The Digestive System of a Giant Roundworm in Humans (Ascaris Lumbricoides)
This giant roundworm consists of one long tube connecting the mouth to the anus of the worm. This consists of a mouth, a short pharynx, a long intestine, a short rectum, and an anus. The roundworm's food consists of blood, which is sucked in by the pumping inside its pharynx. Next, digestion happens inside of the intestine. This digestion is extracellular, meaning it happens outside of the cells. Then the digested food is absorbed by cells and is distributed throughout the body of the worm. Some cells do however digest the smaller particles of food inside of them. Food digested can also be absorbed directly through the skin. Finally, the digested food enters the short rectum, and the process is finished by excreting the waste through the anus.