1. Phylum Platyhelminthes: the Flatworms

2. Platyhelminthes Vocabulary
Use the blue modern bio textbook to do these on your grid. Color should be on front. It doesn’t matter how you write the back. Remember to complete your squares and # them correctly on the back.
1. Pharynx Flame Cell
3. Cerebral ganglion 4. Eyespot
5. Fluke Tegument
Primary host Scolex
Cyst Proglottid
11. Schistosomiasis Strobila
12. Intermediate host

3. Taxonomy Kingdom: Animalia Phylum: Platyhelminthes (Plat = flat)
Class Turbellaria
Class Trematoda
Class Cestoda

4. Intro to Flatworms http://www.youtube.com/watch?v=w0QzSYQGsnA

5. Characteristics of Flatworms
They are acoelomates (they don’t have body cavities)
They have bilateral symmetry
Show cephalization
Single opening to digestive tract (pharynx)
Protostomes

6. Characteristics cont. Simplest animals to have 3 germ layers.
Triploblastic

7. All flatworms rely on diffusion for:
Characteristics cont.
Because they are flat, all cells are close to the animal’s external surface.
All flatworms rely on diffusion for:
respiration
excretion
circulation.

8. Digestive System
Most parasitic worms do not need a complex digestive system…WHY?
They obtain nutrients from foods that have already been digested by their host.

9. Copyright Pearson Prentice Hall
Excretory, Nervous, and Reproductive Structures of a Planarian
Ganglia
Nerve cords
Excretory system
Ovary
Testes
Flame Cells maintain water balance and remove waste
All flatworms, including this planarian, have organ systems that perform essential life functions. The excretory system (in purple) consists of many flame cells (in red) that maintain water balance and may remove waste. The nervous system (in dark gray) consists of ganglia and two nerve cords that run the length of the body. The reproductive system (in green) has testes and ovaries, or male and female reproductive organs, along both sides of the body.
Flame cell
Excretory tubule
Copyright Pearson Prentice Hall

10. Movement Free-living flatworms move in two ways:
Cilia on their epidermal cells help them glide through the water and over the bottom of a stream or pond.
Muscle cells controlled by the nervous system allow them to twist and turn.
*The development of directional movement is correlated (works in relation) with cephalization.
-some members have light sensitive receptors in head region called ocelli
-in other members there are chemoreceptors & balance receptors that sense water movement (not all in head region)

11. MOVEMENT

12. Review Questions 1. What phylum are flatworms part of?
2. What are the three classes of flatworms?
3. What type of coelomate are flatworms? Name and describe.
4. How do they breathe?
5. What type of cells remove waste?

13. Class Turbellaria Free-Living flatworms Eat protozoans
Examples are planarians
Eat protozoans

14. Planarians – Nervous System
Spade-shaped at the anterior end
Have two, light-sensitive eyespots
Can sense light, touch, taste, & smell

15. Planarians – Nervous System
Have 2 clusters of nerve cells or ganglia to form a simple brain
Nervous system composed of a nerve net

17. Reproduction Sexual Reproduction
Hermaphrodites Cross fertilize eggs

18. Asexual Reproduction by Regeneration

19. Planaria regeneration pt 1

20. Planaria regeneration part 2

21. Class Trematoda Liver Fluke Are parasitic flukes
Have suckers on both ends
to cling to host & suck blood, cells, & body fluids
Can live inside or outside of host
Liver Fluke

22. Class Trematoda Nervous and excretory systems like turbellarians
Hermaphrodites
Have complex life cycles
Require 2 hosts
Schistosome

23. http://www.youtube.com/watch?v=0xOO7e6tSzE liver fluke
FLUKE ANATOMY
liver fluke

24. Japanese Lung Fluke Burrows into lung tissue and begins laying eggs
Causes response of severe coughing up of blood and release of body fluids
Can be transmitted through raw crabs
80% of freshwater crabs in Asia are infected
Causes inflammation in the lungs
Blood that is coughed up is filled with eggs
It is then reswallowed and excreted in feces
Has many intermediate hosts
Coughing up blood is a major sign of infestation

25. Example Schistosomiasis
Disease caused by a parasitic blood fluke called a Schistosome.
Infects people in Asia, Africa, & South America causing intestinal bleeding & tissue decay that can result in death.

