1 / 27

River Blindness

River Blindness. A patient infected suffering from river blindness. This elderly man shows nodules, skin changes and blindness, all manifestations of the disease. Cause: parasitic roundworm transferred by fly bites. Micro worms swarm through skin and eyes. Economic implications:

khuyen
Download Presentation

River Blindness

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. River Blindness • A patient infected suffering from river blindness. • This elderly man shows nodules, skin changes and blindness, all manifestations of the disease.

  2. Cause: parasitic roundworm transferred by fly bites. • Micro worms swarm through skin and eyes.

  3. Economic implications: • Increased disease frequency has resulted in limited farm laborers who can grow and harvest crops.

  4. Unsegmented Roundworms

  5. Unsegmented Worms Phylum Nematoda (round worms) -simplest animal to have a digestive system with TWO openings (mouth and anus advanced animal) -found in soil, lakes, oceans, polar and tropical environments, hot springs (everywhere)

  6. Ascaris the ones we will be dissecting

  7. Feeding: -most are free living carnivores/omnivores that eat algae, fungi, animals, decaying matter -have a pharynx (suck in food) -some are parasitic (affect plants and animals)

  8. Respiration -Diffusion of gases through body walls • Excretion: -metabolic wastes through body walls via diffusion and undigested wastes through anus NH3 O2 CO2

  9. Response: -simple nervous system -ganglia (group of nerve cells -not quite a brain) -sense organs and nerves that run down the body (movement/chemical detection) • Reproduction: -sexual reproduction (separate sexes) -complex life cycle (2 to 3 different hosts/organs)

  10. Four types of Nematoda • Ascaris-parasitic roundworm that lives in humans (and relatives in horses, dogs) Life Cycle Intestine (human) → produces eggs → leaves in feces → enters mouth via food/contaminated water → hatch in new host(human) → small intestine → blood vessel → lungs → throat (cough)→ swallowed → back in intestine...cycle starts from beginning

  11. 2. Hook worm -serious human intestinal parasite common in Southern US/tropical countries (1/4 people are infected) Life Cycle Eggs hatch outside of body and develop in soil → unprotected foot → sharp teeth/hook to burrow in the skin → enter blood stream → lungs → throat → back to intestine

  12. 3. Trichinosis/Trichonella -live and mate in the intestine -burrow eggs in intestine wall (1500 larvae) Life Cycle In a pig/rat: Larvae travel in blood vessels→ go to organs → tissues where it forms a cyst (inactive) -This inactive cysts is then eaten by humans (raw meat contains cyst, which becomes an active worm)

  13. Dinner is Ready?

  14. Filarial Wormsl -Tropical Asia/Africa -live in blood/lymph vessels of birds and mammals Life Cycle Host (carrying worms)→ mosquito (now carrying worms)→ releases worms and blocks passage of lymph vessels → swelling in vessels/tissues **cause elephantiasis **The following pictures may be disturbing… viewer discretion is advised 

More Related