Roundworms have no heart or formal blood vessels.
Their circulartion system is very similar to humans (closed circulatory system)
I think is because the circulatory system of a reptile has the ability to redirect deoxygenated blood from the lungs to save energy.
A birds circulatory system consists of two loops.
Tigers are mammals and so their circulatory system is very similar to that of humans.
All bird species have different circulatory systems, for the most part the smaller species have an open system, while larger birds have a closed system.
Neither, it does not have one
Annelids are segmented whereas roundworms are not. Annelids have a true coelom while roundworms have a pseudocoelom. Annelids have a more complex nervous system than roundworms. Annelids have a more complex circulatory system than roundworms.
Yes roundworms have nervous systems!
closed circulatory system (double circulatory system)
They're both the circulatory system.
Amphibians have closed circulatory system Closed
There's many of them, but here are some of the bigger ones; Annelids, unlike roundworms (or flatworms for that matter) are segmented. That is after all how they get their name (annelida = little ring). Annelids also have a very complex organ system. Roundworms only possess a reproduction system as they usually live in an organism's intestines and don't need to digest food. Annelids posses both a reproduction system, and a digestive system as well as a circulatory system. As they are true coelomates their organs and organ systems are organised rather than just kinda' being tossed in there. =)
no
The circulatory system
open circulatory systemclosed circulatory system.
yes
The cadiovascular system, sometimes called the circulatory system when it includes the lymphatic system.