1. Belongs to Phylum: Nematoda
Roundworms
Belongs to Phylum: Nematoda

3. Roundworms are EVERYWHERE!!
Roundworms are all around us.
They vary in size from microscopic to a meter long
A single rotting apple can have as many as 90,000 roundworms and a small bucket of soil or pond water can have as many as 1 million

4. Main Characteristics of Roundworms
Unsegmented- meaning they have no distinguished body parts
Simplest animal to have a digestive system with two openings-both an anus and a mouth
Have a pseudocoleom-meaning their colon is not completely covered in mesoderm

5. Anatomy of a Roundworm
Simplest animals with a digestive system with two openings – a mouth and an anus
Have several ganglia-groups of nerves-but lack a brain
Muscles run in strips along the length of the body walls
Breath and excrete their metabolic wastes through their body walls

6. Pseudocoelomates
Roundworms have a pseudocolon meaning that they have a colon that is not completely covered by mesoderm.
mesoderm

7. Roundworm infection
Heartworm
Guinea Worms -
Break out of skin when
mature

8. Ascaris Life Cycle
1.Adult worms live the intestines. Eggs are passed with the feces
2. Fertile eggs become infective after several weeks
3.Infective eggs are swallowed
4.the larvae hatch
5 invade the intestinal wall, and are carried through circulation to the lungs.
6.The larvae mature further in the lungs (10 to 14 days), penetrate the alveolar walls, ascend to the throat, and are swallowed.
7.reaching the small intestine, they develop into adult worms

9. Roundworm Reproduction
Roundworms reproduce sexually
Most species have separate male and female, though some are hermaphrodites
Fertilization takes place inside the female
She later then lays eggs, which turn to larvae, then to adult worms
Roundworm Egg

10. Affects on Human Life
Though they are very numerous around the world, roundworms do not exert a lot of positive influence in the everyday lives of humans so they are easy to ignore
parasitic roundworms are responsible for some terrible diseases
Heartworm

11. Hookworm Found in the tropics
Nearly ¼ of the population are infected with hookworm
The eggs hatch and develop outside the body of the host
Burrow into un-protected skin (often the feet) and enter the blood stream
Travel from the lungs up to the pharynx and are swallowed
They dig into the intestinal wall and suck the blood of the host
cause weakness and poor growth

12. HOOKWORMS

14. Trichinosis Cyst The adult worms live and mate in the intestines
The females burrow into the intestinal wall and lay up to 1500 eggs
This “burrowing” causes Great Pain towards its host
Worm
The larvae then travel through the blood stream until they find a tissue to burrow into
The larvae form cysts inside the muscle tissue of the host and become inactive.
Larvae

15. complete their life cycle when the muscle tissue is eaten
(only carnivores can be infected)
Most common animals infected are rats and pigs
People get this disease from eating not completely cooked rat or pork
PIGS
RATS

16. Filarial Worms Found in tropics Thread-like worms
Live in blood/lymph vessels of birds and mammals
Transmitted by mosquitoes
Can block the vessels – causing elephantiasis (now rare)

17. Elephantiasis

18. Eye Worms Related to filarial worms Found in Africa
Infect humans and baboons
Live in sub-cutaneous tissues
Sometimes travel across the eye