Less than one quarter, about 20 %.
brain
The brain consumes 40% of the oxygen in your blood.
Yes. In fact, such is the brain's demand for oxygen that it requires 20% of your total oxygen supply. This explains why it is served by so many blood vessels.
Asphyxiation - lack of Oxygen to the brain!
Carbohydrates and oxygen.
Because oxygen is used to burn glucose, the fuel preferred by the brain. At rest, you use about 20% of the oxygen you breathe to keep your brain running.
Mammoths are now extinct, but they were mammals just like we humans (unless you're not a human). They breathed in oxygen through their lungs and give out carbon dioxide.
Actually, no human being can go without oxygen for 4 minutes and be expected to live
The vital function that oxygen serves in the human body is respiration. Oxygen is needed for the lungs to function and for the proper functioning of other vital organs such as the heart and brain.
If by "shut down" you mean "die," then yes.
they supply oxygen to red blood cells, which in turn supplies oxygen to your muscles and brain...which are required to live.
It is a large muscle which constantly exercising your entire lifetime. However, the human brain requires even more glucose and oxygen. The brain consumes 20% of the energy available.