Hypoxia and Medicine

When a commercial airliner flies above 10000ft, why doesn't anyone on board suffer from hypoxia?

Having worked on fighter aircraft, I realise that they have liquid oxygen to supplement the poorer oxygen at higher altitudes, but I know that commercial airliners do not carry LOX, so how is the extra oxygen found when they travel at 30000ft while cruising?

Public Comments

1. The cabin is pressurized. http://www.craggyaero.com/hypoxia.htm
2. The reason nobody suffers from hypoxia is that the plane cabins are all pressurized which is essential over the 10,000 feet level.
3. The cabins are pressurized to around 8000 feet. There is supplemental oxygen provided for the crew and passengers in the event of depressurization. The emergency oxygen is ether in high pressure bottles or in solid form in oxygen candles.