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Sarcomastigophora
- Phylum of Single-celled Protozoan parasites,
- Sarco = amoebas Mastigo = flagella Phora = bearers
- 2 subphyla:
- Mastigophora (flagellates) & Sarcodina (amoebas)
- In both groups, reproduction is mostly asexual (binary fission)
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Mastigophora
- Subphylum of Sarcomastigophora
- Flagellates: have long, thread-like extension of cytoplasm that functions in locomotion
- # & position of flagella vary in different species
- Examples: can be found in blood (Trypanosoma like in Sleeping Sickness), intestine (Giardia - Giardiosis), vagina or urethra (Trichomonas - Trichomoniasis) - all highly pathogenic
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Sarcodina
- Subphylum of Sarcomastigophora
- Sarcodines: include amoebas; they move by means of cytoplasmic extensions called pseudopodia
- These amoebas includes free-living, commensal & parasitic ones
- Example: Entamoeba histolytica- important pathogen
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Apicomplexa
- Phylum of parasitic protazoans
- Sporozoans: they are tissue parasites, with complex life cycle (have alternating sexual and asexual generations)
- No locomotory organelles, rely on circulatory system of host and vectors as transportation
- Examples: 4 species of Plasmodium are found primarily as blood parasites and cause malaria
- Isospora, Cryptosporidium, Sarcocystis are parasitic in the intestinal mucosa
- Toxoplasma, Pneumocystis and Babesia are found in various organs and tissues
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Ciliophora
- Phylum of parasitic protozoans
- Ciliates: include a variety of free-living and symbiotic forms, many multinucleated (macronucleus and micronucleus)
- Locomotion is accomplished by cilia: short threads of cytoplasm arising from basal granules
- Cilia are structurally similar to flagella but are shorter and more numerous
- The only ciliate parasite of humans is Balantidium coli, found in the intestinal tract. They may produce severe intestinal symptoms
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Platyhelminthes
- Phylum of flatworms
- Multicellular, with flat body
- Bilaterally symmetrical, with incomplete gut (no anus)
- Hermaphroditic (monoecious) having both male and female organs in same individual
- Their size range is highly variable.
- Most members are symbionts, living on or in the body of their hosts
- Divided into three classes
- Free-living ones belong to class Turbellaria
- Classes Trematoda and Cestoda are parasitic
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Trematodes
- Class of parasitic flatworms
- Flukes: leaf-shaped or elongate, with attachment organs in form of hooks or cup-shaped muscular depressions called suckers
- Simple incomplete digestive tract is present
- Members have complex life histories with at least 2 hosts in life cycle; the 1st intermediate host is always a mollusk
- Parasitize the intestinal tract, the liver, the blood vessels, and the lungs
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Cestoda
- Class of parasitic flatworms
- Tapeworms: typically have an elongated, ribbon-like, segmented body that bears a specialized attachment organ, the scolex, anteriorly
- Digestive tract is absent; absorb nutrients directly through body wall.
- Adults mostly reside within the small intestine
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Nematoda
- Phylum of Roundworms
- Elongate, cylindrical worms, with pointed ends & tough/stiff cuticle
- Sexes are separate (dioecious), males are almost always smaller than the females
- A well-developed complete digestive system is present, with both mouth and anus
- While most nematodes are free-living, many are parasites to humans, plants, and animals
- Intermediate hosts are necessary for the larval development for some forms (never a mollusk)
- Parasites of humans include intestinal & tissue-inhabiting
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Arthropoda
- Phylum of insects, arachnids, crustaceans, etc.
- Paired and jointed appendages
- Segmented
- Bilateral symmetry
- Tough exoskeleton
- Digestive system is well developed
- Dioecious i.e., sexes are separate
- several subphyla, classes, orders, etc.
- most successful animal phyla; many insects, arachnids, crustaceans serve as parasites and vectors
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