Immune System & Disease

1. Immune System & Disease Mrs. Geist Biology, Fall 2010-2011 Swansboro High School

2. Disease • Communicable disease: a disease that can be easily passed from one person to another through close contact • Ex: herpes, malaria, mumps, HIV/AIDs, influenza (“flu”), chicken pox, ringworm, whooping cough • Non-communicable disease: a disease that cannot be easily passed from one person to another through close contact • Ex: diabetes, high blood pressure, cystic fibrosis, PKU, hemophilia, cancer • The genes you inherit from your parents can make you more likely to develop a non-communicable disease

3. Sickle Cell Anemia • Non-communicable • Recessively inherited • Red blood cells shaped like crescents and deliver less oxygen to the body • More common in people of African and Mediterranean descent • Carriers have resistance to malaria

4. Malaria • Caused by the protist called Plasmodium • Transmitted via mosquitoes • Red blood cells rupture  anemia • Liver and kidney failure

5. Lung/Mouth Cancer • Non-communicable • Uncontrolled cell growth in the tissues of the lung or mouth • main causes: carcinogens (such as those in tobacco smoke) & radiation

6. Skin Cancer • Non-communicable • Uncontrolled cell growth of abnormal skin cells • Known risk factors: light complexion, family history, sun exposure and sunburn, over the age of 40

7. Diabetes • High blood sugar levels • Non-communicable • Caused by too little insulin, resistance to insulin, or both • Insulin is the hormone produced by the pancreas that controls blood sugar

8. Phenylketoneuria (PKU) • Missing enzyme to break down an amino acid called phenylalanine • Builds up in the brain  brain damage • Phenylalanine found in NutraSweet (aspartame) • Recessively inherited • Non-communicable

9. Koch’s Postulates • Koch’s Postulates: 4 experimental steps for directly relating a specific pathogen to a specific disease • Pathogen must be found in the host in every case of the disease • Pathogen must be isolated from the host and grown in a pure culture (contains no other organisms) • When the pathogen from the pure culture is placed in a healthy host, it must cause the disease • The pathogen must be isolated from the new host

10. Koch’s Postulates

11. Immune Response • Histamine: causes capillaries to expand and blood flow to increase, which causes inflammation (swelling) in the damaged area • Localizes the infection • Allows the body to destroy pathogen and repair damaged tissue • Fever: increase in overall body temperature • Slows the growth of bacteria • Increase the production of disease-fighting cells

12. The Immune Response

13. Innate Immunity • Provides general protection against various pathogens • Skin- provides a physical barrier • Mucus- prevent various areas of the body from drying out and trap microorganisms and other foreign substances in the respiratory and digestive tract • Gastric juice- destroys most bacteria and their toxins in the stomach • Sweat, tears and saliva contain lysozyme, an enzyme that breaks down bacterial cell walls

14. Innate Immunity

15. Immunity: ability to resist disease • Active immunity: acquired naturally when a person is exposed to antigens and produces antibodies specifically to these antigens • Long-term • Passive immunity: antibodies are introduced in the body • Mother transfers antibodies to an infant through breast-feeding • Inject a person with antibodies (ex: anti-venom)

16. Antibodies & Antigens • Antigen:foreign substance in the body • Ex: virus, bacteria, toxin, or a piece of these foreign substances • Antibody:proteins created by white blood cells in response to an antigen • Specific to one antigen • Ex: measles antibody will only combine with a measles antigen

17. Vaccinations • Vaccine: weakened, dead, or pieces of pathogens or antigens that cause an immune response when they are injected into the body. • 1790s Edward Jenner- developed a smallpox vaccine. • Infected a boy with cowpox, a disease that is similar to, but milder than, smallpox • Boy developed immunity to smallpox

18. Lymphatic system • Defends the body against disease & maintains homeostasis by keeping body fluids at a constant level • Lymph vessels contain fluid called lymph. • Lymph node: small mass of tissue that contains lymphocytes and filters pathogens from lymph • Lymphocyte: a type of white blood cell that defends the body against foreign substances • Tonsils: provide protection against pathogens that enter your nose and mouth • Spleen: stores certain types of lymphocytes & filters blood.

19. Lymphatic system

20. Lymphatic system • Thymus gland: stores immature lymphocytes until they mature • T cell: lymphocyte that is produced in bone marrow and stored in thymus gland. • Helper T cells: activates B cells • Killer T cells: release enzymes into pathogens, causing them to lyse and die • B cell: produces antibodies. Activated by Helper T cells.

21. Nutrition • Nutrients: substances needed by an organism to carry out life functions • Ex: carbohydrates, fats, proteins, nucleic acids, vitamins, and trace minerals • An organism in good health is more likely to fight off diseases and remain healthy.

22. Activity • Read p. 218 in EOC review books and respond to the activity question • Skim through Chapter 11 (pp. 209-219). • Answer Part B on p. 214. • Parts B & C on p. 220. • Answer Ch. 11 Review Questions on pp. 221-222.