26. Schistosomiasis

27. Schistosomiasis (video notes)
Caused by blood fluke – Schistosome
Infects blood vessels around the host’s bladder and reproduces rapidly
Excreted in the urine & can come in contact with skin
Starts as eggs in freshwatergrows in snailwaterhuman
Creates a red rash if eggs are lodged in the skin
Massive buildup in tissue can cause cancer
200,000,000 world wide..many in Africa
Snail-intermediate host
Human-primary host
If infected, you are susceptible to get worm again even after treatment
Unsanitary water – Global disease #4
The flukes are attracted to the fatty acid in the skin
Can go undetected for 20 years

28. Schistosomiasis http://www.youtube.com/watch?v=Hkqk5Ljc3ko

30. White Tail Deer Liver Fluke
Japanese Lung Fluke Case

31. Review Questions 1. Which class is made up of flukes?
2. Where can flukes live?
3. Why do they have suckers?
4. What does hermaphrodite mean?

32. Class Cestoda About 2,000 species Parasitic Tapeworms
Long, ribbon-like bodies
No digestive system
Absorbs nutrients from host
Hermaphrodites
Can live in intestines of almost
almost all vertebrates
Humans can harbor any of SEVEN
different species
Tapeworm may cause: digestive
problems, weight loss, lack of energy, and anemia (decrease in # of RBCs)

33. Different from other flatworms because they…
Lack eyespots and other light sensitive structures
Have no mouth/pharynx
Instead they have hooks & suckers
No Gastrovascular cavity
No other digestive organs

34. SCOLEX of the tapeworm

35. Reproduction
Proglottids are the segments that make up most of the worm's body.
Mature proglottids contain both male and female reproductive organs.

36. Tapeworm Anatomy Scolex Young proglottids Mature proglottids Uterus
Zygotes
Testes
Ovary

37. Reproduction cont
Mature proglottids are released in excrement (feces).
Eggs are ingested by grazing animals
Eggs hatch into larva
Larva infect muscle tissue of animal and form cysts
Humans can become infected by eating undercooked meat.

40. Tapeworm life cycle

42. Pork Tapeworm

43. TAPEWORMS http://www.youtube.com/watch?v=txSiApFzaZE overview
Pork Tapeworm

45. End of PP. review questions.
5. How do livestock ingest tapeworm eggs?
6. Where do tapeworm larvae form cysts?
7. Cysts can survive in _____ or ________ meat.
8. Where does the tapeworm attach itself?

46. Platyhelminthes
REVIEW QUESTIONS

47. Flatworms are the simplest animals to have
two germ layers.
bilateral symmetry.
radial symmetry.
two openings in the digestive system.

48. An individual that has both male and female reproductive organs is known as a. turbellarian. b. proglottid. c. hermaphrodite. d. parasite.

49. The function of flame cells in flatworms is to:
a. digest food and move it to various parts of the body.
b. detect the presence of chemicals in the surroundings.
c. remove excess water and metabolic wastes
d. move reproductive cells into position for fertilization.

50. A flatworm that lacks a digestive tract is the
a. planarian.
b. free-living flatworm.
c. tapeworm.
d. fluke.

51. Turbellarians differ from most other flatworms because they a
Turbellarians differ from most other flatworms because they a. live freely on land. b. live freely in fresh and salt water. c. are marine parasites. d. are land-dwelling parasites.

52. 6. The eyespots of a planarian can be found at the _.
Base of the organism
Anterior end of the organism
Posterior end of the organism
In the gut

53. 7. Which of the following is a parasitic flatworm that causes inflammation in the lungs?
Planarian
Fluke
Tapeworm

54. 8. _ on the epidermal cells of flatworms help them glide & move.
Flame cells
Muscle cells
Cilia

55. 9. What major organ in a human is able to regenerate?
Heart
Brain
liver

56. 10. What flatworm is aiding in the research of stem cells?
Fluke
Planarian
Tapeworm

57. 11. Which of the following is NOT a class of Platyhelminthes?
Cestoda
Agnatha
Trematoda
Turbellaria

58. Foldable 1 Take a sheet of paper and cut in half. 2
Lay one sheet on the other and offset by ~ 1/2 inch.
Fold in the middle to form 4 tab booklet.
Staple the top. 2
3 & 4

59. Phylum Platyhelminthes
Label the tabs as shown.
Under each tab List the following and answer for each:
Example:
Coelom:
Symmetry:
Germ Layers:
Digestive System:
Nervous System:
Reproduction:
Habitat:
Phylum Platyhelminthes
Class Turbellaria
Class Trematoda
Class Cestoda