Phylum Platyhelminthes Flashcards
What are the two classes
Cestoda: hemaphroditic (monoecious) tapeworms w/ flattened segmented bodies. They don’t have a digestive system, but nutrients are absorbed thru tegument/epidermis. Anterior (scolex) attaches to intestine of definitive host, and segments (proglottids) mature posteriorly. Transmission by ingestion of cysticerci or eggs
Trematoda: hermaphroditic or dioecious (Schistosomes) flukes of the lungs, liver, intestine, and bood, unsegmented, flattened leaf-like bodies (except schistisomes) with oral and ventral suckers mouth and anus out of same hole. Simple, blind eating suckers. One or more intermediate hosts (eg snail) transmission ingestive or invasive (Schistosomes)
Cestodes
- Worm>location>transmission
- Taenia saginata>intestine (adult)>eating undercooked beef
- Taenia solium>intestines (adult) all tissue (larva)> eating undercooked pork or free eggs
- Diphyllobothrium latum>intestine (adult)>ingestion of undercooked fish
- Echinococcus Granulosus>all tissues (larva)>ingestion of free eggs
Trematodas
*Schistosoma spp (bloodflukes)> mesenteric venules/venous plexus of bladder (adult)>skin penetration by cercaria
Taenia solium
Intermediate host: pigs get cystercerci in meat
Definitive host: humans. they shed eggs and proglottids in poop
Transmission: eating cysts in meat->Taeniasis (tapeworm in gut)
eating tapeworm effs->cystcercosis (life threatening)
Treatment: PREZIQUANTEL for taeniasis
Albendazol and niclosamide for cystecercosis
Dexamethazone to reduce inflammation
immunity: humoral response to tape worm, reinfection possible
Diphyllobothrium latum
Fish Tapeworm. human poops out unembryonated eggs,, eggs get embryonated in water, larva hatch and infect crustaceans, little fish eat, then big fish eat, then a human eats raw fish (w/ plerocercoid larvae) which become adults in small intestine
Epidemiology: global in temperate zones w/ cool lakes
Pathology: like taeniasis. B12 deficiency, megablastoma anemia
No immunity, Preziqual and niclosamide, B12 supplement
Echinococcus Granulosus
Dogs eat sheep w/cysts (sheep eat dog poop w/ eggs).
humans accidentally eat eggs from dog poop. Causes hydatid cysts and hatches and becomes an adult in intestines. Cysts can be latent, until they rupture causing anaphylaxis
e
Albendazole or mebendazole
Schistosoma ssp.
Mansoni (lateral spine on egg), Japanicum (Barely any spine), and Heamatobium (large spine terminal)
The intermediate host is a snail that ate poop w/ eggs
The larvae enter skin (causing rash) then they travel into liver (mansoni or japanicum) or they enter bladder (haematobium). Bloody diarhea and hemauria
Preziqual is drug of choice single for m or h multiple for j
Egytians and africans by rivers
worms in blood, eggs in tissue
echinococcus mutilocularis
like Echinococcus granulosus, but hase many definitive hosts and causes alveolar echinococcosis
transmission thru fur or poop
avoid wild animals
