Parasitology Flashcards
What is parasitism?
A symbiotic relationship in which one organism (the parasite) benefits at the expense of the host
Where is an endoparasite found?
Internally
Where is an ectoparasite found?
On skin and hair
What are the two main classifications of parasites?
- Protozoans
- Helminths
Are protozoa eukaryotes or prokayrotes?
Eukaryotes, they have nuclei
What are protozoa?
Single celled simple animals
How are protozoa classified?
Based on locomotion
Protozoa exist in what two forms?
- Trophozoite
- Cyst
What happens when protozoa are in trophozoite form?
Cell is vegetative
Feeding off the host and multiplying
What happens when protozoa are in cyst form?
Dormant and resistant phase for outside the host
What is the method of locomotion of sporozoa?
No method of locomotion
What is the method of reproduction of sporozoa?
Simple fission followed by sexual reproduction (2 cycles)
What is the etiologic agent for malaria?
Plasmodium spp.
What is the vector of plasmodium spp. causing malaria?
Anopheles mosquito
What is the most prevalent species of plasmodium in sub-Saharan Africa?
Plasmodium falciparum
Responsible for the majority of malaria deaths globally
What is the second most significant species of plasmodium?
Where is it prevalent?
Plasmodium vivax
Prevalent in Southeast Asia and Latin America
What is the most prevalent parasitic disease worldwide?
Malaria
What is malaria?
Febrile illness caused by plasmodium infection of RBCs
What are some symptoms of malaria?
- Fever
- Anemia and circulatory changes
- Splenomegaly
- Bone marrow suppression
- Hemoglobinuria
What is hemoglobinuria?
“Black water fever”
High amounts of hemoglobin in urine
What is the etiologic agent of toxoplasmosis?
Sporozoa: toxoplasma gondii
What is the vector of toxoplasma gondii causing toxoplasmosis?
Feces of infected domestic cats
How might toxoplasma affect a pregnant woman?
May cause miscarriage or severe neurological damage to the fetus
How might toxoplasma affect someone with AIDS?
Important cause of AIDS-related dementia
Toxoplasmosis requires no treatment unless symptoms are severe, except for…
- pregnant women
- HIV positive individuals
How is sporozoa cyptosporidium transmitted?
Fecal-oral transmission usually via water
What is the most common symptom of cryptosporidiosis?
Watery diarrhea
Rhizopods are amoeboid
What does this mean?
They can change shape
What are the most primitive of all protozoans?
Rhizopods
How do rhizopods reproduce?
Binary fission
What is the method of locomotion of rhizopods?
Pseudopods (false foot)
How do rhizopods adapt to environmental stress?
Can exist as cyst
What is the etiologic agent of amebiasis?
Rhizopod: entamoeba histolytica
Rhizopod entamoeba histolytica colonizes…
the colon
Which parasite causes the disease “Montezuma’s Revenge” and “New Delhi Belly”?
Rhizopod: entamoeba histolytica
What are symptoms of acute amebiasis?
Diarrhea (occ. bloody), flatulence, cramping, and abdominal pain
What are symptoms of chronic amebiasis?
Alternating bouts of diarrhea and constipation
What class of parasite is the largest to infect humans?
Mastigophora
How do mastigophora reproduce?
Binary fission
What is the method of locomotion of mastigophora?
Flagella
Mestigophora exist solely in which form?
Trophozoite (vegetative)
What is the vector of mastigophora: trichomonas vaginalis?
Sexually transmitted