An earthworm's digestive system has many body parts, including the pharynx, crop, esophagus, gizzard and intestine. The digestive system processes food and absorbs the nutrients. The crop stores food.
Earthworms have closed circulatory systems, which means they circulate blood exclusively through blood vessels to supply organs with blood. The main vessels are the dorsal blood vessels, the ventral blood vessels and the aortic arches.
Earthworms breathe air through their skin. The earthworm's skin must stay moist for carbon dioxide and oxygen to pass through.
Earthworms are hermaphroditic creatures, which means they contain both female and male sex organs. Despite this, most earthworms must have a mate to reproduce.
Earthworm bodies are segmented into 100 to 150 joined rings. Their segmented bodies make earthworms flexible, strong and mobile.