|
1. Blood flows through large open spaces called lacunae and sinuses
|
1. Blood flows through closed system i.e. heart and blood vessels
|
|
2. No capillary system so tissues are in direct contact with blood (hemolymph)
|
2. Capillary system present so blood is not in direct contact with tissues
|
|
3. Exchange of nutrients and gases takes place directly between blood and tissue
|
3. Nutrients and gases pass through the walls of capillaries to tissue fluid which is then taken up by the tissues
|
|
4. Volume of blood flowing through tissues cannot be controlled as blood is flowing through open spaces
|
4. Blood flow is controlled by contraction and relaxation of muscles of blood vessels
|
|
5. Blood flow is very slow
|
5. Blood flow is rapid here
|
|
6. Found in higher invertebrates like most arthropods such as prawns, cockroach etc. and in some molluscs
|
6. Found in some molluscs, annelids and all vertebrates
|
