The Immune System

1. The Immune System Chapter 37 1

2. 37.1 Infectious Diseases • Infectious disease – caused when a pathogen is passed from one organism to another. • Pathogens – agent, such as a bacterium, virus, protozoan, or fungus, that cause disease • Remember: not all bacteria, virus, protozoa, and fungi are bad for you.

3. Identifying Disease Pathogens • Robert Koch – a German physician in 1800s who identified the pathogen for Anthrax.

4. Koch’s Postulates • Postulate 1 – isolate the pathogen • Postulate 2 – grow the pathogen in isolated media.

5. Koch’s Postulates • Postulate 3 – Inject the isolated pathogen into a host. The pathogen must cause the same disease or symptoms.

6. Koch’s Postulates • Postulate 4 – Isolate pathogen from the new host. Grow in isolated media. Pathogen should have the same characteristics as before.

7. Kingdoms • Bacteria – unicellular prokaryotes • Archaea – unicellular prokaryotes (extremophiles) • Protista – unicellular or multicellular eukaryotes • Fungi – decomposers with cell walls • Plantae – multicellular autotrophs • Animalia – multicellular heterotrophs with motility

8. Characteristics of Bacteria • Shape • Cell Wall Composition

9. Bacteria Shapes • Cocci – round • Bacilli – elongated rods • Spirochete – spirals

10. Cell Wall Characteristics • Gram Positive – stain dark purple due to peptidoglycan • Gram Negative – stain pink due to the presence of a lipid layer

11. Transmission • Direct contact – touch • Indirect contact by objects – door knobs • Indirect contact via air – sneeze • Vectors – mosquitoes

12. 37.2 Immune System

13. Nonspecific Immunity • Nonspecific Immunity – this is your bodies defense. • Barriers – block pathogens from entering the body. • Cellular Defenses – protect cells from the spread of pathogens.

14. Barriers • Skin – provides a physical barrier • If the skin is broken, it will bleed or ooze which forces contaminants out • Some organisms live symbiotically on our skin . They digest the oils & produce acids that deter harmful bacteria.

15. Barriers • Chemical Barriers • Lysozyme (found in saliva, tears, and nasal secretions) break down bacterial cell walls (destroying the bacteria’s defense). • Mucus blocks bacteria from sticking to the inner epithelial cells • HCl in your stomach kills many microorganisms found in food that could cause disease.

16. Cellular Defenses • Phagocytosis – white blood cells surround and ingest microorganisms

17. Interferon • Virus infected cells produce interferon. • Interferon binds to the outside of the neighboring cells. • The presence of interferon on uninfected cells stimulates the production of antiviral proteins. • This prevents the spread of the virus.

18. Inflammatory Response • Inflammatory response is a complex reaction to invasion that enhances the body’s ability to fight infection. • After tissues are damaged by pathogens, chemicals are released. • These chemicals attract phagocytic cells, increase blood flow, make blood vessels more open to the movement of white blood cells. • Symptoms include pain, heat, & redness.

20. Specific Immunity • If a pathogen breaks through the body’s defenses, then you need to have a good offensive line.

21. Lymphatic System • Lymphatic system – includes the organs and cells that filter lymph and blood and destroy microorganisms. • Lymph – the fluid that leaks out of capillaries to bathe body cells. • This fluid circulates among tissue cells, drains into lymphatic vessels, and is returned to veins near the heart.

22. Lymphatic Organs • Lymphocytes – a type of white blood cells that are produced by red bone marrow. • Lymph nodes – filter and remove foreign matter from the lymph. • Tonsils – a protective ring of lymphatic tissue between the nasal and oral cavities.

23. Lymphatic Organs • Spleen – stores blood and destroys damaged red blood cells. • Thymus gland – stores and matures a special type of lymphocyte called the T cell. • Lymphatic vessels – connect the lymphatic system to the rest of the body.

24. B Cell Response • B-Cell – a type of lymphocyte that produces antibodies • B-Cells are found in all lymphatic tissues. • Antibodies – proteins, produced by B-cells, that reacts to specific foreign bodies (called antigens). • Antigen – a foreign substance that causes an immune response.

25. Passive Immunity • Passive immunity – when antibodies are made by someone else and transferred to you. • Example: breast milk & tetanus shot

26. Active Immunity • Active immunity – the immune system is exposed to disease antigens and memory cells are produced. • Memory cells – long living cells that are ready to respond rapidly if you are exposed to the same pathogen again. • Example: chicken pox exposure or immunizations

27. 37.3 Noninfectious Disorders

28. Genetic disorders • Genetic disorders – disease caused by the inheritance of genes tha tdo not function properly. • Example: Sickle Cell Anemia, Huntington disease, Coronary Artery Disease

29. Degenerative Diseases • Degenerative diseases – are the result of the body wearing out. • Example: Degenerative arthritis & arteriosclerosis

30. Metabolic Diseases • Metabolic diseases – result from an error in a biochemical pathway. • Examples: Type 1 & 2 Diabetes

31. Cancer • Cancer – abnormal cell growth

32. Inflammatory Disease • Inflammatory disease – the body produces an inflammatory response to a common substance. • Examples: allergies & autoimmune diseases • Autoimmune disease – the immune system fails to recognize “self” • Examples: Lupus & Multiple Sclerosis

33. Immunology Lab • http://www.hhmi.org/biointeractive/vlabs/

34. Staying Healthy • Wash Your Hands • Don’t Drink After Each Other • Finish Antibiotics • Supplements: Vitamin C, Yogurt, Zinc (in pumpkin seeds) • Stress management