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The Immune System. The Job of the I mmune System. The immune system protects our bodies from a variety of pathogens (organisms that cause diseases). Types of Pathogens *Virus- ultramicroscopic infectious agent that replicates itself only within cells of living hosts.
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The Job of the Immune System The immune system protects our bodies from a variety of pathogens (organisms that cause diseases).
Types of Pathogens*Virus-ultramicroscopic infectious agent that replicates itself only within cells of living hosts.
*Pollution-undesirable state of the natural environment being contaminated with harmful substances as a consequence of human activities .
*Germs- microbe: a minute life form (especially a disease-causing bacterium)
is a poisonous substance produced by living cells or organisms. *Toxins-
*Fungi- including yeast, molds, smuts, mushrooms, and toadstools; distinct from the green plants.
*Bacteria- single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll.
*Parasites- an animal or plant that lives in or on a host (another animal or plant); it obtains nourishment from the host without benefiting or killing the host.
How Diseases are Spread *Person to person -Direct physical contact (kissing, hugging, shaking hands). -Indirect contact such as sneezing and coughing. *Contaminated Objects -Water and food -Using towels and silverware -Contaminated nail *Animal Bites -Animals biting a person can transfer the pathogen. *The environment -Naturally occurring in soil and water.
How does the body defend itself? • Barriers -Breathing passages • Skin • Mouth and stomach