1. Mr. Bombick 7th Grade Science
Immune System
Mr. Bombick
7th Grade Science

2. Immune System Definition
Immune system protects the body from harmful viruses and organisms (bacteria to parasites).
Immune system protects the body from foreign matter from molecules to microscopic and macroscopic materials.

3. Initial Lines of Defense
Not true immune responses
Skin acts as a protective barrier to foreign materials
Respiratory tract clears foreign materials with nasal filtration and mucociliary movement helped by sneezing and coughing
Digestive tract starts to kill foreign organisms with saliva and stomach acid.

4. Second Line of Defense
White blood cells attack foreign organisms and bacteria
Inflammatory response results as a way of “recruiting” more white blood cells
Interferon is a substance that is released by some immune cells that prevent some viruses from replicating

5. Third Line of Defense Antibody production by immune cells
Antibodies are made in response to an antigen (foreign proteins) found on a foreign substance or invading organism
T (from thymus) and B (from bone marrow) cells involved in antibody production
Certain T cells activate some B cells to produce antibodies
Combination of the antibody and antigen begins various cellular processes to destroy the source of the antigen

6. Immunity
Immunity is the bodies resistance to a disease causing organism or a harmful substance
The two basic types of immunity are active immunity and passive immunity

7. Active Immunity
Results when antibody production occurs in the same individual exposed to an antigen
Vaccination is an example of active immunity
Memory B cells can react to the specific antigen years after the vaccination (the memory B cells can initiate the production of a large amount of antibodies in a short period of time

8. Immune Disorders
Allergies are the result of antibodies formed in response to various allergens (dust, feathers, fur, pollen, or types of foods)
Histamine is produced in the allergic response (antihistamines help alleviate some of the symptoms)
Severe allergic responses can result in anaphylactic shock

9. Immune Disorders (cont.)
AIDS (Acquired Immune Deficiency Syndrome) occurs in some individuals exposed to HIV (Human Immunodeficiency Virus)
In these individuals the virus attacks a type of T cell that results in decreased immune function
Decreased immune function eventually leads to death