Immune System
Functions of the Immune System Body’s defense against disease-causing organisms (pathogens)
Which of the following is a disease that is caused by a pathogen? Diabetes Cancer Flu Allergies 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Three Lines of Defense Barriers = keep pathogens from entering the body skin, hairs & mucus in nose, sneezing and coughing, saliva, stomach acids
Three Lines of Defense General defense = when body cells are damaged Inflammatory response = fluid and white blood cells leak from blood vessels into surrounding tissue
Three Lines of Defense General defense = when body cells are damaged Inflammatory response = fluid and white blood cells leak from blood vessels into surrounding tissue White blood cells (phagocytes) = attack invaders & eat them
Three Lines of Defense General defense = when body cells are damaged Inflammatory response = fluid and white blood cells leak from blood vessels into surrounding tissue White blood cells (phagocytes) = attack invaders & eat them Interferons = substances produced by body cells when attacked by viruses; interfere with the production of new viruses
Three Lines of Defense Immune response = distinguishes between different pathogens White blood cells (macrophages) = patrol the body looking for invaders Send off chemical signals to Helper T-cells when an invader is found
Three Lines of Defense Immune response = distinguishes between different pathogens Helper T-cells = call other cells in the immune system to the battle This causes fever, swelling, & aches—signs that your body is working to fight a disease Signal Killer T-cells where the invader is hiding Send chemicals that increase production of B-cells
Three Lines of Defense Immune response = distinguishes between different pathogens c. B-cells = produce antibodies
How do your body’s barriers help keep you healthy? Keep pathogens inside your body Keep pathogens out of your body Interfere with the production of pathogens Break down pathogens 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
What’s the major difference between general response & immune response? General response can tell the difference between different pathogens. Immune response can tell the difference between different pathogens. General response takes longer to respond to an invader. Immune response involved white blood cells. 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Which best describes the relationship between macrophages & helper T-cells? Macrophages & helper T-cells both do the same job. Macrophages signal helper T-cells, which kill the invader. Macrophages signal helper T-cells, which signal other immune cells to fight the invader. Helper t-cells attack macrophages. 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Antibodies & Antigens Antibody = protein produced by the immune system which destroys certain kinds of pathogens Antigen = the part of the pathogen that the antibody recognizes and binds to
Preventing Disease No cure for viral disease; only prevention Vaccine = made from damaged virus particles that can’t cause disease anymore
Preventing Disease No cure for viral disease; only prevention Vaccine = made from damaged virus particles that can’t cause disease anymore 1st Vaccine = Dr. Edward Jenner (1798) developed a vaccine for smallpox from the cowpox virus The arm of Sarah Nelmes, a dairy maid, who had contracted cowpox. Jenner used material from her arm to vaccinate an eight year old boy, James Phipps (1798).
Which is not true about the relationship between antibodies & antigens? Every pathogen has a unique antigen on its surface. The first time an antigen enters your body, you already have an antibody for it. Each antibody can only bind to a specific antigen. The second time an antigen enters your body, the antibodies will recognize & attack it. 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
If you had chicken pox once, what would happen if you were exposed to the virus again? Your body wouldn’t be able to fight the virus & you would get sick. Your body would have antibodies from the first time you had chicken pox & you wouldn’t get sick. Your body would make different antibodies than the first time & you wouldn’t get sick. The virus would recognize the antibodies & leave.
Which type of disease can be prevented by a vaccine? Virus Bacteria Fungus Parasites
Why doesn’t the flu virus used in the flu vaccine make you sick? The virus does make you sick. There is no virus in the vaccine. The virus can’t reproduce. The part of the virus that makes you sick was removed.