DD- HUMAN PARASITES

Question 1

an organism which lives upon or within another living organism at whose expense it obtains some advantage

Answer 1

a parasite

Question 2

helminths are

Answer 2

worms

Question 3

arthropods are

Answer 3

insects

Question 4

definitive host

Answer 4

species in which the parasite undergoes sexual replication

Question 5

intermediate hosts

Answer 5

species in which asexual replication

Question 6

Tropism

Answer 6

ability to infect specific tissues

Question 7

helminths that cause parasitic diseases

Answer 7

1. Roundworms/Nematodes
2. Flatworms/Trematodes/Flukes
3. Tapeworms/Cestodes

Question 8

Schistosomiasis

Answer 8

disease caused by parasitic worms of the Schistosoma type. It may infect the urinary tract or intestines.

Question 9

Schistosomiasis is transmitted to humans by exposure to contaminated

Answer 9

fresh water

Question 10

Schistosomes are

Answer 10

trematodes/flatworms.

Question 11

______ is the most important parasitic disease

Answer 11

Malaria

Question 12

Infected mosquitos bite humans and inject

_____ into the blood.

Answer 12

sporozoites

Question 13

a serum-sickness like illness that occurs 4-8 weeks after skin invasion, coincident with worm maturation and onset of oviposition, and often accompanied by lymphadenopathy and hepatosplenomegaly

Answer 13

acute phase of schistosomiasis (also called Katayama fever)

Question 14

_____ are released into the blood, infect erythrocytes, and undergo additional asexual replication

Answer 14

merozoites

Question 15

symptoms of malaria are primarily associated with the rupture of______and release of merozoites

Answer 15

infected erythrocytes

Question 16

involves granulamatous and fibrotic changes in the liver or in the bladde

Answer 16

chronic stage of schistosomiasis

Question 17

A ______is an organism which lives upon or within another living organism at whose expense it obtains some advantage

Answer 17

parasite

Question 18

parasitology is concerned with pathogenic protozoa (unicellular eukaryotes) and pathogenic metazoa (multicellular eukaryotes), including ______

Answer 18

worms and insects.

Question 19

Many parasites of humans have complex life cycles that require

Answer 19

one or more additional hosts

Question 20

The definitive host is the species in which sexual reproduction occurs. Hosts in which sexual reproduction does not occur are called inter- mediate hosts. Not all parasites replicate_______

Answer 20

sexually

Question 21

The ability of parasites to infect specific tissues (_________) is often essential for their life cycles.

Answer 21

tropism

Question 22

Many parasites have mechanisms to avoid immune responses

Answer 22

encapsulation
intraluminal location
immunosuppression
acquisition of host antigens

Question 23

Major Groups of Human Parasites- worms

Answer 23

Roundworms
Flatworms (Flukes)
Tapeworms

Question 24

Major Groups of Human Parasites- Protozoa

Answer 24

Amebas
Flagellates
Ciliates
Sporozoa
Microsporidia

Question 25

Schistosomiasis Phases are Associated with

Answer 25

Cercarial invasion Worm maturation and onset of oviposition Host responses to eggs in tissues

Question 26

dermatitis (“swimmers itch”) at 2-3 days after skin invasion (also with avian Schistosomes)

Answer 26

Cercarial invasion

Question 27

in Falciparum Malaria, Infected erythrocytes containing mature asexual forms of P. falciparum stick to small blood vessels (_______). They also stick to each other (_______) and to uninfected erythrocytes (__________), thereby enhancing sequestration

Answer 27

- sequestration - agglutination - rosetting

Question 28

Because of sequestration, only ring forms (immature) and sexual forms of P. falciparum are found in circulating erythrocytes. Sequestration of infected erythrocytes interferes with the host’s____________________

Answer 28

microcirculation and metabolism

Question 29

Acute Schistosomiasis (a.k.a. Katayama fever) - a serum sickness-like illness with lymphadenopathy and hepatosplenomegaly at 4-8 weeks after skin invasion

Answer 29

Worm maturation and onset of oviposition

Question 30

Acquired Immunity against Malaria ___________ prevents high-level disease but does not eradicate infection (premunition).

Answer 30

Acquired immunity

Question 31

Acquired Immunity against Malaria Asymptomatic parasitemia is common among adults and older children in areas with _________________

Answer 31

stable and intense transmission

Question 32

Chronic granulomas and fibrotic changes in liver (from S. mansoni, S. japonicum, S. mekongi, or S. intercalatum) or in bladder (from S. hematobium)

Answer 32

Host responses to eggs in tissues:

Question 33

Genetic Diseases that Increase Resistance to Death from Falciparum Malaria

Answer 33

Sickle cell disease Ovalocytosis Glucose-6-phosphate deficiency Thalassemia