1. Immune System
Biology 20

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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!

8. 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)

9. 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

10. 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

11. 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