CIRCULATORY SYSTEM

The circulatory system is the blood and the heart  .Do that circulate blood throughout the body.The system you also leads unidirectionally toward the heart to the heart and blood pump back out through the body.

The main function of the circulatory system is to pass nutrients .

*Closed circulatory system: In this type of circulatory system blood travels through the interior of a network of blood vessels, without leaving them.

*Open circulatory system: In this type of circulation system in which blood is not always contained in a network of blood vessels.

*Simple blood circulation, blood passes once through the heart at every turn . 

*Double circulation, blood passes twice through the heart at every turn.