Study Guide Animal Parasitology

Chapters 18-25

 

Warning:  These questions are only a guide, they are not meant to take the place of reading the text and studying the class notes.  You are responsible for the material covered in class even though I may have forgotten to cover it in this study guide.

 

Chapter 18

 

Phylum Platyhelminthes

Class Trematoda

        Subclass Digenea  -  continued

Order Plagiorchiformes

       

Family Dicrocoelidae

 

Dicrocoelium dendriticum is usually a parasite of what kind of animals?  How do these animals become infected?

Dicrocoelium dendriticum is found where in the body of the host?

Dicrocoelium dendriticum has an interesting morphological feature - what is it?

In the Dicrocoelium dendriticum life cycle, how do the cercaria leave the snail first intermediate host?

In the Dicrocoelium dendriticum life cycle, how does the second intermediate host be come infected?  What is the second intermediate host?

How does the metacercaria of Dicrocoelium dendriticum affect the second intermediate host?

In what geographical area(s) is Dicrocoelium dendriticum  found?

 

What is another example (name another parasite) that has an effect on the behavior of the second intermediate host.  What is the final host for this parasite?

 

Family Troglotrematidae

 

As adults, Paragonimus spp. are all parasites of what kind of animal?

The adults of Paragonimus westermani are found where in the body of the host?

What are the second intermediate hosts for Paragonimus westermani?

How does man become infected by  Paragonimus westermani?

 What type of food preparations might appear "cooked" but do not kill parasites?

Besides the normal location for the adult of  Paragonimus westermani, where else might the parasites be found and what affect might these have on the host?

What is the most distinctive morphological feature of Paragonimus westermani?

In what geographical area(s) is Paragonimus westermani found?

 

In what geographical area(s) is Nanophyetus salmincola found?

 

Family Opisthorchidae

 

What is the common name of Clonorchis sinensis?

In what geographical area(s) is Clonorchis sinensis found?

What morphological characters distinguish Clonorchis sinensis?

Where in the body of the host are Clonorchis sinensis adults found?

What is the second intermediate host for Clonorchis sinensis?  What form (life cycle stage) is found in this host?

What practices by humans have enhanced the incidence of this parasite?  How do humans become infected with this parasite?

How are infections of Clonorchis sinensis diagnosed?  What is the treatment?

 

Family Heterophyidea

 

What morphological character distinguishes Heterophyes heterophyes?

Where in the host are adult Heterophyes heterophyes found?

What kind of fish are the most common hosts for the metacercaria of Heterophyes heterophyes?

Do you think Heterophyes heterophyes could parasitize people in Puerto Rico?  How do humans become infected with this parasite?

What is a complication of infection by Heterophyes heterophyes that is common in the Philippines?

 

General

 

Parasites may be vectors of other diseases.  Name a digenetic trematode that is a vector of a rickettsial disease.

What is a treatment for digenetic trematodes?

 

 

Chapter 19

 

         Class Monogenea

 

Monogenea are mostly parasites of what animals?  Where on these animals are they found?

What is the major attachment organ in Monogenea called?

Do Monogenea have a digestive tract?

Are monogenea monoecious or dioecius?

What are the life cycle stages of monogenea called?

What artificial situation enhances the density of Monogenean parasites?

 

 

Chapter 20

 

         Class Cestoidea

 

General

 

How do cestodes differ from the digenea?

As adults, cestodes (Eucestoda) are parasites of what group of animals?

What are the three regions of the body of cestodes?

An individual segment in the chain of segments in cestodes is called what?

A narrow, unsegmented, undifferentiated area just posterior of the scolex is called what?

What is the process of forming the chain of segments called?

Define immature, mature and gravid segments.

What are two different types of attachment organs on the head of a tapeworm?

What type of scolex has two (sometimes four and six) longitudinally arranged, shallow depressions?

The "skin" of cestodes is called what?

What unique structures are found on the surface of the "skin" of cestodes?

What type of cells form the osmoregulatory system of cestodes?

What type of nervous system is found in cestodes?

As segments are pushed posteriad during development what sex organs develop first?  What advantage might there be for having one sex develop before another?

How many testes do cestodes have?  How many ovaries?

What is the pattern of arrangement of vitelline cells in the cestodes?

In some cestode species, posterior segments filled with eggs may break off the end of the chain and pass out of the body of the host.  What is this process is called?

What type of scolex has four muscular suction cups in the equatorial region?  What is another type of scolex (with another type of attachment organ)?

Pseudiphyllidean tapeworm eggs are characterized morphologically by having ...

Dipylidean tapeworm eggs are characterized morphologically by having ...

Taenioid tapeworm eggs are characterized morphologically by having ...

