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IMMUNE SYSTEM NON-SPECIFIC DEFENSE. PP. 957-960. FUNCTION. Fights pathogens to prevent infections and disease Works with the lymphatic system (collects fluid and returns it to the blood). WHITE BLOOD CELLS (wbc). Also called leukocytes
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IMMUNE SYSTEMNON-SPECIFIC DEFENSE PP. 957-960
FUNCTION • Fights pathogens to prevent infections and disease • Works with the lymphatic system (collects fluid and returns it to the blood)
WHITE BLOOD CELLS (wbc) • Also called leukocytes • Type of wbc present indicates specific disease or have specific job IE. Neutrophils respond to bacteria
STRUCTURES • Bone marrow: produces blood cells • Lymphocytes: wbc • Thymus: mature wbc • Lymph nodes: stores wbc • Spleen: contains wbc that clean out pathogens as blood filters through
INITIATING THE IMMUNE SYSTEM • pathogens: cause disease 1. viruses: protein shell containing DNA or RNA 2. bacteria • allergens: cause allergies (over-reaction of the immune system to a harmless invader)
FIRST LINE OF DEFENSE • Skin: block entry • mucous membranes: trap pathogens and move them out of the body • stomach acids: destroys pathogens
SECOND LINE OF DEFENSE • Inflammatory response 1. Injured cells release a chemical signal called histamine to increase blood flow to area 2. platelets cause clotting trapping pathogens 3. Area swells, becomes warm, and macrophages/phagocyte (wbc) move in and engulf bacteria
interferons: enzymes that stop virus protein production • fever: increase activity of wbc
KOCH’S POSTULATES • Study page 957