Immune System Biology 20

Immune Response 1st Defense skin - prevents the invader from getting in lungs - trap bacteria in mucus, remove by cilia stomach - strong acids tears - lysozyme (enzyme) destroys cell walls

Immune Response 2nd Defense specialized leukocytes (white blood cells) seek out an destroy the invader Macrophages - phagocytotic w.b.c, they can leave the blood vessels in search of invaders, once found they are ingested

Bodies Response to Harmful Agents 1A. Invader Enters complementary proteins (plasma proteins) are activates and bind to the membrane of the invader the binding acts as sign for the macrophages (white blood cell that will ingest it) the macrophage releases enzymes that destroy the invader as well as itself

Bodies Response to Harmful Agents 1B. Invader Enters invader cell is marked with antigens Macrophage engulfs it – moves antigens to its cell membrane lymphocytes respond - - antibody producing w.b.c Helper T-cells, B-cells, Killer T- cells and suppressor T-cells

i. T-cells - made in marrow, lives in thymus gland, scans the body for invader cells, then signals attack - B-cells and Killer T-cells (the T-cell is also referred to as the helper T-cell) ii. B-cells –multiply and produce the weapon – antibodies, with the help of globumins

Bodies Response to Harmful Agents iii. Killer T cells - drill holes in the membrane of the invader (bacteria, fungus, protozoan, parasite, not viruses- destroys the cell) Killer T cells also destroy mutated cells vi. Suppressor T cells - signal the immune system to shut down once the battle has been won!

Antigen - Antibody Reaction Antibodies are Y shaped they only bind to specific antigens the attachment of antibodies to antigens increase the size of the invader for detection by macrophages (phaygocytotic w.b.c. found in the lymph nodes)

Poisons work by . . . binding to cell receptor sites designed for hormones and nutrients cell engulfs the poison antibodies bind to poison and change its shape, this does not allow it to bind to the receptor sites on the cell

Immune Memory a lot of Natives died when Europeans began colonizing Canada as a result of exposure to different types of viruses their bodies had no similar antibodies to fight them remember : T-cells recognize antigens : B-cells make antibodies

a blue print of the antibody is stored in Memory T-cells if the same or similar invader attacks the body , memory T-cells will recognize it, signal B-cells and destroy it before it becomes established as long as Memory T-cells survive you are immune

http://youtu.be/CeVtPDjJBPU