| The circulatory system includes a heart that pumps blood into an open body cavity or hemocoel. |
| Maturation of the oocysts leads to sporozoite release into the hemocoel. |
| The main body cavity is a hemocoel through which blood and coelomic fluid circulate and which encloses most of the other internal organs. |
| Arthropods also have a hemocoel, an open body cavity in which blood flows and bathes the tissues and organs. |
| Each gill has an incoming blood vessel connected to the hemocoel and an outgoing one to the heart. |
| The circulatory system is open and consists of a heart, arteries, and the open spaces of the hemocoel. |
