1. Lab
Worms, worms & worms

2. Class Turbellaria
planaria
dugesia

3. Planaria

4. Dugesia
Asexual reproduction

5. Class Trematoda
female
male
female
male

6. Class Cestoida
scolex
tapeworm

7. tapeworm oncospheres
tapeworm cystericoids
tapeworm oncosphere
pinworm cystericoids

8. Phylum Nematoda
male is smaller, thinner & has a hooked end

10. intestine
intestine
testes & vas deferens

11. Enterobius vermicularis: human pinworm
most common roundworm parasite in the US
very common in children
adults live in the lower region of the large intestine
at night – gravid females migrate out of the cecum to the perianal area – deposit eggs – extreme itching
ingestion eggs continues the lifecycle

12. Necator americanus: the New World hookworm
found in the southern US
adults live in the small intestine – hold onto the intestinal wall with teeth
feed on blood and tissue fluids
females may produce as many as 10,000 fertilized eggs per day which pass out through the feces
egg hatches in warm, moist soil and releases a small larvae called the rhabditiform larva
this larva molts to become the infective filariform larval stage – penetrate the skin of humans (between the toes)
burrows into the circulatory system
symptoms: most individuals with hookworm infection are asymptomatic
very high loads of the parasite or poor nutrition combined with infection lead to anemia.
pain in the stomach, pica (or dirt-eating), obstinate constipation followed by diarrhea, palpitations, small and unsteady pulse, coldness of the skin, pallor of the skin and mucous membranes, diminution of the secretions, loss of strength and, in cases running a fatal course, dysentery, haemorrhages and oedema.
hookworm prevalence is often higher among adult males

13. Ascaris lumbricoides: giant intestinal roundworm
800 million humans worldwide may be infected
adults live in the small intestines of humans
penetrate the intestinal wall
generalised digestive disorders, such as a vague abdominal discomfort, nausea, colic.
may contribute to malnutrition in the host,
in heavy infections, the mass of worms may block the intestine and need to be surgically removed.
produce large numbers of fertilized eggs that exit with the feces
can be carried via the circulation to the lungs – molt twice, travel up the trachea and are swallowed
migration of larvae through the lungs can give rise to severe haemorrhagic pneumonia.
may lead to breathing difficulties, pneumonia and/or fever.
Infections with A.lumbricoides are easily treated with a number of anthelmintic drugs
levamisole, mebendazole, albendazole

14. Trichinella spiralis: porkworm
adults live in the mucosa of the small intestine of omnivores like pigs
in the intestine, the female gives birth to larvae that are carried to skeletal muscle
the young larvae encyst in the muscle and remain infective for many years – eaten by humans
causes the disease trichonosis
symptoms: usually start with fever, muscle soreness, pain and swelling around the eyes. Thirst, profuse sweating, chills, weakness and tiredness may develop. Chest pain may be experienced since the parasite may become imbedded in the diaphragm (the thin muscle separating the lungs from abdominal organs).
incubation period: 10 to 45 days
treatment: mebendazole, thiabendazole

15. Wuchereris species: filarial worms
tropical countries
over 250 million humans infected – transmitted by mosquitos
larvae are threadlike in structure & live in the lymphatic system of humans
tend to clog up lymphatic vessels and block the return of lymphatic vessels to the CV system
results in an accumulation of fluids in the peripheral tissues – can result in extremely enlargened appendages known as elephantitis
in the U.S a filarial worm – Dirofilaria immitis – lives in the large arteries of the heart and lungs of dogs - heartworm

16. Phylum Annelida Class Polychaeta – bristle worms
e.g. Nereis
marine worms
possess parapodia with setae
brightly colored – many are luminscent
range from plankton to burrowing species
found in all marine temperatures
Class Oligochaeta: marine and terrestrial worms
e.g. earthworms – Lumbricus
700 species – native to Europe, invasive in North America
many lack parapodia and setae
Class Hirudinea: leeches

17. Class Polycheata Eunice pennata Hermodice carunculata X-mas tree worm
plankton polycheate

18. Class Polycheata

19. Class Oligochaeta
Lumbricus

20. Class Oligochaeta
(stomach)

22. Class Oligochaeta

23. Class Oligochaeta metanephridia seminal vesicles pharynx hearts
dorsal blood vessel
crop & gizzard
(Stomach)
pharynx
metanephridia
seminal vesicles
intestine

24. Class Oligochaeta
intestine
stomach
seminal vesicles
hearts

25. Class Oligochaeta intestine ventral nerve cord ventral blood vessel
metanephridia
intestine
ventral nerve cord
ventral blood vessel
lateral nerves