Chapter 18 LAB Flashcards
Parasites
organisms that cannot live on their own as they derive all their nutrients from their host
Helminths
multicellular eukaryotic worms
Three main groups of helminths
Termatodes (flukes)
Cestodes (tapeworms)
Nematodes (roundworms)
Termatodes
flukes: flat, segmented, and can be up to 1-2 cm long
Cestodes
tapeworms: flat, segmented, and can be up to 50 cm long
Nematodes
roundworms: round, tapering at the ends
Oriental liver fluke (Clonorchis sinensis)
Found in people living in Japan, Korea, China, and Vietnam. Eating undercooked infected fish. Migrates to the bile ducts of the liver and begins to lay eggs. Damages bile ducts and liver tissue
Lung fluke (Paragonimus westermani)
Found in Asia, Africa and South America, eating undercooked crabs or crayfish which contain cysts. Travel from small intestines to lungs to mature. Lung damage caused by inflammatory response.
Dog Tapeworm (dipylidium caninum)
usually occurs in children. worms reside in intestines and release proglottids (segments containing egg packets). Can be seen around the anal area of infected host. Abdominal discomfort and loss of appetite
Beef Tapeworm (Taenia saginata), Pork Tapeworm (Taenia solium)
Proglottids are passed into the environment by a human and infect animals when they eat them
Human Roundworm (Ascaris lumbricoides)
49cm, contaminated soil or food, larvae migrate through the lungs and can cause pneumonia. Adults reside in the small intestine- malnutrition and intestinal blockage
Hookworms (Ancylostoma spp)
eggs live in the ground, hatch out and penetrate the skin travel to lungs, up into pharynx and are swallowed. Mature in intestines and feed on blood– bloody diarrhea and anemia
Pinworm (Enterbius Vermincularis)
fecal-oral route, adults live in intestine, itching and discomfort
Heartworms
transmitted by mosquitoes that inject larvae when the dog is bitten, can be fatal
