Quote:
|
I believe that the yawn response is brought on by the body's need to increase the oxygen level in the blood.
|
Quote:
|
Originally Posted by C1ay
This article supports that claim... |
Actually, it contradicts that idea:
Quote:
|
A long-standing theory behind yawning is that yawning is caused by an excess of carbon dioxide and lack of oxygen in the blood. The brain stem detects this and triggers the yawn reflex. The mouth stretches wide and the lungs inhale deeply, bringing oxygen into the lungs and thence to the bloodstream. It is almost certain however, that this hypothesis is not correct;
|
