Circulatory system

This is very good and simple explanation about the circulatory system!

The respiratory system

Go inside the human body and see first-hand how the respiratory system works. Vivid animation and real-life examples demonstrate the respiration process, including the transfer of oxygen into the bloodstream and the effect of exercise on the respiratory system. From the Australian educational program 'The Body in Motion: An Introduction',

The circulatory system song

Hey! This song is really funny and we heard/watched it for the first time
 in science which was part of our human biology unit! If you actually learn 
to memorize it it can be really helpful! LOL! So hope you enjoy!

Modelling the human body