Flashcards in World of Parasites Deck (22)
What is the common name for platyhelminthes?
What is the common name for cestodes?
What is the common name for trematodes?
What is the common name for nematodes?
What is the common name for arthropoda?
insects, spiders, mites, and ticks
These are single celled parasites that contain many phyla.
What are flatworms, tapeworms, flukes, and roundworms known as?
What protozoan stage would you find in formed stool?
Cysts (and eggs); trophs wall themselves up to form cysts as protection
What protozoan stage would you find in liquid stool?
Trophs (and eggs); these are more motile and fragile, commonly found higher up in the GI tract
What protozoan stage can be found in semiformed/soft stool?
cysts, trophs, and eggs
What is the ratio of preservative to stool?
3 parts preservative : 1 part stool
This preservative serves as a fixative (mercuric chloride), is a resin for adhesion to the slide, and is used for PERMANENT smears.
This preservative is used for concentrations or wet mounts, NOT smears.
10% buffered Formalin
What two methods of concentration are based on specific gravity?
Flotation and sedimentation
What preservative is used in the floatation concentration technique?
Modified Zinc Sulfate
What is the specific gravity in concentration techniques?
What are the disadvantages of using the flotation technique?
dense eggs sink and operculated eggs rupture
What are advantages of doing flotation techniques?
allows detection of most eggs, larvae, and cysts; also eliminates debris (will settle to the bottom)
What are the advantages of doing the sedimentation concentration techniques?
allows detection of most eggs, larvae, and cysts by gravity or centrifugation
What are the disadvantages of using the sedimentation concentration techniques?
Smaller eggs may not sediment; more fecal debris than flotation methods
What are the advantages of doing permanent stains?
Able to view internal structures (trophs or cysts)