開かい放ほう血けっ管かん系けい

noun

open circulatory system; open blood-vascular system

Biological term referring to a circulatory system where blood (hemolymph) is not always contained within vessels, as seen in arthropods and most mollusks.

• 昆こん虫ちゅうは開かい放ほう血けっ管かん系けいを持もつ。