1. Worms
What’s Eating You for Dinner ?

3. FLATWORMS PHYLUM: Platyhelminthes
FREE LIVING PARASITIC
Planaria Flukes
& Tapeworms
FLATWORMS ARE ACOELOMATES

4. PARASITIC WORMS
Animal host where ADULT feeds and reproduces = PRIMARY HOST
Animal host where LARVAL form lives and feeds = INTERMEDIATE
HOST

5. HUMAN BLOOD FLUKE Schistosoma
Adult worms mature & reproduce in blood vessels (PRIMARY HOST) ; eggs travel to intestines or bladder
Immature worm burrows through skin into blood vessels
Larvae grow tails and leave snail
Eggs leave body in urine or feces
Larva hatches from egg & infects snail (intermediate host)

6. PARASITIC FLATWORM Schistosoma
Eggs can block blood vessels to organs causing irritation, bleeding, tissue decay
= __________________
SCHISTOSOMIASIS

7. TAPEWORMS PARASITIC FLATWORM (lives in HOST animal intestines)
Dog tapeworm
PARASITIC FLATWORM (lives in HOST animal intestines)

8. TAPEWORM Attaches by scolex and absorbs nutrients through skin
Tegument protects them from host digestive enzymes and immune system

9. COVERING for PROTECTION
CUTICLE- NON-CELLULAR coating made by cells
TEGUMENT-
CELLS fused together
like armor

10. Tapeworm SCOLEX
Head with suckers and hooks to help hold on inside host

11. PROGLOTTIDS hermaphroditic reproductive structures
TAPEWORMS
PROGLOTTIDS hermaphroditic reproductive structures
(contain both male & female sex organs)
EGGS INSIDE

12. TAPEWORMS Can grow 30-50 ft (2000 proglottids)
Add new proglottids behind scolex
Mature ones drop off at tail end and leave body in feces

13. BEEF TAPEWORM Intermediate host Primary host
Adults attach inside intestines
and absorb
digested food
Humans eat undercooked meat
containing cysts
Intermediate
host
Primary host
Proglottids burst releasing eggs with larvae inside on ground
Proglottids are released in feces
Cows eat grass; larvae travel through blood vessels;
make cysts in muscle

14. ROUND WORMS PHYLUM: Nematoda
Some FREE LIVING PARASITIC
Ascaris
Trichinella
Hookworms
Pinworms
Filarial worms
ROUND WORMS ARE PSEUDOCOELOMATES

15. Ascaris PARASITIC ROUND WORM
Lives in intestines of humans, pigs, horses
Feed on passing food
Females can grow up to 1 ft long & produce 200,000 eggs/day

16. ASCARIS LIFE CYCLE
Larvae are coughed up & swallowed; Return to intestines; mature & mate
Eggs leave body in feces and enter new host in contaminated food/water   
Develop into larvae and burrow through wall into blood vessels

17. PARASITIC ROUND WORMS Trichinella
Intermediate host
Cysts release larvae that burrow into intestinal wall & mature
Humans infected by eating undercooked meat containing cysts  
Primary host
Larvae forms cysts in muscle
Adults release larvae that travel through bloodstream to muscles 

18. PARASITIC ROUND WORMS Trichinella – TRICHINOSIS-
Larvae leave intestine and travel through blood vessels to muscle where they make cysts
Muscle pain & stiffness Can be fatal if cysts form in heart
= _______________________
TRICHINOSIS-

19. PARASITIC ROUND WORMS FILARIAL WORMS larvae are carried by insects
EX: DOG HEARTWORM Carried by mosquitoes

20. FILARIAL ROUND WORMS Elephantiasis
Adult worms live in lymph nodes causing blockage so fluid back ups

21. ELEPHANTIASIS Common in tropical countries
Adult worms can grow to 4” long

22. ELEPHANTIASIS

23.   Mosquito picks up larvae from blood when it feeds
Larvae develop into juveniles inside mosquito
Mosquito injects juveniles which migrate to lymph nodes and mature
Adult worms live
and reproduce in
lymph vessels  

24. FILARIAL ROUND WORMS Guinea worm

25. PARASITIC ROUND WORM Guinea worm
Blisters pop and larvae are released in water 
Female bodies under skin fill with eggs and break open; larvae form blisters
Larvae eaten by small crustaceans Humans infected by drinking water  
Larvae mature and adult worms migrate to skin

26. FILARIAL ROUND WORMS Loa loa

27. Loa Loa worm Humans are infected with larvae when bitten by loa fly
Larvae mature & crawl around under skin (especially near face)
Adults mate and produce larvae which can be picked up by another fly and transmitted to another person

28. PARASITIC ROUND WORMS Hookworms
Ancylostoma

29.      HOOKWORM LIFE CYCLE Return to intestines; mature & mate
Larvae are coughed up & swallowed;   
Adult worms live in intestine and feed on blood
Larvae enter body by burrowing through skin on feet & travel to lungs  
Eggs leave body in feces and hatch as larvae in soil

30. Hookworms in Humans PROBLEMS caused by migrating larvae
Cause intense reaction in skin at site
Infect 40 million people worldwide

31. PARASITIC ROUND WORMS Pinworms
Most common parasitic infection in United States
1/5 children are infected

32. PARASITIC ROUND WORMS Pinworms
Worms live in intestine
Females crawl out through anus at night and lay eggs on skin
Intense itching causes host to scratch
Eggs under fingernails and on hands are spread back to self or to others when objects/food are touched

33. SEGMENTED WORMS PHYLUM: Annelida
FREE LIVING PARASITIC
Earthworms Leeches
SEGMENTED WORMS ARE EUCOELOMATES

34. LEECHES
Medical uses