Interactive resources for schools

Select an age range to seek interactive content for...

What is the circulatory system?

The circulatory system is the transport system of your body. It delivers food and oxygen to your cells and removes the waste products such as carbon dioxide and urea. It is made up of blood (the transport medium), the blood vessels which act as the pipes and the heart which pumps the blood around the body.


The circulatory system

Your cells need a constant supply of food and oxygen to provide the energy needed for all of the reactions of the body. At the same time the cells are constantly making waste products which are poisonous if they are allowed to build up.

Food is absorbed from the digestive system and oxygen is picked up in the lungs to be carried in the blood around the body. The food molecules and oxygen move into the cells from the blood by diffusion.

Waste products also move from the cells into the blood by diffusion. They are removed from the body in the lungs or by the kidneys.

The blood is carried around the body in a system of blood vessels which vary in size and structure. The main types of vessels are the arteries, veins and capillaries.

To transport substances the blood must be moved around the circulatory system and this is the function of the heart. Your heart is a muscular pump which starts beating long before you are born and continues to beat throughout your life around 70 times every minute.

How to use this site

There are a number of interactive features in this e-source:

  • A glossary of terms: any word with a glossary entry is highlighted like this. Moving the mouse over the highlighted word will show a definition of that word.
  • Quick questions: at the end of most pages or sections there is a question or set of quick questions to test your understanding.
  • Animations: most of the animations can be expanded to full screen size, ideal for showing on an interactive whiteboard. The animations will play all the way through or can be viewed one section at a time.
  • Downloads: Teachers can download individual diagrams, animations and other content from the Download Library area of the website. Terms and Conditions apply.