What do you call the two basic life cycle patterns in human tapeworm infections?  What type of life (habitat) is each adapted for? 

What are the intermediate stages in the two basic life cycle patterns of human tapeworm infection?

Cestodes are more closely related to Digenea, Turbellarians or Monogenea?

 

 

Chapter 21

 

                  Order Pseudophyllidea

                           Family Diphyllobothriidae

 

What is the common name for  Diphyllobothrium latum?

What morphological features distinguish Diphyllobothrium latum?

What is the morphology of the egg in Diphyllobothrium latum?

What features characterize the proglottid of Diphyllobothrium latum?

The life cycle of Diphyllobothrium latum includes what life cycle stages?

Diphyllobothrium latum is apolytic or anapolytic?

What is the first intermediate host of Diphyllobothrium latum?  What is the second?

How does a human become infected with Diphyllobothrium latum?

What unusual deficiency occurs with Diphyllobothrium latum infections?

 

What is a condition in humans caused by plerocercoid larvae of several pseudo­phyl­lidean tapeworms infecting tissues?

 

                  Order Cyclophyllidea

                           Family Taeniidae

 

The immature worms of taeniid tapeworms are commonly called what?

What group of animals serve as the intermediate hosts for taeniid tapeworms?

What is the species of the beef tapeworm?

Geographically, where is the beef tapeworm found?

What is the morphology of the scolex of the beef tapeworm?  How does it differ from the pork tapeworm?

How is the proglottid of the beef tapeworm distinguished from the proglottid of the pork tapeworm?

How is the egg of the beef tapeworm distinguished from the egg of the pork tapeworm?

How do humans become infected with beef tapeworm?  How can human infections be prevented?

Where in the body of the beef do the parasites live?

 What are the intermediate hosts for  the beef tapeworm? - the final host?

How does the intermediate host become infected with the larval stage of this tapeworm?

A common name for a cysticercus is what?

 

The human pork tapeworm is what species?

How are humans infected with Taenia solium?  What are the life cycle stages of Taenia solium?

What are the intermediate hosts for  the pork tapeworm? - the final host?

The proglottid of Taenia solium is characterized by what morphology?

In pigs, cysticerci are found in what organs?  How did they manage to get to these sites?

How does a pig become infected with the pork tapeworm?

The cysticerci of beef or pork tapeworm is more likely to infect humans?

In human cysticercosis, what organs can be infected?

How can infections by pork tapeworm be prevented? 

How does a human become infected with cysticerci?  How can this be prevented?

How are infections by adult pork tapeworms detected?

 

What is unusual about the strobila of Echinococcus?

Describe the scolex of Echinococcus granulosus.

What life cycle stages are found in Echinococcus?

What are intermediate hosts for Echinococcus?  

The definitive hosts of Echinococcus are what kind of animals?

Are humans intermediate of definitive hosts for Echinococcus?

The life cycle of  Echinococcus takes advantage of what relationship between intermediate and final hosts?

What is the most dangerous life cycle stage of Echinococcus?

How do humans become infected with Echinococcus?

What group of humans are most likely to become infected with Echinococcus?

How do domestic dogs become infected with Echinococcus?

What are hydatids in visceral tissue of humans called.  It is the least pathogenic and most common form.

 

In Echinococcus multilocularis, hydatids have a thin wall and are difficult to distinguish from surrounding tissue.  Connective tissue septa divide the cyst into numerous irregular compartments called what?

 

                           Family Hymenolepididae

 

What is the common name of  Vampirolepis nana ?

The proglottid of Vampirolepis nana is characterized by having what morphology?

The life cycle of Vampirolepis nana includes what stages?

What is unusual about the life cycle of Vampirolepis nana?

What group of humans is most affected by Vampirolepis nana?

What animals can serve as possible intermediate hosts of Vampirolepis nana?

What animal besides humans can serve as a definitive host for Vampirolepis nana?

How are infections by Vampirolepis nana contracted?

How can human infections of Vampirolepis nana be prevented?

What is autoinfection and how might it affect the host?

 

Hymenolepis diminuta is commonly a parasite of what animal?

How does the scolex of Hymenolepis diminuta differ from that of Vampirolepis  nana?

What are the intermediate hosts for Hymenolepis diminuta?

Can humans become infected with this worm?

Why do we talk about this parasite – what is its importance?

 

         Family Dilepididae

 

Dipylidium caninum is usually a parasite of what domestic animal(s)?

How can human infections of Dipylidium caninum be prevented?

What is unusual about the uterus of Dipylidium caninum?

What happens to the eggs of Dipylidium caninum?

What morphological features distinguish the proglottid of Dipylidium caninum?

It is said that the free proglottid of Dipylidium caninum looks like some type of seed, what is it?

