The Immune System Defenses Against Disease

1. The Immune SystemDefenses Against Disease By: Ryan Ellis November 13, 2014

2. Mechanical Barriers • Skin • Even injured skin is sealed by blood clots • Mucous Membranes • Mucous traps viruses & bacteria • Some viruses/bacteria infect these membranes • Cold – upper respiratory system • Flu = most common • Ciliated cells of respiratory system • Sweeps mucous • Tears

3. Chemical Barriers • Digestive enzymes • Mouth • Stomach (HCI) • Generalized Immune Response • Leukocytes – WBC’s • Recognizes foreign cells • Digest by phagocytosis • Cells circulate in lymph, extracellular fluids, and blood

5. Specific Immune Response • Antigen = foreign protein/carbohydrate • Foreign tissue • Rattlesnake venom • Foreign protein • Come from other life form (species) • Antibody • Molecule produced by immune system • Attaches to antigen = lock and key fit • Produced by 2 types of cells • T-cell • B-cell

6. B-cell • Produce 1 type of antibody • Release antibodies into blood B-Cell Simulation by Antigen Plasma Cell Memory Cell

8. T-Cells • Produce specific antigens on cell surface • Antigen bonds to antibody • Disables • T-helper cells medicate other cells ofimmune system • EXAMPLE: T-helper cell stimulate other cells inimmune system • 1° immune response • = slow – no memory cells 3-5 days • 2° response • = Fast – memory cells respond before illness

10. Allergies • Histamines released by mast cells in response to foreign protein • Pollen • Molds • Etc. • Histamines cause blood vessels to dialate and release WBC’s into extracellular fluid • Interferon • Produced by cells that areinfected by viruses

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