Overview Flashcards
(17 cards)
What is the general morphology of nematodes?
Unsegmented, elongated, circular, vast size variation
Example sizes include Strongyloides stercoralis (~2 mm X 35 μm) and Dioctophyma renale (< 100 cm X 1.2 cm)
What are the shape variations of nematodes?
Spherical, whip-like
Examples include Tetrameres spp. (spherical) and Trichuris spp. (whip-like)
What is the life cycle of eucestodes?
Proglottids passed, thousands of eggs released, eggs ingested by intermediate host, development into metacestode
Forms include cysticercoid, cysticercus, coenurus, hydatid cyst, and tetrathyridium.
What are the general characteristics of trematodes?
Unsegmented, flattened, leaf-like, vast size variation
Example sizes include Nanophyetus salmincola (~0.5 – 1.1 mm) and Fasciola magna (< 10 cm X 2.5 cm)
What types of hosts do digenetic trematodes require?
2-4 obligate hosts, potential paratenic hosts
Hosts can include animals and humans.
What is the function of the oral sucker in trematodes?
Attachment and feeding
Other mouth structures include pharynx and esophagus.
What is the basic structure of cestodes?
Dorsoventrally flattened, ribbon-like, segmented body
Includes scolex (attachment), neck, and strobilia (body).
What is the reproductive strategy of cestodes?
Hermaphroditic with self and cross-fertilization
Mature from front to back.
What are the types of eggs produced by nematodes?
- Ascarid: round/oval, thick outer shell
- Strongyle: oval/elliptical, thin smooth shell
- Spiruroid: oval/rectangular, thin smooth shell
- Trichuroid: elliptical, polar plugs
Each type has specific stages and characteristics.
Fill in the blank: The life cycle of nematodes can be _______ or indirect.
[direct]
What is the defining feature of apicomplexans?
Pathogenicity and life cycles integrated into host physiology
Includes coccidia like Eimeria spp. and Toxoplasma gondii.
What are the characteristics of pathogenic ciliates?
Motile trophozoite form, resistant cysts
Examples include Balantidium coli and Ichthyophthirus multifiliis.
What is the general morphology of acanthocephalans?
Elongated, cylindrical, tapering ends, retractable proboscis
Size variation ranges from 14 mm to 70 cm.
What is the life cycle of acanthocephalans?
Eggs passed, ingested by intermediate host, larva develops, definitive host ingests intermediate
Adult attaches to intestine.
What is the morphology of protozoa in the Sarcodina group?
Motile trophozoite with amorphous pseudopods
Pathogenic forms include Entamoeba histolytica.
True or False: All trematodes have a GI tract.
False
Trematodes absorb nutrients directly through the body surface.
What is the main characteristic of the trophozoite form in mastigophorans?
Motile in liquid environments
Includes pathogenic flagellates like Leishmania spp. and Giardia spp.
