Why is Yawning Contagious? : Everything You Ever Wanted to Know About the Human Body and Some Things You'd Rather Not Know Paperback
Everything you ever wanted to know about the human body - and some things you'd rather not...A wonderfully entertaining yet authoritative treasure trove of facts about our anatomy - it answers all the questions about our bodies we're usually too embarrassed to ask.* Why is yawning contagious?
Some experts think that yawning may have developed as a means of communication.
It may, for example, be a way of signalling to others that it's important to remain alert and stay awake in a certain situation.
Another theory is that our early ancestors used it as part of their social behaviour, and as a way to help build a bond with the rest of the group.* Why are bogies green?
When white blood cells meet germs, they make a large amount of an enzyme called myeloperoxidase, which is green because it contains a lot of iron.
The colouration therefore comes from the iron.
- Format: Paperback
- Pages: 240 pages
- Publisher: Little, Brown Book Group
- Publication Date: 25/10/2007
- Category: Popular medicine & health
- ISBN: 9780749951580