Flashcards
Tapeworms & Fluke 1
Cards in this deck (58)
- 1What is the latin binomial for liver fluke?Fasciola hepatica
- 2What is meant by Linnean classification?Classification from Kingdom-Species
Latin binomials - 3What is meant by a helminth?Worm
- 4Which phylum do tapeworms and flukes belong to?Platyhelminthes (flatworms)
- 5What is the technical term for flukes?Trematodes
- 6What is the technical term for tapeworms?Cestodes
- 7Where do fluke attach in fish?Gills - good blood supply
- 8Why are fluke that infect fish flat?Hydrodynamics
- 9Which organs are present in a trematode?Blind-ended gut
Excretory system
Reproductive system - 10Which reproductive organs are present in trematodes?Hemaphroditic so have both male and female reproductive organs
- 11What is the term for the skin-like structure of trematodes?Tegument
- 12What is the definitive host of liver fluke?Sheep
- 13Where does adult liver fluke live in the definitive host?Bile ducts
- 14What is the intermediate host of liver fluke?Galba truncatula
Amphibious mud snail - 15What do eggs develop into once passed out in the faeces of infected sheep?Miracidium - embryonic structure developing within egg
Once fully developed and in wet conditions egg is shed - 16How is the miracidium able to swim?Cilia
- 17How does the miracidium develop in the snail?Multiply asexually
- 18Which form of liver fluke is shed from snails?Cercaria
- 19How is the cercaria able to swim?Flagellum
- 20Why does the cercaria require water?Swim to grass
- 21What happens to the cercaria when it reaches vegetation?Loses tail and encysts
Known as metacercaria - 22How do sheep become infected with liver fluke?Ingesting grass contaminated with metacercaria
- 23What is the definition of the definitive host?Where parasite reaches maturity and reproduces sexually
- 24What is the definition of the intermediate host?Necessary secondary host required for the parasite to complete its life cycle
- 25What is meant by the pre patent period?Time between infection by parasite and when the parasite begins to reproduce and produce eggs
- 26How long is the pre-patent period in liver fluke?12 weeks
- 27Describe how liver fluke reaches the bile duct once ingestedPenetrates through intestine into abdominal cavity
Migrates up suspensory ligament of liver
Digests chemically and physically through the liver capsule and parenchyma until it reaches the bile duct - 28What physical changes occur to the liver as a result of liver fluke migration?Haemorrhagic tracts
Eventually followed by healing and fibrosis - 29What causes the acute phase of liver fluke?Damage to liver during migration
- 30When does the acute phase of liver fluke occur?Approximately 6 weeks following infection when fluke are migrating through the liver
- 31What may cause death in acute phase liver fluke infection?Severe liver damage
- 32What causes chronic phase fluke infection?Blood loss from feeding in bile ducts
- 33When does chronic phase fluke infection occur?Approximately 12 weeks following infection when fluke reaches bile ducts
- 34Give a symptom of chronic phase fluke infectionEmaciation
- 35Give an example of a change in the bile ducts that may occur due to the host immune response to liver flukeCalcification of bile ducts
- 36What is the immune response to liver fluke?Antibody and complement reaction
- 37How does liver fluke carry out immune evasion?Sheds tegument to prevent antigen recognition
- 38Why can the immune response to fluke be problematic?When tegument is shed immune complexes bind to migration trail rather than the actual organism
Results in inflammation and damage - 39What is meant by immune modulation?Chronic phase of liver fluke affects the host immune response
- 40How can humans become infected with fluke?Metacercaria grow on vegetation (such as watercress) in water that has been contaminated with sheep faeces
If humans ingest the vegetation without properly washing they can become infected - 41Which part of the body does fluke infect in people?Eye
- 42Give 5 disadvantages of regular worming to prevent flukeRepeated treatments needed
Costly
Drug residues in meat and milk
Environmental effects
Parasite resistance - 43What is the optimal temperature for fluke development?15-22 degrees Celsius
- 44Below which temperature does fluke development cease?5 degrees Celsius
- 45What is meant by aestivation of liver fluke?Dormant infection when snails (intermediate host) hibernate
- 46What is the main risk period for fluke?Late in grazing season
- 47Describe the calendar of fluke infection when snails are infected in SummerOverwintered eggs on pasture or shed by chronically infected animals
Hatch in early Spring or Summer
Summer infection of snails
Take time to develop in snail = metacercaria in Autumn
Ingested late in grazing season - 48When does acute disease occur with Summer infection of snails?Autumn
- 49When does chronic disease occur with Summer infection of snails?Throughout Winter
- 50Describe the calendar of fluke infection when snails are infected in WinterEggs hatched in Autumn (shed by infected animals)
Infection of snails before hibernation so infection 'carries over' to following Spring
Metacercaria on pasture in Spring - 51Give 2 conditions that can be caused by SchistosomaBilharzia
Swimmer's itch - 52What is the reason for itching caused by Schistosoma?Penetrate skin
- 53Why is the lancet fluke Dicrocoelium dendriticum less pathogenic?Less migration
Enters bile duct directly from small intestine - 54Describe the life cycle of Dicrocoelium dendriticumInfects land snail
Extruded in slime
Infects ants
Modifies ant behaviour to increase chance of re-ingestion by grazing animal - 55What is meant by a direct life cycle?No intermediate host
- 56What is meant by pathogenesis?Changes to host caused by parasite
- 57Give 2 general symptoms of liver flukeAnaemia
Hypoalbuminaemia - 58Give 3 changes in the liver that may be caused by liver flukeHyperplasia of bile ducts
Hepatic fibrosis
Ischaemia of parts of the liver
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- Animal Disease 1 (Parasitology) Flashcards on Tapeworms & Fluke 1, created by Florence Edwards on 26/01/2017.
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