Trematodes Flashcards
What are trematodes?
Hermaphrodites
What kind of eggs do the females store?
Operculated eggs
Where do flukes like to live>
Water
When the egg hatches in the water, it releases a ciliated, motile what?
Miracidium
What does the miracidium penetrate?
The skin of an aquatic snail.
What is required for all flukes?
The aquatic snail
What does the miracidium develop into in the skin of the snail?
Sporocyst
What is a sporocyst and what develops inside it?
A sack in which the multiple redia develop
What are developing in within the single redia that emerges from the snail and into the water?
Cercariae
A cercaria can develop in 3 ways. What is the direct method?
Penetrates the skin of the definitive host, travels to the predilection site and becomes the adult
If a cercaria attaches to vegetation what happens?
Loses its tail
Forms a cyst to become a metacercaria
The definitive host ingests the vegetation
Cyst is digested and the fluke travels to the predilection site and becomes an adult
What happens to the cercaria if it does not attach to the vegetation?
Loses its tail
Penetrates the skin of the intermediate host
Encyst in the muscle
Becomes a metacercaria which is ingested when the definitive host ingests the muscle of the 2nd intermediate host
Cyst is digested
Fluke travels to the predilection site
Becomes an adult
What is the common name of Fasciola hepatica and Fasciola gigantica?
Common liver fluke
Sheep liver fluke
Giant liver fluke
What is the host of Fasciola hepatica and Fasciola gigantica?
Ruminants
What is the predilection site of Fasciola hepatica and Fasciola gigantica?
Biliary ducts in the liver and gallbladder
What is the life cycle of Fasciola hepatica, Fasciola gigantica?
Ingestion of contaminated vegetation