It uses the Latin words for heart (cardio) and a small vessel (vasculum).
respiratory.
The Cardiovascular System is comprised ot the heart and all of its arteries and veins. There is no particular organ called 'the cardiovascular'.
Because if it wasn't you would have massive internal bleeding, be extremely cold and die within seconds, imagine your circulatory system is like central heating which is also a closed system ,what...
the cardiovascular system works with the respitary system and... im not sure what else