Multicelluar Eukaryotic Parasites

Question 1

What are metazoa?

Answer 1

Parasitic worms

Question 2

What is an Endoparasite?

Answer 2

Live inside the body, and often have complex life cycles with several hosts ie) tapeworms, roundworms

Question 3

What is an ectoparasite?

Answer 3

Like on the body (typically only when feeding). Can serve as vectors for other pathogens. Ie) leeches, ticks

Question 4

Give some examples of Helminthes

Answer 4

1) platyhelminthes (flat worms)
- > cestodes (tapeworms) ie) Taenai
- > Tremtodes (flukes) ie) Schitosoma
2) Nematoda (unsegmented roundedworms) eg) Ascaris
3) Annelida (segmented roundworms) ie) Hirundinea (leeches)

Question 5

What is a definitive host

Answer 5

Where an organism reproduces sexually

Question 6

What is an intermediate host

Answer 6

Where an organism may develop but doesn’t reach sexual maturity. May reproduce asexually or not at all

Question 7

What is taeniasis?

Answer 7

Tapeworm infection

Question 8

What is Taenia saginata?

Answer 8

Beef tapeworm. Humans are the definitive and cattle are the intermediate host.

Question 9

What is Taenia saginata lifecycle?

Answer 9

1) immature tapeworm if found encysted within the muscle of cow (usually jaw/tounge)
2) the cyst is consumed by human (meet not cooked properly.
3) the worm grows into adult forms inside human small intestine.
4) the worm fertilizes itself and releases its eggs in human feces. (Which is used to fertilize crop)
5) Eggs are consumed by cow, hatch, migrate to tissues to develop into cysts.

Question 10

How does the adult tapeworm reproduces? Specifically Tanenia saginata

Answer 10

The adult worm has both ovaries and testies and self fertilizes. The eggs are released into feces.

Question 11

What is a scolex?

Answer 11

Head (tapeworm) has suckers and hooks.

Question 12

What is a proglottids?

Answer 12

A body segment of a tapworm.

Each contains ovaries and testis and is filled with eggs and are shed with feces.

Question 13

What is Taenia solium?

Answer 13

Pork tapeworm

Question 14

What happens in the intermediate host of Taenia solium?

Answer 14

In the intermediate the eggs hatch and the larvae migrate to other tissues. If enters normal muscle no issue, will form a cyst called Cysticerci. If moves into a speciality like eye, heart, brain spinal cord very serious can cause Cysicercosis.

Question 15

What are the two main hosts in a fluke (trematode) life cycle?

Answer 15

Definitive host is a vertebra and intermediate is usually a snail.
Typically leaf shapped

Question 16

What is an example of a fluke?

Answer 16

Clonorchis sinensis.

Lifecycle includes snails, fish and humans.

Question 17

What is Paragonimus westermani?

Answer 17

It’s a human lung fluke. Lifecycle includes snails, crustaceans and humans

Question 18

What are blood fluke?

Answer 18

Schistosoma. Penetrates human skin, (definitive host) where eggs are shed in feces/urine. Eaten by aquatic snails. (Intermediate)

Question 19

What is swimmer’s itch?

Answer 19

Cercarial deratitis. It’s a species of Shistosoma in which the deck is the definitive host. The Laraval form penetrates the skin but soon dies

Question 20

Give an example of a nematode (non-segmented round worm)

Answer 20

Trichinella spiralis.

Question 21

How lg are nematodes (non-segmented round worms)

Answer 21

Vary from 1mm-1m

Question 22

What is a pin worm?

Answer 22

It’s a type of nematode (specifically Enterbius vermicularis)

Question 23

What is the life cycle of Enterobius vermicularis?

Answer 23

Oral fecal.

Migrates to anus and lays eggs->itchy and scratch. Can self infect or transfer to new host

Question 24

What is a hookworm and give some examples

Answer 24

A hookworm is a form of nematode. Ie) Neactor americanus & Ancylostoma anemia

Question 25

How do hookworms enter their host?

Answer 25

They can crawl and penetrate skin-> get into blood-> lungs-> digestive track and lay eggs

Question 26

What do hookworms look like

Answer 26

Like a bic pen

Question 27

What is Ascaris lumbricoides?

Answer 27

The “giant intentional roundworm’

Question 28

How do you become infected with Ascaris lumbricoides?

Answer 28

Eggs from feces ends up in the soil. Ingested from unwashed fruits and veggies.

Question 29

What happens once Ascaris lumbricoides is ingested?

Answer 29

It penetrates the gut->lungs-> digestive tract.

Question 30

What is the danager with a heavy infection of Ascaris lumbricoides?

Answer 30

A heavy infection can lead to intestinal blockage. Also migrating larvae may cause pneumonia

Question 31

How are Filarial worms transmitted?

Answer 31

By mosquitoes.

Question 32

What disease does Filarial worms cause?

Answer 32

Elephantiasis

Question 33

What is an example of Annelida (segmented round worms)?

Answer 33

Hirudinea (leeches)

Question 34

What are some examples of lice?

Answer 34

Pediculus capitis (head lice)
Pediculus humanus (body lice->clings to clothes)
Phthrius pubis (pubic lice->crabs)

Question 35

What does a Bot fly do?

Answer 35

They lay eggs on body typically in open wounds. The larvae (maggots) live off of tissue and secretions.

Question 36

What classification do mites belong to?

Answer 36

Arachnida (as well as ticks)

Question 37

What is the difference between scabies and chiggers?

Answer 37

Both are caused by mites. In Scabies they tunnel through skin to lay eggs. In Chiggers the larval mites burrow into skin and die