The biological associations (symbiosis, mutualism, commensalism and parasitism); definition of definitive and intermediate host, and carrier; contact with the host; movement and adhesion to host; overcoming the defense systems; internal migration, reproduction; exit from the host; parasitic specificity; the concept of zoonoses; notions of immunoparassitologia; parasitosis and immunodeficiencies; systematic of animal parasites. Parasitology as a branch of ecology. Notes on the application of biotechnology in parasitology. Classification and morfobiologic characteristics of the main forms of propagation of parasites (eggs, larvae and oocysts). Morfobiologia of protozoa, Nematodes, Trematodes, Cestodes, Arthropods.