The aortic arches in an earthworm function like the valves in a human heart. An earthworm has five pairs of aortic arches that pump blood into the dorsal and ventricle blood vessels throughout the worm’s body.
An earthworm's circulatory system is a closed system, and there are three main vessels that run through an earthworm’s body, including the aortic arches and the dorsal and ventral blood vessels. The dorsal vessels carry blood to the front of the earthworm's body, and the ventricle vessels carry blood to the back of the earthworm's body. The aortic arches are an important part of the circulatory system.