2006-10-30 07:40:22 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Biology
It is thought to be related to being tired or sleepy, but the exact cause of yawning still is unknown. sorry.
2006-10-30 07:48:32 · answer #1 · answered by tiff-so-fierce 5 · 0⤊ 0⤋
When I was little, I got a book called why does my nose run. In the book was a little part on yawning. We all think we yawn because we are tired, but in reality, we yawn because we have been sitting quietly and breathing shallowly. Yawning is our bodies way of forcing us to take a deep breath and take in large amounts of oxygen.
2006-10-30 15:49:03 · answer #2 · answered by iceprincess_12_04 3 · 0⤊ 0⤋
your lungs need more oxygen ....and usually when your tired u take smaller breaths of air so your body makes you yawn to take in more oxygen!
2006-10-30 15:47:55 · answer #3 · answered by ~jessi~ aka....mommy 5 · 0⤊ 0⤋
Physiological trigger by the brain to pull in more oxygen.
2006-10-30 15:43:08 · answer #4 · answered by ntoriano 4 · 1⤊ 0⤋
lack of air circulation, which is why it appears to be contagious in a room full of people and also why opening a window seems to cure it.
2006-10-30 15:49:53 · answer #5 · answered by Diana P 3 · 0⤊ 0⤋
im tired
2006-10-30 15:42:07 · answer #6 · answered by Anonymous · 0⤊ 0⤋