Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Immune System Important system that helps fight off pathogens What is a Pathogen? – Microorganism that causes infection or a disease: Bacteria Viruses Fungi Protists/Parasites Made of many cells each with a specific job including: a. Lymphocytes – White blood cells or WBC Target specific Pathogens Types of Lymphocytes T cells Identify Pathogens by recognizing their Antigens B cells Produce chemicals called Antibodies Macrophages – Surround pathogen and digest or eat it Also called Phagocytes Types of Lymphocytes What are the Two Types of T – Cells? 1. Natural Killers Cells 2. Cytotoxic Cells * Destroy pathogens after they are marked by antibodies * Destroy cells that are infected with a virus * Also recognize cancer cells and destroy them What are Memory Cells ? Remember what type of antigens a pathogen has Help immune system recognize the pathogen if it invade our body again!! AMAZING ! ! ! ANTIGENS AND ANTIBODIES What are Antigens? Special proteins on surface of cells and pathogens They are recognized by the Immune System Why? So that the White blood cells know which pathogens they need to destroy!!! What are Antibodies? Special proteins that recognize specific Antigens on Pathogens Mark the pathogens for destruction by WBC’s Pathogens What are Pathogens? Organisms that cause disease Infectious diseases are? Diseases that are caused by Staphyloccocus aureus pathogens . Magnified 20,000X When you have an About 1 um in size infectious disease pathogens are inside your What type of pathogen is Staph? body causing harm BACTERIA 4 TYPES OF COMMON PATHOGENS Can you guess what they are? Viruses Fungi Bacteria Protists/Parasites 1. Viruses Flu HIV Measles Virus 2. Fungi Athlete’s Foot Candida albicans Fungus 4 TYPES OF COMMON PATHOGENS 3. Bacteria STAPH Strep throat Bacteria 4. Protists Paramecium Giardia Giardia The Immune System • The immune system includes T cells and B cells. • The cells work together to fight infections. • How does the immune system work? Let’s find out!! T-Cells have more than one job One job may be to…………… What happens when a virus infects a cell? What is another job of the T- cells? So, why do B–cells produce antibodies? Because…………….. Immunity How does a person become immunized? How does the Immune System work T cells recognize bacterial or viral antigen. Some T cells attack cells infected with pathogens. Other T cells signal B cells to produce antibodies . Antibodies attach to the antigens on virus or bacteria (Lock & Key) Antibodies help phagocytes destroy the bacteria or virus Two Types of Immunity Active Immunity Immune system produces antibodies on its own in response to a pathogen Passive Immunity Antibodies are injected into a patient to help prevent a disease from a pathogen Vaccine Contain a weakened pathogen that stimulates production of antibodies without causing the actual disease, or………… Antibodies are already in the vaccine Active Immunity Both The body makes antibodies. Memory cells recognize antigens from the pathogen. Immunity may last for years or a lifetime. Can prevent diseases May involve an injection Passive Immunity Antibodies are given; the body does not make antibodies. Immunity can be acquired from the mother during pregnancy. Immunity lasts only a few months. Review Questions 1. Question: What is the function of the immune system? Answer: Helps fight off pathogens. 2. Question: Which 3 white blood cells or lymphocytes help destroy pathogens? Answer: Macrophages, B cells and T cells 3. Question: What is an antigen? Answer: Special protein on surface of pathogens recognized by the immune system 4. Question: What is an antibody? Answer: Special protein in the immune system that recognizes and attaches to a specific antigen on a pathogen and marks it for destruction. 5. Question: Explain the difference between Active and Passive Immunity? Answer: * In Active immunity the immune system produces the antibodies. * In Passive immunity the antibodies are injected into a patient to destroy the pathogens 6. Question: Which cells of the immune system produce antibodies? Answer: B cells 7. Question: Which cells produce B cells? Answer: T cells 8. Question: What are the 3 important jobs of T-cells? Answer: a. Destroy pathogens after they are marked by antibodies b. Destroy cells that are infected with a virus c. Also recognize cancer cells and destroy them 9. Questions: What are the 3 main functions of T-cells Answer: * Destroy pathogens after they are marked by antibodies * Destroy cells that are infected with a virus * Also recognize cancer cells and destroy them 10. Question: What are the 4 common pathogens? Answer: Virus Bacteria Fungi Protists/parasites 11. Question: Why can’t scientists produce an effective vaccine against HIV? Answer: Because the virus mutates and the vaccine no longer works