The real function and purpose of the Circulatory system is to keep us alive (of course working in conjunction with the other systems of the body). The Circulatory system carries food and oxygen to all the cells of the body and then in response to that removes all waste products.
How does this question make sense. The heart allows for us to HAVE the circulatory system. The circulatory system is also known as the "transport system" without our heart (AKA the PUMP) there is no circulatory system.