Though it is said that Yawning is often connected to sleepiness.Yawning is not just a human response. Most animals yawn as it provides relaxation too.Technically, a yawning is a reflex widening of the mouth which is followed by the the process of deep inhalation and slow exhalation of oxygen .
It is an involuntary reflex action controlled by the spinal and nerve centers of our body.A yawn lasts about six seconds.One should very well know about the physical benefits of yawning,it is generally seen on a plane, as it aids to balance the air pressure between your middle ear and cabin air during take off and landing of the airplane.thus we notice that we yawn because oxygen levels in our lungs is ow.A wide prolonged yawn has some benefits. It helps in exercising our jaw and facial muscles and stretches our lungs too. It also increases blood flow to the brain, raises our heart rate and helps with breathing. The out come is that we feel a little more awake after wards.
Researchers has also found out that our brain burns up to 33% of the calories we consume and generate heat.yawning cools our brain cells as it is involved in a process of long inhaling of oxygen and thus make them more efficient as it is known fact by know that oxygen activates the cells ,It has also been found that the process of yawning increases the blood flow and helps maintaining the optimum level of functioning ,They say we are hard wired to yawning .It helps us to stay alert and protect our self from danger.
Finding show that fetuses have been observed yawning in the womb,even though they don't inhale oxygen in through their lungs.Moreover it is also observed that we yawn when we get up in the morning, even after a good night's rest.May be we start a day with a long yawning because inhaling plenty of oxygen help us to activate our mind for a day's work.
Studies have shown that during our normal, at-rest breathing position, we often don't use our lung to their full capacity and breathe enough air,our body typically just use the air sacs at the bottom of the lungs, these air sacs called alveoli,when do not get enough fresh air, they partially collapse and our lungs stiffen a bit. As a result,our brain send message to our body to take a yawn to get more air into the lungs by deep breathing.