Helminths Flashcards
(39 cards)
The life cycle of helminths
Egg —Miracidium(larva)— Sporocyst— Cercaria— Metacercaria— Adult
What are he three groups of helminths
Platyhelminthes( flatworms); Tramatodes(flukes)
Cestodes
Nematodes(roundworms)
Schistosomes is the only fluke with separate sexes
True
What blood fluke causes causes intestinal schistosomiasis.
Schistosoma mansoni
Schistosoma japonicum
Schistosoma intercalatum
Schistosoma mekongi( milder in men)
What causes vesical (urinary) schistosomiasis.
Schistosoma haematobium:
Where does the female fluke lie in the male
In the gynecophoral canal
Where do fluids feed and grow to maturity after cercaria stage
Within the intrahepatic portion of the portal system.
Patients infected with____ suffer from cercarial dermatitis (swimmers itch) and dysentery as well as enlargements of the spleen and liver.
S.mansoni
____ causes squamous carcinoma in the bladder
S.harmatobium
What is used to treat shistomiasis
Praziquantel- all spp
Oxamniquine- intestinal
Metrifonate- urinary
.
What stage in the life cycle of fluke do the have snails as intermediate host
Sporocyst stage
Tapeworms are hermatrophrpdotic means?
They require immediate hosts
What does scolex and strobilla contain
Scolex- suckers
Strobilla- proglottis- main bulk
They have separate sexes with separate appearances. They have a tough protective covering or cuticle. They have a complete digestive tract with both oral and anal openings.
Nematodes
What are the three intestinal nematodes with tissue stage
- Ascaris
- Hookworms
- Strongyloides
The Penetration of the ascaris larvae from capillaries into the lungs can lead to
Loeffler’s syndrome, (pools of blood and dead epithelial cells clog air spaces in the lungs; inflammation of the lungs) pneumonia-like symptoms.
What are the two species of hookworm
Ancylostoma duodenale and Necator americanus.
How does filariform larvae of hookworm enter they body
It penetrates the skin
What does the hook worm cause
feed on blood; causing iron deficiency anemia.
•The larvae may cause inflammation of the lungs.
What are the 2 types of larva migrans
Ancylostoma braziliens: infects both dogs and cats.
•Ancylostoma caninum: infects only dogs.
What do FILARIAL WORMS cause
Filariasis (characterized by fever, chills, headache, and skin lesions in the early stages).
•if untreated, can progress to elephantiasis (gross enlargement of the limbs and genitalia).
Where do filarial worms inhabit in man and what diseases do they cause
- lymphatic system - lymphatic filariasis (leads to elephantiasis when the lymph nodes are blocked)
or the subcutaneous tissues of man.
_____ elephantiasis infection can affect the legs, arms, vulva, scrotum and breasts.
But ___elephantiasis affects the legs below the knees
- W. bancrofti
2. Malayan
If conjunctiva filariasis is left untreated what can it cause
blindness known as onchocerciasis (River blindness).
