1. Roundworms

2. Phylum Nematoda 1.Nematode: “round” 2.Live in most envir. 3.Free-living or parasitic 4.Smaller than flatworms, taper at both ends 5.Thick outer covering to protect them from stomach acid

3. 1.Move bodies with thrashing motion 2.Bodies have two openings: mouth and anus 3.Pseudocoelomates 4.Sexually reproduce: a.Male & Female b.some hermaphrodites

4. Life Cycles of Parasitic Roundworms A. ASCARIS 1. Lives in intestines & feeds off blood 2. Ingest eggs from dirty hands or unwashed veggies contaminated w/fecal matter 3. Eggs hatch in int. & enter bloodstream 4. Larval worms bore into lungs 5. Must be coughed up and swallowed 6. Move to intestines where they mature

6. 1. Bore into muscles 2. Cause painful cysts 3. Live in intestines 4. Ingest cysts in undercooked raw meat undercooked raw meat (usually pork) (usually pork) 5. Cysts open up in intestines & reprod. 6. Larvae move into muscle tissue & form cysts B.TRICHINELLA

8. HOOKWORMS C. HOOKWORMS Lives in intestinesLives in intestines Feeds on bloodFeeds on blood Causes major damage to intestinesCauses major damage to intestines Eggs deposited on soil from contaminated wastesEggs deposited on soil from contaminated wastes Larvae live in soilLarvae live in soil Burrow into feet or exposed skin of hostBurrow into feet or exposed skin of host Larvae travel through bloodstream, to lungs, coughed up, swallowedLarvae travel through bloodstream, to lungs, coughed up, swallowed Attach to intestinal wall where they matureAttach to intestinal wall where they mature

10. C. PINWORMS Most commonly infects childrenMost commonly infects children Lives in intestinesLives in intestines Ingest eggs from contaminated soil or sandIngest eggs from contaminated soil or sand Hatch in intestinesHatch in intestines Female lays eggs near anus at night causing severe itchingFemale lays eggs near anus at night causing severe itching

12. D. Filarial Worm  Filiariasis is the name for a group of tropical diseases caused by various thread-like parasitic round worms (nematodes) and their larvae.  The larvae transmit the disease to humans through a mosquito bite.  Filariasis is characterized by fever, chills, headache, and skin lesions in the early stages  If untreated, can progress to include gross enlargement of the limbs and genitalia in a condition called elephantiasis.

13. Quiz: Roundworms 1.Nematodes are ___ worms. a. flat b. round c. segmented 2. Roundworms have two body openings: ___. a. mouth, pharynx b. osculum, anus c. mouth, anus 3.Ascaris worm infections come from ___. a. dirty hands or infected vegetables b. infected fish or other meats c. pond water 4. Hookworm infections come from ___. a. dirty hands or infected vegetables b. infected fish or other meats c. walking barefoot on infected soil 5.Female ___ lay their eggs near the anus at night causing severe itching. a. ascaris worm b. pinworms c. trichina worms