Ascaris lumbricoidis (NEET Life cycle)


Ascaris lumbricoidis
  • Ascaris, an intestinal parasite causes ascariasis. 
  • Symptoms of these disease include internal bleeding, muscular pain, fever, anemia and blockage of the intestinal passage. 
  • Toxins produced by Ascaris may interfere with protein digestion.
  • Monogenetic- no intermediate host is required to complete the life cycle.
  • The eggs of the parasite are excreted along with the faeces of infected persons which contaminate soil, water, plants, etc. 
  • Egg is mammilated, oval in shape and has 3 layer (outer- protein, middle- chitinous, inner- esterified glycosides membrane)
  • Embryonic development takes place only out side of the host body (at low temperature).
  • Invective eggs can remain viable six years.
  • The larva is called as Rhabtiform larva (Rhabtoid)
  • The first stage larva is not infective.
  • A healthy person acquires this infection through contaminated water, vegetables, fruits, etc.
  • Drugs: albendazol, oil of chenopdium, santonin, antipar, tetrachloroethylene, alcopar, decaris, diethylcarbamazine.
Migrations
  • Primary: intestinal wall>hepatic portal> liver> hepatic vein> heart> pulmonary artery> lungs
  • Secondary: lungs> bronchi> trachea> pharynx> gullet> esophagus> stomach> intestine
  • Aberrant migration: migration from lungs to brain, spinal cord and eye
Life cycle







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