They worried about air at first, but a few experiments proved there would be adequate oxygen even with the opening completely closed.

Reduced brain function is caused by inadequate oxygen in the blood despite adequate environmental oxygen.

Only in very confined spaces such as an empty refrigerator, does one have to be concerned with a lack of adequate oxygen for respiration.

If you're going to put airmen into earth orbit, how do you process their waste products, provide adequate oxygen, and sustain them during prolonged periods?

Problems with the placenta can prevent it from providing adequate oxygen and nutrients to the fetus.

You need adequate oxygen supplied to body tissues in order to feel properly energetic and have a zest for life.

In addition, you must breathe more to take in adequate oxygen.

Vicki on the surprising blessing of getting adequate oxygen (:40)

It showed that he still had adequate oxygen, though he did not.

In such disease conditions the microvascular arteries fail to provide adequate oxygen to the myocardium.