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Flashcards in Helminths (complete) Deck (101)
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1

What are the three categories of helminths that are pathogenic to humans

Cestodes (tapeworms)
Trematodes (flukes)
Nematodes (roundworms)

2

What are helminths

macroscopic, eukaryotic, multicellular worms

3

can the larvae of helminths typically support themselves?

no, they typically need support from intermediate hosts

4

What does it mean that helminths can be dioecious or monoecious?

Dioecious means that there are male and female worms that need to "get together" to reproduce
monoecious means that the worm has both male and female sex organs

5

What types of helminths are dioecious

blood flukes and nematodes

6

What types of helminths are monecious

all helminths except blood flukes and nematodes

7

Cestodes and trematodes are both platyhelminths, what does that mean

that they are flatworms

8

how long do helminth infections last

usually years

9

What is the immune response generated by helminths

a TH-2 immune response with eosinophilia, mucosal mastocytosis, and elevated IgE

10

How well does the immune system work against helminths

it struggles to completely eliminate the helminths, and reinfections are common, but the parasite load does decrease over time reflecting partial immunity

11

What are the two different places you find helminths in the body, and what are the problems they cause

Intestinal helminths = anemia from chronic blood loss
Systemic helminths = organ damage from inflammatory responses to eggs or worms

12

What are some of the larger problems caused by helminths

liver failure
epilepsy
elephantitis

13

do helminths generally replicate in mammalian hosts?

nope, passage through intermediate hosts of through soil and water is required

14

do helminth infections have a high morbidity rate

yes

15

What are the three ways helminths can enter the body

through the mouth
bite of insect vector
penetration (burrowing through skin)

16

Where in the body do helminths localize

liver, lungs, intestines, CNS
Dermal and lymph tissue
Blood vessels (around intestine and bladder)

17

What are the two ways helminths directly cause damage

They cause cysts to grow in organs which damages them by putting pressure on them
they physically block intestines

18

What is the beef tapeworm

taenia sangiata

19

what is the pork tapeworm

taenia solium

20

Which humans have the high incidence of infection with Taenia

those working in close proximity to livestock (cows and pigs)

21

How do the cattle and swine get infected with taenia

by eating contaminated vegitation

22

What is Cysticerci

the larvae of helminths in meat

23

What are the body parts of Cestodes (tapeworms - taenia)

Scolex - point of attachment
chain of proglottids
Those near the scolex are immature
those near the middle are mature
those near the end are gravid (full of fertilized eggs)

24

What happens with the gravid proglottids (gravid meaning full of fertilized eggs)

they are released into the feces

25

How many proglottids can a mature T. sanginita worm have, and how many eggs does each have

they can have 1-2000 proglottids, each of those having about 100,000 eggs.

26

how many proglottids do infected humans pass per day

6

27

Where do the taenia attach

the intestinal epithelium

28

do most humans infected with taenia have symptoms

nope, they just shed proglottids (they only have symptoms if the worm gets large enough to block the intestines)

29

How do you prevent taenia infection

thoroughly cooking or freezing meat

30

How large can taenia sanginita become

10 meters long