Blood And Circulation! (Introduction)

Small, single-celled organisms can gain no use by a circulatory system. But large, multicellular organisms (i.e. animals) need a circulatory system.

I think I already have 9 or something systems in my body. Do I have to have some nore extra weight into this body of mine?!

The answer is (drumroll please!)  Yes! You need this body system because it is very important! I mean you need your blood up and pumping to get to work right? Who doesn't? Well, I guess single-celled organisms won't but I certainly do!

Well.. Check out the next post about the types of the circulatory systems and the need of circulatory systems!