Ch 45 Parasitology Part 1 Flashcards
What is the common name for organisms in the Phylum Nematoda?
Roundworms
What is the body shape of nematodes?
Cylindrical
What type of body structure do nematodes possess?
Multicellular
What is the cuticle in nematodes?
A body wall composed of an external, acellular, protective layer
What lies beneath the cuticle in nematodes?
Hypodermis
What type of muscles do nematodes have for locomotion?
Longitudinal somatic muscles
Describe the digestive tract of nematodes.
Tubular and suspended in the pseudocoelom, one straight tube from mouth to anus
How are the reproductive organs of nematodes characterized?
Tubular but longer than the body, wrapping and coiling around the intestinal tract
Do nematodes have a respiratory system?
No
What are the developmental stages in the life cycle of nematodes?
Egg, four larval stages (wormlike), sexually mature adult
What is the infective stage of a nematode?
Egg containing a larva, free-living larva, or larva within an intermediate host
What is the difference between direct and indirect life cycles in nematodes?
Direct - no intermediate host needed; Indirect - an intermediate host is needed
Where can diagnostic stages of nematodes be found?
Feces, blood, sputum, urine, lungs, kidney, urinary bladder, heart
Name two taxonomic superfamilies of nematodes relevant in veterinary medicine.
- Ascaroidea
- Strongyloidea
What is the prepatent period for Toxocara canis?
21 to 35 days
What is the length range of adult ascarids?
3 to 18 cm
What is the common name for Ancylostoma caninum?
Canine hookworm
What are the eggs of Strongyloides characterized by?
Oval or ellipsoid with thin walls and 8 to 16 cells
What is needed for diagnosis of Strongyloides?
Fresh feces
What type of parasites are strongyles?
Parasites of the large intestine in horses
Which strongyles are considered most pathogenic?
- Strongylus vulgaris
- S. edentatus
- S. equinus
What is the identification method for bovine trichostrongyles?
Fecal culture and larval identification
