Why do we yawn?

@bryanski (497)
Philippines
September 28, 2008 2:47am CST
Do you know why do we yawn? Is it because of boredom and drowsiness or is it really only of scientific reasons?
2 responses
sunuxu
@sunuxu (91)
• Vietnam
28 Sep 08
yawning is a conditioned reflex of the body when someone is getting bored or sleepy. When you yawn, you will get more oxygen into the body, which to let you become more concious. That's why we yawn when we get sleepy. Yawn~..
corngrass
@corngrass (727)
• Malaysia
28 Sep 08
From what i was told is because our body is lack of oxygen so the body forces us to take in a big breath so the oxygen can go in and circulate to the needed part of the body, especially the brain.