1. THE IMMUNE SYSTEM

2. VOCABULARY

3. VOCABULARY  Pathogens = viruses, bacteria, microorganisms that cause disease

4. VOCABULARY  Antigen = any substance that causes an immune response (viruses, bacteria, or combination of proteins from a different body)

5. VOCABULARY  Antibodies = proteins in the blood that bind to help destroy foreign substances in the body

6. VOCABULARY  Immunity = the ability of the body to fight infection through the production of antibodies or cells that deactivate foreign substances or cells

7. HOW OUR BODY FIGHTS INFECTIONS AND DISEASES Our Lines of Defense

8. First line of defense Physical and chemical barriers:  Skin and membranes are physical barriers  Sweat, tears, saliva are chemical barriers  Mucus traps particles  Stomach acid kills bacteria in food

9. The Second Line of Defense The Inflammatory Response  Swelling, redness, warmth, and pain  Infected cells secrete chemicals that increase blood flow to the area  White blood cells ingest pathogen and damaged tissue (pus)  Pus drains out or is reabsorbed  If pathogen is a virus, infected cells produce interferon which blocks reproduction of a virus

10. The Inflammatory Response

11. The Third Line of Defense The Immune Response  An immune response which includes bone marrow, white blood cells, and lymphatic system

12. The Immune Response  White blood cells (lymphocytes)  B lymphocytes (B cells) produce antibodies  T lymphocytes (t cells) attack foreign cells directly  Primary immune response 1st exposure – not much response the first 5 days, then gradual rise in # of antibodies over the next 10-15 days1st exposure – not much response the first 5 days, then gradual rise in # of antibodies over the next 10-15 days 2nd exposure – high levels of antibodies within the first 1-2 days2nd exposure – high levels of antibodies within the first 1-2 days

13. The Immune Response

14. Types of Immunity

15. Active immunity Body produces its own antibodies (T cells) to attack an antigen Body produces its own antibodies (T cells) to attack an antigen Examples: Examples: –having chicken pox only once –getting a vaccine of a dead or weakened virus (you develop immunity without getting ill with the disease

16. Types of Immunity Passive immunity  A person is given antibodies from the blood of another person  Examples – –Fetus protected by the mother’s blood –Baby protected when nursing

17. DISEASES  A condition that prevents the body from working the way it should  Results in the body failing to maintain homeostasis

18. Human diseases usually are a result of any of the following 1.Pathogens a)Foreign invader organisms 2.Abnormal cells a)May lead to cancer 3.Toxic substances a)Lead poisoning b)Radiation poisoning

19. Human diseases usually are a result of any of the following 4.Poor nutrition a)Scurvy – vitamin C deficiency b)Goiter – iodine deficiency 5.Organ malfunction a)Heart attack b)Diabetes 6.Inherited diseases a)Down syndrome b)Cystic fibrosis c)Sickle cell anemia

20. Human diseases usually are a result of any of the following  Risky personal behavior a)Lung cancer b)Drug addiction c)Skin cancer

21. PATHOGENS (organisms that cause disease) and THE DISEASES THEY CAUSE

22. VIRUSES  Composed of nucleic acid and protein, will reproduce when they invade living cells  Examples: Common cold, the flu, HIV, chicken pox

23. BACTERIA  One celled organisms (least harmful to man)  Examples: Strep throat, syphilis, food poisoning  Treat with antibiotics (penicillin)

24. FUNGI  Organism made of one of many cells  Yeasts and molds  Examples: athlete’s foot, ringworm  Treated with fungicides and antibiotics

25. Ringworm

26. Athlete’s Foot

27. PROTOZOANS  Single celled parasites  Examples: tapeworms and leaches malaria, heartworm (in dogs and cats)

28. DISEASES

29. CANCER  Life threatening disease where abnormal cells multiply uncontrollably and destroy healthy tissue  Often caused by genetic mutations  The resulting mass is called a tumor Benign tumor = noncancerousBenign tumor = noncancerous Malignant = cancerousMalignant = cancerous  Cancer cells steal nutrients needed by other cells, block nerve conductions, prevent organs they invade from functioning properly

30. CAUSES OF CANCER 1.Viruses Small number of cancers are caused by virusesSmall number of cancers are caused by viruses Viruses cause normal cells to become cancerousViruses cause normal cells to become cancerous 2.Radiation Sunlight, nuclear, X-rays produce mutations in the DNASunlight, nuclear, X-rays produce mutations in the DNA 3.Chemicals Carcinogens cause mutations in the DNACarcinogens cause mutations in the DNA 4.Genetic tendency to develop a type of cancer Breast cancer, colon cancerBreast cancer, colon cancer

31. VACCINES  Made using pathogens  Treat the pathogen to weaken or kill it  Inject the altered pathogen into the person (this doesn’t cause the disease, just stimulates the body to develop immunity to the disease)  The immune system “remembers” the disease and will kill it off quickly if a person is exposed again.

32. DAMAGE TO THE IMMUME SYSTEM

33. ALERGIES  A rapid and over reaction of the immune system to environmental substances  Examples: Food, pollen, chemicals in insect bits  Histamines – are released by cells in the respiratory tract that increases blood flow to the area and increases mucus production  Antihistamines – reduces the effects of histamines and the symptoms they cause

34. AUTOIMMUNE DISORDERS  When the body’s immune system attacks its own cells  Examples: Rheumatoid arthritis – destructive inflammation of the jointsRheumatoid arthritis – destructive inflammation of the joints Type I diabetes – autoimmune reaction against the insulin producing cells of the pancreasType I diabetes – autoimmune reaction against the insulin producing cells of the pancreas Multiple sclerosis – nerve disease from the destruction of the outer portion of the nerve cellsMultiple sclerosis – nerve disease from the destruction of the outer portion of the nerve cells

35. AIDS Acquired immune deficiency syndrome This is the disease HIV Human immune deficiency virus This virus causes AIDS  The virus grows within the immune system and is not affected by the antibodies  This cripples the immune system and the body cannot fight off infections and forms of cancer that would normally have little effect on a person