1. Annelida: Symmetry
  2. Annelida: # Germ Layer
    • 3 (ecto, meso, endoderm)
    • true coelom and organs
  3. Annelida: Metamerism
    • very evident, segmentation (somites)
    • somites: division of body of animal
  4. Annelida: Coelom
    yes (protosome)
  5. Annelida: Skeletal System
    hydroskeleton: coelomic cavity filled with fluid
  6. Annelida: Cephalization
    • Some
    • suprapharyngeal ganglion (in somite 3) connects to ventral nerve cord
    • nerves branch out to adjacent tissues
  7. Annelida: Nervous System
    • ganglion, ventral nerve cord
    • suprapharyngeal ganglia (in somite 3) connects to ventral nerve cord
  8. Annelida: Digestive System
    • GI tube with typhlosole
    • Complete (both mouth and anus)
    • includes pharynx, esophagus with calciferous glands, crop, gizzard, and intestine
  9. Annelida: Circulatory System
    • closed blood contained w/in vessels
    • doral blood vessel and ring-like hearts contract rhythmically
  10. Annelida: Respiratory System
    • Skin
    • use hemoglobin as respiratory pigment dissolved in blood (no RBC)
  11. Annelida: Respiratory Pigment
    dissolved hemoglobin
  12. Annelida: Excretory System
    • Metanephridia, anus
    • pair of nephridia (primative kidneys) within each somite connected to nephrostome (funnel-like component towards coelom)
    • opens into coelom by a ventral viliated funnel and empties into exterior by pore in ventral wall
  13. Annelida: Sexual Cycle
    • monoecious, sexual and asexual
    • hermaphroditic with cross-fertilization
    • clitellum secretes mucus for reproductive processes
  14. Annelida: Asexual Cycle
    budding (in some)
  15. Annelida: Classes
    • Polychaeta: nerels, tubeworms, bristleworms
    • Oligochaeta: earthworms
    • Hirudinea: leeches
  16. Annelida: Notes
    • ciliated intestinal lumen
    • 15,000 species
    • 550mya
  17. Clitellum
    • swelling that extends over several somites
    • secretes mucus used during reproduction
  18. Dorsal Blood Vessel
    dark streak running length of body
  19. "Heart"
    dark ring like structures that encircle GI tube at anterior end
  20. Calciferous Glands
    • located on esophagus near crop
    • excrete excess calcium into GI tract for elimination in feces
  21. Crop
    • Large thin-walled sac posterior to esophagus
    • stores food
  22. Gizzard
    • thick walls
    • fragments food
  23. Thin-Walled Intestine
    • where most absorption takes place
    • waste being expelled out anus
  24. Metanephridia
    • elimination of nitrogen waste
    • fine coiled tubes
    • adhere to body wall
    • each long tube opens up to coelom by the nephrostome
  25. Nephrostome
    ventral ciliated funnel that opens up the metanephridia to the coelom
  26. Metanephridiopore
    metanephridium empties to the exterior thru this fine pore
  27. Spermatheca
    • seminal receptacles
    • two pairs
    • spherical
  28. Earthworm Body Layers
    Cuticle -> Epidermis -> Circular muscle -> Longitudinal muscle -> (ventral nerve cord) -> Coelomic lining (peritoneum) -> Coelom -> (2x metanephridia/ nephrostome) -> Peritoneum -> Chloragogen cell -> muscles -> Typhlosole -> Intestinal lumen
  29. Chloragogen
    • glycogen storage and detox
    • functions like liver
    • yellowish in color
  30. Typholosole
    fold in dorsal wall of intestine that increases surface area
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