% of the inspired volume at normal atmospheric pressure, and exhaled air still contains roughly 16% oxygen. The situation is even more wasteful of oxygen when the oxygen fraction of the breathing gas is higher. By adding sufficient oxygen to compensate for the metabolic usage, and rebreathing the gas, most of the volume is conserved. However, if this is done without removing the carbon dioxide, it will rapidly build up in the recycled gas, resulting almost immediately in mild respiratory distress, and rapidly developing into further stages of hypercapnia, or carbon dioxide toxicity. To avoid this problem, carbon dioxide is chemically removed in a component known as a carbon dioxide scrubber.
Read more about this topic: Rebreather
Famous quotes containing the word function:
“Every boy was supposed to come into the world equipped with a father whose prime function was to be our father and show us how to be men. He can escape us, but we can never escape him. Present or absent, dead or alive, real or imagined, our father is the main man in our masculinity.”
—Frank Pittman (20th century)
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