Biology, asked by vinay25dhyani, 1 year ago

why do a human yaun ? what is the reason for it ?

Answers

Answered by vamshimotla
1
the scientific reason is that when blood supply becomes less the jaw muscles strech, and increse the blood flow towards the head.  
            The deep intake of breath during a yawn forces downward flow of spinal fluid and blood from the brain.
     Cool air breathed into the mouth cools these fluids.
Answered by Anonymous
0
When we are tired our lungs don't work properly, so our body receives less oxygen. Then the brain sends signals to yawn or to widely open mouth.

Anonymous: plz mark mine as best n click thnk u
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