Transcript Slide 1
The Body’s Army THE IMMUNE SYSTEM INFECTIOUS DISEASES Viruses Human body is the only thing that can defeat a virus since it is not a living thing Some can be prevented with vaccinations Examples: flu, common cold, smallpox, chicken pox, AIDS, viral pneumonia http://www.youtube.com/watch?v=Rpj0emEGShQ INFECTIOUS DISEASES Bacteria Pathogen – organism that causes disease (not all bacteria are pathogenic to humans) They affect the body by Producing toxins or poisons Killing or damaging cells in certain parts of the body Most can be killed by medicines such as antibiotics since they are living organisms Examples: strep throat, tetanus, pneumonia, food poisoning http://www.youtube.com/watch?v=tqOVYpkZ0qs&NR=1 INFECTIOUS DISEASES Protists Act like parasites as they move throughout a host Disease-causing protists are usually spread by contaminated water and food or by bites or contact with some animal Examples: malaria, African sleeping sickness, amoebic dysentery http://www.bing.com/videos/watch/video/malarialifecycle/c1f4276d8612c38f6f63c1f4276d8612c38f6f63764068627082?q=malaria+life+cycle&FROM=LKVR5>1=LKVR5&FORM=LKVR INFECTIOUS DISEASES Fungus Occur when people come in contact with the spores of the fungus Very difficult to treat and often will recur Examples: ringworm, athlete's foot, lung infections Penicillin is a fungus that is used to fight bacterial infections INFECTIOUS DISEASES Parasites Parasite – organism that lives off of and harms another organism Host – the organism that a parasite infects Enter the body through contaminated water or food, direct contact with the parasite, undercooked food, food that has not been properly cleaned and cuts in the skin Examples: elephantitis, bedbug bites, tapeworms, trichinosis INFECTIOUS DISEASES Parasites http://www.youtube.com/watch?v=AMqtC8jXvTw &feature=BFa&list=SP85C902E5A8A1D956&inde x=24 http://www.youtube.com/watch?v=90exkFR2iSM &feature=relmfu http://www.youtube.com/watch?v=AdR2U0yPLc&NR=1 http://www.youtube.com/watch?v=BqjMYEfViKA &feature=related IMMUNE SYSTEM http://kidshealth.org/kid/htbw/_bfs_ISmoviesource.html Complex system of organs, tissues and specialized cells whose primary function is to defend the body from infectious organisms and other foreign invaders Uses the skin, circulatory system, respiratory system and digestive system to help protect the body from pathogens BODY’S DEFENSE SYSTEMS First Line of Defense – Barriers Skin – forms a physical and chemical barrier Breathing passages – mucus and cilia trap potential pathogens and a sneeze or cough can remove pathogens Mouth – enzymes in saliva destroy some pathogens Stomach – acid in stomach destroys many pathogens Pancreas and liver release enzymes that can destroy pathogens BODY’S DEFENSE SYSTEMS Second Line of Defense – Inflammatory Response http://www.dnatube.com/video/342/Inflammatory-Response Caused by capillaries in an area enlarge to allow more blood to flood the area. Fluid and phagocytes leak into the surrounding tissue. Phagocytes are white blood cells that engulf (eat) and destroy pathogens. The affected area becomes red, swollen and warm. BODY’S DEFENSE SYSTEMS Third Line of Defense – Immune Response http://www.youtube.com/watch?v=1tBOmG0QMbA Occurs when the pathogen gets in the circulatory systems Fever – a rise in body temperature due to the inability of the white blood cells to completely destroy a pathogen Antigen – molecules that the immune system recognizes as not part of the body (foreign) BODY’S DEFENSE SYSTEMS Third Line of Defense – Immune Response Types of White Blood Cells (WBC) Phagocytes – engulf and destroy pathogens Lymphocytes – WBC that target specific pathogens T cells – identifies pathogens by recognizing their antigens B cells – produce antibodies that bind to a pathogen’s antigens and mark it for destruction. IMMUNITY The body’s ability to destroy pathogens before they can cause disease. THE IMMUNE SYSTEM It’s a war that is fought daily for your life!