What Makes Us Yawn?

Question

I used to think it was being sleepy. But now- getting older and wiser- I find that when I yawn I am not tired at all! I yawn randomly when I am in class, dancing, or even talking to someone. So- what makes us yawn?

Answer 1

Well i found some of these possible causes:

   1. The deep inhalation during a yawn is means of preventing alveolar collapse within the lung.

   2. The deep inhalation while yawning stretches type II alveolar pneumocytes, which release the surfactant dipalmitoylphosphatidylcholine (DPPC) into the layer of fluid on the alveolar surface.

   3. A means of cooling the brain.[4]

   4. An action used as an unconscious communication of psychological decompression after a state of high alert.

   5. An excess of carbon dioxide and lack of oxygen in the blood. [2]

   6. A way of displaying (or indicative of) apathy.

   7. Tiredness.

   8. A means of equalizing middle ear pressure, which can be triggered by another's yawning.

Also on another site i found these causes of excessive yawning:

    * Drowsiness or weariness

    * Disorders associated with excessive daytime sleepiness

    * Vasovagal reaction

          o Heart attack

          o Aortic dissection

Answer 2

When you get tired your breathing slows and then your body reacts to it. Once your breathing slows from your tiredness your body yawns to get more air into its system.

Answer 3

You yawn to allow your brain to get more oxygen, not because you're tired. It's a very common myth.

Answer 4

OH heck its just exercising your jaws...Well you might be tired and sleepy and dont even know it..