Also, the hookworm takes in food through the intestine which stretches from the esophagus to the proctodeum and is a simple, tube-like structure made of a single layer of cells. Just about all of the digestive functions that occur in a hookworm occur in any other nematodes in which hookworms are just as parasitic.he stomodeum consists of the âmouth and lipsâ, buccal cavity, and the pharynx (esophagus). Each of these regions are used extensively in taxonomy as well as classification of nematodes, and for providing as indication of feeding habit or trophic group.