1. ., Phylum: Platyhelminthes Parasite Monster Inside Me Part 2

2. Platyhelminthes Origin of the word platyhelminthes: Latin for flat Animals in this phylum include: tapeworms, planarians, saltwater flatworms Level of organization: -organs and organ systems -Acoelomate (no body cavity) Symmetry: Bilateral (found in most higher organisms)

3. Basic Platyhelminthes body plan Three Germ Layers: First phylum to have all three 1) Ectoderm (outer) 2) Endoderm (inner) 3)Mesoderm (middle)

4. Organ Systems Digestive system: -Three branch system. -Gastrovascular cavity (same as cnidarians) - Gastro = digests food - Vascular = distributes food and gases like the circulatory system Reproductive System:

5. Organ Systems Digestive system: -Three branch system. -Gastrovascular cavity (same as cnidarians) -Gastro = digests food -Vascular = distributes food and gases like the circulatory system Reproductive System: - Hermaphrodite (carry both male and female reproductive organs)

6. Organ Systems Nervous System: -A ladder-like nerve network extending down from an anterior brain. Head -Anterior Eyespots detect light -Chemosensitive organs at auricles Note: Sensory functions collecting at the anterior end of an organism = Cephalization

7. Organ Systems Excretory System: Parts -A web of interconnected tubes that end in flame cells -Flame Cell: Contain beating cilia that create a continuous flow of water out the excretory pore Function -Waste moves out of the cells by diffusion and are pushed into the current created by the flame cells which leads it out of the body through the excretory pore

8. Platyhelminthes and Parasitism Half of the flatworm species are parasitic Two main groups of parasitic flatworms 1)Tape worms: -Endoparasite -Adult stage survives in the intestine of a vertebrate host Parts: Scolex: Anterior end equipped with rings of hooks (B) and suckers (A) that hold onto host intestine. Proglottids: Reproductive segments (Carry eggs) released in feces

9. Platyhelminthes and Parasitism Characteristics that make tapeworms successful parasites 1) Strong outer skin that resists breakdown by hosts digestive enzymes and acids 2) Produces millions of eggs per day (only a few will make it to a proper host)

10. Platyhelminthes and Parasitism Fish tapeworm (Diphyllobothrium): -Found off the West coast of Canada and Alaska (AKA here  ) -Reaches up to 30ft in length -Found in raw muscle meat of predatory fish (eg. Salmon, trout)

11. Tapeworm Lifecycle Tapeworm lifecycle movie youtube

12. Tapeworms Prevention: Freezing meat at -10 C for several days kills the cysts OR Cooking the meat thoroughly will kill cysts Symptoms: - Usually asymptomatic (4/5 cases) -Weight loss -Abdominal pain -Diarrhea -Vomiting -Fatigue

13. Platyhelminthes and Parasitism Two main groups of parasitic flatworms 2) Flukes: -Endoparasite -Adult stage survives in the intestine of a vertebrate host Parts: - Oval shaped body similar to free living planaria with a reduced digestive and nervous system Types: Named after the organ they infect -Liver fluke -Lung fluke -Blood fluke

14. Assignment Crossword Vocab 628-629