1. Phylum Platyhelminthes

2. 2

3. Flatworms are simple bilateral animals.
Flatworms have a solid body and incomplete or absent gut.
There are three classes of flatworms.
planarians
head
pharynx
mouth
sucker
eyespot
reproductive
system
gut cavity

4. Flukes

5. Tapeworms

6. Cerebral ganglia “brain” (Breathe through skin)
CHARACTERISITCS
OF ALL WORMS
Invertebrate
Elongated bodies
Bilateral symmetry
Cephalization
Cerebral ganglia “brain”
No respiratory organs
(Breathe through skin) 6

7. FLATWORMS PHYLUM: Platyhelminthes
FREE LIVING PARASITIC
Planaria Flukes & Tapeworms 7

8. Phylum Platyhelminthes
Flat worms
Acoelomate
Bilateral symmetry
Hermaphroditic
Monoecious
One opening for digestive system
Paired lateral nerve cords & cerebral ganlion
Flame cells

9. Class Turbellaria Eye spots Ciliated surface Regenerate if cut in two
Most are free-living 9

10. Acoelomate Phylum Platyhelminthes: Class Turbellaria
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Phylum Platyhelminthes: Class Turbellaria
Acoelomate

11. Copyright © The McGraw-Hill Companies, Inc
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Turbellaria 11

12. Fig. 14.2 12 12

13. Nervous System

14. Brain
Auricle
Cerebral
ganglion
Paired
nerve cords

15. Copyright © The McGraw-Hill Companies, Inc
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Excretory System

16. Fig. 14.6a

17. Class Trematoda Flukes Parasites Holdfast devices Most
Complex life cycle
Intermediate host
Animal with juvenile stage
Definitive host
Animal with adult stage

18. Fig. 14.7

19. Clonorchis sinensis Chinese liver fluke 50 million people
Cirrhosis of liver
Diarrhea
Edema
Pain

20. Clonorchis sinensis Oral sucker Intestine Uterus Yolk gland Ovary
Seminal recepticle
Testes

21. Fig

22. Fascioloa hepatica Sheep liver fluke Sheep, cattle and man Weight loss
Eat vegetation with metacercaria

23. Life Cycle of the Sheep Liver Fluke
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Life Cycle of the Sheep Liver Fluke

24. Fasciolopsis buski Intestinal fluke 10 million people Man and pigs
Hemorrhage and abscesses of small intestine

26. Paragonimus westermani
Lung fluke
Carnivores, pigs, rodents and man
May be fatal

29. Schistosoma
Blood flukes
200 million people
1 million deaths/year

30. PARASITIC FLATWORM Schistosoma
NOT IN USA but infects over 250 million people worldwide
Worms can block blood vessels to organs causing irritation, bleeding, tissue decay producing disease called = SCHISTOSOMIASIS 30

31. HUMAN BLOOD FLUKE Schistosoma
HUMAN BLOOD FLUKE Schistosoma
Adult worms mature & reproduce in blood vessels; eggs travel to intestines or bladder
Immature worms burrow 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) 31

32. Schistosome
Cercaria have forked tail

34. Swimmers Itch

35. Class Monogenea One host Ectoparasites Mainly fish Opisthaptor
Attachment to host

36. Class Cestoidea
Tape worms
No digestive system
40 feet long

37. TAPEWORMS PARASITIC FLATWORM that lives in HOST animal intestines
TAPEWORMS
Dog tapeworm
PARASITIC FLATWORM that lives in HOST animal intestines 37

38. SCOLEX - Head with suckers and hooks to help hold on inside host38

39. 39

40. PROGLOTTIDS hermaphroditic reproductive structures
(contain both male & female sex organs)
Contain fertilized
eggs
Shed in feces 40

41. Proglottid Testes Uterus Vas deferens Seminal receptacle Ovary
Yolk gland

42. Thickened PROTECTIVE layer on the outside of worms made of CELLS
TEGUMENT
Thickened PROTECTIVE layer on the outside of worms made of CELLS
CUTICLE
NON-CELLULAR PROTECTIVE coating found on the outside of worms 42

43. TAPEWORM NO DIGESTIVE SYSTEM
NO DIGESTIVE SYSTEM
absorbs nutrients through skin
TEGUMENT protects them from host digestive enzymes and immune system 43

44. TAPEWORMS Can grow up to 30 ft (2000 proglottids)
TAPEWORMS
Can grow up to 30 ft
(2000 proglottids)
REPRODUCE WITH PROGLOTTIDS
Add new proglottids behind scolex
Mature ones drop off at tail end
Leave body in feces 44

45. MCDOUGALL VIDEO – CH.14 PREDATOR PREY 2 - TAPEWORM

46. EX: BEEF TAPEWORM Adults attach inside intestines and absorb
digested food
Humans eat undercooked meat
containing cysts
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 46

47. Pork Tapeworm (Taenia solium)
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Pork Tapeworm (Taenia solium)

48. Taenia saginata

49. Life Cycle of the Broad Fish Tapeworm
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Life Cycle of the Broad Fish Tapeworm
Diphyllobothrium latum
Source: Redrawn From Centers for Disease Control, Atlanta, GA.

50. Dipylidium caninum

51. Echinococcus granulosus
Parasite of dogs
Host
Juveniles in sheep, man and other mammals
Intermediate host
Hydatid cyst

53. Hydatid Cyst
Cysticercus
Juvenile stage