Helminthes Flashcards
Macroscopic, multicellular eukaryotic worms. Many of which are pathogenic
Helminthes
Complex life cycles may differ in reproductive strategies
Monoecious
Dioecious
Each worm has both sex organ (hermaphrodites)
Monoecious
Male and female sex organs in different worms
Dioecious
Parasitic Helminths divided into 3 group
- Cestodes
- Trematodes
- Nematodes
These are acoelomate animals
- No real body cavity
- Lack their own digestive structures, line in intestines of Hosts
Cestodes
These are segmented tapeworms/flatworms
-Up to 60 feet
Have a more complex life cycle
Cestodes
Class Cestoda are composed of
Scolex
-Body
like the head; has Hooks at the top attach to tissues (No mouth)
Scolex
Is flat and long; made of proglottid: repetitive segments divide continuously; and has both sexes inside (monecious)
Body
(middle proglottid) working reproductive structures
Mature in the body
Filled with fertilized egg, ready to infect a new host
Gavid in the body
Break off, pass through feces
Gravid proglottids
10’-15’ long 75’ has been reported
Beef Tapeworm
Humans are the definitive Host
- Humans shed eggs and egg filled proglottids
- Cows eat the egg (Alternate Host)
- Eggs hatch in the cow and become immature larvae called cysticercus
Life Cycle
Eggs hatched in the cow and become immature larvae called
Cysticercus
Are usually harmless to the cow. however, when humans eat undercooked meat they get infected with the cysts
Cysticercus
Symptoms of Beef Tapeworms
Weight low, abdominal pain, headache, nausea
- Made of proglottids and pass them via fecal matter (similar to beef tapeworm)
- Humans can get the cysticerus in their muscle
Pork tapeworm
Make human the definitive host
-Can also be a intermediate host……. not likely
Pork tapeworm
Symptoms of a pork tapeworm are
Weight loss, abdominal pain, headache, nausea
Beef tape worm is also known as
Taenia Saginata
Pork tapeworm is also know as
Taenia solium
This is Dog Tapeworm
- only 3 proglottids (immature, mature, gravid)
- once an immature proglottid is formed, a gravid proglottid is released
Echinococcus Granulosus
Life cycle: The dog is the definitive host (echinococcus granulosus)
The adult worm lives in the intestines of the dog
- Sheds eggs (poop) and herbivores (ex. cattle) eat the eggs
- Occasionally humans can ingest food contaminated by dog feces and ingest larvae which form hydatid cysts
- Dogs like anus, then humans mouth/face
(Echinococcus granulosus) Hydatid Cysts:
Can rupture and larvae can spread through body
Protozoan are____________.
Animal-like eukaryotes that belong to the kingdom protists
