Lecture 10- Intro to parasites Flashcards
parasitic infection is distinct from
parasitic disease
2 parasite types
helminths
protozoa
many parasitic infections are… which is when its caused by agents that infect animales
zoonoses
humans are… hosts for some parasite
dead end (life cycle doesnt complete)
there are about 65000 species of… but most are harmless free-living inhabitants of water and soil
protozoa
…protozoa have single nucleus, reproduce by sexual repr., some lack mitochondria and golgi, most are cysts and free-living and most are solitary
flagellated/mastigophora
…, most of these are not motile except male gametes. They produce sporozoites following sexual reproduction, important in transmission of infections. Most form oocysts, entire group is parasitic
Sporozoa/apicomplexa
examples of sporozoa/apicomplexa
plasmodium
toxoplasma gondii
cryptospordium
examples of flagellated/mastigophora
trypanosoma
leishmania
giardia
trichomonas
… was caused by failure of drinking water treatment in 93.
400k people infected
cryptospordium
helminths/worms are…. and they are… due to large size.
They are protected by..
Larvae can develop into..
multicellular (metazoa)
extracellular
cuticle
dormant cysts
disease of helminths is NOT a consequence of…
replication
subdivisions of flatworms
cestodes (tapeworms)
trematodes (flukes)
flatworms are from the phylum… and they are thin and often…
platyhelminthes
segmented
the roundworms are from the phylum… and are also known as… they elongate are cylindrical and are unsegmented
aschelminthes
nematodes
in malaria, the mosquito is the… and are essential step of life cycle
parasite vector
3 entry ways of parasittes
- oral (contaminated water or food)
- penetration of skin (hookworm can get through unbroken skin)
- arthropod-borne (get bitten)
schisotosomiasis, … is required to allow parasite to grow which are not in N.A. or europe
snails
spread and multiplication is determined by … and… tropisms
species
tissue
leishmania donovani replicates at…
leishmania tropica replicates at..
degrees
37
25-30
clinical manifestations of parasites can be through … or…
direct tissue damage (cytolysis)
immune response
… disease presents with a swollen eye, symptomless stage, biten by a bug, causes damage to other organs, is irreversible and weakens body, sometimes fatal
chagas
treatment and prevention (3)
must have 2 for eradication
- chemoprophylaxis- preventative drugs
- immunization
- field control measures
immunization problem with parasites is that many parasites… and sometimes continually change surface antigens
masquerade by coating themselves in host antigens