Digestive system: The structure of the digestivesystem of round worm is very simple. The
Pharynx alimentary canal is formed of mouth aperture, buccal cavity, pharynx
and intestine. Mouth is situated at the anterior end of the body. Mouth
aperture opens into the buccal cavity. The pharynx is situated behind the
buccal cavity. The pharynx is somewhat bulk muscular and divided into three
chambers. With the help of the pharynx the roundworm sucks food materials from
the intestine of its host-body and gets nutrition. Behind the pharynx is
situated the narrow intestine. Posteriorly the intestine joins the rectum. The
rectum opens outside through the cloacal aperture.
Round worm has no digestive gland. As they directly absorb simple liquid
food from the body of the host they do not require digesting it further.