The ventral blood vessel carries blood to the back portion of the worm's body. The ventral blood vessel is only one part of the worm's closed circulatory system. The other parts of the worm's circulatory system include the aortic arches and the dorsal blood vessels.
Blood is circulated exclusively through the worm's three main vessels to carry supply to its organs. There are five pairs of aortic arches, and they serve the same function as the heart does in humans. The arches pump blood into both the dorsal and ventral blood vessels. The dorsal blood vessels carry blood to the front of the worm's body.
The worm's anatomy consists of a segmented body, digestive system, circulatory system and respiratory system. Its segmented body features a number of small rings that are fused together to provide structural support for the worm's body. Each ring also forms a section that contains muscles and hairs, called setae, that allow the worm to move through dirt. The worm's digestive system is made up of the pharynx, the esophagus, the crop, the intestine and the gizzard. Soil enters the worm's mouth and is swallowed by the pharynx before traveling to the esophagus. From there, the soil moves to the crop, where it is stored before moving to the gizzard.