This diagram shows how our blood flow changes!

Want to know more about warm-blooded animals?

Follow this twitter page to learn more about warm-blooded animals!

https://twitter.com/#!/learnabtwb

All you need to know about homeostasis!

This website is the easiest way to learn about every aspect of homeostasis!

http://www.brainpop.com/health/bodysystems/homeostasis/preview.weml

Homeostasis activity!

The video on this website is aa easy and fun way to learn all about homeostasis!

http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel/responses_to_environment/homeostasisact.shtml

Ever wonder why our arm hairs stand up?

So, we have all noticed that when we are cold the hair on our arms stand up right? This isn't magic guys! As you have already probably guessed, it has a scientific explanation!

The hairs on our skin trap more air if they are standing up, and of course less if they are lying flat. So then can you figure out why they stand up when its cold and why they lay flat when it's hot?

In colder weather the hairs stand up, because the hair muscles contract, to trap a thicker layer of air. So it cuts down even more on heat loss.

In hot weather the hairs lie flat, because the hair muscles are now relaxing, so less air is trapped close to the skin. So more heat is lost by radiation. 

Ever wonder why we sweat or shiver?

When it's hot our blood vessels widen at our skin surface, allowing more blood to flow to the surface so more heat is lost by radiation. This is called vasodilation. Our sweat glands also produce more sweat, so that it evaporates and this cools you down!

When it's cold our blood vessels close up at our skin surface. Cutting down the flow of blood to the surface, so less heat is lost by radiation. Sweat glands stop producing sweat. And our muscles start to contract quickly, in order to produce extra heat that warms your body. This is why we shiver!

Want to learn more about vasodilation?! Check out this blog:

http://vasodilationbuzz.blogspot.com/

How does the brain control our temperature?

As we said before, the brain is sort of the "thermostat" in our bodies. Depending if you are too cold or too hot the brain sends nerve impulses to the skins, in order to react depending if it is to increase or decrease the heat loss from the body's surface.