Closed circulatory system, but fluid constituents of blood leak out of capillaries and return to the heart by the second component of the circulatory system, the lymphatic system. Considerable ...

As organisms with complex systems, there's a ton of messages that need to be passed between organs as well as an immune system that needs to respond to threats anywhere in the body. On top of this ...

3. Circulatory and respiratory systems - 2 weeks to do circulatory system - This week, do heart, blood vessels above the heart, respiratory system - Table 1 - heart to subclavian arteries - Table 2 ...

Learn about the circulatory system with these interactive learning resources for KS2 Science students aged 7-11 from BBC Bitesize.

The circulatory system takes oxygen around the body. Find out more in this Bitesize Primary 2nd level Science guide.