End Show Slide 1 of 31 Biology LB: Use cover that doesn’t have sticker on it LB: Use cover that doesn’t have sticker on it Mr. Karns Immune disorders

End Show Slide 2 of Immune System Disorders Ragweed Pollen

End Show 40-3 Immune System Disorders Slide 3 of 31 Immune Disorders Although the immune system defends the body against pathogens, sometimes disorders occur in the immune system itself. There are three different types of immune system disorders: allergies autoimmune diseases immunodeficiency diseases

End Show 40-3 Immune System Disorders Slide 4 of 31 Allergies Overreactions of the immune system to antigens are allergies. Common allergies include pollen, dust, mold, and bee stings. Antigens that cause allergic reactions are called allergens.

End Show 40-3 Immune System Disorders Slide 5 of 31 Allergies When allergy-causing antigens enter the body, they attach themselves to mast cells. Mast cells are specialized immune system cells that initiate the inflammatory response. The activated mast cells release histamines.

End Show 40-3 Immune System Disorders Slide 6 of 31 Allergies Histamines increase the flow of blood and fluids to the area. They increase mucus production in the respiratory system, which induces sneezing, watery eyes, and runny nose. Antihistamines are drugs that counteract histamines.

End Show 40-3 Immune System Disorders Slide 7 of 31 Asthma Some allergic reactions cause asthma. Asthma is a chronic respiratory disease in which the air passages become narrower than normal. This causes wheezing, coughing, and difficulty in breathing. If not treated, asthma can lead to permanent damage or destruction of lung tissue.

End Show 40-3 Immune System Disorders Slide 8 of 31 Autoimmune Diseases What is an autoimmune disease?

End Show 40-3 Immune System Disorders Slide 9 of 31 Autoimmune Diseases When the immune system attacks the body's own cells, it produces an autoimmune disease.

End Show 40-3 Immune System Disorders Slide 10 of 31 Autoimmune Diseases Some examples of autoimmune diseases include: Type I diabetes attacks insulin-producing cells. Rheumatoid arthritis attacks connective tissues around joints. Myasthenia gravis attacks neuromuscular junctions. Multiple sclerosis (MS) destroys functions of brain and spinal cord neurons.

End Show 40-3 Immune System Disorders Slide 11 of 31 Autoimmune Diseases Some autoimmune diseases are treated with medications that alleviate specific symptoms.

End Show 40-3 Immune System Disorders Slide 12 of 31 Immunodeficiency Diseases An immunodeficiency disease is one in which a person has a weakened immune response. In one type of immunodeficiency disease, the immune system fails to develop normally. A second type of immunodeficiency disease is AIDS.

End Show 40-3 Immune System Disorders Slide 13 of 31 AIDS In 1983, researchers identified the cause of AIDS—a virus that is caused by the HIV for human immunodeficiency virus. HIV is a retrovirus—a virus that carries its genetic information in RNA, rather than DNA.

End Show 40-3 Immune System Disorders Slide 14 of 31 AIDS HIV attacks and destroys helper T cells. As the number of helper T cells decreases, the body becomes more susceptible to other diseases. The diseases that attack a person with a weakened immune system are called opportunistic diseases.

End Show 40-3 Immune System Disorders Slide 15 of 31 AIDS HIV Infection

End Show 40-3 Immune System Disorders Slide 16 of 31 AIDS Reverse transcriptase enzyme Envelope Virus attaches to host cell membrane by recognizing specific molecules on the cell surface. Viral RNA Capsid Protein coat 1 1

End Show 40-3 Immune System Disorders Slide 17 of 31 AIDS Viral coat fuses with cell membrane and viral RNA enters the cell 2 2

End Show 40-3 Immune System Disorders Slide 18 of 31 AIDS Reverse transcriptase uses viral RNA as a template to make viral DNA. 3 3

End Show 40-3 Immune System Disorders Slide 19 of 31 AIDS Viral DNA enters nucleus and attaches to host chromosome. There it may remain dormant or begin directing the synthesis of viral mRNA and RNA. 4 4

End Show 40-3 Immune System Disorders Slide 20 of 31 AIDS Viral mRNA directs the host cell to assemble viral proteins. 5 5

End Show 40-3 Immune System Disorders Slide 21 of 31 AIDS Capsids are assembled around the viral proteins and RNA. The new viruses bud off from the host cell membrane. 6 6

End Show 40-3 Immune System Disorders Slide 22 of 31 AIDS Transmission of HIV HIV is not transmitted through casual contact. HIV can only be transmitted through the exchange of blood, semen, vaginal secretions, or breast milk.

End Show 40-3 Immune System Disorders Slide 23 of 31 AIDS How can AIDS be prevented?

End Show Slide 24 of Immune System DisordersAIDS Preventing HIV Infection The only no-risk behavior with respect to HIV and AIDS is abstinence. People who share contaminated needles to inject themselves with drugs are at a high risk for contracting HIV. People who have sex with drug abusers are also at high risk.

End Show 40-3 Immune System Disorders Slide 25 of 31 AIDS Can AIDS Be Cured? At present, there is no cure for AIDS. The virus can be controlled by expensive multidrug and multivitamin “cocktails” that fight the virus.

End Show - or - Continue to: Click to Launch: Slide 26 of

End Show Slide 27 of Allergies result when antigens from allergens bind to a.histamines. b.pathogens. c.mast cells. d.T cells.

End Show Slide 28 of An example of an autoimmune disease is a.polio. b.multiple sclerosis. c.asthma. d.smallpox.

End Show Slide 29 of In Type I diabetes, antibodies attack a.connective tissues around the joints. b.neuromuscular junctions. c.insulin-producing cells in the pancreas. d.epinephrine-producing cells in the adrenal cortex.

End Show Slide 30 of The retrovirus HIV causes a.AIDS. b.myasthenia gravis. c.asthma. d.polio.

End Show Slide 31 of The principle targets of the HIV virus are the body’s a.red blood cells. b.helper T cells. c.connective tissue in the joints. d.B cells.

END OF SECTION