Yawning is a simultaneous reflex motion of air and a stretching of the eardrum that ends with exhaling. The average yawning duration occurs for five seconds.
The cause of yawning is still unclear until now. There are many theories associated with this activity. Here are some of the medical theories about yawning:
1. The body feels fresh
The refreshing effect after yawning is caused by the stimulation of the carotid artery that is suppressed when the movement of yawning. The pressure in the carotid arteries causes blood to flow in the face area to increase and the body responds by releasing the hormone adenosine and catecholamine that play a role to make the body feel fresh.
2. Yawning is the same as drowsiness
Many people associate both. According to some studies, yawning is closely related to fatigue and is a sleepy episode.
3. Bored
According to research, yawning is also closely related to repeated activities. For example learning activities in the classroom, driving, studying, and watching television.
4. Cooling the brain
One of the theories links yawning as a way of cooling the brain. When yawning, hot air in the brain is believed to come out because of cold air come into the body when we are taking a deep breath.
5. Empathy
When someone yawns usually people around him will also yawning. According to research, this activity is contagious and is a form of communication to show empathy to others.
6. Reduce discomfort in the ear
Yawning is also a body's defense mechanism while at altitude. You do this by reducing the air pressure inside the middle ear and equating with outside air pressure.
7. Too much to eat
When you eat food in large quantities, the body will automatically parse the food with the help of oxygen. When all oxygen supplied to the digestive organs, the brain will a shortage of oxygen supply, it's causing the reaction to yawn.
Apparently, yawning not only has a connection with sleepy. There are still many other factors that can cause a person to yawn.
