YAWNING!

Serena Gutierrez

Dr. Boyd

Anatomy T/Th

September 21, 2011

Why Do We Yawn?

Did you know that if you yawn in front of a dog it may relax them. Yawning is often associated with being bored or tired, but there's actually more to yawning than that. Yawns usually last around six seconds and it increases your blood pressure, and heart rate. The earliest occurance of yawning is 11 weeks after conception. Yawning becomes contagious after the first year or two of life.

So you may ask, why do we yawn? The purpose of yawning is to cool the brain when it's overheated. Sleep deprivation and exhaustion increase deep brain temperatures and also prompt yawning in an attempt to cool the brain. However, excess yawning could increase brain-cooling issues. Yawning is also a way to stretch facial muscles. It relaxes the facial muscles after an open mouthed yawn.

Are yawns REALLY contagious? Studies show that the contagiousness of yawning is a sign of empathy. It is believed that in the past, yawning used as a signal to communicate with other humans and that it remained contagious now as a leftover response from human ancestors.