Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
16 Cards in this Set
- Front
- Back
|
Describe trematodes (flukes)main features:
|
1. unsegmented, flat leaf-life worms (except schistosomes)
2. 1-70 mm long 3. oral and ventral suckers 4. hermaphrodites (except schistosomes) 5. operculated eggs (except schistosomes) 6. eggs develop in water 7. snails are intermediate hosts |
|
|
Describe the main features of Cestodes (tapeworms):
|
1. segmented/tape like
2. 3-10 cm 3. hermaphrodites 4. eggs released from gravid segment rupture |
|
|
Nematodes (roundworms) main features:
|
1. cylindrical worms
2. up to 1 m (guinea worm) 3. separate sexes 4. infection from swallowing eggs or larvae penetrating skin 5. larvae may migrate through the heart and lungs |
|
|
What is the liver fluke life-cycle?
|
1. metacercariae ingested on water plants and they excyst in duodenum
2. Penetrate liver while immature and then become grown up in the bile ducts 3. eggs are produced and passed in feces 4. eggs hatch (miacidia) that enter snails 5. in the snails they become CERCARIAE and encyst on plants |
|
|
What is the life-cycle of intestinal schistosomiasis S. mansoni?
|
1. CERCARIAE the get into the skin from bad water
2. the CERCARIAE become SCHISTOMSOMULAE and go the the lungs and liver 3. then migrate to intestine 4. eggs are laid in vein (of intestine) and passed in feces 5. when the eggs touch water, the MIRCACIDIA (miracle dia) hatch and penetrate snail to become CERCARIAE which leave for people hosts |
|
|
What is the life-cycle of schistomsomiasis S. haematobium?
|
like the intestinal schistosomiasis, only the flukes migrate to the bladder veins, burrow into the bladder and the eggs are passed in URINE.
|
|
|
How is S. mansoni diagnosed (lab)?
|
1. eggs in faeces
2. rectal biopsy 3. kato-katz technique 4. serological techniques for antigens |
|
|
How is S. haematobium diagnosed (lab)?
|
1. eggs in urin (microscope)
-used membrane filtration technique 2. rectal, bladder biopsies |
|
|
How is Taenia saginata transmitted to people?
how long are they? |
eating infected beef
4-10 meters with 2000 segments! gross |
|
|
how is taenia solium transmitted to people?
|
infected pork
2-3 meters with 900 segments. |
|
|
what is the taenia life cycle?
|
1. CYSTICERCI ingested in undercooked meat
2. they attach to intestinal wall 3. gravid segments become detached and pass in faeces...eggs then ingested by animal 4. CYSTICERCI develop in the muscle |
|
|
What are the symptoms of taenia infection?
|
1. eating the cysticerci in meat causes GI upset
2. eating the larvae by ingesting EGGS causes infection in brain, muscle, connective tissue. can cause epilepsy |
|
|
What is lab dx of taenia?
|
1. detect eggs (faeces, perianal skin, worm head after treatment causes it to be expelled)
2. serolgy (ELISA) for t. solium |
|
|
What is the life-cycle of Ascaris lumbricoides?
|
1. ingest eggs
2. larvae hatch and migrate through the liver/lungs 3. larvae pass up the trachae and are swallowed 4. mature in the small intestine 5. eggs made and passed in faeces and become infective in the soil |
|
|
what symptoms can be caused in Ascariasis?
|
1. hypersensitivty (asthma, coughing, eosinophilia and uticaria)
2. obstruction of gut/bile duct, 3. malnutrition: Vit A deficiency, hypoalbumnamia 4. abdominal pain, nausea, vomiting, diarrhoea |
|
|
How is ascaris lumbricoides diagnosed (lab)?
|
1. eggs in feces (microscopy)
2. worm passed from body orfice (anus, mouth, nose) yuck! |
