Do Now: Define

1. Do Now: Define • Infectious Disease • Pathogen • Microorganism • Tetanus • Antibodies • Active immunity • Passive immunity • Vaccine • Bacteria • Virus • Fungi • Protozoan

2. INFECTIOUS DISEASES • Infectious Disease- are caused by organisms or viruses that enter and multiply within the human body. • Pathogens – can cause infectious disease when they enter your body and multiply.

3. Examples of Pathogens • Bacteria • Viruses • Fungi • Protozoans • Other pathogens

4. Bacteria - single-celled microorganisms • Live everywhere air, soil, food, on the bodies of animals, plants and humans • Most bacteria are not pathogens • Can produce a toxin – a substance that kills cells or interferes with their functions

5. Viruses • Are the smallest pathogens • Can only multiply after entering a living cell • Invade different types of cells • Ex. – common cold invades the respiratory tract

6. Fungi • Organisms such as yeasts, molds, and mushrooms that grow best in warm, dark, moist areas. • Ex. Athletes foot and ringworm

7. Protozoans • A large and complex single-celled organism. • Have the ability to move through fluids in search of food. • Ex. Malaria

8. Other Pathogens • Caused by: • Animals • Mites • Lice • And certain worms

9. How are Pathogens spread? • A.) Contact with an infected person. • B.) Infected animal • C.) Contaminated objects • D.) Contaminated food, soil or water

10. Infected People – some form of contact with a person who has the disease • Direct physical contact: • Shaking hands • Kissing • Hugging • Touching • Sexually transmitted

11. Indirect contact: • If an infected person coughs or sneezes, you can inhale the pathogens in tiny droplets of moisture in the air. • Blood – needles • Chicken pox and measles can spread by droplet infection

12. Infected Animals • Bites from an infected animal (dog or raccoon) • Rabies – deadly disease of the nervous system • Malaria- mosquito bites

13. Contaminated Objects • Pathogens can survive for a period of time outside a person’s body. • Can be spread from person to person on objects doorknobs, towels, cups • Touching something that has been contaminated can be transferred to you when you touch your mouth or food

14. Contaminated Food, Soil or Water • Food poisoning: • Salmonella (bacteria)– poultry, meat and eggs • E. Coli-beef • Cook foods thoroughly to kill these bacteria

15. Defenses Against Infection • Physical and Chemical • Inflammation • Immune system

16. Physical and Chemical • Your bodies first line of defense is its protective coverings. • Ex.- Skin is a physical barrier to pathogens • Sweat is a chemical barrier – contains acids that kill many bacteria. • Skin sheds old cells and the pathogens on them are spread too

17. Those include: • A.) Skin- are hard and have no gaps between them. • B.) Mucous membranes- the protective lining that covers any opening into the body (mouth, eyes and nose) • What is does with pathogens: • They secrete mucous which is a sticky liquid which traps many pathogens and washes them away.

18. C.) Cilia- tiny hairlike structures that line some of the mucous membrane. • When you cough or blow your nose the pathogens are removed along with the mucus • D.) Saliva and tears- trap pathogens and wash them away.

19. E.) Digestive system – acids in your stomach, kill many pathogens.

20. Second line of defense: Inflammation • Inflammation – is your body’s general response to all kinds of injury, from cuts, scrapes to internal damage caused by infectious diseases. • Fights infection and promotes the healing process

21. Inflammation process begins within seconds after injury • Damaged cells release chemicals that cause several responses • Tiny blood vessels in the injured area enlarge, allowing more blood to flow to the area. • Fluids leak out of the blood vessels along with cells called Phagocytes.

22. Phagocytes – white blood cells that “eat up” foreign cells • Process: • A. Phagocyte “spots” pathogen • B. Phagocyte begins to surround pathogen • C. Phagocyte engulfs pathogen • D. Phagocyte digests and kills pathogen

23. 3rd defense = Immune System • Fights disease by producing a separate set for each kind of pathogen it encounters. • Made up of cells in your blood, lymph, bone marrow, and other tissues.

24. Immunity- is your body’s ability to destroy pathogens that it has previously encountered before the pathogens are able to cause disease. • Lymphatic system is a network of vessels that collects fluid from the tissues of your body and returns it to the blood.

25. Lymphocytes – white blood cells that carries out most of the immune system’s functions. • B cells – produce antibodies • T cells- 3 types that live blood of the lymphatic system

26. T Cells • Helper “T” cells • Killer “T” cells • Suppressor “T” cells Helper “T” cells help fight infection

27. Passive Immunity • Is acquired by receiving antibodies from a source other than one’s own immune system. • Temporary • Example – newborn babies

28. Active Immunity • Immunity that your immune system creates • Immunizations/vaccination – an injection that causes the body to become immune to an infectious disease

29. Vaccine – contains small amounts of dead or modified pathogens or their toxins that is injected during an immunization.

30. Bacterial Diseases • Strep Throat –sore throat, fever, enlarged lymph nodes. Treated with antibiotics. • Lyme Disease - caused when bitten by an infected deer tick. • Tuberculosis • Bacterial Meningitis

31. Treating Bacterial Diseases • Antibiotic- a drug that inhibits or kills bacteria. • Prescription medicine only available with a written order from a qualified healthcare professional. • Important to use as prescribed to avoid developing resistance from the medication.

32. Viral Diseases • Common Cold - group of symptoms caused by a number of different viruses • Influenza- common viral infection of the upper respiratory system. • More serious illness in infants and the elderly.

33. Pneumonia- an infection of the lungs in which the air sacs fill with pus and other liquids. **A serious infection to the lungs. Many people die each year from pneumonia which can be caused by viruses, bacteria or fungi.

34. Hepatitis- inflammation of the liver. Caused by chemicals and many other pathogens. No cure – but vaccines for A and B. • “A” – spread through contact with feces of an infected person. Not washing hands properly before handling objects or food.

35. “B” – more serious than “A”. Found in most bodily fluids, especially blood. Transmitted sexually. Drug use, piercings, tattoos, etc. • “C” – most common, transmitted by direct contact with infected blood.

36. Treating Viral Diseases • No particular medicine that can cure a viral infection, can take over the counter medications. • Antibiotics for instance are only effective against bacteria not viruses. • Best treatment for viral infections are rest, a well-balanced diet and plenty of fluids.

37. 5 stages of Illness • 1.) Incubation - virus enters the body and multiples, you feel fine. • 2.) First symptoms • 3.) Severe symptoms

38. 4.) Recovery • 5.) End of infection

39. 3 Ways to Prevent Illness • 1.) Avoid contact with pathogens • 2.) Make sure your immunizations are current • 3.) Choose healthy behaviors

40. Other ways of Prevention: • Washing hands • Handling Food Properly • Balanced Diet • Avoid sharing • Proper Food Storage • Unnecessary Contact with people who are ill • Vaccinations • Abstinence