What is the circulation of the arthropoda?

Answer 1

The arthropod circulatory system is described as "open" and revolves around a strategy of having an internal body cavity (hemocoel) in which the organs and cells are bathed, and from which nutrients are acquired. The fluid used is called hemolymph and could be said to combine the function of blood and lymphatic fluid as in chordates. Not all arthropods use hemolymph to oxygentate tissues; insects for instance have tubules connected directly to the air through holes in their segments called spiracles, connected to tubules which supply tissues with oxygen. Those arthropods that do oxygenate the hemolymph capture oxygen using hemocyanin, a substance which floats freely in the hemolymph and is not bound to proteins on the surface of blood cells.

The circulatory fluid drains into open-ended pores called ostia, and may be pumped through a simple dorsal tube-like "heart". Arthropods movements can also be responsible for the hemolymph circulation but they do not have well-developed mechanisms like most vertebrates to deliver circulatory fluid to a specific organ or body location.