Parisitology Flashcards
Define parasite
An organism that lives in or on another to its own advantage and to the disadvantage of the host
What is an obligate parasite - give 1 example
The parasite cannot complete their lifecycle without exploiting a host
Tapeworm
What is a facultative parasite - give 1 example
Organism is not normally parasitic but enters host accidently
Free-living nematode
What is an accidental parasite - give 1 example
When a parasite enters the body of a species different from its normal one
Nematode
What is an opportunistic pathogen
One that only causes severe disease in immune-deficient hosts
What is a definitive host
Host in which the parasite reaches sexual maturity
What is an intermediate host
Host required for completion of lifecycle but parasite cannot reach sexual maturity
What is a reservoir host
An animal that harbours infection that can be transmitted to humans
What is a direct lifecycle
Parasite completes life cycle in a single host
What is an indirect lifecycle
Multiple hosts or involvement of a vector
Give 2 examples of arthropod parasites
Ticks - Lyme disease
Salmon louse
What are Schistosoma better known as - what do they cause
Blood flukes
Schistosomiasis
The parasite produces eggs in the gut that hatch externally in fresh water - what do the eggs release
Miracidia
What do the Miracidia then produce once they have infected a snail
Tailed cercariae
The cercariae burrow through human skin and goes undetected in the human body until they reach the liver - How?
The parasite covers itself in human proteins
Give a stage 1,2 and 3 symptom of schistosomiasis
(1) Blood in faeces
(2) Inflammation of abdomen
(3) Bladder cancer
What drug is used to remove the covering of human proteins on the parasite
Praziquantel
What does lymphatic filariasis cause
Elephantiasis due to blockage of lymph nodes
What does the drug used to treat L. filariasis do - what else can be done when a person is infected
Sterilises the adults
Regular washing to reduce secondary infection
What are the 4 protozoan parasite classes
Flagellates
Amoebas
Sporozoa
Ciliates
What is a trophozoite
Vegetative state in the lifecycle of a parasite
What is the name of the most deadly form of malaria
Plasmodium falciparum
What kind of mosquito is responsible for malaria
Female Anopheles
What is released into the circulation when one is bitten and where do they go
Sporozoites
To the liver
When the sporozoites have increased in number what happens to the cells - what is released
The liver cells burst
Merozoites are released
What do the merozoite infect - what do they turn into
Red blood cells
Trophozoites
What do the trophozoites form into and where do these go
Gametocytes
Taken back up by mosquito
What occurs in the mosquito to circle back to sporozoites
Fertilisation to form a haploid zygote which undergoes meiosis to form the haploid Oocyst
Give 2 symptoms of malaria
Flu-like
Amaemia
What stain is used to examine blood cells in parisitology
Giemsa
What doe Leishmaniasis grow in and give 1 detail on morphology
Macrophages
Flaggellated
1 detail on cutaneous, mucocutaneous and visceral leishmaniasis
C - form nodules and ulcers on the skin
M - destruction of mucous membranes in mouth, nose and throat
V - enlargement of liver/spleen
What is the vector for leishmaniasis
Sandfly
What does T. brucei cause, what does it produce and what is the vector
African sleeping sickness - tsetse fly - tryptophan
What does T. cruzi cause, what part of the body does it affect and what is the vector
Chagas disease - heart - kissing bug
What are the two stages of the Entamoeba histolytica parasite
Cyst and Trophozoite
What is 1 symptom of E. histolytica
Dysentery
Give 1 detail on morphology of Giardia intestinalis parasite - what must be ingested to become infected
Flagellated - resistant cyst
Give 1 symptom of G. intestinalis
Explosive diarrhoea
