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PARASITIC PROTOZOA. Biology of the protozoa:. Protozoa are unicellular animals that occur singly or in colony formation. MORPHOLOGY:. The vital functions of the protozoa are carried out by the protoplasm. Protoplasm is differentiated into nucleoplasm and cytoplasm. Physiology:.
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Biology of the protozoa: Protozoa are unicellular animals that occur singly or in colony formation.
MORPHOLOGY: • The vital functions of the protozoa are carried out by the protoplasm. • Protoplasm is differentiated into nucleoplasm and cytoplasm.
Physiology: • All essential metabolic, reproductive, and protective functions are carried on by either specialized properties of the protoplasm or by structural and functional adaptations known as the organelles. • Pseudopodia produce amoeboid movements in sarcodina, cilia rhythmically propel the infusoria, and flagella the mastigophora
Transmission: • The parasites pass from host directly or through food and water after an extracorporeal existence.
Pathology and Symptomatology: • Protozoa, in contrast to worms, multiply in their hosts, so disease can result from infection initiated by only a few organisms.
Diagnosis: • Clinical impressions should always be confirmed by laboratory diagnosis that identifies the parasite in intestinal contents or in blood and tissues.
Immunity: • Natural resistance may be lowered by malnutrition, concurrent disease, or immunosuppressive drugs. • Protective immunity often develops to protozoan infections involving the blood and tissues.
Prevention: • The usual methods of reducing the sources of infection, blocking the channels of transmission, and protecting the susceptible host are employed.
AMEBAS: • Members of this group of protozoa, which includes many free-living and parasitic amebas, are probably the most primitive of animal forms. • 6 species of Amebas in Man • :1.Entamoeba histolytica, 2.Entamoeba coli, 3.Entamoeba gingivalis, 4.Dientamoeba fragilis, 5.Endolimax nana, 6.Iodamoeba butschilii.
Life Cycle: • The resistant infective cysts, formed in the lumen of the large intestine, pass out in the feces, and are immediately infective. • Human beings are the principal host and source of infection.
Pathology: • The pathogenic activities of E. histolytica depend upon 1.the resistance of the host, 2.the virulence and invasiveness of the amebic strain, and the 3.conditions in the intestinal tract.
Symptomatology: • The clinical response is exceedingly variable, depending upon the location and intensity of the infection. • Asymptomatic infections are the most common, especially in temperate zones.
Diagnosis: • The final diagnosis of amebiasis rests upon the identification of the parasite an the feces or tissues, and serologic studies. All available methods should be exhausted before accepting a clinical diagnosis. On the other hand, diagnosis by therapy must be resorted to occasionally.
Prevention: • Carriers should be removed from the food-handling occupations, instructed in personal hygiene and, treated. • Effective environmental sanitation • Boiling water