What is an intermediate host for Dipylidium caninum?

How do humans become infected with Dipylidium caninum?

 What group of humans is most affected by Dipylidium caninum?

 

General

 

What is the smallest adult tapeworm found in man

What is the largest adult tapeworm found in man?

What is the most common tapeworm found in man?

 

A practice exam for some of this material is included at

 

http://www.ksu.edu/parasitology/classes/625exam1.html

 

 

 

Chapter 22

 

Phylum Nematoda

 

What is a common name of nematodes?

Nematodes are divided into two classes based on the presence of minute sensory structures called what?

The body of a nematode contains a body cavity called what?

Nematodes have a complete or incomplete digestive system?

Describe the body wall of nematodes. What are the three basic components?

What two types of chemoreceptor organs are there in nematodes and where are they located on the body of the worm?

How are muscles arranged in Nematodes?

What are the main nerve centers in nematodes?

What is the hydrostatic skeleton?

The excretory system of nematodes is composed of what cells?

How many times does a nematode molt before becoming an adult?

How many juvenile stages are there?

What are some morphological differences between male and female nematodes.

How many testes do nematodes have?

How many ovaries do nematodes have?

What are the layers formed in the shell of the egg of nematdes?

What are rhabditiform larvae?

What are filariform larvae?

What are microfilariae?

 

 

Chapter 23

 

Trichuris truchiura

 

What is the common name for Trichuris truchiura?

In what group of people are Trichuris truchiura infections most commonly found?

What is the life cycle of Trichuris truchiura?

How are Trichuris truchiura infections acquired?

What is unique about the morphology of Trichuris truchiura?

What glandular cells are found along the esophagus of Trichuris truchiura?

What ecological conditions are necessary for the survival and transmission of Trichuris truchiura?

How are Trichuris infections diagnosed?

What are some of the symptoms of Trichuris infections?

What chemotherapy is effective against Trichuris truchiura?

What behavioral modifications might help prevent the transmission of Trichuris truchiura?

 

Trichinella spiralis

 

What are some of the species of Trichiella?

Which species is the most common in temperate and tropical areas?

What is the name of the disease caused by Trichiella?

What is the life cycle of Trichinella spiralis?

What unique structure is formed in the host cell that supports life for Trichinella spiralis juveniles in muscle tissue?

How are Trichinella spiralis infections acquired?

How can Trichinella spiralis infections be avoided?

What is the infectious stage of Trichinella spiralis?

What is Urban or domestic trichinosis?  What hosts are involved in the perpetuation of disease?

What is sylvatic trichinosis?

What are the three clinical phases of Trichinella infection?

How are Trichinella infections prevented?

What is the treatment for Trichinella infections?

How is trichinosis diagnosed?

 

What is the most common nematode infection of man?

 

Chapter 24

 

 

Strongyloides stercoralis

 

Why is this an unusual worm?

The parasitic worms are all what sex?

The free living phase occurs where?  If conditions turn unfavorable what happens?

In the parasitic phase - what happens?  What is the migratory route of the J3's in the body of the host?

How does autoinfection occur?  What are some of the results of autoinfection?

How do humans contract this infection? (2 ways).

What geographic area is affected by this worm?  What other animals may serve as sources of human infection?

How does this worm affect the skin due to penetration?

How does this worm affect the lungs?  What symptoms may be experienced?  What do these symptoms resemble?

How does this worm affect the intestine due to penetration of the mucosa?  What symptoms may be experienced?

How is this infection diagnosed?  What samples can be examined

What is the treatment?

How can infection be prevented?

 

Chapter 25

 

 

Human hookworm –

 

Hookworms infect nearly how many people world-wide?

What two species of hookworm infect humans?

Which is larger in size?

What hosts are infected by each species?

What is a distinctive morphological feature of male hookworms? 

What morphological or anatomical feature can be used to distinguish the species regardless of sex?

What stage hatches out of a hookworm egg?

What stage is the infective stage?

Where is the infective stage found?

How does a human become infected with hookworms?

What is the migratory route of the larvae of hookworms once they enter the body of the host?

Where in the body of the host does the final molt take place?

What four factors are needed for the spread of hookworm?

What is the common name of the inflammatory reaction that is elicited by the entry of larval hookworms?

In heavy infections of hookworms, what pathological effect may be seen in the lungs of the host?

Once in the intestine what do hookworms eat? 

How many worms of each species are necessary for a severe pathological effect to occur?

What are some of the pathological effects of infection by hookworms?

What climatic conditions favor transmission of this parasite?

How are hookworms diagnosed?

What is the treatment?

How can hookworm infections be prevented?

 

Define cutaneous larval migrans or creeping eruption.

What are the species usually involved in this condition?