why do we yawn ?

Question

why do we yawn ?

anonymous · Answer

Acording to many studies, we yawn because we have low levels of oxygen in our lungs. Usually this is associated with sleeping, and we have lower breathing rates when we sleep. So when we wake up, we tend to yawn.

priths · Answer

but we also yawn when when we are not waking up . what you have got to say about this ?

anonymous · Answer

You yawn usually in the day when you are sleepy. when you are sleepy you have lower blood pressure and you are calm, and the oxygen is being transported around your body at a lower rate. It can be an involuntary reflex also

anonymous · Answer

Yawning might serve a social function (to communicate boredom) and a physiological function (regulation of body state). http://www.loc.gov/rr/scitech/mysteries/yawn.html

anonymous · Answer

Ooh I highly recommend you watch this! Vsauce is such an awesome YouTube channel: http://www.youtube.com/watch?v=jGIbUK4nw00

anonymous · Answer

Also, according to the video, people do not yawn more when they exercise (and need more oxygen in the body to fuel the mechanical reactions) so that kind of disproves the myth of "yawning to get more oxygen in our lungs."