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Defense Against Infectious Disease

Defense Against Infectious Disease. How does my body fight disease?. http://img.yasalud.com/uploads/2012/02/sistema-inmune.jpg. Pathogen. An organism or virus that causes disease. This includes virus, bacteria, protozoa, fungi and worms of various types.

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Defense Against Infectious Disease

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  1. Defense Against Infectious Disease How does my body fight disease? http://img.yasalud.com/uploads/2012/02/sistema-inmune.jpg

  2. Pathogen • An organism or virus that causes disease. • This includes virus, bacteria, protozoa, fungi and worms of various types. Tripanosoma cruzi protozoans in blood – Chagas disease http://imgc.allpostersimages.com/images/P-473-488-90/64/6468/EWOH100Z/posters/david-phillips-trypanosoma-cruzi-protozoans-in-blood-the-pathogens-of-trypanosomiasis-or-chagas-disease-lm-x160.jpg

  3. http://www.scientificamerican.com/media/inline/fungal-meningitis-pathogen-discovers-new-appetite-human-brains_1.jpghttp://www.scientificamerican.com/media/inline/fungal-meningitis-pathogen-discovers-new-appetite-human-brains_1.jpg http://1.bp.blogspot.com/-CxlppkLnEOA/TcqWn0A1I5I/AAAAAAAAASM/8zfU8jAt870/s320/Imagen1.jpg http://t2.gstatic.com/images?q=tbn:ANd9GcQcjNzc8mkJpoHS391T6yqepoiz4IYsQYXjwfM4M2gyBP4lgwg0 http://microbiology2009.wikispaces.com/file/view/plasmodium.gif/71399637/plasmodium.gif http://www.primeradx.com/assets/infectious-disease-PrimeraDx.jpg

  4. Not every pathogen that enters our body results in disease • This is because for most pathogens, our body has developed immunity. • There are also chemicals called antibiotics that work against bacterial cells without affecting our body cells. http://1.bp.blogspot.com/-iItc7sF33UA/T4ZZfoBMFPI/AAAAAAAAA-c/AhWRMeowGWQ/s320/macrophage-2.jpg

  5. How antibiotics work • Saprotrophs, including bacteria and fungi, compete with each other for death organic matter on which they feed. • To inhibit the growth of their competitors, some saprotrophs produce antibiotics. • An antibiotic is a chemical that inhibits the growth of microorganisms. • Antibiotics produced by fungi mostly inhibit bacteria. • There are smaller number of antibiotics produced by bacteria that inhibit fungi.

  6. How antibiotics work • Antibiotics interfere with various metabolic processes • Antibiotics are not effective against viruses. http://www.wiley.com/college/pratt/0471393878/instructor/activities/bacterial_drug_resistance/antibiotic_targets_web.gif

  7. Preventing pathogens from entering our bodies.- • The ability to resist infection by a disease is termed immunity. • There are two types of immunity: • Non specific immunity allows the body to resist infection by a wide range of pathogens. • Specific immunity allows the body to resist a specific pathogen

  8. http://4.bp.blogspot.com/-x6_92YIWEOA/UKEUN5vk-zI/AAAAAAAAByE/LlHatSUli6k/s1600/first+line+of+defense.jpghttp://4.bp.blogspot.com/-x6_92YIWEOA/UKEUN5vk-zI/AAAAAAAAByE/LlHatSUli6k/s1600/first+line+of+defense.jpg

  9. Non-specific immunity

  10. Second line of defense http://t0.gstatic.com/images?q=tbn:ANd9GcTzc7-fqo6nkudsPRDJC33ZpEPfYbnbyJHDgnE1xauVFQuFc6AY

  11. Antibodies are produced in response to a specific pathogen.- • If a microorganisms gets past the physical barriers and the phagocytes, a second level of immunity exists. • Proteins and other molecules on the surface of pathogens are recognized as foreign by the body and they stimulate a specific immune response.

  12. The body is capable of responding in a highly targeted way to pathogens. • A protein called antibody binds to antigens. • Our body can produce a large variety of antibodies, each one specific to a certain antigen.

  13. The binding of an antibody to an antigen produces many benefits, including: • Makes the pathogen more recognizable to phagocytes • Prevents viruses from docking to host cells so that they cannot be taken up by host cells. • Cause agglutination (sticking together) of pathogens so they cannot enter cells and are easier for phagocytes to ingest.

  14. Immune response depends on different types of lymphocytes, each with a specific function. The process includes:

  15. http://waynejoseph.files.wordpress.com/2010/03/immune20system.jpghttp://waynejoseph.files.wordpress.com/2010/03/immune20system.jpg

  16. HIV and AIDS • The human immunodeficiency virus (HIV) targets helper T-cells. • In the early stages of infection, the immune system makes antibodies against HIV. • If these can be detected in a person’s body, they are said to be HIV-positive. http://aids.gov/images/aids-infographics/what-is-hiv-aids-2.jpg

  17. HIV • HIV invades and destroys lymphocytes called helper T-cells resulting in the reduction of their number and the progressive loss of the capacity to produce antibodies. • The rate at which this occurs varies considerably and it can be slowed down by using anti-retroviral drugs.

  18. AIDS •  In most HIV-positive patients antibody production eventually becomes so ineffective that a group of opportunistic infections strike. • Several of these are normally so rare that they are “marker” diseases for the latter stages of HIV infection. • When several infections affect someone due to HIV, the person is said to have acquired immune deficiency syndrome (AIDS).

  19. http://whichcountry.co/wp-content/uploads/2013/03/symptoms-of-AIDS.jpghttp://whichcountry.co/wp-content/uploads/2013/03/symptoms-of-AIDS.jpg http://www.dreddyclinic.com/images/aids.jpg

  20. AIDS • AIDS spreads by HIV infection. • The virus only survives outside the body for a short time. • Infection normally only occurs if there is a blood to blood contact between infected and uninfected people.

  21. Ways in which an infection of HIV can occur include: http://2.bp.blogspot.com/-m3VGVfwyq9M/T45OZ7bmuwI/AAAAAAAAAu4/Bf4Yri19JSI/s1600/how-is-hiv-aids-transmitted-4.gif

  22. Social implications: • Sufferers are stigmatized in terms of employment, insurance, education access, social acceptance and others • families lose members • Those that die are both parents and workers • Grandparents may be left to look after orphaned children • Economic productivity is lost • The costs of treating the disease are high and may overburden health services • In countries where infection rates are high, there may be an undermining of social cohesion. http://archive.thedailystar.net/photo/2010/12/01/2010-12-01__pcp02.jpg

  23. Sources: • Allot, A., & Mindorff, D. (2010). IB Biology Course Companion. New York: Oxford University Press. • Allot, A., & Mindorff, D. (s.f.). IB Biology Course Companion 1st ed. Obtenido de Actual BookPages: http://aura.edu.in/read/IB/BIOLOGY_COURSE_COMPANION_(OXFORD)/original/Page-226.html • Damon, A., McGonegal, R., Tosto, P., & Ward, W. (2007). Biology Higher Level. London: Pearson Baccalaureate.

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