Why do we yawn?



Why do we yawn?

Introduction

All living beings yawn in all phases of life regardless of age factor. It is observed to be a non voluntary activity involving opening of mouth, inspiring deeply, short apnea, and slowed expiratory procedure in mammals. The process of yawning may also involve activities like stretching. The process of yawning takes about 6 seconds in human beings and the number of its occurrences remain stabilized over a weak time period. Whereas yawning can also be found in birds, where they open their mouth slowly for a time period of about 3 second and once done close it instantly. Yawning is a common process observed in all living species with the similar conditions and activities. The researchers have observed and found that yawning has some sort of advantage and many hypothetical behaviors have been considered as logical reasoning behind yawning. The scientists have observed that 90% of yawn incurred among mammals is during the resting sessions and others yawns are usually result of social and environmental effects. On the basis of this explanation yawns can be categorized into social and physiological types. As per physiological characteristics of yawn, it is worth mentioning that yawning has the particular effect on regulating the level of oxygen in blood and brain that is why the process of yawning is referred to as a homeostatic system having negative feedback. Therefore, the process of yawning is either a result of up or down state of body or it simply occurs as a analogous function of body. The social phenomena of yawning demonstrate that yawning may be result of social communication and interaction (Walusinski, O., Deputte, B.L., 2004).

Discussion

Yawn is controlled by various neurotransmitters, hormones, and neuropeptides. Substances of Neuroendocrine assist the process of yawning. Yawning occurs as a result of interaction between some intermediaries and PVN i.e. paraventricular nucleus of the hypothalamus. Earlier in 4th century, scholars and scientists used to agree on common phenomena that yawning is a process that results in reduction of bad air from lungs and also helps in increasing the circulation of oxygen in brain. On the contrary, some scientists observed that yawn is incurred as a result of insufficiency of oxygen in blood and brain and also due to increase of carbon dioxide. But it is worth taking in to account that normally people are not observed to yawn while working out and need ...