1. INNATE AND ADAPTIVE IMMUNITY IMMUNE SYSTEM AND DISEASE

2. MECHANISMS OF PATHOGENICITY Pathogenicity : The ability to cause disease Virulence : The extent of pathogenicity PORTALS OF ENTRY Mucous membranes Skin Blood Respiratory tract Gastrointestinal tract

3. MECHANISMS OF PATHOGENICITY Figure 15.9

4. THE CONCEPT OF IMMUNITY Susceptibility : Lack of resistance to a disease Immunity : Ability to ward off disease Innate immunity : Defenses against any pathogen Adaptive immunity : Immunity, resistance to a specific pathogen

5. AN OVERVIEW OF THE BODY’S DEFENSES Figure 16.1 Innate immunity : Defenses against any pathogen Adaptive immunity : Induced resistance to a specific pathogen

6. FIRST LINE OF DEFENSE INNATE (NON-SPECIFIC) IMMUNITY

7. PHYSICAL FACTORS Skin Epidermis consists of tightly packed cells with Keratin, a protective waterproof protein Figure 16.2 Mucous membranes Mucus : Traps microbes Ciliary escalator : Microbes trapped in mucus are transported away from the lungs

8. CILIARY ESCALATOR Figure 16.4

9. CILIARY ESCALATOR Figure 24.7

10. PHYSICAL/CHEMICAL FACTORS Lacrimal apparatus : Washes eye Saliva : Washes microbes off Urine : Flows out Vaginal secretions : Flow out

11. CHEMICAL FACTORS Fungistatic fatty acid in sebum Low pH (3–5) of skin Lysozyme in perspiration, tears, saliva, and urine Low pH (1.2–3.0) of gastric juice Low pH (3–5) of vaginal secretions

12. GENETIC RESISTANCE Some individuals may have enough of a genetic difference that will allow them to be immune to a specific pathogen. Ex: Humans carrying a gene for sickle-cell anemia are immune to malaria! Other examples: leprosy, tuberculosis (20% exposed are resistant), certain fungal infections Asymptomatic carriers – Herpes simplex

13. SECOND LINE OF DEFENSE INNATE (MAINLY NON-SPECIFIC)

19. Red Blood CellsTransport O 2 and CO 2 White Blood Cells: NeutrophilsPhagocytosis BasophilesHistamine EosinophilsKill parasites FORMED ELEMENTS IN BLOOD FUNCTION CELL MORPHOLOGY

20. FORMED ELEMENTS IN BLOOD MonocytesPhagocytosis Dendritic cellsPhagocytosis Natural killer cellsDestroy target cells FUNCTION CELL MORPHOLOGY

21. FORMED ELEMENTS IN BLOOD T cellsCell-mediated immunity B cellsProduce antibodies PlateletsBlood clotting FUNCTION CELL MORPHOLOGY

22. Percentage of each type of white cell in a sample of 100 white blood cells Neutrophils60–70% Basophils0.5–1% Eosinophils2–4% Monocytes3–8% Lymphocytes (T and B cells)20–25% DIFFERENTIAL WHITE CELL COUNT

23. DEVELOPMENT OF A MACROPHAGE

24. PHAGOCYTOSIS Phago: From Greek, meaning eat Cyte: From Greek, meaning cell Ingestion of microbes or particles by a cell, performed by phagocytes Figure 16.6 Neutrophils Fixed macrophages Wandering macrophages VIDEO

25. Figure 16.7 PHAGOCYTOSIS

26. HOW DO WBC SURVEY AND RECOGNIZE? PRRs – Patten Recognition Receptors Protein located on surface of WBC PAMPs – Pathogen Associated Molecular Pattern Proteins, lipids, or carbs located on the pathogen that are distinguishable from other non-pathogenic cells such as: Peptidoglycan, lipoteichoic acid, lipopolysaccharides, flagellin, zymosan, double stranded RNA, etc… Adherence

27. COMPONENTS OF LYMPHATIC SYSTEM Figure 16.5a

28. MAJOR FUNCTIONS OF LYMPHATIC SYSTEM 1. Provide a route for the extracellular fluid to return back to the circulatory system 2. Acts a “drain off system” for inflammatory system 3. Involved in immune response by transporting numerous WBC (esp. T & B cell, and antibodies)  Imp differences from circulatory system:  Lymph fluid travels only in ONE DIRECTION (extremities to heart)  Lymph is moved only by contraction of the skeletal muscles

29. THE LYMPHATIC SYSTEM Figure 16.5b–c

31. INFLAMMATION Identifiable signs of inflammation: Redness (rubor) Swelling (tumor) Pain (dolor) Warmth (calor) Acute-phase proteins activated (complement, cytokine, and kinins) Vasodilation (histamine, prostaglandins, and leukotrienes)

32. WHAT CAUSES AN INFLAMMATORY RESPONSE? Tissue injury or death (physical – bump, fall, etc..) Trauma from infection Allergic reactions (diet or environmental factors)

33. PRIMARY FUNCTION OF THE INFLAMMATORY RESPONSE 1. mobilize and attract immune response to site of injury 2. sets scene to repair tissue damage & clear away harmful substances 3. destroy and block microbes from further invasion

36. THE PROCESS OF INFLAMMATION Figure 16.8a, b

37. PHAGOCYTE MIGRATION AND PHAGOCYTOSIS Figure 16.8c [Insert Animation Inflammation: Overview, Steps.]

39. FEVER Hypothalamus normally set at 37°C Toxins from bacteria trigger the deregulation of the hypothalamus (exogenous pyrogen). Examples are endotoxins (remember them?). Pyrogen – substance that causes a rise in body temp Monocytes, neutrophils, and macrophages  endogenous pyrogens as part of inflammatory response. (ex: macrophages -> interleukin 1 (IL-1) & tumor necrosis factor (TNF)). Vasodilation and sweating: Body temperature falls

40. FEVER Advantages Inhibits multiplication of temp sensitive microbes Lower iron concentrations (nutrient used by some microbes that can limit their growth) Speeds up immune response such as phagocytosis Produces Interferons Disadvantages Tachycardia Acidosis Dehydration 44–46°C fatal

41. INTERFERONS (IFNS) IFN-  and IFN-  : Cause cells to produce antiviral proteins that inhibit viral replication Gamma IFN: Causes neutrophils and macrophages to phagocytize bacteria

42. ANTIVIRAL ACTIONS OF INTERFERONS Figure 16.15

43. IMMUNE CELL TYPES (AGAIN…)

44. Good site for review (click here)(click here)