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29 Cards in this Set
- Front
- Back
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metazoa
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multicellular
nematodes, trematodes, cestodse |
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protozoa
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unicellular, all fxns of repro, digestion, respiration, excretion
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nematodes characteristics
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body- noncellular cuticle secreted by underlying hypodermis, shed 4x during ontogeny
classes: separated by presence of phasmids or not dioecious w/ sexual dimorphism size 1mm- 1 meter |
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roundworms
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Large Intestines
T. trichiura E. vermicularis Tissue D. medinensis T. spiralis larvae Filarias Small Intestines A. lumbricoides N. americanus A. duodenale C. philippinensis T. spiralis S. stercoralis |
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gen life cycle
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eggs > fertilized, embryonated > larvae (rhadbiditiform, filiarform) > adults > eggs again
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modes of transmission
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Ingestion/Inhalation of embryonated ova
A. lumbricoides T. trichiura E. vermicularis Skin penetration by filariform larvae S. stercoralis Hookworms Bite of a vector Filarias Ingestion of encysted larvae C. philippinensis T. spiralis D. medinensis Autoinfection/Retroinfection C. philippinensis S. stercoralis E. vermicularis |
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capillaria philippinesis morph
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adults small 2.3-3.2 mm male, 2.5-4.3 females
males- small caudal alae, spineless spicule sheath female; esophagus half long as body eggs in stool- unembryonated, peanut shaped w/ flat bipolar mucous plugs |
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capillaria philippinens
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Habitat: small intestines
Mode of Transmission: Ingestion of larvae in encysted fish muscles Life Cycle: encysted larvae excyst and are released to mature into adults; some females lay eggs, others larvae (autoinfective stage); eggs in water are ingested by freshwater fishes |
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c. philippinens patho
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worm penetrate mucosa SI > re enter lumen esp jejunum > progressive degeneration of epi and mucosa
>>>loss proteins, electro w/ mala fats, sugars s/sx: diarrhea, abd pain > weight loss, anorexia, emaciation, death from electrolyte loss, <3 fail, bacterial infection d/x: adults and eggs, larval forms in stools |
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tococara canis
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cause visceral larvae migrans
toxocara cati |
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strongyloides stercoralis
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Habitat: submucosa of small intestines
Mode of Transmission: penetration of skin by filariform larvae Life Cycle: Filariform larvae penetrate the skin and go to the intestines through any possible route circulatory & pulmonary system included, to become parthenogenitic females which lay eggs that immediately become rhabditiform larvae |
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s. stercoralis epi, patho
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Epidemiology: Primarily a parasite of the tropics but maybe seen in temperate zones; prevalent in low sanitation conditions where people are exposed to contaminated soil and water.
patho; invasive> pulmo >intestinal |
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s. stercoralis d/x
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rhabditiform larvae- short buccal cavity, large genital primordium @ post to midpoint of body) IN STOOLS
-culture fecal samples> filariform larvae in long standing stools, forked or blunted tails, esophagus body 1:1 serodiagnosis |
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ancylostoma duodenale
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Habitat: small intestines
Mode of Transmission: penetration of skin by filariform larvae Life Cycle: filariform larvae migrate to the lungs via the circulatory & pulmonary system and brought to the intestines by the swallowing reflex; males & females copulate; eggs are deposited |
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a. duodenale
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eggs in stools are in 2, 4, cell stages, oval or ellipital in shape, colorless, transparent hyaline shell
rhabditiform larvae- long buccal cavity, tiny genital primordium @ post midpoint of body Epidemiology: favorable environmental conditions presence of paratenic hosts Pathology: Cutaneous phase Pulmonary phase Intestinal phase |
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d/x a. duodenale
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eggs/adults worms in feces
filiaform larvae on culture= pointed tails esoph : body 1:3 secrete neutrophil inhibition factor, anticoagulant blood loss 0.25 ml/worm/day |
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necator americanus
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ant portion adults- pair dorsal and ventral cutting plates surrounding ant margin of buccal capsule, pair of subdorsal and subventral teeth near rear of buccal capsule
like anccylostoma eggs life cycle same MC species in humans female: 5-10k eggs/day, live 3-5 yrs same enviro conditions |
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n. americanus patho
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Pathology:
Same as that of A. duodenale Also secrete glutathione-S-transferase & superoxide dismutase interfering with ADCC Blood loss at 0.03ml blood/day/worm |
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d/x n americanus
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eggs FRESH STOOLS
long standing- rhabditiform larvae, long buccal cavity, small genital primordium @ midpoint/ant filariform larvae- sharply pointed tails, esoph : body 1-3 |
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causative agents of cutaneous larva migrans
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a. caninum, a brazileiense, ancylstoma ceylanicum
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wuchereria bancrofti
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Habitat: Adults in lymphatic channels
microfilariae in the blood Mode of Transmission: bite of an infected mosquito vector – Anopheles, Aedes, Mansonia & Culex Life Cycle: occurs in 2 hosts, man and the mosquito vector |
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w. bancrofti
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microfilaria
cephalic space length = width somatic nuceli in rows no terminal nuclei body curved gracefully |
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w. bancrofti
epi, patho, d/x |
Epidemiology
Nocturnal Periodicity/subperiodicity Presence of mosquito vector Pathology: Asymptomatic Phase Inflammatory (Acute) Phase Obstructive Phase Diagnosis: Demonstration of microfilariae in the blood |
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brugia malayai
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life cycle- same as w. bancrofti
microfilaria- cephalic space longer than wide, somatic nuclei @ random, presence terminal nuclei, body thrown into kinks/folds |
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b. malayai epi
patho, d/x |
Epidemiology
Nocturnal Periodicity/subperiodicity Presence of vector: aedes, culex, mansonia Diagnosis: Demonstration of microfilariae in the blood |
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other species filarias
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Wuchereria pacifica – SE Asia
Brugia timori - Indonesia Brugia pahangi – for experimental rodents Onchocerca volvulus – Africa & Americas Formation of nodules Loa loa – West Africa esp. Sudan In subcutaneous tissues |
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drancunculus medinensis habitat, mode transmission, life cycle
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Habitat: subcutaneous connective tissue
Mode of Transmission: ingestion of intermediate host, the copepod in infected waters Life Cycle: 2 hosts: man and an intermediate host, the copepod |
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drancunculus medinensis morph
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very large
females: 800mm, 1 m, mouth small, traingular surrounded by quadrangular sclerotized place, no lips, vulva atrophiedd, nonfunctional males 12-40mm long, unequal spicules, gubernaculum |
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drancunculus medinensis
epi,and major disease (3) |
3 conditions:
1. Skin of infected individual must come in contact with water 2. Water must contain appropriate species of microcrustacean 3. The water must be used for drinking 3 Major disease conditions due to: Emergent adult worms Secondary bacterial infection Nonemergent worms |
