Parasites

Question 1

How do anthelmintics work? (2)

Answer 1

• affect the parasites CNS leading to death or paralysis
• some cause digestion of the parasite

Question 2

Effect of host and environment on parasitism

Answer 2

• Older animals more resistant to parasitic infection

- Parasites reproduce better in warm, moist conditions

Question 3

Control and prevention of parasitism (3)

Answer 3

• Daily removal of feces from housing areas
• Prevent ingestion of intermediate or paratenic hosts
• Perform routine laboratory tests to screen for parasite infections

Question 4

Internal Parasites (4)

Answer 4

1. Nematodes (Roundworms)
2. Cestodes (Tapeworms)
3. Trematodes (Fluke worms)
4. Protozoa

Question 5

Which group of parasites are considered the most important?

Answer 5

Nematodes

Question 6

Where are nematodes found within the body?

Answer 6

there is a nematode for every organ

Question 7

What is the structure of an adult nematode?

Answer 7

elongated and cylindrical

Question 8

What size can nematodes get to?

Answer 8

1mm to 100cm

Question 9

Encyst

Answer 9

when a nematode goes dormant

Question 10

What can stimulate an encysted nematode?

Answer 10

horomones

Question 11

Which group of parasites is an Intermediate host necessary in life cycle?

Answer 11

Cestodes

Question 12

Where do adult cestodes live in the definitive host?

Answer 12

The intestines

Question 13

What is the structure of an adult cestode?

Answer 13

Long flat worms divided into segments

Question 14

What are the structures of cestodes? (2)

Answer 14

1. scolex

2. proglottids

Question 15

Scolex

Answer 15

head of a cestode

Question 16

1. What does a scolex contain?

2. What is their purpose?

Answer 16

1. has suckers and hooks

2. to help it attach to the wall of the intestine

Question 17

A proglottid is a…

Answer 17

fully functional unit with digestive, reproductive, and other organs

Question 18

What is contained within a proglottid?

Answer 18

Eggs

Question 19

Where are trematodes usually found within the host?

Answer 19

1. intestine
2. liver
3. lung

Question 20

What is the intermediate host for trematodes?

Answer 20

Snail

Question 21

What is the structure of trematodes?

Answer 21

Flat worms with leaf-shaped body

Question 22

Protozoa are…

Answer 22

Unicellular organisms

Question 23

Where are protozoas found with in the host?

Answer 23

Found in different organs w/in the body

Question 24

How are protozas seen?

Answer 24

Only visible with a microscope

Question 25

Definitive host

Answer 25

animal harboring sexually mature parasite

Question 26

Prepatent period

Answer 26

time elapsed between infection with parasite and when it reaches reproductive maturity

Question 27

Paratenic host

Answer 27

animal serving as a transport host for immature stages of the parasite, no development occurs

Question 28

Intermediate host

Answer 28

animal used by the immature stages of the parasite to continue development

Question 29

Ways parasites can affect their host (3).

Answer 29

1. Malnutrition - compete w/ host for ingested food
2. Mechanical - destroy tissue, cause obstructions
3. Blood loss - anemia

Question 30

Accurate diagnosis is dependent on…

Answer 30

Performing the right test, at the right time, and doing it correctly