Yawning!

I think this comes under as health.
Why do you yawn when you're tired? I know yawning is a reaction to lack of oxygen but why is it also a sign of tiredness (if you yawn a lot while your tired)?

Reply 1

Glory

when your tired, your body isnt sending enough oxygen to your brain, its going to your other organs which keep you alive. Not sending it to your brain makes you sleep and eventualy helps you nod off. If you fight sleep you end up yawning more because you brain needs more oxygen to fight off the sleep.

Reply 2

Big Fat Mel

Yawning, as well as enabling the body to take in more oxygen, stimulates the Neumann Glands along the sides of the neck which, along with baroreceptors in the carotid sinuses, increase bloodflow to the brain and make the characteristic "yaawwwnnn" noise, associated with yawning.

Reply 3

generalebriety

Yawning also does weird things like regulate the pressure inside your ear. But that's a minor effect (albeit an important one). :smile:

Reply 4

grace

matt@internet

I think this comes under as health.
Why do you yawn when you're tired? I know yawning is a reaction to lack of oxygen but why is it also a sign of tiredness (if you yawn a lot while your tired)?

so it was you who neg repped me :rolleyes:

Reply 5

matt@internet

I ain't negged repped no-one :confused:

Reply 6

generalebriety

*jumps on double negative*

Ok then, new question. Why is yawning contagious? :smile:

Reply 7

Strictly Business

/yawns at this thread

Reply 8

pumpkin7

http://en.wikipedia.org/wiki/Yawning

Reply 9

The Mudman

There's also the fact that yawning is present in animals which cannot talk. It's a signal to the others that one member of the pack is tired, which in turn leads to others yawning, and feeling tired. This in turn leads to group bonding, and the pack going to sleep at the same time.