Question

Why do we yawn when we feel drowsy or sleepy?

Answer 1

Hi there!

Same Query here:
https://brainly.in/question/2471971


Yawning is a stereotypical reflex characterized by a single deep inhalation (with the mouth open) and stretching of muscles of the jaw and trunk. 

It occurs in many animals, including humans, and involves interactions between the unconscious brain and the body.

Though the mechanism remains unclear. I'll tell most common reason "why we yawn?"

• We yawn when we’re sleepy or bored or if we see someone else yawn. 

• Some people also yawn when they’re anticipating something important and when they’re stressed. 

• Many think it’s because the brain lacks oxygen, but according to a new study, the thing most of these instances have in common is thermoregulation. 

• Yawning helps cool the brain. 

Cheers!

Answer 2

we yawn when we are tired,bored,feel sleepy or drowsy.we breathe slowly and take much less oxygen to make energy.so we need to open our mouth wide to take oxygen and fulfill our requirement of energy.