Body requires fluids to transfer all necessary nutrients throughout the body. The human body requires certain implied organs to take of distribution of nutrients. One such essential organ is heart. The heart functions throughout lifetime of any organism rendering effective supply of nutrients and gaseous essentials. The whole circulatory system that functions with blood as carrier can be treated as cardiovascular system.
Cardiovascular system differs for organisms termed vertebrates and their counterparts referred as invertebrates. The living beings grouped under vertebrates have morphologically structured to have channeled transfer of blood with closed blood vessels. Also the movement of blood can carry oxygen and also carbon dioxide to all basic units of body. Invertebrates are characterized to have open supply of blood in their body.