1. Objective: Phylum Platyhelminthes, Nematoda.

3. Body Plan Bilateral Symmetry - Mirror image (left side mirrors right side)

4. Body Plan 3 Tissue Layers: Ectoderm: body covering Mesoderm: internal tissue (muscle) Endoderm: - Gastrovascular cavity or digestive tract

5. Body Cavities - Coelom- body cavity that holds organs Acoelomate: animal that lacks a fluid filled body cavity

6. Digestion -Gastrovascular cavity: food enters and exits through this muscular sac

7. Major Characteristics Movement: -Ventral cilia -Muscles Eyespots: detect light Nervous system: anterior clusters of nerve cells, side flaps for sense of smell

8. Class Turbellaria Example: Planarians (marine, freshwater), free- living

9. Class Trematoda Example -Blood fluke, parasites http://www.youtube.com/watch?v=uWvHvl2 5oXI

10. Class Cestoidea Description - Parasitic No digestive or circulatory system Absorb nutrients Ex: Tapeworm! http://animal.discovery.com/videos/monster s-inside-me-meter-long-tapeworm.html

11. Phylum Nematoda (Roundworms) Have bilateral symmetry and 3 tissue layers like flatworms Different from flatworms because they have: Complete Digestive Tract: - Opposite mouth and anus - Digestive tube

12. Body Plan Pseudocoelm: - fluid filled body cavity in direct contact with the digestive tract, worm thrashes to distribute nutrients

13. Diversity Most are free-living and decomposers Some are Parasites Ex: Heartworm http://animal.discovery.com/videos/monster s-inside-me-flesh-eating-hookworm.html http://animal.discovery.com/videos/monster s-inside-me-lymphatic-filariasis.html

14. Phylum Annelida (Annelids) aka Segmented Worms Body Plan -Divided into sections by internal walls- -Digestive tract, nerve cord, and main blood vessels not segmented Have bilateral symmetry and 3 tissue layers

15. Closed Circulatory System: Blood remains in vessels - nutrients, oxygen, and wastes diffuse

16. Coelm True, fluid filled body cavity in contact with internal tissues

17. Anatomy Pharynx: beginning of digestive tract Crop: stores food temporarily Gizzard: soil mixture is ground up Clitellum: flat area near anterior end Responsible for secreting mucus for mating and creating cocoons for offspring Setae: tiny hairs on ventral side for movement

18. Class Polychaeta

19. Class Oligochaeta Example: Earthworms

20. Class Hirudinea Example: Leeches