Medical helminthology, Flat and Round Worms, Life Cycle of Trematodes, Cestodes and Nematodes
Helminths or parasitic worms are multi-cellular, bilaterally symmetrical elongate, flat, or rounded animals. Helminths that occur as parasites in man belong to two phyla, Phylum Platyhelminthes (Flat Worms), and Phylum Nematoda (Round Worms).