1. Phylum Nematoda

2. Nematoda Are known as round worms Bilateral symmetry Simple systems: they have a digestive system with two openings, a mouth and an anus Range in size from microscopic to a meter in length.

3. Nematoda There are more round worms on earth than any other multicellular animal. For example: A single rotting apple that you might find under a tree might have as many as 90,000 roundworms in it. A small bucketful of garden soil may have more than a million round worms

4. Nematoda Most species of roundworms are free- living. They are found in soil and in aquatic environments.

5. Nematoda The free-living species are mostly carnivores that catch and eat other small animals Some species eat algae, fungi, or pieces of decaying organic matter

6. Excretory System Like flatworms, the roundworms breathe and excrete their metabolic waste through their body walls. They have no internal circulatory system; therefore, they use diffusion to carry nutrients and waste through their body.

7. Nervous System Have a simple nervous system. They have Cephalization; cerebral ganglia found in the anterior end. Several nerves extend from the ganglia running lengthwise to the body

8. Conti. Nervous System The lengthwise nerves transmit sensory information and control movement. The muscles of the roundworm run in strips lengthwise from anterior to posterior, and they use these muscles to move from place to place.

9. Reproductive System Reproduce Sexually A few species are hermaphroditic, but MOST have SEPARATE sexes. Internal fertilization

10. Nematoda Many species are parasitic. Parasitic roundworms can affect both plants and animals. Plant parasites live in the soil attach to the root hairs of a green plants and suck out plant juices

11. Parasitic Nematods There are about 10,000 species of roundworms Around 50 species are parasitic in humans

12. Ascaris A parasite of the vertebrate intestinal tract The ascaris lives in the intestines of people, horses, cattle, pigs, dogs, cats and many other animals. This worm is the main reason to why we worm puppies

13. Ascaris Life Cycle 1. The adult ascaris produces eggs that leave the host by its feces. 2. Food or water that is contaminated by the infected feces is eaten by another host; the eggs hatch in the small intestine of the new host

14. Ascaris Life Cycle 3. The young worms burrow into the walls of the intestine and enter surrounding blood vessels. Carried around in the blood the tiny worms end up in the lungs.

15. Ascaris Life Cycle 4. Here they break out into the bronchial tubes and climb up into the throat and are swallowed. 5. The worms then grow and develop into adults in the small intestine. 6. While in the small intestine they mate and produce eggs.

16. 7. The eggs pass out of the host in the feces, and the cycle repeats itself Ascaris Life Cycle

17. Hookworms A parasite, who's larva develops in the moist soil and find their way into the bodies of humans by boring through the skin of the foot, especially between the toes

18. Hookworm Infection They burrow through the foot. They enter a blood vessel and travel to the heart. From the heart they reach the lungs; there they make their way through the bronchial tubes and into the windpipe.

19. Hookworm Infection 4. Then they are coughed up and swallowed. 5. Next, they move to the intestine where they attach to the intestinal wall by using hooks. 6. The worm then suck blood from the intestinal wall.

20. Hookworm Infection 7. The adult hookworm eggs pass out of the body of the host and develop into the soil. Here the life cycle repeats itself.