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11 Cards in this Set
- Front
- Back
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What are protozoa?
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They are free living, single celled, eukaryotic cells with a cytoplasmic membrane and organelles including 1 or 2 nuclei.
Size varies from 5um to 2mm, with an endoplasm and ectoplasm. It ingests through a mouth called a cytostome. |
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How do protozoa reproduce?
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They reproduce asexually, undergoing DNA replication followed by division into 2 cells. They also produce sexually by the fusion of two cells followed by DNA exchange.
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protozoa can secrete a protective coat and shrink into a round armoured form called a cyst. TRUE/FALSE
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TRUE.
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There are 5 intestinal protozoa that cause diarrhea. What are they?
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1. Entamoeba histolytica- causes bloody diarrhea
2. Giardia lamblia and 3.Cyclospora cayetanensis- cause a non bloody diarrhea 4. Cryptosporidium, and 5. Isospora belli cause severe diarrhea in immunocompromised individuals. |
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About 10% of the world population and 1-5% of the US population are infected with E. histolytica. TRUE/FALSE
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TRUE. Most of these are asymptomatic. These carriers pass the infective form, the cyst to other individuals via the fecal oral route.
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What is a trophozoite?
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It is the motile feeding form of the amoeba. It cruises along the intestinal wall, eating bacteria, intestinal and RBCs.
It can convert to a precyst form with 2 nuclei, that matures into a tetranucleated cyst as it travels down and out of the colon. |
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What is a chromotoid body.
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It is a precyst that contains aggregates of ribosomes. It is the cyst that is eaten, infecting others.
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Sometimes the trophozoites invade the intestinal mucosa causing erosions. THis results in loose stool with flecks of blood. TRUE/FALSE
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TRUE.
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Can the presence of trophozoites cause death.
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Yes. They may penetrate the portal blood circulation, forming abscesses in the liver, the lung and diaphram. Pulmonary abscesses can result in death.
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How are the protozoa diagnosed?
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Stool is examined for the presence of cysts or trophozoites. Trophozoites with RBCs in the cytoplasm suggest active disease, and those without suggest asymptomatic carriage.
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How are protozoa treated?
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Metronidazole(Flagyl)
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