Benefits of yawning

Yawning

Yawning serves as thermoregulatory mechanism in other words it is like a radiator. The human brain takes upto 40 percent of body's metabolic energy. So it tends to consume more than other organ systems.
When we yawn the big gulp of air travels through the upper nasal and oral mucosa. When we stretch our jaw and mouth it increase the flow of blood to the skull. The deep inhalation through yawning cools the blood in the brain.
It mostly happen around bedtime or early in the morning as the temperature changes most at these times