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PP. 957-960. IMMUNE SYSTEM NON-SPECIFIC DEFENSE. FUNCTION. Fights pathogens to prevent infections and disease Works with the lymphatic system (collects fluid and returns it to the blood). STRUCTURES. Lymphocytes: white blood cells (wbc) Bone marrow: produces blood cells
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PP. 957-960 IMMUNE SYSTEMNON-SPECIFIC DEFENSE
FUNCTION • Fights pathogens to prevent infections and disease • Works with the lymphatic system (collects fluid and returns it to the blood)
STRUCTURES • Lymphocytes: white blood cells (wbc) • Bone marrow: produces blood cells • Lymph nodes: stores wbc • Thymus: matures wbc • Spleen: contains wbc that clean out pathogens as blood filters through
INITIATING THE IMMUNE SYSTEM • Antigen: any substance that the immune system responds to. • pathogens: cause disease • viruses: protein shell containing DNA or RNA • Bacteria • Fungi (spores) • Parasites • Toxins (snake bites etc) • Allergens: Cause allergies • Put Your Hands Together
Nonspecific Defense • Protects body against any pathogen, regardless of the pathogen’s identity.
FIRST LINE OF DEFENSE • Skin • Block entry • Toxic-Sweat & Oil • mucous membranes • Mucous-traps pathogens • Cilia-moves pathogens out of body • stomach acids • destroys pathogens
SECOND LINE OF DEFENSENon Specific Response • Inflammatory response • Injured cells release a chemical signal called histamine to increase blood flow to area • Platelets cause clotting trapping pathogens • Area swells, becomes warm, and macrophages/phagocyte (wbc) move in and engulf bacteria
SECOND LINE OF DEFENSENon Specific Response • interferons: enzymes that stop virus protein production • fever: slow growth of bacteria and increase activity of wbc • Should a fever always be treated? Why or why not?
SECOND LINE OF DEFENSENon Specific Response • Your body has many different types of lymphocytes (WBC) • Types of Phagocytes (engulf) • Neutrophils: Ingest pathogens • Macrophage: Engulf pathogens & other cell debris • Natural Killer Cells: Burst pathogen infected cells