1. Round & Segmented Worms

2. 3 Phyla of Worms Nematoda – Round worms (round as a toad)
Annelida – Segmented worms
What is the phylum for flat worms?

3. Nematoda (roundworms)
Slender, unsegmented worms
Range in size from microscopic to a meter
Some are free living, and some are parasitic

4. Nematoda (roundworms)
Have 3 germ layers
What are the 3 germ layers?
Are protostomes
What does protostome mean?

5. Nematoda (roundworms)
Have 2 openings in their digestive systems
Means have both a mouth and anus
Pseudocoelomates
Fluid filled cavity only partially lined with mesoderm

6. Parasitic roundworms Trichinosis-Causing Worms Filarial Worms
Ascarid Worms
Hookworms

7. Trichinosis-Causing worms
Terrible disease
Adult worms live and mate in the intestines of their host
Host include: humans, pigs, and other mammals
Females carrying fertilized eggs burrow into intestinal wall and release larvae

8. Trichinosis-Causing worms
Larvae travel through the bloodstream and burrow into organs and tissues
Larvae forms cysts and become inactive in the host’s muscle tissue
Life cycle complete when another animal eats muscle tissue containing these cysts

10. Filarial worms Found mostly in tropical regions of Asia
Threadlike – live in the blood and lymph vessels of birds and mammals
Transmitted from one primary host to another through biting insects
MOSQUITOES
In severe infections a large number or worms block the passage of fluids within the lymph vessels
Causes elephantiasis

11. ELEPHANTIASIS

12. Ascarid worms
Causes malnutrition in more than 1 billion people worldwide
Spread by eating veggies or other foods that are not washed properly
Matures in the intestines of host
Produce eggs that leave body in feces

13. Ascarid worms Gets in new host by eating contaminated food or water
Eggs hatch in small intestine and burrow into walls and enter bloodstream
Go to lungs – then go into air passages – then to throat and are swallowed which sends them back to intestines

14. annelida Segmented worms
Name means “little ring” because the segments look like rings
The divider between the segments are called septa (singular septum)

15. question
Why would having body segments be beneficial?

16. Body segments Can have segments that perform specific functions
Some have multiple eyes
Some have antennae
Other sense organs
Specialized for respiration

17. setae Bristles attached to body segments
What are some possible uses for setae?

18. coelomates
Annelids have a true coelom
What is a coelom?

19. Classes within annelida
Oligochaeta
Hirudinea

20. oligochaetes Typically have streamlined bodies
Relatively few setae compared to other annelids
Live in soil or fresh water

21. Earthworm (oligochaetea)
Use setae to keep from being pulled from the ground
Clitellum – secretes mucus for eggs
Hermaphrodite – has both male and female reproductive organs

22. External Structure Nephridiopore – opening into equivalent of kidney
Seminal Receptacle Pore – sperm comes in through here
Oviduct Pore – egg

23. hirudinea Leeches External parasites What do they eat?
Have suckers on both ends of their body

24. Medicinal use of leeches
Pros of using leeches medicinally
Reduce swelling post surgery
Help circulation in graft areas/reattachment areas
Secrete an “anti-clotting” fluid – so helps relieve pressure in healing tissues