Photo credit: Yves Adams
Scientifically speaking, yawning is a reflex of simultaneous inhalation of air and stretching of the eardrums, followed by exhalation of breath. Researchers have found that the reflex is definitely contagious. Continue reading to see ten more images that are designed specifically to make you yawn.
5 Interesting facts about yawning:
- Yawning is a behavior found in fish, reptiles and birds, as well as in humans. Described in ancient times by Hippocrates (who thought it served to evacuate fever), yawning did not become a subject of serious interest until the advances achieved in neuroscience in the 1980s.
- Generally speaking, yawning consists of three phases: first, a long intake of air, then a climax and finally a rapid exhalation, which may or may not be accompanied by stretching. After yawning, you generally experience a sense of well being and relaxation and feel much more present in and aware of your body than before a yawn.
- Contrary to what was believed for centuries, yawning does not serve to improve oxygenation in the brain. This myth was first laid to rest when it was discovered that the human fetus can yawn as early as the age of 12 weeks, even though it is surrounded by amniotic fluid in its mother's belly and so is unlikely to get any more oxygen to its brain from this effort.
- The role of yawning has yet to be fully determined. But because we yawn more often when we first awaken, when we are bored, and when we are trying not to fall asleep, its primary function would appear to be to help make us more alert. Yawning also seems to play a role in non-verbal communication, especially among primates.
- There is no nerve center strictly associated with the yawn reflex, but certain brain structures, such as the hypothalamus, the pituitary gland, and the brainstem are essential for its expression. Some scientists have even hypothesized that the strong contractions of the jaw muscles during yawning may stimulate the reticular formation and thereby encourage wakefulness.
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