1. Flatworms and Round Worms!

2. Phlylum Platyhelminthese = Flatworms

3. Flatworms had it FIRST!! Bilateral symmetry
Directional motion = 1st mobile predator
Cephalization – development of a head
Ganglia: bundle of nerve cells make up a pre-brain
Nerves concentrated at ‘head end’ since sensory cells were concentrated at that end
Sensory nerves formed bundles = ganglion
Eyespots detect light,
Auricles detect chemicals ‘smell’
2 nerve cords transmit info to rest of body

4. New Innovations in Excretory System
cellular waste still removed by diffusion
Protonephridia (NEW)
flame cells help regulate solute concentration
Evolve in to the nephrons of mammal kidneys
First Kidney

5. Flatworm Reproduction
1st internal fertilization
Evolutionary advantage
Make fewer gametes
Save energy
Hermaphrodites = make both eggs & sperm
Evolutionary advantage = you can mate with any other member of your species that you can find!

6. Ancestral Traits Gastrovascular cavity for digestion & circulation
Mouth in center of body
Respiration (gas exchange) by diffusion
feeding flatworm

7. Free-living Flatworms = Class Turbellaria
Marine
Fresh-water

8. Flukes = Class Trematoda
Parasites of blood and liver

9. Swimmer’s Itch =Schistosoma

10. Tape Worms = Class Cestoda

11. Human Tape Worm Sources =Under cooked Prevention Beef (N. America)
Pork(S. America)
Fish (Asia)
Prevention
Cook your meat!!!

13. Round Worms = Phylum Nematoda
1st Animal with a body cavity =pseudocoelom
Fake body cavity – just a space between layers.

14. Types of body cavity (coelom)
Acoelomate Pseudocoelomate Coelomate

15. Digestive Tract
1st Alimentary Canal = one way digestive tract with mouth at one end and an anus at the other
Evolutionary advantage
Specialization
Can eat new meal before the old one is finished processing

16. Alimentary Canal

17. Spicule injects sperm for internal fertilization
Spicule inside body
Spicule extended

18. Ascaris…………………………… One of the most common parasite of humans
Up to 64% of
people in some
S.eastern states
Eggs injested
on Vegetables
or from Soil

19. Hookworm in Humans Eggs in feces on ground Juviniles live in soil
juviniles burrow into human skin
Travel in bloodstream to lungs
Juvilinles coughed up & swallowed
Mature in small intestine
Adults suck blood from intestine wall (cause anemia)
Common in Southern States

20. Heartworm Larva in Blood