Defense External Defense Integumentary System Internal Defense Respiratory

Defense External Defense: üIntegumentary System Internal Defense: ü Respiratory System ü Digestive System ü Circulatory System ü Lymphatic System ü Immune System

Defense External Line of Defense: Skin, Mucus, Enzymes & Acid Skin § Function: üWhy do we have Skin ? ? üProvide a barrier to Bacteria, Viruses, Fungi, Protist & parasites § Structures: üSweat & Oil glands secrete acid

Defense Internal Defense Respiratory System: § Function: üTraps Pathogens with Cilia & Mucus • Enzymes § Structures: üCilia ( hair) üMucus Membrane

Defense Internal Defense Digestive System § Function: üKills pathogens with Enzymes üAcid (Hydrochloric acid) üMucus § Structure: üSalivary glands üStomach glands üIntestinal glands Produce Acid & Enzymes

Defense Internal Defense Circulatory System: § Function: üContains White Blood Cells • Surround & digest pathogens § System: üWhite Blood Cells üProduce Antibodies ü Target Antigens Ø A protein on the surface of an infected cell

Defense Internal Defense Lymphatic System/ Immune System: § Functions: üDefends against Germs üLymphocytes destroy Bacteria o Killer T –cells o White Blood Cells o B-cells: Antibodies üRemove excess Tissue Fluids (Lymph) o filters & purifies Lymph fluid üProduces Antibodies that stay in the blood

Defense Internal Defense Lymphatic System/ Immune System: § Structures: üLymph nodes üLymph Vessels üLymphocytes: T-cells & B-cells üAntibodies

Defense Internal Defense Natural Killer Cells Specific Immunity: § Functions: üTargets & destroys cells with foreign Antigens üMakes Antibodies o B-cells § Structures: üLymphocytes called T cells: o Helper T – cells ØStimulate B-cells ØStimulate Killer T -cells o Killer T –cells ØDestroy pathogens üLymphocytes called B cells: o Make Antibodies

Defense Working Together § Both External & Internal Defenses keep your body germ free & healthy ü Homeostasis Nate’s Immune System Cartoon