A2 - Immunity PDF

A2 – Immunity Component of Immune System Role Analogy Skin, tears, stomach acid, mucous Macrophage Helper T-cell B-Cell Killer T-Cell Suppressor Cell Memory T and B Cells The immune system...

A2 – Immunity Component of Immune System Role Analogy Skin, tears, stomach acid, mucous Macrophage Helper T-cell B-Cell Killer T-Cell Suppressor Cell Memory T and B Cells The immune system prevents the entry of pathogens into the body’s tissues. If pathogens get in, they are recognized as foreign threats, disabled, killed, and removed from the body. Information is retained so that further threats can be quickly dealt with. Qr code Description automatically generated Your Magic Doctor 22:00  PARASITE BACTERIA VIRUSES A pathogen is any agent that causes illness FUNGI TOXIN INERT PARTICLES FIRST LINES OF DEFENCE (Castle Walls) Skin Eye lashes / Ear hair / eyebrows / nose hair Saliva (contains digestive enzymes) Stomach acid Tears Earwax Mucous Cilia (tiny hairs in ear canals / upper airways) Antigens: protein on surface of cells/virus. antigens Every every virus and bacteria has its own very specific antigens with their own very specific shapes. Each piece of virus or bacteria that causes an infection has its own different genetic makeup. This genetic makeup is expressed in the proteins that are displayed either on its surface or on the surface of an infected body cell. These proteins are called antigens. Qr code Description automatically generated Why do blood types matter? 4:40 Macrophage (big eater) is the largest WBC that that surrounds and kills microorganisms and stimulates the action of other immune system cells. A macrophage recognizing a A macrophage engulfing an A macrophage displaying the foreign invader invader invader’s antigen  Helper T-cells are a type of WBC that dock with macrophages to collect information on antigen shape. They activate killer T cells and B cells to make immune responses.  Helper T-cells dock with macrophages They activate killer T cells and B cells. to collect information on antigen shape. B-cells are type of WBC that divide to form a massive army that produce antibodies specific to the invader’s antigen. B-cells release the antibodies into the blood stream. Antibodies bind to the antigens of foreign invaders and then…macrophages gobble them up. Helper T-Cells also activate killer T-cells (a type of WBC) to divide and go in search of bacteria/virus/cancer cell with the specific antigen Killer T-cells go in search of bacteria with the specific antigen or human cells infected with the specific virus. Suppressor T cells block the actions of other types of immune cells to prevent the immune system from becoming over-active once the infection is under control. Most B and T-cells die off after the immune response is called off. A few remain and become dormant memory cells. If the same antigen is detected in the future, the memory cells are activated and an attack is launched much quicker – often the attack is dealt with before any symptoms arise. This process is called acquired immunity. Pair and Share: Watch these videos and then summarize why vaccines work Qr code Qr code Description automatically generated Description automatically generated Why Vaccines Work Immunity and 7:20 Vaccines 2:10 Pair and Share: Describe the importance of “herd immunity” Vaccines introduce weak/dead pathogens (or their antigens) into body. Immune system produces antibodies and remembers them for future. If pathogen reappears, antigens recognized faster and attacked more aggressively before pathogen can spread and cause sickness.  In 1929, Alexander Fleming discovered penicillin, which is a very effective antibiotic drug to this day. Many other antibiotics have been developed since then. (Does not work on viruses) In a transplant, donor tissue antigens must match recipient very closely. The immune system of the recipient may recognize the donor antigens as foreign and mount an attack against the transplanted cells. This called rejection. Transplant recipients must take immunosuppressant drugs to reduce the risk of rejection. Allergies, are an immune disorder in which the immune system attacks a harmless substance (allergen). An autoimmune disorder is one in which the immune system attacks the body’s own cells. Treatment often includes immunosuppressant drugs. Common Autoimmune Diseases 3:10